ohm/ - Electronics General

[Anonymous No.2777077]

>I'm new to electronics. Where to get started?
It is an art/science of applying principles to requirements.
Find problem, learn principles, design and verify solution, build, test, post results, repeat.

>Incredibly comprehensive list of electronics resources:
https://github.com/kitspace/awesome-electronics
Additional resources below:

>Project ideas:
https://adafruit.com
https://instructables.com/tag/type-id/category-technology/
https://makezine.com/category/electronics/
https://hackaday.io

>Don't ask, roll:
https://github.com/Rocheez/4chan-electronics-challenges/blob/master/list-of-challenges.png

>Archive of Popular Electronics magazines (1954-2003):
https://worldradiohistory.com/Popular-Electronics-Guide.htm
>Microchip Tips and Tricks PDF:
https://ww1.microchip.com/downloads/en/devicedoc/01146b.pdf
>Li+/LiPo batteries required reading:
https://buster-spb.ru/files/SAFT/li-ion_user_manua.pdf

>Books:
https://libgen.rs/

>Principles (by increasing skill level):
Mims III, Getting Started in Electronics
Geier, How to Diagnose & Fix Everything Electronic
Kybett & Boysen, All New Electronics Self-Teaching Guide
Scherz & Monk, Practical Electronics for Inventors (arguably has minor issues with mains grounding)
Horowitz and Hill, The Art of Electronics

>Recommended Design/verification tools:
KiCAD 6+
Circuitmaker
Logisim Evolution

>Recommended Components/equipment:
Octopart
eBay/AliExpress sellers, for component assortments/sample kits (caveat emptor)
Local independent electronics distributors
ladyada.net/library/procure/hobbyist.html

>More related YouTube channels:
mjlorton
jkgamm041
EcProjects
Photonvids
sdgelectronics
paceworldwide

>microcontroller specific problems?
>>>/diy/mcg
>I have junk, what do?
Shitcan it
>consumer product support or PC building?
>>>/g/
>household/premises wiring?
More rules-driven than engineering, try /qtddtot/ or sparky general first
>antigravity and/or overunity?
Go away

[Anonymous No.2777080]

Well I screwed that image up. My oscope that I picked up used is showing 1 volt even when not plugged in. Any suggestions on how to troubleshoot this?

[Anonymous No.2777085]

>>2777080
What? The image or the 1 V 60 Hz hum picked up by your antenna-like leads?

[Anonymous No.2777153]

>>2777149
new bread, old question

[Anonymous No.2777303]

>>2777085
No leads are plugged in. But is that what I’m seeing? 1v 60hz from the mains? I guess I can check the frequency later myself, but the 1V seems high. Does that mean a volt of energy is traveling through the air?

[Anonymous No.2777328]

What's the use for solder iron tips like these? I get pointy, less pointy and more point, but what would you use a flat tip for?

[Anonymous No.2777364]

Sup cool guys, can anyone tell me what the fuck did i buy? Usually i buy power supplies for a variety purposes, this one is the biggest i bought yet and those two white things look scary. It seems to output 5, 12, 15v whatever taps on the front, but on the back it has two industrisl looking prongs, its supposed to produce like 5000V ig? Board says "hy108-d", search gives nothing

[Anonymous No.2777415]

I recall this thread moving way faster, what went wrong?

[Anonymous No.2777416]

I’m trying to use https://www.tooltos.com/cdn/shop/files/tooltos-jewelry-tool-automatic-cnc-touch-pulse-argon-arc-jewelry-spot-welding-machine-42191258681643_1024x.jpg?v=1693920773 as a spot welder for batteries. I attached a dental pick to the ground, pressed on the foil then touched the iron to the foil. I am having a very hard time dialing this in. I can adjust the power and duration. My results include : clicking noise nothing happens. Increase power, get a nice click noise and spark. But the adhesion is minimal or none at all. Increase power or duration, and then I’m blowing holes in the foil or battery.

[Anonymous No.2777422]

>>2777415
My hideous phone-poster OP image has scared everyone off.

[Anonymous No.2777431]

>>2777416
Just solder them, or, if low current, use 18650 holders for them (picrel) or use/make ones with better cell contact.
When soldering, sink the heat away from the cell body and do it quickly.
Welding them on (oneself) is a meme, welding tabs is done in the factory to save money and time.
Also cells can come with tabs already welded on there.

[Anonymous No.2777434]

>>2777364
If the grey things are iron cores, then maybe inductors or some kind of transformers. But they don't really look like iron, they look more like transformer primary windings encased in plastic.

[Anonymous No.2777436]

>>2777328
Bevels are my fav. You can use them for everything EXCEPT super precise work. They hold enough solder on their surface when you tin them for individual contacts, and still work for drag-soldering.

[Anonymous No.2777500]

>>2777328

[Anonymous No.2777502]

>>2777328
>>2777500

[Anonymous No.2777504]

>>2777500
What's that brush thing using to clear the flux? Just alcohol? No way it comes off that easy.

[Anonymous No.2777537]

>>2777504

[Anonymous No.2777542]

>>2777504
>>2777537

https://youtu.be/S2PQ0Rj-wAs?t=791

[Anonymous No.2777544]

>>2777328
I like these. Small enough to get into most areas, big enough to heat larger parts. Very versatile.

[Anonymous No.2777581]

>>2777502
painfully slow

[Anonymous No.2777596]

>>2777077
>deleted part that links to the previous thread
>deleted and ignored the part where it said "bake at page 8-10, post in old thread"
>didn't post new thread link in old thread, almost 50 posts in the old thread after you posted this one (half are shitposts)
>somehow had the presence of mind to delete "(embed)"
i swear you people are fucking with me

[Anonymous No.2777600]

>>2777303
>Does that mean a volt of energy is traveling through the air?
>1V @ 1MΩ
congrats, you picked up 1µW of radiated power from the wires all around you

>>2777364
Flyback transformers. Could be for a gas discharge / plasma production, maybe it's an all-in-one PSU for a CO2 laser cutter.

>>2777415
Half the people getting left behind on the old thread, of course.

>>2777416
Are you spot-welding nickel to nickel? Dissimilar metals may not adhere well to one another, or might become brittle at the joint.

>>2777544
For anything other than drag soldering, a chisel tip is going to be more versatile. You can put them to a component at basically any angle, not just the angle built into the tip.

[Anonymous No.2777608]

I present... The rats nest! Any advice on getting a really strong solenoid? Ive looked on digikey and mouser but there doesnt seem to be much of an option for something powerful. 12v and maybe 50N of force for a 10mm throw

[Anonymous No.2777612]

>>2777608
>Any advice on getting a really strong solenoid?
Force is directly proportional to current. They can handle higher pulsed current than they can continuous current, all that matters is they don't heat up, and don't pull themselves to pieces. Current through an inductor is governed by: V = L*dI/dt, so in order to give them a steep current ramp you need to give them a high voltage. I'd see about using a circuit like an ignition coil to create that voltage; pulling current through an inductor or transformer, then turning off the transistor to create a spike of high voltage. You can calculate the energy in the storage inductor as E = L*I^2, that same energy will roughly be the work that the solenoid actuator can perform, so size it based off that.
The only downside is you can't fire the solenoid with no prior warning, you need to charge up the storage inductor for a short period of time first. Current through the storage inductor will increase as a ramp through the aforementioned V = L*dI/dt equation, which defines the time required to charge as T = L*I/V.
You could also just get/make a much higher voltage power supply and switch this to the solenoid for a short enough time.

Consider some beefier shock-absorbing end-stops if you follow this method.

[Anonymous No.2777614]

It's mainly two questions.
1. How hard would it be to build one-of-a-kind pcbs using sharpies, masking tape, and an exacto knife? My idea is to lay the tape out, and cut out the tape where traces won't be. I use a sharpie to mask over traces. Then I etch. This is because I have no laser printer or uv lamp. Is this worth the effort?
2. Does the bipolar 555 timer's push-pull output have enough speed (transistion time) and strength (mA) to power a 12V 6ma charge pump circuit? Would common germanium diodes balk at the current peaks?

[Anonymous No.2777615]

>>2777600
> Are you spot-welding nickel to nickel?

I don’t know. Strip is Nickle but unsure if battery. I also tried two random pieces of metal. See picrel. Am I supposed to touch both edges of the metal, so it superheats and melts together?

I thought that perhaps if I put positive on circle and ground on strips the electricity flowing through would attach the pieces. But it only seems to happen at the point of contact with the positive tip ( and sometimes ground )
Pk2n

[Anonymous No.2777626]

I remember there was old Windows program which allowed you to simulate PCB's in retard friendly way, anyone have a clue?

[Anonymous No.2777630]

>>2777612
you may as well have written that in Chinese but I appreciate your response nonetheless! (pic is me)

[Anonymous No.2777633]

is this fake? it propably is, but maybe it's worth trying

[Anonymous No.2777638]

>>2777077
I bought something pic rel for charging my laptop from a 12v source. Thanks to everlander youtube. It wants 20v 3.5a min. Problem is I am electronics nooblet. It seems really easy. Hook up 12v source, turn screw on device, do some multimeter tsting etc... anythign that can wrong or is electronics sometimes as easy as this?

Also for better connecting my car stereo, do very small Amass connectors exist or should I just do bullet or something. The speakers got two wires, I want to be able to connect and disconnect with one plug

[Anonymous No.2777640]

Hi I am trying to make a hot knife out of single soldering iron. I dont understand the connections at all. One of my soldering irons has a screw on tip the other has a tip that is made out of three parts. I just want a cutting tip from ali expres but I cant get the compatibility right. God shopping gives me headaches

[Anonymous No.2777643]

>>2777416
that's a tig welder, not a spot welder.
what you're doing will never work.

[Anonymous No.2777647]

>>2777614
Sharpie isn't that reliable as an etch resist. I think instead you'd be better off using a tape with strong adhesive as the etch resist itself. Maybe something iron-on. You could even cut vinyl on a vinyl cutter or laser cutter for this purpose.
Personally when I do one-off boards I just lay out measurements by scribing with my callipers and paint on an etch resist. For this you could use any waterproof paint, I use UV-cure solder mask because putting it in the sun or in a UV lamp cures it really fast. Though lately I've been using a laser engraver to burn away an etch resist instead, much more consistent and less time consuming. I've also been using vero-board for prototyping where I don't need SMDs, it's not as compact but it's perfectly usable.

>>2777630
Multisim? Micro-Cap?

>>2777633
The markings look wrong compared to image search results, and the chinks don't seem to make clones of them. I'd guess those to be fakes, probably shitty op-amps in disguise. Buy used from eBay instead.

>>2777638
>anythign that can wrong or is electronics sometimes as easy as this
Assuming that thing does constant-current, you'll want to ensure the current limit is set to something sensible that won't overdraw from the 12V supply. You could ignore the current limit, but in that case I'd swap the fuses to something closer to what you'd encounter.
>small Amass connectors
Like XT30s? There might be smaller still, but 30A is sorta the minimum for car audio stuff.

>>2777640
Shoulda bought an iron that used 936 tips, they're ubiquitous.

[Anonymous No.2777659]

>>2777638
damn went a little OTT with that beast

[Anonymous No.2777660]

goofy board cutouts

[Anonymous No.2777663]

>>2777647
>the chinks don't seem to make clones of them
they go for ~7€ a piece. I'm lucky I found a whole bunch of them in some garbage bin. Ufortunately I gave away 2 for free to some normalnigger in my electronics class who turned out to be a nigger. I

[Anonymous No.2777678]

>>2777647
Yeah the guy in the Everlander videos explains it too, if you got sensitive electronics hooked up to a battery that might experience sharp fluctuations you need to put a part in between to protect against that. But I dont think my 12v "house" battery on the boat will experience that as the diesel motor is hooked up to a separate starter battery

[Anonymous No.2777698]

>>2777153
yjk

[Anonymous No.2777699]

>>2777500
>>2777502
so you dont need to heat the leads/pads like with thru hole components?
you just use the solder as "glue"?

[Anonymous No.2777798]

>>2777614
sharpies suck, flake off if you look at them funny
try nail polish. or better yet, solder point-to-point/dead bug over a ground plane

[Anonymous No.2777799]

>>2777643
Ok thanks. I see now. Or at least I see that it’s a small tig welder. I don’t understand why it won’t work though. It delivers a surge of electricity - isn’t that what a spot welder does?

[Anonymous No.2777820]

>>2777077
I'm more or less a noob at electronics, I only know the complete basics since I had to learn a bunch of things at the electrician school. My most recent project was building a pair of speakers with a two way crossover that I've designed and they turned out good.

Now I'm looking to buy a retro cheap broken turntable to fix and use and maybe buy a retro broken amp then, from the 80s or 90s.

How complicated are those? Is a beginner like me going to be able to fix most of those things if I put some elbow grease to it? Any other suggestions or tips?

[Anonymous No.2777825]

Ok so I need something to operate procreate with on my ipad while drawing since it takes a lot of time when switching brushes etc.

I looked up this guy that made a wireless controller for ipad:
https://folio.procreate.com/discussions/11/29/28104?page=3

My question is how would I create something like this, he posted his parts which are:
-Adafruit Feather nRF52 Bluefruit LE - nRF52832
-Duracell DRSBX1 Replacement Camera Battery for Sony NP-BX1
-buttons

but he didn't mention that PCB he's using and as a scrub in the subject I don't know if some universal PCB will suffice or not.

tl:dr
How do I create 12-16 buttons keypad for drawing in procreate on ipad from scratch.

Help much appreciated

[Anonymous No.2777827]

>>2777825
forgot the pic

[Anonymous No.2777837]

>>2777820
>How complicated are those?

mechanically, they're supremely fiddly
parts are impossible to find
the more you fix it, the more it'll be broken

[Anonymous No.2777840]

>>2777825
>a scrub in the subject

this is an expert level project
wait til some chinese shop puts a cheap clone on Ali

[Anonymous No.2777844]

>>2777837
You're talking about the turntables, right? I don't think amps have too many mechanical components.

Will I encounter problems with parts when it comes to old amps?

[Anonymous No.2777845]

>>2777840
>this is an expert level project
I mean beside knowing which PCB to use and disregarding the 3D printed case I really don't think it's much more complicated that just soldering stuff together and coding.

Just like these ones:
https://www.themadnoodle.com/product-page/the-noodle-pad-v-2-custom-macro-pad

https://www.youtube.com/watch?v=RIj4IV7Zo8g

[Anonymous No.2777856]

EE bros, the tranny "coders" that got obsoleted by Nvidia's AI have infiltrated /ohm/. They are clueless about electronics in general, but they'll pretend like they're experts.
Thank you for reading this public service announcement.

[Anonymous No.2777858]

>>2777844
>Will I encounter problems with parts when it comes to old amps?

yes
the most common fault is dead output power transistors
you likely wont be able to find exact replacements, but substitutes abound
big problem tho, is adjusting the bias current on these transistors
at the factory, the amp is tuned just right such that these transistors are safe, but just on the edge of destruction
unless you know the factory procedure to replicate this condition, you'll be burning transistors like mad

[Anonymous No.2777868]

>>2777845
>which PCB to use

this is a custom job
unless the dude gives out (or sells) the gerber files, you're stuck
otherwise, you could get pcbway to make them for you
other potential roadblocks are
- sourcing parts that fit exactly
- programming the micro-controller; you might need a programmer and an entire software tool-chain

[Anonymous No.2777880]

>>2777868
>unless the dude gives out (or sells) the gerber files, you're stuck

oh! just checked the guy's store and he sells 6 PCBs for $35

[Anonymous No.2777893]

So I was pulling apart an old hotline electric fencer energiser, it bumps up from a 6v dc battery to pulses of a couple of thousand volts.

It had a low voltage circuit that then connected to a transformer.

In the low voltage circuit there was this big round thing about an inch high and 1.5 across bolted flat to the board that I don't really recognise any clue what it might be? sorry I don't have any images to share of the actual board

I found a replacement board on sale on ebay with the same component in the bottom left

Any idea what it is or does?

[Anonymous No.2777894]

>>2777893
>Any idea what it is or does?

step-up transformer used to generate the high voltage
uses ferrite core which, of course, easily breaks if you hit it

[Anonymous No.2777898]

>>2777894
So it has two transformers? there's a big square transforemer on a separate board that connercts to the output wires?

[Anonymous No.2777927]

I just fixed a CRT monitor where the horizontal width was way too wide and folding over itself by changing a bunch of caps in the deflection IC circuit and now it works properly, but I can't figure out why, because I tested every single one of the capacitors with an ESR meter as I was replacing them and they were all within spec. Why did this fix it if everything was all seemingly working already? Could you have a capacitor that tests perfectly normal but still is bad?

[Anonymous No.2777933]

>>2777927
Maybe you had a cold solder joint or two.

[Anonymous No.2777945]

>>2777820
Old amplifiers, if you can find a service manual, are the ideal thing to fix. They're pretty simple, easy to troubleshoot with a DMM, and actually valuable. Even if you need to replace the power transistors with different ones, there should be a guide to getting the bias correct in the service manual. Plus you can also modify them to have a bluetooth or Toslink input channel using off the shelf components. Without a service manual, I'd be somewhat cautious, but if it's class A/B/AB it should be relatively easy to reverse engineer.

>>2777880
Does he have a github? If you can't find the code it's kinda worthless to have the boards, unless you can trust yourself to roughly replicate his code without a schematic. The schematic files might be on github as well as the code, in which case you could aorder them yourself for $5 instead of $35. Order the 3D printed enclosure at the same time to save on shipping, if you're not able to print it yourself.

>>2777898
Reverse engineer by following the traces if you're curious. It's only a single-sided board.

[Anonymous No.2777948]

Hello everyone,
i am trying to make my own air filter and i found three major components for it

https://de.rs-online.com/web/p/axiallufter/1251642

https://www.amazon.de/Steckernetzteil-Netzadapter-Transformator-Radiowecker-Lichtleisten/dp/B0B3J2F2DZ/ref=sr_1_40?__mk_de_DE=%C3%85M%C3%85%C5%BD%C3%95%C3%91&crid=2OCOTFSO9UK8D&keywords=24v+1w+netzteil&qid=1707145941&sprefix=24+v+1w+netzteil%2Caps%2C236&sr=8-40

https://www.amazon.de/vhbw-Staubsaugerfilter-passend-Staubsauger-Faltenfilter/dp/B0829ZX5SS/ref=sr_1_19?__mk_de_DE=%C3%85M%C3%85%C5%BD%C3%95%C3%91&crid=1INM2Y113IW5S&keywords=hepa+luftfilter+rund&qid=1707145873&sprefix=hepa+luft+filter+rund%2Caps%2C226&sr=8-19

sorry for the links being in german, i do not know how to get them in english
and yes i know amazon = evil, it´s just all my vendors of trust closed operation years ago
anyways, is there anything i am missing? the Power output should be neough for the expected input, the diameter of the filter is not matching exactly to the measurements of the fan but i think that should not be a biggie or is it?
i was also concerned if the air current/ air flow caused by the fan is sufficient for an air filter and is the filter good enough for this application?

thanks for your help

[Anonymous No.2777951]

I posted in one of the previous threads about making a PCB slip ring.
I've ordered the PCB's and will get the contacts sorted when I've got time
I had to get the top PCB ENIG'd, the bottom PCB will have 4 contacts per channel.
Top PCB gets bolted to the moving piece using the 4 holes in the centre. Bottom PCB gets bolted to the fixed outer casing using the outside holes.
Bottom PCB is ~76mm OD Top PCB is ~62mm OD
7 channels
Wires will be soldered to pads on the underside of the PCB.
No idea if it works. God I hope it does. I'm not spending £80 per unit on aliexpress. This (assuming it works) turns out to be £25 per 5 boards + the cost of wires & contacts.

[Anonymous No.2777961]

>>2777948
>air flow caused by the fan is sufficient for an air filter

it's only 4 watts of power and moves 112 cubic feet of air per minute
that sounds like it's gonna take a long time to clean a room
a typical ceiling fan, for example, is 60 watts and 4000 CFM

[Anonymous No.2777966]

>>2777961
i get your point, i think i used the wrong words, i mean an air purifier

like this

https://www.amazon.de/Luftreiniger-Allergiker-Luftqualit%C3%A4ts-Feedback-Raucherzimmer-Schlafmodus/dp/B08L73QL1V/ref=sr_1_3?dib=eyJ2IjoiMSJ9.wtOQxlcripaUZuEnTSLw3A08RjEvlSKKSE2ff9mdpYenIdc-qm4rtUrtekOurtfqnxvpy1PjmgYPrlqh_YfrpuZ4txl60I4Qut4fVy2ZvONnnGmvlprI1JPeWJlusN-oCeY8AM3QsW3w9Bf6WBIMWirnWsoWi7LzFpRkE_Hh5CF8n2chQQ7i4t5DyXCsh4ztM2vVnYdbjB019fgJ8Xlih6cioxRmpCZz4_Bw8-g_tHM._JmibF9L4EmmpFAQLNx_VluDLG6U8ZlZU-4xrG9nSwI&dib_tag=se&keywords=luftfilter&qid=1711575780&sr=8-3&th=1

the linked one has 240 m3/h, the fan 4300 N series by ebm has between 100 ~ 285 m3/h so i wondered if 100m3/h are enough or if i should go higher

[Anonymous No.2777968]

>>2777966
This is a courtesy post to let you know that you can omit most of that link like this:

https://www.amazon.de/Luftreiniger-Allergiker-Luftqualit%C3%A4ts-Feedback-Raucherzimmer-Schlafmodus/dp/B08L73QL1V

The rest of the link is tracking shit.

[Anonymous No.2777971]

>>2777968
thanks, i think i´ll see myself out for today just don´t have the mental capacity anymore to post something usefull

[Anonymous No.2777975]

>>2777971
Sorry if that came off as ill-tempered as I didn't mean it that way. Long ago I owned a Honeywell branded air purifier with HEPA filter and the fan wasn't really strong at all. As long as it moves air through the filter continuously it'll be fine, but it's only meant for a small area. Keep it near you as opposed to the opposite side of the room, and keep it clean.

[Anonymous No.2777977]

>>2777975
t

[Anonymous No.2777978]

>>2777966
>i wondered if 100m3/h are enough or if i should go higher

there's no right answer.
you can choose slow and quiet, or faster/cleaner and a bit more noise.
if it's gonna run 24 hours a day, then slow is fine, it'll get all the air eventually.

[Anonymous No.2777983]

>>2777948
The fan doesn't move enough air, so unless you're looking to filter the air for your hamster cage it's pointless. Look up the Corsi–Rosenthal Box for something that will actually make a difference to the air quality in your home. Lots of websites and youtube vids on the subject.

>>2762589 Here is a recent thread on the subject.

https://www.printables.com/model/741704-dual-filter-solder-fume-extractor-hepa-carbon-acdc
Here is a good place to start if you do - for whatever reason - want to just make something small. Check out the parts list and recommended fan.

[Anonymous No.2777986]

>>2777971
https://www.youtube.com/watch?v=aw7fUMhNov8

[Anonymous No.2777989]

>>2777978
No it's not. The volume of air that naturally moves in and out of your home is far greater than that. It would be like trying to heat your home with a candle. It's not eventually going to heat the home up. You need a fireplace

[Anonymous No.2777999]

>>2777951
>slip ring
Any reason not to do magnetic coupling instead?

>>2777966
Go for UVC + titanium white autocatalysis of VOCs in the air

[Anonymous No.2778005]

>>2777989
>volume of air that naturally moves in and out of your home is far greater than that

if you have air circulation, that's the best purifier there is. no need for fans.

[Anonymous No.2778008]

Some symbols on snapeda are ugly as sin and i am too lazy to change them.

[Anonymous No.2778009]

>>2778005
yeah if you live in the open country side maybe. Next to a road or just in a built up area an air purifier is a good idea. Ill stop talking about this now, very off topic

[Anonymous No.2778017]

>>2777945
Thanks bro, I guess I'm heading to eBay

[Anonymous No.2778024]

>>2778017
This might come in handy:
https://elektrotanya.com/

[Anonymous No.2778043]

>>2778017
eBay is probably full of people more talented and more experienced than you picking the site clean for actually good buys. You're better off looking at local 2nd hand stores or junk shops.

[Anonymous No.2778052]

>>2778043
Nonsense. It's all about timing.

[Anonymous No.2778055]

>>2778052
>It's all about timing

which is another word for luck
just as in war, luck seems to favor the side with the most guns

[Anonymous No.2778063]

>>2778055
When was the last time you bought used/broken stuff from ebay?

[Anonymous No.2778069]

>>2778063

i ordered printer ink once about 10 years ago
as always, i placed the order just to see what the total charges would be, then canceled it before completion
for this ebay accused me of being a crook so i never bought anything from those bastards

as for used stuff, thrift stores and taking a walk around the block on garbage days

[Anonymous No.2778077]

>>2778069
Thrift stores are hit and miss, but if you're in the right area they can be a treasure trove. Garage sales are good too. The trick with ebay (in my opinion) is using search terms that aren't overly descriptive, and avoiding items that are currently popular on youtube repair channels. You might not be able to find specific things for a good price right when you search for them, but in my experience it's just a matter of time before it pops up, usually for much less money than expected. It's next to impossible to find old game consoles (ex. TG-16/PCEngine) or old computers for a price that doesn't make your eyes water. That's one of the times when garage sales and thrift shops are a better option.

[Anonymous No.2778085]

>>2777983
> Corsi–Rosenthal Box
Can we quit calling it that? These fraudsters didn’t invent it. Not even close. My dad would make these in 60s. I made my own 20 years ago. It’s been posted in diy in the 2000’s.

[Anonymous No.2778171]

>>2777856
there's been a noticeable drop in quality lately, mostly "how do I repair this consumer garbage? btw I've never held a soldering iron before and have no idea how a power supply works"

[Anonymous No.2778208]

>>2778052
>timing
how do you time a ten day auction? just hope nobody else saw it and bid at the very end? doesn't work well in my experience.

>>2778069
ebay is originally a used item auction site, so maybe they have the same "you can't back out of an auction" rule on "buy now" identical new item listings.

>>2778171
i don't mind the noobs so long as their attitudes aren't shitty and they don't ask questions they can get good existing answers for. like the guy from last thread who said he knew what he was doing, got angry, and started calling people trannies

i volunteer at a "repair cafe" and the attitudes we commonly see are far more pessimistic and complacent than the noobs we get here. some people are interested to learn how we do our repairs, but most are all "i could never do that i'm not smart enough" or whatever. sure half the problems are parts that can't be fixed at all or need specialist parts, but the other half is just simple things, like a dead fuse or motor start cap or whatever. i think we'd all be better off if it was normal for people to take something apart and check the fuse or see if there's any obviously damaged components.

well maybe in the next 10 years you'll just be able to take a photo of the inside of a device, then google's raceswapping ai will reverse engineer it and tell you how to troubleshoot it.

[Anonymous No.2778222]

>>2777415
no idea which one but one of my filters caught this thread and hid it.

[Anonymous No.2778225]

i need to do some SMD soldering and only have a simple iron, and know from past excursions that trying to desolder SMD with a single iron will just lead to ripped pads and many tears shed.
i was looking into soldering tweezers but ran into two problems.
first, i have a weller WS 81 station and the compatible tweezers cost about as much as another one of those stations new. some $250 to $550 depending on where you look, which is a little too much for me.
second problem is that i read that soldering tweezers arent even a good tool for SMD and i should just get a hot air station.
what should i do? some cheap tweezers with no heat regulation or a hot air station?

[Anonymous No.2778230]

>>2778085
>My dad would make these in 60s
You got me thinking about using water (like a bong) as a first stage filter. Maybe a cap full of bleach or iodine for added effect.
>>2778171
>there's been a noticeable drop in quality lately
Consistent with the noticeable drop in quality of people, generally speaking. Niggers can't read or use a search engine.
>>2778208
>how do you time a ten day auction?
I almost never bid on auctions. "Buy it now" with the added "or best offer" attracts my attention.
>>2778225
A hot air station is better imo (versatility). Tweezers are finicky. For hot air, you'll want to get some Kapton tape and aluminum tape to keep the heat focused on only the section you're working on. and secure surrounding components so they don't fall off of the board.

For desoldering small SMDs, it's easy to just add more solder and heat the whole thing with an iron, then pushing it off the pads. It doesn't matter if you kill the bad component.

[Anonymous No.2778274]

This might be a silly question but I'm not sure I quite understand the difference between impedance and resistance?

[Anonymous No.2778287]

>>2778274
Hint: alternating current vs. direct current

[Anonymous No.2778293]

>>2778171
>>2778208
I ask vague noob questions here sometimes like "is fixing amps easy" because I don't want to do that on reddit and if I did it at my local electronics forum I'd get banned, and google often provides dated answers on things like part availability, same goes for chatgpt and other sources.

If you want to see how bad total noob gatekeeping works, just look at this legendary thread at my local Polish electronics forum which has a country-wide meme-like status for its unfriendliness towards noobs and overall a very negative attitude. https://web.archive.org/web/20160707040620/http://www.elektroda.pl/rtvforum/topic3177031.html (translate it using deepl or google if you care).

A kid made an e-cigarette box with a screen using an arduino, a mosfet and a bunch of other things. He showed and explained more or less how it worked and how he made it, provided a list of parts and a video.

People came and said that his post is dumb if he didn't provide a schematic or the code, so he did, he didn't do it before because he doesn't have a program for it and just made it in paint. Now people started bashing him for his project being unimpressive, pointless (because he could get a working e-cig for more or less the same cost). They were even criticizing him for buying a manufactured case instead of machining it by himself or something. A guy wrote that this project is form over content, a waste of an arduino, and he did it just to flex on his friends.

Then they've told him that the project isn't even DIY since all he did was soldering a microcontroller to a mosfet and a bunch of other mostly pre made parts and writing his own firmware and that he didn't even make his own box. They told him that using a transistor there was pointless and were criticizing him for adding it there, with nobody providing any sensible context as to why. In the end, the mod told him to delete the post.

You really don't want a forum to look like that.

[Anonymous No.2778301]

>>2778274
they're the same. one's just time-dependent.

[Anonymous No.2778311]

>>2777500
>>2777502
Huh, neat

[Anonymous No.2778320]

>>2778301
that is correct in a sense, but an inductance or a capacitance or an impedance can have a fixed value that does not vary with time, while a resistance can vary with time and not be an impedance. So, when trying to help a noob, I'd say you failed.

The other guy wasn't much help either. But, having said that, I'm not suggesting that this general turn into EE 101. My answer to the original question would be go to wikipedia and do a lot of reading.

[Anonymous No.2778321]

>send a pcb to JLCPCB to print
>2 weeks later they arrive
>solder stuff
>nothing works
>everything worked on the breadboard
>turns out the SOT-23 transistor pins are inverted on the kicad footprint (I used through hole transistors on the breadboard)
Lesson learned I guess. I only wasted like 5 euro. Need to wait 2 more weeks now

[Anonymous No.2778323]

>>2778320
>The other guy wasn't much help either
>My answer to the original question would be go to wikipedia and do a lot of reading.
That's why "hint" was the first word of my response, Anon.

ATTENTION ALL NOOBS:
Ask Jeeves before you ask here and your life will improve. That is all.
>>2778321
>turns out the SOT-23 transistor pins are inverted on the kicad footprint
Common mistake. Don't feel bad because it happens to pretty much everyone.

[Anonymous No.2778324]

>>2777966
What particles are you trying to get rid of, and why?

[Anonymous No.2778337]

>>2778324
The germs that make you gay.

[Anonymous No.2778340]

>>2778337
They hated Ivermectin because he told them the truth.

[Anonymous No.2778342]

>>2778321
>SOT-23 transistor pins are inverted
Yeah, euro-transistors have different pinouts from the american/japanese standard because of protectionism and “as a nation, we’ll invent our own pinout against the existing world wide standards”

> wasted 5 euro
Sorry. Try not to buy or design with european transistors.

The IEC logic symbols and rectangular schematicized resistor representations are two more crazy examples of this shit.

[Anonymous No.2778343]

>>2778320
or better yet, make an "impedance divider" with a resistor and a cap

[Anonymous No.2778344]

>>2777975
it was not received as ill-tempered, i was just realy tired
for context the room it is supposed to operate in is an attic room of 16m2(~172 square feet)

>>2777978
>>2777989
seems like a unsettled matter

>>2777983
>overlooked an entire thread for his question
maybe i am just retarded

>>2777986
appreciated

thanks, i think i´ll get the project done now

[Anonymous No.2778373]

>>2777600
>congrats, you picked up 1µW of radiated power from the wires all around you
what is the nature of this power? changing magnetic fields?

[sage No.2778407]

herp
i bumped the needle and after the thing was off by -5V (not enough range to readjust with the knob)
then i fiddled some with the slotted screw, now it obviously isnt tracking anymore
How do i reset the dial on this thing? It has to be possible, the factory chink did it too.
There is one slotted screw, a counter nut and a preload spring washer

[Anonymous No.2778409]

>>2777999
>Any reason not to do magnetic coupling instead?
I need to transfer power, video and UART which all use electricity not magic waves. I've seen contactless power transfer systems before but they're in the £1k+ range and are very large.

[Anonymous No.2778435]

>>2778321
If your footprint of choice isn't listed as a default footprint, check the pinout before adding it. It isn't usually a problem for me since I use BC547s on breadboards and BC817s on PCBs. And TO-220s share the pinout with DPAKs and D2PAKs. But I have been tripped up by chinky TL431s actually being TL432s.

>>2778373
Probably electric fields not magnetic fields.
Magnetic fields happen due to current flowing, but in your walls there will only be a couple of amps, and magnetic fields need to be picked up by a loop of wire, not an open probe. I've seen instances where connecting the tip of your probe to its ground clip creates a small loop, and that loop can pick up strong magnetic fields, but it's not something you'd see with mains unless you're doing something specifically with magnetics.
Electric fields happen due to voltages in wires capacitively coupling to things. In the wall, you have a ground wire, neutral wire, and live wire, all right next to each other, and everything will be capacitively coupled to all of those. Inside the scope's power supply too. Going between light switches you can have live wires that aren't anywhere near neutrals or grounds. Assuming you get even capacitive coupling to live and neutral and ground, a point in your room could float up to 40VAC with respect to ground. Your oscilloscope's circuit itself is ground referenced, so if its probe will pick up the electric field around you. If you set the probe to 10MΩ instead of 1MΩ, you might measure up to 10VAC instead. Also note there will be some capacitive coupling to the earth beneath your floor, and any nearby metal pipes. But ignoring those, we can crudely calculate the capacitance to your scope probe:
>X_C = 1/(2πf*C)
>R = 1MΩ
>V_max = 40VAC
>V_scope = 1
>V_scope = V_max * R / (X_C + R)
>X_C = (V_max * R - V_scope * R) / V_scope
>X_C = 39MΩ
>C = 68pF
Cool.

>>2778409
Are you doing composite video down a slip ring?

[Anonymous No.2778447]

>>2778435
>Are you doing composite video down a slip ring?
Yes, it does work on the shitty chinese ones I've bought. You get some flicker when it moves due to resistance changes but the picture is still usable. More contacts mean less fluctuation.
Here's a guy who says it can be done:
https://youtu.be/D76IQJ6yO7U?t=335

[Anonymous No.2778450]

How would I go about setting up garden lights that silently flashed on and off to a piece of music?
Or would this be a terrible seizure inducing nightmare to behold?
I assume I would just take a waveform then tie the frequency ranges to certain leds along a path.

[Anonymous No.2778454]

>>2778450
Why do you want to do this? To anger your neighbors? So now they not only have to listen to your music, but they have to see it as well?

[Anonymous No.2778456]

>>2778454
No, I want it to be silent, I would likely arrange it along the hedge so I can see it from the window, it wouldn't need to be that bright.
I was thinking of using some sort of instrumental piece

[Anonymous No.2778457]

>>2778456
Sorry, but I can't help you.

[Anonymous No.2778460]

>>2778450
>>2778456
Have you tried taking a bluetooth speaker, cutting the wires to the speaker and putting a light bulb in there instead?

[Anonymous No.2778498]

We need a reporting system for power tripping jannies.

[Anonymous No.2778500]

>>2778498
can you make one on an arduino or an atmel?

[Anonymous No.2778503]

>>2778500
Prolly. I'll need to crowdfund it though. Shouldn't be more than $5k or so. lol

[Anonymous No.2778510]

>>2778503
I can only pay you in hotpockets

[Anonymous No.2778516]

>>2778510
>hotpockets
Are you speaking euphemistically? I don't want or need 3rd degree burns from lava in crust. Honestly though, jannies make this site suck just as much as they enforce rules fairly. It's ridiculous how sensitive some of them are to innocuous commentary. Maybe they never developed socially.

[Anonymous No.2778535]

Oof, released the smoke on that SOIC-8 in the middle, an EG2131 chinky half-bridge driver. Not sure how it died instead of the FETs, it failed when I was pushing high current through the FETs to see when my motor driving firmware current limit would kick in (it didn't). Well maybe the FETs died too, they'd be a pain to replace since they're PowerPak-SO8. The MCU is alive at least.

[Anonymous No.2778536]

>>2778535
How long did it take between the moment power was applied and the driver's fiery death?

[Anonymous No.2778542]

>>2778536
It was fine, but I kept turning up the duty-cycle on the motor while watching it on my scope to see if it would stop going up, the limiting wouldn't kick in so I kept turning it up. At around 25% the duty-cycle dropped to zero. Sniffing the enclosure told me all I needed to know.

[Anonymous No.2778549]

>>2778535
>>2778542
Replacing the driver and it works again. Anyhow I figured out why my current limiting wasn't working, turns out the current sense signal gets inverted because I'm high-side switching and measuring the current on the low-side transistor. So I need to check whether the ADC value is BELOW the limit, not above. Lesson learnt.

[Anonymous No.2778552]

>>2778549
You figured that out pretty quick. Nice job. I'm still staring at the datasheet with squinty eyes.

[Anonymous No.2778563]

>>2778552
I bought the EG2131s because they were a lot cheaper than the comparatively specced IR2184, but the shitty documentation isn't very confidence inspiring.

FYI, to test the current limit, I was powering a motor while holding the shaft stationary with pliers. I'll do testing with my new clampmeter from now on. Maybe I should make a current clamp probe for my scope using a toroid, an analogue hall sensor, and a 3D printed hinge.

[Anonymous No.2778565]

>>2778450
>How would I go about

you can bing schematics for a color organ (top) or vu-meter (bottom)
both circuits require signal conditioning; if you just stick straight audio on a lamp, it'll look shit
obviously you'll need power transistors for 12V DC lamps, or triacs for AC 12V - 120V lamps

[Anonymous No.2778568]

>>2778563
>I was powering a motor while holding the shaft stationary with pliers.
lmao
>I'll do testing with my new clampmeter from now on.
Probably a better idea. I admire your dedication though.

[Anonymous No.2778572]

>>2778563
Whoo yeah, even on low duty-cycle it gets up past 10A real fast, maybe the PSU shut down and the brownout killed the half-bridge driver IC. I'll be sure to be more careful now.

[Anonymous No.2778573]

>>2778572
Is the IGBT in the linear region?

[Anonymous No.2778577]

>>2778573
I'm using a pair of MOSFETs in a normal half-bridge configuration, with a brushed DC motor in parallel with the low-side MOSFET. This low-side FET acts like a synchronous freewheeling diode. The current sense resistor is underneath the low-side MOSFET. Which means my average current actually goes down with increasing duty-cycle, but I think I'm compensating for that by measuring the maximum and minimum values, then taking the point halfway between the min and max, with some decay. Using a bitshift instead of division, of course.

If the PSU actually dropped its output voltage, I can see the motor pushing energy back into the EG2131's pin 6 or pin 8, frying it that way. The actual failure mode isn't that important, rather I need to ensure that the current sensing and limiting code is working.

[Anonymous No.2778592]

>>2778535
>A Bridge Too Far
i chuckled

[Anonymous No.2778661]

>>2778577
Ok it was too unreliable with that current sensing topology. So I desoldered the SMD resistors going to the LM358 current sense differential amplifier, replaced the current sense resistor (length of solid core copper wire ≈ 4.2mΩ) with a slightly shorter length of solid core copper wire, bodged a THT current sense resistor hanging in the air, then soldered a pair of THT resistors from either end of that to my sense amp. I tuned it to limit itself to 9.2A on a 12V 10A PSU, but now somehow it's stopped limiting. I don't understand.

[Anonymous No.2778663]

>>2778565
thank you, that looks closer to what I had in mind I was sure there had to be a system that implemented the underlying concept I just wasn't sure what the name would be.

[Anonymous No.2778688]

>>2777077
Start here:
https://www.youtube.com/@BenEater/featured

[Anonymous No.2778733]

God I wish I hadn't thrown all of my components in a their respective box (one for capacities, one for ICs, etc), but instead kept them in their original packaging with manufacturer number. I have no idea about tolerances of my resistors etc.

How do you store your components? Looking for inspo.

[Anonymous No.2778783]

Should I trust the probes on a cheap chinese multimeter to not kill me or do I need to get something like a fluke if I want to measure higher voltages like 120v ac?

[Anonymous No.2778865]

>>2778783
>measure higher voltages like 120v ac?

you shame this hobby with your candy-ass fraidy-cat yellow-belly attitude
you're a danger to the rest of us, so begone, lil girl
try crochet instead

[Anonymous No.2778869]

>>2778783
I used a chinkshit to measure between 2 230V phases without dying, so I think they're safe enough.

[Anonymous No.2778870]

>>2778865
It's not the voltage I'm afraid of, it's the quality of chinese products. I've seen enough videos of things spontaneously combusting in china to never trust anything they make.

[Anonymous No.2778872]

>>2778783
Okay, so I’ve been doing this a long time and have touched 120V many many times. Sometimes intentionally to test if it’s live or to try and trip an RCD. However, I don’t have sweaty hands and live in a dry, cold place so you’re milage may vary. I still don’t do that kind of thing in, say, the rain, nor do I route it through my body. I use the one-hand rule.

I think what scares people is the loud “pop” and melted wire when you bridge AC mains with a screwdriver.

Now, I live in north america so everything is mostly 120 V. It’s pretty unlikely I’d be doing any of that with 220 V. And a cheap chinese multimeter is probably at least rated for 220. Most PVC wire (even doorbell and speaker wire) is rated for 300 V.

If you have concerns, you can always use some insulating gloves and test it until you feel confident.

[Anonymous No.2778876]

So I've built this using 2.6 mH inductors (it's what I have) and I can get unstable 2 kHz but one side heats up and I don't think the other is doing anything. I think the problem is the protoboard connections.
What are some alternatives for prototyping? Always worrying about connections and they still disconnecting after I finish checking is so demoralising.

[Anonymous No.2778890]

can anyone recommend any amazon breadboards that aren't cheap shit with weak pins that wear out with a few insertions

[Anonymous No.2778960]

>>2778890
>amazon

no
try some decent manufacturer like http://www.assemblyspecialist.com/WebStore/breadboards.html

or Manufacturing Solutions Group
or Keystone
or Busboard

[Anonymous No.2778961]

I want to make a little exposure meter for my film cameras.
1. Should I use a photoresistor or a photodiode as a sensor?
2. How do I make sure to buy one with sufficient dynamic range? I'd like to have fifteen stops (≈five decades) with bright sunlight at the high end

[Anonymous No.2778981]

>>2778961

[Anonymous No.2778990]

So resistor colour codes are in ohms, capacitors are in picofarads (?) and inductors are in microhenries? Is that right?

[Anonymous No.2779006]

>>2778890
dont do amazon do digikey or mouser or something. >>2778960
this guy is right. I recommend busboard, love em

[Anonymous No.2779012]

>>2778870
yeah itll be fine the chinese make good stuff nowadays its not 2005 anymore

[Anonymous No.2779022]

>>2778876
Those circuits don’t always oscillate, you’re best off playing around with a current limited power supply until you can find a configuration of Ls and C that works reliably.

As for prototyping, consider manhattan for this sort of circuit. If delaminating is a problem, try to get protoboards that use FR4 instead of FR2, and improve your soldering technique by getting in and out fast. Having a good tip geometry helps.

>>2778890
IIRC Ben Eater has a list of known good breadboards.

>>2778961
Two methods. One, make an analogue circuit with an analogue meter of some sort, getting high dynamic range will require a logarithmic circuit or meter, which would be a fun challenge but difficult to calibrate. Two, use a microcontroller instead. It would be trivial to have multiple sensor diodes or LDRs to cover a very wide dynamic range, and have a display of your choice with numbers or whatever. You could even use the microcontroller to time a remote shutter based off user-input ISO and aperture. A must have for long exposure photography.

>>2778990
Picofarads usually, but sometimes microfarads, maybe farads for supercaps, but I’ve never seen a supercap using shorthand notation. Otherwise yes I think you’re right.

[Anonymous No.2779045]

>>2779022
don't forget nf (1000 pf's) thats getting used more nowadays.

[Anonymous No.2779144]

>>2779045
When a cap's value is written in nanofarads, it has "nF" written after the number. I'm talking about caps with "104" or what have you written on it, the shorthand notation. I don't think I've ever seen a capacitor with coloured bands instead of numbers on it, they might exist, but the resistor colour codes use the same numbers followed by an exponent method as these capacitors. If 102 could mean both 100pF AND 100nF, we'd be in a spot of ambiguity. But 102 being both 100pF AND 100µF isn't an issue, because you can tell the difference via context (ceramic vs electrolytic, size of the film cap, etc).

[Anonymous No.2779155]

>>2778733
Keep each type in its own ziplock baggie, then organize by decade.

[Anonymous No.2779207]

My retard manlet.boss asked me to "make up a chime and have our robots beep it"
I'm gonna make it play the tune from Short People by Randy Newman lol what should I use.to make it beep boop
https://youtu.be/8bfyS-S-IJ
Do not.click that link if you are under 6 feet

[Anonymous No.2779244]

[Anonymous No.2779267]

anyone have good courses for learning RF circuits? I want to get into video transmission and radar

[Anonymous No.2779306]

>>2778990
Caps suck to read sorry anon, they could be in micro, nano (pretty rare), or pico, and they have other naming schemes that vary by manufacturer

[Anonymous No.2779309]

>>2779306
That guy is talking about ones that have band color codes like resistors do
I've never worked with color coded caps but he's right, the value on them is (10A+B) × 10^C pF where A, B, and C are the digits corresponding to the band colors (Bad Beer Rots Our Young Guts etc)

[Anonymous No.2779318]

>>2779144
>102 could mean both 100pF AND 100nF
Wouldn't it be 1000pF or 1000nF? 10 is the number is 2 means two zeroes added, so 1000.

[Anonymous No.2779394]

>trying to get back into hobby electronics
>looking at this project
>suggests that i use two chips
>look up their diagrams
>they dont look too complicated
should i get the chips or just build them out? is it better to start out with chips or only get them after you know how to build them?

[Anonymous No.2779405]

>>2779394
Which would be more fun for you? What do you want to get out of this project? Do you understand what is going on inside the chips?

[Anonymous No.2779411]

>>2779394
>how to turn a $5 gimmick into a 10 year project

[Anonymous No.2779422]

>>2779411
You're not cool unless you make your own semiconductors from scratch

https://youtu.be/IS5ycm7VfXg?si=L-Y5cdBHJnFz7IZ7

[Anonymous No.2779434]

Amazing news anons. Apparently a 0402 part fits onto a 0805 footprint just fine. I couldn't find a 0805 cap and was afraid I'd have to use some kind of an ugly jumper but shockingly despite 0805 pads being wider and larger there is not that much of a difference lengthwise.
The opposite is obviously not true so if in doubt, use larger footprints for R and C.

[Anonymous No.2779448]

>>2779309
>bad beer mnemonic
Black boys rape our young girls, bam virginity gone west. Get some now!

[Anonymous No.2779450]

>>2779309
>>2779448
>mnemonics
I just memorised the colours themselves.

[Anonymous No.2779466]

>>2779318
I meant 101.

>>2779394
>should i get the chips or just build them out
Does "build them out" mean make them from simpler chips? Sounds like a form of feature creep, I wouldn't unless there's a good reason to. You're better off picking up projects that are intrinsically more complicated, as opposed to deliberately complicating simple projects. That way you get better practice at simplifying projects within the bounds of what's reasonable, which is good for avoiding feature creep, is good for hitting deadlines, and is just a good engineering practice overall.

>>2779434
There are hybrid footprints available that makes this even more flexible. I don't think they're available in KiCAD's default library for passives, but I've seen them for diodes. You have tapered pads, pic related.

[Anonymous No.2779473]

>>2777077
does anyone has a comprehensive video about using hot air soldering? i have been looking for a good tutorial but i have found only stick soldering tips.
i have been burning my test boards and i want to repair an old xbox one, but the chip has internal terminals, it need heat air to come off
pic of my terminators to get attention.

[Anonymous No.2779477]

>>2779405
right now i want to get the hardware built so i can focus on the software portion. after that i would be open to modifying the hardware or software to expand on the initial design. that way i can say that i did more with a project than just copy someone else's design.

>>2779411
pic related

>>2779466
>Does "build them out" mean make them from simpler chips?
yeah building it out from their basic components, assuming the chips arent too complicated
>You're better off picking up projects that are intrinsically more complicated, as opposed to deliberately complicating simple projects. That way you get better practice at simplifying projects within the bounds of what's reasonable, which is good for avoiding feature creep, is good for hitting deadlines, and is just a good engineering practice overall.
whats an example of simplifying a complicated project?

[Anonymous No.2779492]

>>2779477
>whats an example of simplifying a complicated project?
The retard me of 8 years ago wanted to make a variable frequency generator by having a bunch of shift registers, with rotary switches for each one to set what the division ratio would be, ultimately running on a MHz crystal. I bought all the parts and made a faceplate. The cool part would be that it would have an LED for each shift register output, so you could see the outputs spinning around. But then I realised I'd get a better result far easier by just using a 555 timer with switchable capacitors and variable resistor. Or an arduino. Or just get a function generator for free from my university, which is what ended up happening.

In a similar vein, I'm on and off designing a powerful benchtop variable CC/CV power supply with a split-H switching topology and linear postregulator, even able to sink current as a load. But my daily driver for two years now is just an LM2596 module rattling about a plastic box with pots and a panel meter.

More recently, I was designing a board to PWM solenoids and switch motors and stuff for commercial customers, an all-in-one board that could be reprogrammed to suit whatever purpose it was needed for. It would have 2-4 MOSFET half-bridges on it that could be switched together to drive motors, or independently to switch solenoids, or even used as a class-D amplifier. But then I got bogged down deciding how I'd keep the high-side transistors on with 100% duty-cycle, thinking about adding charge pumps to each stage, and trying to decide what microcontroller would be a good fit. Then a customer came knocking, and I decided that while such a design could definitely suit his purpose, it would be more complicated (and more expensive) than necessary and wouldn't be designed in time. So I mocked up a board with two relays and six diodes and got them fabbed. But I also went out of my way to add alternative footprints and options for different configurations.

[Anonymous No.2779500]

>>2779466
Those tapered pads could probably work both ways. I just realized I also picked a 0402 footprint but only have 0603 parts of that value and it certainly doesn't work the other way. I had to slap on a couple of bridges and the gap is too wide for a bridge and it took me a while. What a mess.

[Anonymous No.2779506]

>>2779466
>deliberately complicating simple projects.
Heh I am really good at that. I figured instead of having three separate devices, I'd combine a power supply, a current sink, and a signal generator in the same box with separate controls/inputs/outputs but a shared display and a microcontroller. I mounted 3 separate boards on standoffs on top of one another and wired a bunch of interconnect cables and sockets, and then I realized that there are not enough DAC pins and had to share them for different functions, and added a bunch of extra buttons and confusing switches on the panel and then I also decided to add a thermistor and a fan, and then I realized that the tiny transformer I could squeeze into this tiny box would sag too much under high current, so I used center tap for dual supply but had to use two ends to double the voltage to power the fan and some other circuitry. So I had to also add an optocoupler since I had to deal with two separate grounds / reference points and on and on. Instead I should have just built 3 separate devices and used properly sized transformers so I wouldn't have to deal with this madness. Anyway, I never finished the project. But it was fun. kind of. Something something the journey not the destination.

[Anonymous No.2779530]

>>2779267
This board is too low IQ for RF, you need to ask somewhere else.

[Anonymous No.2779532]

>>2779207
>what should I use to make it beep boop
Like, hardware wise? A piezo disc or dynamic driver, depending on what voltage you have to work with. Firmware wise, most MCUs have the ability to change the overflow value of a hardware timer, and so can produce square waves with varying period pretty easily. Just store all the period values for sequential notes in a lookup table. If you wanted something better than a square wave, you could maybe filter off the square edges, but you'd probably need to use a DAC of some sort, which would additionally need a waveform lookup table. Maybe you can do some additive synthesis with square waves to approximate something less square, like what a delta sigma modulator does, or what cnlohr did recently with his cool LoRa project.
>https://youtu.be/8bfyS-S-IJ
Dead link
t. 5'10"

>>2779506
Feature creep is a disease.

[Anonymous No.2779569]

Damn I done goofed again. Now it it turns out I accidentally flipped one of the footprints while routing my PCB and it was fabbed with the SOT-143 footprint upside down. I tried to fit the part and kept rotating it and couldn't figure out why the wide pin1 is on the wrong side and it didn't make any sense. I must have accidentally flipped the footprint, there is no other explanation. Anyway I have to solder the part upside down now. I am not sure if I should try pushing on the leads to kind bend them down the wrong way and risk breaking them or just slap 4 blobs of solder on each pin tall enough to reach the pins or at least avoid bending them down too much? God this is silly.

[Anonymous No.2779572]

>>2779530
RF shit's basic as fuck everything's solved already

[Anonymous No.2779573]

>>2779569
>I must have accidentally flipped the footprint
how did you manage that? KiCAD doesn't let you do that easily, maybe you edited it and changed the layer from front to back or something but that's a hard mistake to make. Maybe it's easier in other software.

I'd bend the legs, you presumably have a bunch of them to test it on anyhow.

Also why did you solder the tiny parts last? That big USB port or whatever is just going to make it harder. And R3/R4 are looking goofy, and you've got some unconnected ground plane, which will only serve to make crosstalk worse.

[Anonymous No.2779575]

>>2779572
Nta but reccomend something then, I've been learning from mcgraw hill Principles of Electronic Communication Systems for school and dont think its a very good resource and want to learn more.

[Anonymous No.2779581]

>>2779575
this + watch w2aew for the basics
watch out for stray capacitances everywhere, learn to make cheap shielding, get an RTL-SDR so you can see what you're doing

if you're the video/radar schizo that sounds like a pretty tough project, maybe start smaller
and lastly, http://toroids.info/T37-6.php

[Anonymous No.2779591]

>>2777364
Those look like flyback transformers. You're right to think of them as scary

[Anonymous No.2779595]

>>2779573
I use Altium. It lets you flip it but warns you that "you are flipping on the same layer" since that would be an odd thing to do so it assumes that I am really trying to move it to the bottom layer or something. I have no idea why I'd even attempt that. There are shortcuts for all kind of rotations so I must have used the wrong one.

>you presumably have a bunch of them to test it on anyhow.
Yes, that is an ESD protection for USB I have a bunch of them.

>And R3/R4 are looking goofy
That's another fuck-up. I picked a 0402 footprint but could only find 0603 resistors. Since it is zero ohm, I made a bridge between the pads, but the pads are tiny and the gap is too wide for an easy bridge and solder mask around the pads makes it harder to bridge them so I had to use a lot of solder and lower the temperature to make it less fluid and stick better. I should have used a jumper wire but it is OK.

>you've got some unconnected ground plane
That's just a top copper pour, it is not connected to any net. The ground plane is on the bottom layer.

>Also why did you solder the tiny parts last?
Good question. This is really my first "real" PCB project, I just practiced before, and I wanted to start with connecting power (USB) then the voltage regulator etc. But yeah, it makes sense to solder the tiny parts first even though in this case it is not a big deal. The USB jack is not really in the way.

[Anonymous No.2779632]

>>2779595
> has some chinese factory make the PCB
> “my first PCB project”

[Anonymous No.2779645]

>>2779632
what kind of retard still makes his own PCBs in 2024 when a 100x100mm 2 layer PCB costs $5 delivered? a 4 layer is just a few dollars more. and i'd instead mess with all those chemicals and shit just for the heck of it? that's just stupid.

[Anonymous No.2779651]

>>2777699
whoever made the video has their process and technique very dialed in. they have their temperature set so the thermal mass in the solder is enough that it stays at least hot enough when it touches the tiny pin and pad. that's a very tiny chip

[Anonymous No.2779653]

>>2778085
yeah, nobody actually calls it that...any time you see it used, that's rosenthal himself. the idea was 100% corsi and he took credit after murdering him.

[Anonymous No.2779669]

>>2779645
It's valuable from the perspective of rapid prototyping where single-sided (or two-sided without plated through-holes) is all you need. I home etch "glue boards" to connect factory-fabbed boards together. But I'm also a diy chemistry enthusiast with a garage, so depending on your interests or living area you may or may not see this as worth doing.

[Anonymous No.2779686]

>>2777077
How much does it cost to get PCBs assembled. I hate soldering and suck at it.

[Anonymous No.2779725]

>>2779686
First time getting PCBs assembled from LCSC is free. But which parts they have, and how to select those parts without using EasyEDA, doesn't seem straightforward to me. It's SMD only, so PCBs made through them may seem a bit unbalanced.

[Anonymous No.2779726]

>>2779645
Because it doesn't cost £5 delivered, it costs £5 PER BOARD delivered if you order a minimum qty of 5 boards AND you don't mind paying £20 for the DHL air freight to receive it in 2 weeks.
So it's actually £45 for a prototype PCB AND you have to wait 2 weeks.
If you have a CNC router you can have a board for <£2 in 45 minutes.
If you want your boards made in europe expect to pay upwards of £20 PER BOARD and you still have to pay DHL £20 to deliver.
If you want the boards made in the UK you can just slit your wrists because the cheapest one I could find that didn't export the manufacturing to china wanted £300 for 5 boards.

[Anonymous No.2779728]

>>2779726
No, it's $5 per 5 boards of the same design from JLC. Shipping can be anywhere from under $5 to $30, depending on what shipping method you pick and the size of your boards. DHL standard was $15 for me last week, DHL express is more expensive still, but there's the standard china post options to pick from if you don't mind it taking another week or two to arrive. For general purpose boards that aren't for the project you're making RIGHT NOW, that kind of delay really doesn't matter. For immediate projects, diy boards are definitely worth considering.

[Anonymous No.2779791]

Help me. I am trying to design circularly polarized rectangular patch antenna with single coaxial feed in CST. Trying to create circular polarization by truncating the patch's diagonal corners but it still radiates linearly polarized.

[Anonymous No.2779803]

>>2777077
I'm wanting to control a 110v house outlet from my PC.
would this suffice for the 'switch' (relay)?
I was going to use an Arduino and relay, but this looks like a cheap combination of what I was going to do

[Anonymous No.2779814]

>>2779645
sometimes you want a board same day and not 2-3 weeks later.

[Anonymous No.2779822]

Can you permanently float 18650 batteries @4.2V?

[Anonymous No.2779837]

>>2779822
>@4.2V?

sure can
dont listen to the fascist nerds who say they must be stored at 3.8 to 3.85 only
they're just freedumb-haters

[Anonymous No.2779840]

>>2779803
>would this suffice

sure
it's just weird that you have to turn on the computer to turn on a light/pump/whatever
a low-power controller that stays on all the time would be preferable
or get one of these (pic) so you dont even have to open up the power outlet and risk life and limb

[Anonymous No.2779841]

>>2779840
>it's just weird that you have to turn on the computer to turn on a light/pump/whatever

in case it's not clear, the relay is powered thru USB so when you turn off computer, the load goes off

[Anonymous No.2779843]

>>2779837
Thanks anon

[Anonymous No.2779863]

What do you call physical switch that switches between two 9 pin inputs? I want to make an SD card 'switcher' so I don't need to constantly pull out the SD card out of my Dreamcast and plug it into my USB adapter.

[Anonymous No.2779865]

>>2779863
Mux

[Anonymous No.2779870]

>>2779863
>physical switch

common term is AB switch or A/B switch

[Anonymous No.2779875]

>>2779822
> float at 4.2 V
I wouldn’t. As mentioned before, if you want long term reliability only charge up to 3.9 V, and even then it stops the charge after that.

If I were going to keep a cell continuously charged, I’d probably start charging at 3 V and stop at 4 V in a cycle, as needed applying like 20–200 mA depending on cell’s capacity.

[Anonymous No.2779881]

>>2779728
> unable to fix a simple fuck-up on PCB
The main problem is PCBs are a stupid meme—the idea of which—needs to be squashed underfoot like the troll of ignorance.
Almost nobody needs a PCB, and it was just a cheap manufacturing method in quantities in the 1000s like SMD parts themselves.
I’ve done my part, now you do yours.

[Anonymous No.2779882]

>>2779870
I'm looking for something like this, it needs to have 9 or more pins. It's basically a toggle switch * 9. There's a lot of stuff on the internet, it's hard to find the right switch.

[Anonymous No.2779910]

>>2779863
Investigate the pinout, you may be able to leave most pins disconnected and just switch a control line or two. Anyhow, a mechanical switch would be called a 9PDT (or 10PDT or 12PDT with unused pins), but a multiplexing IC may be worth considering.

>>2779881
Yeah maybe if you want to make digital logic IC computers or simple analogue circuits that's fine. But in the realm of power electronics and high-speed electronics, to say nothing of RF, that kind of prototyping is unsuitable. Manhattan works better for high speed, but lacks the ability to handle the heat sinking that modern ICs do through their thermal pads. Plus multilayer boards allow for higher density and better shielding, both of which reduce radiated and received emissions. It would be impossible to design an equivalent THT board for my current TMC4671 project.

[Anonymous No.2779918]

>>2779882
>something like this

oh, then you want a 9-pole double throw, aka 9PDT
it's easier to find a 10PDT
make sure it's a toggle, not a momentary type
in my pic you can tell it's toggle, coz it's described as ON-ON
and also coz it has that metal pin i highlighted

[Anonymous No.2779919]

>>2779840
I bought a 110v air raid siren.
It needs power for a few seconds then a pause for X seconds.
I don't know the interval.
I'm enough into software that it'd be easy for me to write and host a local website so I can trigger it anytime I want.
I run the PC 24/7. I just need a 'switch' to turn it on and off. That seems like a cheap and easy solution unless USB power (3.xv) won't work with this 5v device.

[Anonymous No.2779925]

>>2779919
>USB power (3.xv) won't work with this 5v device

USB data lines are 3.6V but the power lines are 5V
that's the law
it's possible but unlikely the relay will operate at 3.x

[Anonymous No.2779928]

>>2779925
Thank you!
Time to piss off the family from a safe distance :)

[Anonymous No.2779936]

Hello again /ohm/
I have posted a while ago >>2757695 about 433mhz fm transmitter. Now I have finally managed to get it to work (see pic related). The only problem I have now is that I need to hold the antenna in very specific way with my hand in order to make it work. Is there any particular reason for that? Do I need some specific antenna rather than a piece of wire? Thanks in advance.

[Anonymous No.2779939]

>>2779936
forgot to add the circuit, my bad.

[Anonymous No.2779944]

>>2779936
You need a 17.30903337 cm lenght of wire. Is that what you have on there?
Also see /diy/ham for detailed antenna knowledge

[Anonymous No.2779945]

>>2779944
>You need a 17.30903337 cm lenght of wire. Is that what you have on there?
Not really. I have just cut a few centimeters of insulated 0.4mm copper wire and soldered it to the transistors collector. Is there a way to calculate the length of the antenna?
>Also see /diy/ham for detailed antenna knowledge
I have asked this question in this thread as well but I have got slightly better answers in /ohm/ here. But I will inspect /ham/ more deeply, thanks!

[Anonymous No.2779951]

>>2779945
Yeah, compute the wavelength, λ = 29972458 ÷ 433000000 Hz.
λ= .6923134 m.
Most monopole antennas are some multiple of λ, so ¼λ seems convenient at just over 17 cm.

This doesn’t take into acount things like propagation delay and whatnot, but it’s a good first approximation. You can tune the length by nibbling bits of wire off the end of your antenna until your reception is best.

[Anonymous No.2779954]

>>2779951
Thanks a lot, anon!

[Anonymous No.2779964]

>>2779954
>Thanks

people have been harping on antennas but i think that's bullshit
i have a dozen pairs of those units and they work just fine with or without the pig-tail antenna
the fact that you need to handle the circuit in a certain way suggests to me that the circuit is not oscillating
but when you touch it, you're adding some capacitance somewhere, which is starting oscillations

[Anonymous No.2779969]

>>2779964
I have also had those but I just thought about building a transmitter like that on my own that will be a little more powerfull (the one I made takes like 300 miliwatts).
>the fact that you need to handle the circuit in a certain way suggests to me that the circuit is not oscillating
Is it the matter of soldering it in a better way? I plan to make it again on a perf board after those sot23 adapters will be delivered to me from china.

[Anonymous No.2779986]

Does anyone know if JLCPCB promotion is for a fixed number of orders or a certain period since the first order and what is the full price for a 100x100mm 2 layer board once the promotion expires?

[Anonymous No.2780009]

>>2779964
> needs more capacitance
That’s exactly what an antenna is for, and it fundamentally works by capacitive coupling. A bigger antenna will have more capacitance.

There might be other problems, but we can address those one at a time.

[Anonymous No.2780186]

>>2777614
555 sinks 45mA at 18v max Idk about your diodes, read the data sheets.

>>2777633
Even fakes will “work” most of the time depends on your application and if you’re ok with that level of uncertainty

>>2777638
That’s a switch node power supply. Idk if your laptop will appreciate the extra noise, add decoupling capacitors because they’re cool or make a linear regulator. I used to use crimp butt splice connectors for car stereo, quick and dirty, solder and tape will be more reliable.

Should I set up knob and tube dc distribution in my basement? I’m getting tired of plugging in all the wall worts.

[Anonymous No.2780215]

Took apart an analog old alarm clock. Saw the lavet, quartz and gears, but there was one thing i didn't understand- How does the circuit make the buzzer change intervals? When the alarm goes off, the buzzer first has one frequency, (once per second or something) and then after a while it speeds up until you press the off / snooze button

[Anonymous No.2780290]

>>2780215
I’m guessing it’s an RC oscillator with a contactor and it switches out some capacitance or inductance.
Where’s some pics of the mechanism?

[Anonymous No.2780293]

>>2780186
> knob and tube dc distribution in my basement?
No. The voltage drop is not worth it unless it’s short runs.

[Anonymous No.2780306]

>>2777638
> small amass
XT30

Or break out the amass pins and sockets out of the yellow nylon housing and use them like banana jacks with heat shrink to insulate them.

[Anonymous No.2780311]

I made a stupid mistake on a PCB. I forgot to specify having in-pad vias (.4mm hole diameter) be filled with conductive epoxy, and the solder wicked into the via instead of onto the connector pin it was supposed to go to.

These fuckers were expensive, so do I have any recourse here? I was thinking of just trying to flow more solder into the via, or maybe threading some magnet wire through the via and using it as a wick onto the pin.

[Anonymous No.2780368]

Mech engineer here. I'm slowly getting into electronics, I read Mims, Scherz & Monk, and Horowitz and Hill. They were good to learn the core principles behind single components and other basic building blocks. I got the minimum viable equipment to experiment (lab PSU, which came in handy with other projects, signal generator, a cheap 2ch digital scope, a nice breadboard various components) with very simple circuits and it was fun enough to keep me going, however I'm starting to hit a wall: I now want to start designing my own small circuits and I realize there's a lot of knowledge I lack and putting everything I learned so far is quite difficult.

[Anonymous No.2780369]

>>2780368
Fuck, I accidentally erased half post right before posting. Anyway, to make an example, I'm making an analog PID controller with opamps, which is simple enough from a theoretical standpoint, however I'm at a loss on how to properly size all the various components, choosing values, etc.
Is there any comprehensive resource to refer to, or is it more a experience/work knowledge kind of thing?

[Anonymous No.2780373]

Anons, I wonder if you could resolve a question I had.
I pulled apart an old grinder to salvage some parts from it a while back, I finally got around to looking over what I salvaged, and came across this weird blocky thing over the on/off switch, took me a while to figure out what it was but I realise it's a 0.22uf x2 safety capacitor now after a good bit of research and reading around the topic I understand they can work as a safety breaker to the fuse and also filter out high frequencies.
My only real question is what sort of frequency range are these things looking to exclude, I couldn't pin down specific details when I searched and I don't have a way to test the inductance of the little torroid I dug out from deeper in the circuitry. So I was curious what sort of frequency ranges these EMI filters were generally tuned for.

[Anonymous No.2780376]

>>2780373
It can also be used to provide phase-shifted AC to a motor, ensuring that it starts in the right direction,

[Anonymous No.2780377]

>>2780376
I'm aware that capacitors are used to supply a phase offset to efect to asychronous motors but I thought it was a diferent capacitor?

I think I understand the x-class safety capacitors but I'm not as sure on y-class yet.

Anyway how does the capacitor induce the phase shift, is it just because it has to go into and out of the cap, doesn't the starting cap usially get disconnected somehow after the initial start up?

[Anonymous No.2780381]

>>2780369
Op amps have a ridiculously high gain, so typically you use high value resistors for things like voltage dividers since it needs bugger-all current on the back end.
If you take the simple voltage divider, the voltage is the same if you use two 100Ω resistors or two 1MΩ resistors except the current available in the latter configuration will be a lot lower.
Many times I just don’t know how low I can go on the current, so I use potentiometers and adjust them so it works, then increase the values until it stops working, then back up a bit.
I also find this useful for biasing transistors for one-offs and because transistor gain is very wide-ranging.

[Anonymous No.2780382]

>>2780373
>My only real question is what sort of frequency range are these things looking to exclude

all of them
in example plot for a (small) given cap, it has an equivalent resistance of
100,000 ohms at 10Hz
100 ohms at 1000Hz
2 ohms at 100,000 Hz
0.2 ohms at 1,000,000 Hz

given that it's in parallel with the motor, it's heroically slaying all the high frequencies
which are the ones most likely to escape into the environment and cause neural infetterence

[Anonymous No.2780383]

>>2780311
I use slightly blunted stainless steel hypodermic needles for that since my wife is a nurse and she can get a bunch of different sizes. Stainless doesn’t stick very well to solder.

[Anonymous No.2780385]

>>2780382
Just a thought you sparked in me, I understand it's filtering what comes in through the wires but does it also have an effect on frequencies that migh be generated within the device from the various generator effects?

[Anonymous No.2780389]

>>2780385
>various generator effects?

99.9% of the noise is sparking from the brushes
marconi's first radios were essentially spark generators until 1912

[Anonymous No.2780390]

>>2780381
That was my idea too, but that's too specific for that singular problem. I was thinking about the kind of rules of thumb every industry has. For instance, in my field, there are shorthand rules for hole sizes, bend distances from edges in sheet metal, thickness variations for injection molded parts, all of which to an extent are also codified. All these design rules of sorts must also exist for electronics, like what cap type use where and when, main resistor values, etc, otherwise nothing would get done in a timely manner.

[Anonymous No.2780393]

>>2780389
But why would an ac induction motor have brushes?

[Anonymous No.2780394]

>>2780377
> capacitor disconnected
My grinder has a big induction motor and it disconnects the capacitor when running, but they can be designed where it doesn’t have to, usually a special winding.

Ideally you want a band-pass filter at 50 or 60 Hz so it rejects everything except the AC mains.

[Anonymous No.2780397]

>>2780393
>induction motor have brushes?

oh, you mean a bench grinder, not an angle grinder

[Anonymous No.2780398]

>>2780390
Yeah, there is; like typically you use a 10 kΩ resistor in front of a switching transistor on the base.
It would be hard for me to enumerate everything though!
The audiophile subdiscipline knows the most about minor perceived differences in capacitor qualia.

[Anonymous No.2780399]

>>2780397
No, it was an angle grinder, I just assumed it must be an ac motor does that mean there's some sort of rectifier hidden deeper in the grinder body I didn't see?
I'll have to get it open again and see.

[Anonymous No.2780401]

>>2780398
>The audiophile subdiscipline knows the most about minor perceived differences in capacitor qualia.
It is somewhat insane the amount of high quality content these guys put out. or the setups they invest a small fortune into.

[Anonymous No.2780403]

>>2780401
> high-quality content
Shame on you for not saying “high-fidelity content”

[Anonymous No.2780420]

>>2780399
>No, it was an angle grinder

an angle driver will almost certainly have brushes
no rectifier needed, as universal motors work on both AC and DC
we know how noisy they are
if it used an induction motor, you'd hear nothing but the gears

as for bench grinders, they also create some minor sparks across the power switch
every time they're switched on
and especially every time they go off

[Anonymous No.2780447]

They surely mean mm? or I don't know anymore.

[Anonymous No.2780469]

>>2780377
Very small induction motors can repurpose X2 caps as start caps, but it is unlikely for a power tool. You should be able to tell based on whether it’s in parallel or in series with a winding of the motor.

To learn about the phase shift, look into capacitive reactance. Calculus required.

>>2780390
For small signal stuff, assume 10kΩ and 100nF. Vary from there. Some stuff is better at 1kΩ, like a TL431. Going into the MΩ can be bad for noise susceptibility, going into the hundreds of ohms can mean higher quiescent current and often more distortion. It’s always context dependent, but these rules of thumb get me where I’m going 90% of the time. Read datasheets and appnotes for to get a feel for how to design circuits that connect to your ICs of choice.

[Anonymous No.2780480]

>>2780469
> into the MΩ can be bad for noise
Is that still true? I heard the old resistors that are packed with carbon dust and wax were bad for noise, but that newer metal film resistors had less noise. And maybe the ultimate is wire wound, but it’s hard to find a 1 Gigohm wirewound resistor. The sometimes use around 1 gigohm resistors in jfet microphone preamps with phantom power. In practice, a reverse-biased signal diode is in the gigohm range.

[Anonymous No.2780503]

>>2780480
It’s less about thermal noise, more about the high impedance making it easier to receive radiated electric field noise. Like when my op amps started picking up AM radio.

[Anonymous No.2780521]

Anyone know where I can buy the thin-flat legs from chips by themselves? Or what they're called? I was just looking for "ic legs".

[Anonymous No.2780559]

>>2780521
That’s the most pathological question I’ve seen in a while. Anyway, those are DIP packages or nowadays “PDIP” but single in line (SIP) packages also had the dual in line style “pins”

[Anonymous No.2780564]

>>2780398
>>2780469
Excellent. Thank you. One last question: what can I read next? I want something more applied than theoretical. I was thinking about inductors and transformers design, with a side of SMPS design.

[Anonymous No.2780569]

>>2780564
The two easiest places to start is examining how (and building) a “joule thief” … sample exercises:
Can you build one using an air core? A steel nail core? If not, why?
Convert your joule thief into a high voltage version that can output 90 V to power a neon bulb instead of a LED.

The other thing worthy of study is the “black regulator” by roman black. You might want to find replacements for his euro-style transistors.

A lot of commercial SMPSs work in similar ways, rectifying mains, chopping it up at a high frequency, then stepping it down and regulating it.
Rule of thumb: mains smoothing usually 400 V electrolytic capacitors.
Someone will post some magic chip like the TL494 but you’ll get more out of doing it at the bare metal (and they’re not that much more complicated from a user perspective) than a magic chip.

[Anonymous No.2780577]

>>2780394
>Ideally you want a band-pass filter at 50 or 60 Hz so it rejects everything except the AC mains.
Well from what I was reading these sorts of caps gradually lose their capacitance over time due to spot burn outs and electrolyte degradation so I figured they must be designed as a low pass filter that gradually raises its range as the cap degrades.

This is obviously just speculation from a brief tear apart of a cheap 4.5 grinder. I did physics at school where we covered electrrical circuit theory but I feel like it was somewhat a waste that they didn't simply incorporate practical elements such as building a circuit that used the rc time constant for some practical purpose.

[Anonymous No.2780580]

I'd just like to clarify something from a safety perspective.
I've been fiddling with a breadboard (mostly turning leds off and on at the moment) I'm powering it via an old v5 500mA samsung phone charger I cut the end off of and attached jumper wires from it to the power lines.
Am I setting myself up for some sort of problem by doing this that might catch me unaware?

[Anonymous No.2780583]

>>2780580
Stop trusting anonymous trolls on the internet instead over your local authorities on topics on electrical and fire safety.
Even batteries can short and become a life threatening fire hazard.

[Anonymous No.2780600]

>>2780580
>Am I setting myself up for some sort of problem by doing this that might catch me unaware?
Old low power phone chargers often lack protection circuitry. There's no telling what might happen if you accidentally short it and leave it like that.
A better option for this would be an ATX power supply. These often have overcurrent protections. As a bonus, you have +12V and +3.3V to work with along with the +5V.
Also use fuses, no matter your power supply.

[Anonymous No.2780613]

Anyone here FUCKS with reel to reel AC motors? Might need to change mine run cap but the wiring is FUCKY

[Anonymous No.2780615]

>>2780369
It's generally not rocket science, especially when you have buffers (OpAmps) involved.
Any value between 1k-1000k resistors and 10pF to 10Uf caps should work.

[Anonymous No.2780627]

[Anonymous No.2780678]

>>2780580
If it’s a real samsung, it’s probably not a problem, most smps wall warts have over current and thermal protection as did the lowly 7805.
Put a beefy 5W, 10 ohm resistor in series with the + line to limit the current to 500 mA and insulate it if you’re worried.
You can also test it to see what happens. As one does.
I’ve been using wall warts and breadboards to power things since the 60s and never had a problem. My wall warts are mostly transformer based with no protection and go way overvoltage if unloaded. Ymmv.

[Anonymous No.2780829]

>>2780521
Maybe you can buy unfolded “DIP leadframes”.

[Anonymous No.2780897]

How would one go about making a timer that switches off a circuit after a specified and programmable amount of time? I know how to do that with arduino, but I want some insight in how that could be achieved with just discrete components and ICs.

[Anonymous No.2780898]

Finally fixed an old crt monitor that's been bugging me for months with messed up horizontal linearity only on certain resolutions. Turns out it was a dead relay switch which was supposed to connect an extra inductor only when the monitor was set to scan at 30khz (vga mode).

[Anonymous No.2780901]

>>2780521
>Anyone know where I can buy the thin-flat legs from chips by themselves?
No, but you can buy 555 ICs in the bazillions for about tree fiddy and clip them off.

[Anonymous No.2780922]

How to solder through-hole components in a double sided PCB when you want to connect their pins that are on front side?

For things like resistors it should be easily doable since their pins are exposed on both sides and you can just solder them on from either/both sides. But for components with pins underneath them, like a LED, you can't really access the pin from the front side

I am thinking of pic related, it is the cross section from the side. For pins that are hard to access, I will drill a hole next to them and put a small wire/pin through that (red line) and connect my new pin on both sides whatever they need to be connected.

[Anonymous No.2780923]

>>2780521
just use a tiny solid wire instead? Does it have to be exact shape

[Anonymous No.2780940]

>>2780922
>connect their pins that are on front side?

proper terminology is ''component side'' vs ''solder side'' or "copper side"
if your PCB is professionally made, say as a kit, or thru JLPCB, etc, there's no need at all to solder on both sides
the feed-thru will connect top and bottom, and wick solder up into itself to make double-sure the connection is made
if you're doing it manually, you just make sure you dont have traces connecting to component side of problematic components like LEDs

[Anonymous No.2780943]

>>2780897
>making a timer that switches off a circuit after a specified and programmable amount of time?

tried asking google?
the fucker seems to know everything

[Anonymous No.2780944]

>>2780943

pic for proof

[Anonymous No.2780952]

>>2780385
Not that anon but yeah that’s what he said. Shutting off motors creates a high frequency pulse when the induced magnetic field collapses. The caps filter the pulse that could otherwise cause interference.

Now, who can tell me why my solar and storage system reports a power factor of -.13 and according to my ameter I’m pulling way too much current for the amount of power being used.
No inductive loads. PF returns to unity when solar and battery are disconnected.

[Anonymous No.2780963]

I have $8.16 left, what should I buy off ebay related to electronics/components?

[Anonymous No.2780966]

>>2780963
adapters or heat shrink tubing

[Anonymous No.2780970]

>>2780922
Either get boards with plated through-holes, or make boards where there are only ever connections on the back of components. Ideally you don’t need any vias, but that implies all the THTs are on one side and any SMTs are on the other side, at which point you might as well just use a single sided board. So you’ll probably need vias, don’t be afraid to solder or rivet solid-core copper wire if you’re doing diy boards.

You can kinda solder the top of some components, but IC sockets and electrolytic caps are a no-go, so you need a contingency. A while ago I wrote a script to delete pads on the same side as their THT component for making diy 2-sided boards, but I haven’t tried using it since KiCAD 5.

>>2780952
Chopping up the sine and using rectifiers without PFC both ruin power factor. Rectifiers only draw current when the mains voltage is higher than their capacitor voltage, which is only true for a short time twice the cycle. Could definitely be that the pulsed current through the rectifier is over five times that of the rms current.

[Anonymous No.2780989]

>>2780963
2 chinese high voltage buck boosters. if ones not DOA wire them in series.

[Anonymous No.2781002]

>>2780989
How high?
Link?

[Anonymous No.2781025]

>>2780897
So how do you want to “program” it? How many times does it need to “store” or just one?
Is it going to be programmed for different times frequently by a neophyte, or just once or infrequently by an expert?
Do you want a numeric keypad, for entry or is the standard up, down, enter buttons OK?
What is the time range like? Like, 0–99 seconds, or do you need milliseconds, or minutes, hours, days, weeks, months or years?
Does it need a display? Or count-down, or count-up. Does it need to display or use (or know) the actual time of day?
Mains powered or battery powered? What is the load… does it make a beep or switch a relay or mosfet or triac?

There is different approaches and minimalizations for timers.

[Anonymous No.2781043]

>>2780989
>wire them in series
w-why?

[Anonymous No.2781085]

>>2781043
Loser
Give up give up you're never gonna make it
Give up give up you're never gonna make it
Give up give up you're never gonna make it
Give up give up you're never gonna make it

[Anonymous No.2781091]

>>2781025
Frequently programmed by a neophyte, a timer in minutes up to an hour is enough (going up to like 3 to 5 hours would be sweet, but not necessary). An option to disable the timer and just run it continuously is also interesting. Load is gonna be a just a couple of watts, less than 10 probably. Powered by a DC power supply. Only needs to remember the last setting. Up and down buttons is great, but I want some sort of display to tell at what setting it is. Would be nice if that display showed the remaining time once its running.

[Anonymous No.2781102]

>>2780600
>>2780678
Thank you for the replies.
I'll add a power resistor to the supply line.
I've got an old PSU sitting around looks fairly simple to set up a bench supply from the tutorials I see online, although some seem pretty radical I think I'll I just set up a mounting board and plug some cables into the molex pins.

[Anonymous No.2781130]

>>2780970
That makes sense, just don’t usually see an issue like this. It’s a commercial system Tesla powerwall and Enphas’s microinverters. Usually they can work side by side, never checked what kind of waveform came off the micros, they’ve got dedicated asic computers for switching so I imagine it’s a pretty clean sine. Only the power being used to charge the battery should be getting rectified AFAIK.

>>2781002
Search it, heres a clue. The one you want has 4 wires and a black case.

>>2781043
Why not?

[Anonymous No.2781147]

>>2780521
What for?

[Anonymous No.2781172]

>>2781091
This is what I’d do as one of the simplest ways to get this together.

you can use one of the 555 timer circuits you found. Just use an appropriate capacitor and use a potentiometer to adjust the time. The setting of the pot “stores” the time. Just label it accordingly on the outside. There’s going to be a button to start it.
The optional display will use a LM3914 chip to generate a bargraph of the voltage across the timing capacitor for the 555 timer. You may have to adjust both your potentiometer and the bar graph generator with a resistive voltage divider, and a switch to run it constantly is simple enough.
You can do the same thing with an lm324 if you only want a 3-led bargraph.
The drive circuit can be either a mosfet or a bjt transistor, if you want old school, use a bjt like a 3055 and mount it on the back on a heatsink like a boomer, although you’d use a real motorola.
All this is 80s boomer tech.

[Anonymous No.2781176]

>>2781102
> old PSU
The problem with that is so e of those voltages and be 100 A and you’re getting into arc welding territory. I have one that does 240 A at 12 V. That’s a lot of current and it can literally melt a screwdriver. Same reason I don’t just use a car battery.
I’m surprised the anon that suggested this didn’t know about this. I’d consider that a lot more dangerous, one wrong wire is going ignite the breadboard in a melt-down event.

[Anonymous No.2781187]

>>2781176
>I’m surprised the anon that suggested this didn’t know about this
I didn't suggest he use some workstation tier monster that can output 3KW on the 12V rail. Even then, I doubt it's all on one rail, high wattage ATX PSUs usually have more than one rail for +5V and +12V.
Anyways, I was thinking of the 300-500W flea market specials you can get for dirt cheap. Most of these can't handle more than 20A on any rail.
Also you didn't read the most important part:
>Also use fuses, no matter your power supply

[Anonymous No.2781211]

>>2781176
According to the data on the side of the box the amperage output is 20A 3.3V on orange, 26A 5V on red, 8A 12V on yellow, 14A 12V on yelllow/black, 2A 5V on purple, 0.8A -12V on blue.
input is 240V 3.5A AC. I think it's dated to 2008

[Anonymous No.2781213]

Is LTSpice still the free SPICE program to use on Windows

[Anonymous No.2781233]

>>2781213
>LTSpice

sure
but if you pirate Proteus, it'll still be free, but you'll have ''industry experience'' as opposed to ''masturbasement experience''

[Anonymous No.2781249]

>>2781211
Yeah, 26 A on 5 V could certain burn up your breadboard.

[Anonymous No.2781251]

>>2780569
Hey anon, thanks, I got my joule thief up and running, got frequency instability at first, swapped inductor and it worked nominally. Then I disconnected the led with the power still on and suddenly realized why snubbers are a thing. I'll try the Black Regulator tomorrow. This is cool stuff.

[Anonymous No.2781259]

>>2781172
Thanks a lot, I'll look into it and the chips you suggested. Not sure I'm actually going to go down that route but it's interesting nonetheless to see how it would be done without arduino.
>All this is 80s boomer tech.
Nowadays it would be done with microcontrollers right?

[Anonymous No.2781264]

>>2781213
Probably, but KiCAD is getting more convenient than it was for simulation, assuming you use it for EDA. There's also MicroCap, but it isn't Spice-derived.

[Anonymous No.2781275]

>>2780963
>>2780966
>>2780989
I ended up buying a few of picrel for a pretty good price.
Thanks guys

[Anonymous No.2781280]

When measuring braided wire to check current rating on a chart, do I strip it and measure the copper itself or do I measure from the outside of the insulation? Mine is 2mm diameter at the insulation.

[Anonymous No.2781292]

>>2781280
Strip it. The insulation isn't carrying the current, and sellers lie.

[Anonymous No.2781293]

>>2781233
who gives a fuck about industry

[Anonymous No.2781303]

>>2781293
>who gives a fuck

productive members of society with kid's orthodontic bills to pay

>who doesnt

said kids

[Anonymous No.2781325]

>>2781264
oh i didn't know kicad did that. thanks, using it for playing around with guitar effect pedal stuff

[Anonymous No.2781356]

>>2781259
There is lots of ways to do it, that was just one.
Nowadays they have ASIC blob chips they use for kitchen timers, microcontrollers are too expensive.
I happen to hate LCD displays, so I tend to do things the old way.
Plus, everything I built in the 80s still works, and is easily repairable if it breaks.
One of the reasons things use microcontrollers is because a lot of them have security fuses that prevent the harvard architecture program memory from being read that prevent the program from being read and, moreover, copied or inspected and I don’t like that.

[Anonymous No.2781363]

>control relay A's coil with relay B's contacts
>relay A can be heard rattling on and off as relay B's contacts bounce
Is there an easy way to prevent this rattling? I don't like the idea of the relay having a lower lifespan as a result of this. There's a switch in series with both relay A's and relay B's coil, I'm not hearing rattling when I turn the switches on and off, but that's probably because I'm testing using rubber dome tactile switches (they're awful, don't buy them).

[Anonymous No.2781367]

>>2781303
you're larping as an engineer dumbass. you think using some software will magically get you a six-figure job?

[Anonymous No.2781372]

>>2781233
Is Proteus better than Altium?

[Anonymous No.2781424]

>>2781372
>Proteus better

definitely
altium gives you this kind of static result after you press ''run''
whereas proteus, like ltspice, is more like having real-time scope(s) showing next to your schematic

[Anonymous No.2781442]

>>2777548
I realize it's about a week later (had a lot of stuff come up), but I finally did a quick test just now. Using one sacrificial LED, I scraped the back with a 3M sanding block (not sure of grit, but it seems relatively fine). I had mostly no issues with getting solder to apply to the pads when isolated, which leads me to some hypotheses:
>The pads developed some kind of film or melted invisibly to plastic in storage (was a warm environment)
>This seemingly invisible film was only removable by lightly scraping it away (which my too-soft tweezers and eraser heads could not do effectively before)
I'll go ahead with lightly sanding the pads of any LEDs in this set I'll be working with. I just hope it doesn't make it more vulnerable to overheating when soldering bridges to the PCB. I hope this will be of use to other anons in the future.
>Pic related: one unsoldered LED, one sacrificial one I globbed solder on after lightly scraping on its pads with a sanding block.

[Anonymous No.2781446]

>>2781424
> not using spice directly by entering netlists
> needing a video-game-like interface
ngmi
It is true though that companies have become so zoomer catering that, yes, just by knowing some software packages will get you the job. As long as you realize you’re just the equivalent of special-purpose typist.

[Anonymous No.2781460]

>>2777927
ESR doesn't tell you if a capacitor is good or not. They get "leaky" over time meaning that DC current leaks through the capacitor. This can show up as "good" on an ESR meter because they don't check for it. You can test this by measuring the DC voltage across it while it's on, it should ideally be zero

[Anonymous No.2781471]

>>2779881
how the fuck does one get that to look so clean?

[Anonymous No.2781474]

>>2781471
Doing the layout beforehand instead of ad-hoc.
Cutting and bending the wires off the board.
Planning.

[Anonymous No.2781477]

>started using my new breadboard wires
>already mangled a bunch of them
is this why boomers use tweezers?

[Anonymous No.2781493]

>>2781474
Exactly. It’s just bending soft wires, it’s not that hard.

[Anonymous No.2781494]

>>2781477
Practice makes perfect. You don’t need tweezers.

[Anonymous No.2781495]

>>2781356
>LCD displays
We use OLEDs now, old man.
>a lot of them have security fuses that prevent the harvard architecture program memory from being read
It's hardly exclusive to harvard arch. Even if you have all your memory in the same address space, or even if it's all the same type of memory, you can definitely have different properties for certain chunks of it. Like some memory being RAM vs flash vs EEPROM. I agree that locked down firmware is a problem for repairability and consumer control, but it hasn't stopped the hoopy frood hardware hackers who can dump the memory of smart meters and modify them with custom firmware. The bigger threat is the manufacturers pushing laws that turn custom firmware into a form of copyright infringement. I can easily see a world where all new computers and other devices with firmware are as locked down as iphones. No 3rd party software allowed, no unlocked bootloader and so no 3rd party OS, and from there they can force whatever arbitrary compatibility requirements they want.

>>2781460
>You can test this by measuring the DC voltage across it while it's on, it should ideally be zero
Why would the DC voltage be zero? The DC current should be zero if there's no leakage, but voltage across the cap doesn't imply anything a potentially leaky capacitor's leakage current. Only way to test is to desolder the cap and measure its leakage current with a nontrivial voltage across it, or maybe to find a resistor in series with it and measure the DC voltage across that during operation. Chucking a hall current clamp around one capacitor lead probably isn't an option.

>>2781493
What do you do when there aren't any THT ICs available for what you need?

[Anonymous No.2781496]

>>2781471
It’s nothing new. Picrel was done in the 1930 before PCBs were really a thing. Someone claimed that high frequency was impossible without PCBs and nothing can be further from the truth. In fact, running tiny radius multi-gigahertz hard line looks a lot like this in modern equipment.
No different from an electrician running emt conduit except you less skill required.

[Anonymous No.2781497]

i went through an entire circuit analysis textbook, am on chapter 7 of sedra smith, and I still don't know fucking anything practical or how to start a project

do all electronics folks in this thread just have PhDs or what

[Anonymous No.2781498]

>>2779881
>>2781493
>>2781494
What pliers do you use to make bends that tight?

[Anonymous No.2781499]

>>2781495
> No THT ICs for what I need?
That will never happen.
In fact, I just got another G.I. speech synthesis chip from a speak n spell I picked up yesterday. Radio shack doesn’t carry them anymore. Win get.
I was planning on getting a bare RP2040 to play with, but obviously I’m going to glue it upside down and solder wires to the underside pads. It’s like when your driving skill level is so high you need z rated tires, but with electronics.

> use OLEDs
I can make my own display out of green rectangular LEDs. Picrel.

[Anonymous No.2781502]

>>2781498
> what pliers?
Nothing special. They were my father’s pliers, I just ended up with them, it would be a shame not to use them. But this is my point. You don’t need anything (a) new or (b) special to get started in this hobby or profession.
The calculus you learn in EE class was all reverse engineered from actual measurements.

[Anonymous No.2781534]

>>2781502
nice wire stacking. do you have a picture of your most densely wired board?

[Anonymous No.2781549]

imagine trying to sell bricked power walls for $1500 a piece
not even worth taking apart for the now drained cells

[Anonymous No.2781554]

>>2781249
14A@12V could also be pretty spicy.
I think the samsung 500mA@5V will probably be fine for most of my breadboard needs.
Got an older Nokia which does 150mA@5V too.
But the PSU based supply could be useful if I develop any projects further. it's got like 20 independent supply wires I just need to figure out something to mount it to.

[Anonymous No.2781558]

luv big supplies

[Anonymous No.2781568]

>>2781442
>This seemingly invisible film was only removable by lightly scraping it away
Thanks for following up on this. It's enough to drive someone to madness.
>I just hope it doesn't make it more vulnerable to overheating when soldering
Should be fine, but it's better than not being able to solder them at all.

[Anonymous No.2781571]

>>2781497
Do you have any broken electronics? Take them apart and start investigating with a multimeter. Then attempt to repair after you practice soldering. If you can't reapir it, then you can practice desoldering and harvest components. Eventually you'll gain a better understanding while becoming more comfortable with stepping up to more complicated stuff and expanding your toolset.

[Anonymous No.2781575]

>>2781571
>If you can't reapir it
You can also set it aside and come back to it later. Sometimes you need to clear your mind and start with fresh eyes to find the problem.

[Anonymous No.2781589]

>>2781495
>Why would the DC voltage be zero?

V=IR if I is zero then V is also zero. In reality there will be a little DC voltage even on a good capacitor, but not enough to make a difference

[Anonymous No.2781614]

>>2781558
It’s getting harder to obtain transformers for cheap since scrappers buy them, spend hours to get the .25 cents (literally, like .25 cents) worth of copper out of them, drive for miles to the metals recycler and back loosing $20 not including their time. After seeing someone do it in a youtube video.
I think this is actually a serious mental health issue like those hoarders.

[Anonymous No.2781617]

>>2781589
>V=IR if I is zero then V is also zero

this applies to a load, not a power source
a charged cap is very similar to a charged battery
both can hold a charge with no current flowing in or out

[Anonymous No.2781619]

>>2781575
>Sometimes you need to clear your mind and start with fresh eyes to find the problem.
Eh? Sometimes what you need to do is find out what the components do and furiously search engine your way to figuring out what the purpose for putting a bloody weird diode with a z on it somewhere is.
knowing when to leave a circuit alone until you can understand it better and not wreck it is an important step.

[Anonymous No.2781623]

>>2781614
>a serious mental health issue

this is not good
disparaging environmental entrepreneurs who are not fond of wage slavery
and for what?
coz they're taking the garbage you wanted for yourself

[Anonymous No.2781625]

>>2781424
So you use EDA for simulations and not actual LTSpice and that's your main criterium to choose an EDA?

[Anonymous No.2781627]

if someone's forte is asking ignorant loaded questions, politics is the job for them

[Anonymous No.2781639]

>>2781623
> garbage for yourself
Nah. Most of them don’t even know what they have. Like I said, most of them are clinically retarded. I’ve got several multi-$1000 TVs that need replacement T-con boards but everyone scraps them and they end up burning the plastic anyway. It’s worse for the environment. A lot of the scrappers have obvious meth habits, too.
Manufacturers would rather people buy new junk TVs that last 2 years or so than let people repair them, that’s why this recycling myth was indoctrinated into the public. I even pay a recycling fee when I buy a new TV and they end up burning it. A couple of local news guys hid air tags in some recycled electronics and the went to the incinerator.
My last TV, a sony, had the audio board die, and then the T-con board about a year later. Still had the original sony batteries in the remote control, I waited two years for the boards to come up on e-bay for a reasonable price. Never happened.
The second R is “re-use” which may mean “repair”

[Anonymous No.2781653]

>>2781639
>T-con board
Pro-tip: If you can find the BGA/QFP/QFN chips that go bad on those boards, they're pretty easy to repair. They tend to overheat and lose connections from thermal stress (hot, cold, hot, cold). A thermal camera makes short work of diagnosing it.

[Anonymous No.2781694]

>>2777077
friends, greetings from /g!
I need some tips on how to proceed - I have some old(ish) cambridge soundsworks 4.1 system, which volume knob/potentiometer started jumping all over the place recently. I quite like it and am not ready to replace it and I like tinkering, so I would like to attempt to patch it somehow.
Seems like the 'B50' pot is nowhere to be found and it's a strange freak with 8 pins (at least for electronics noob like me). I tried disassembling it and cleaning the contact paths, which helped to some extent - the volume now jumps only in the beginning right after the turn on click.
Has anyone in here by any chance repaired stuff like this or knows more? I am confident in my soldering skills, just no idea what replacement to get. I've put couple more pics in here https://imgur.com/a/U4qTzfl

all input appreciated, thanks!

[Anonymous No.2781696]

>>2781694
a dirty hack would also work I guess - back 2 pins are supposed to be on/off, could put a switch on them and a simpler pot on the rest, but still no clear idea

[Anonymous No.2781702]

>>2781694
You should disassemble the pot and clean the tracks with contact cleaner.

https://www.youtube.com/watch?v=5qHflPHMu58

https://www.youtube.com/watch?v=PDURUmM9Ki4

[Anonymous No.2781717]

>>2781702
roger that, will acquire one tomorrow

[Anonymous No.2781724]

>>2781702
>https://www.youtube.com/watch?v=PDURUmM9Ki4 [
richard is a ledg

[Anonymous No.2781752]

>>2781653
> repair t-con
Good tip. Yeah, there is basically a big sony chip with a few other little things scattered around. Are you saying i should try reflowing it?
I heard that chip is basically the whole TV, lol

[Anonymous No.2781754]

>>2781702
Someone once suggested I spray it with wd-40, but I would think that might make it worse. I wonder if contact cleaner is conductive?

[Anonymous No.2781756]

>>2781752
>Are you saying i should try reflowing it?
Yes, but reflowing doesn't always work because they sometimes heat up to the point of no return. It won't hurt to try, though. Just make sure you don't scorch the board because they're pretty small (if they're not integrated with the mainboard like cheap TVs).
>>2781754
WD-40 makes contact cleaner, but the original WD-40 should never be used on PCBs or displays of any kind. Contact cleaner isn't conductive as far as I know, but it is flammable so disconnect power first.

[Anonymous No.2781824]

>>2781549
If the cells aren't dead it may be worth looking at, but it depends on if there's an easy way to diagnose the whole thing. Personally I'd stay away fromLi-NMC for home power storage, LiFePO4 is what I'd use.

>>2781694
I cleaned my pots just by squirting in some IPA and swivelling them around a bunch. If it's never been cleaned before, chances are that's all it needs. But if the tracks are sufficiently worn that you need to buy another one, it's a "switched linear 50k double-gang potentiometer". Size looks like a 16mm, but I'm not certain. Alps are one manufacturer of that sort of pot, but there are others. You may have to browse Mouser or Octopart or maybe even LCSC to find the exact replacement. It might be possible to buy a conventional B50k pot and take the pieces of phenolic board with the tracks out to replace the worn ones, but I've never attempted such a thing myself.

[Anonymous No.2781827]

>>2781824
Tesla only rates them for up to 12 months of unplugged storage in ideal conditions
so a gen 1 power wall would be fubar as several YouTubers have found out

[Anonymous No.2781965]

>>2781824
> I cleaned my pots
Jeez, why do people cling to fragile antequated electromechanical bullshit.
> hot chick comes over
> “want to go to my place and watch netflix and chill?”
> nah. I’m cleaning my potentiometers tonight.
Any time I see a bad potentiometer I’m not cleaning it, I’m replacing it with a rotary encoder and a couple of mosfets with big linear regions.
Every time you clean it, it just goes bad again quickly. In fact, more quickly every time. That black dust inside it? That was the resistive carbon trace that made it work in the first place. And it’s gone now.
> wirewound potentiometer with carbon brushes
Okay

[Anonymous No.2781971]

Why aren't you allowed to use it on PCBs?

[Anonymous No.2781972]

>>2781965
>a couple of mosfets with big linear regions
That sounds awful for a bipolar audio signal. Post an example schematic.

Most equipment with pots don't get turned often, especially volume and gain knobs on a hifi setup. Only insecure people keep tweaking the volume in case they think it could someone. A stereo with open-style pots will get dust inside it over the years, a simple spray with contact cleaner and a few turns is all it takes to get them back in operational condition for another decade. Only frequently used pots will you find the carbon so worn that you need to replace the whole thing. Like game controller analogue sticks after hundreds of hours of continuous use. A volume knob will maybe get a dozen hours total use over a stereo's entire lifespan.

>>2781971
Is that a tip tinning compound? The flux they use for that is a fair bit more active than normal soldering flux, not the kind of stuff I'd like stuck underneath an IC for years.

[Anonymous No.2781980]

>>2781971
You’re allowed. You just want to make sure it’s all cleaned off when you’re done, and use sparingly.
On copper pipes, it’s less of a problem because it “wears out” by eating away at the copper, but it’s many times thicker than a PCB trace so no issues.
Even then, in plumbing, you want to wipe it off though. There is even a procedure for removing flux from inside pipes involving piping hot alcohol through them for 2 hours. PITA.

[Anonymous No.2781982]

>>2781972
Every single radio with the combo volume/on-off switch embedded has gone bad, or soon will.

[Anonymous No.2781983]

>>2781982
Those are bad, but not game controller bad.

[Anonymous No.2781990]

can someone recommend a low-power push-pull transformer driving inverter for lighting up some electroluminescent wire? i want it oscillating at 1-10khz, with the ability to adjust the brightness on the fly. so not a zvs driver, that voltage is fixed. but i look at push-pull tl494 circuits and i dont know why they dont die from big voltage spikes when both transistors are turned off twice per cycle.

[Anonymous No.2782007]

does anyone have any resources on pulsing currents to seemingly make it stronger? i found out about pulse charging being a faster way to recharge batteries, and i've also seen some videos where people are able to power light bulbs pretty good, even when using a smaller current than the bulb is meant to be used at. i want to know if this technique has a name so i can read up more about it

[Anonymous No.2782022]

I'm about to take the plunge into electronics. Why are Arduino's bad? What's the alternative?

[Anonymous No.2782037]

>>2782022
>Why are Arduino's bad?
Arduinos tend to be bad for a few reasons:
A) People dive into arduinos without understanding electronics like resistors and transistors at all, making bad circuit designs, which leads to frustrating troubleshooting. At a maker space I saw a lot of rookie mistakes, like feeding a 12V back EMF signal to an arduino (it got really hot but somehow it still worked), or trying to use a single 270Ω resistor with a whole bunch of parallel LEDs only to find it isn't bright enough and just ditch the resistor and run the whole lot at 5V directly.
B) Arduinos themselves are a layer of abstraction atop microcontroller programming that make it simple to copy paste existing code and have it work 80% of the time, but only serve to increase the slope of the learning curve after that. The abstractions like digitalWrite() and analogRead() are bloaty and take up a lot of clock cycles, and the libraries you'll often import take up a lot of room. When you come to a situation where the default behaviour of these functions and libraries doesn't cut it and you have to write to registers directly, you're up shit creek.
C) A lot of simpler projects are made trivial with the addition of a microcontroller. This is the reason the OP's rolling project list makes a note to exclude where possible. For those of us who make electronics projects for fun and to learn, what would normally be a collection of ICs and passives connected together just turn into a single chip and some trial-and-error programming. That said, a lot of projects are absolutely only really feasible with a microcontroller, especially where precise timing and driving displays is concerned.

[Anonymous No.2782038]

>>2781824
>"switched linear 50k double-gang potentiometer"
thanks, will look around and order one as a backup

I got some car contact spray by nigrin and managed to clean the majority of the tracks - couldn't disassemble completely and reach the one on the other side, but sprayed inside and cleaned whatever I could with a wet q-tip. Works much better now, but I think there is still a slight volume change when touching the knob - like it now allows to be pressed inward and this affects the contact. Will try working it in and maybe try to reassemble or squeeze in place with bigger pliers.

How does picrel look? not worn? thanks

[Anonymous No.2782041]

>>2782038
I think it looks ok, the wear isn't very noticeable at all. Measure the resistance of the whole track with a multimeter, if it's still close to 50k it's probably still fine. Clean the wipers too, it may be that there's gunk on them. Also I'd advise against bending the legs like that, they can fatigue and break. Though desoldering on phenolic board is also asking for delamination.

[Anonymous No.2782057]

Thats one sexy rounded traces PCB

[Anonymous No.2782058]

[Anonymous No.2782091]

>>2782037
>The abstractions like digitalWrite() and analogRead() are bloaty and take up a lot of clock cycles
why are they like this? it should be trivial to AND/OR the output registers, are the designers pythonbabbies?

[Anonymous No.2782094]

>>2782091
>are the designers pythonbabbies?
anon

[Anonymous No.2782096]

>>2782037
I'ma s oftware person and I fucking hate the arduino library babby ecosystem.

[Anonymous No.2782101]

>>2782022
They aren't. It's just some stupid /mcg/ meme that often leaks into here because of the slight overlap between the generals.
Arduinos are great for starting out with microcontroller programming.
Also, don't talk about arduino programming on /mcg/ or you will be crucified.

[Anonymous No.2782124]

>>2782038
>still a slight volume change when touching the knob - like it now allows to be pressed inward and this affects the contact
Desolder the pot so you can squeeze the tabs back together snugly. You don't want to crush the thing, but it shouldn't be loose either. If you happen to delaminate the pads, you can use jumper wire to connect them to the nearest solder joints.

[Anonymous No.2782126]

I'm confused, is arduino a good platform to start learning on or not? Or does it depend on what you intend to do with it?

[Anonymous No.2782127]

>>2781211
5V @ 2A (purple) is the standby voltage which is basically the USB/power on circuit in the PSU which can be used safely. You don't even need to turn the PSU on because it's standby voltage.

[Anonymous No.2782128]

>>2781493
>>2781494
Seems kinda silly to go to all that trouble for a breadboard computer. Don't get me wrong- it looks nice, but it's a little too OCD for my taste.

[Anonymous No.2782136]

>>2782126
The only good thing about starting out with arduinos (opinion) is that there are tons of examples that you can reference or copy for your own projects. The downside is your hand is being held (libraries) and it's a shallow learning experience. If you just want to build something without understanding much, tarduino is the platform for you.

[Anonymous No.2782138]

>>2782126
Arduino is the America Online of micros.

[Anonymous No.2782139]

>>2782126
Generally it allows you to use libraries and examples that are developed for arduino environment which is quite valuable. But it tries providing one interface for all sort of microprocessors so it is an overhead and more limited than what your processor actually supports

[Anonymous No.2782140]

can kicad pcb editor move the lines along with the components you moved? If you also select the lines it works but it will also move the other end. I just want it to move one end & redraw the line that is attached to the component you are moving

[Anonymous No.2782143]

>>2782139
>But it tries providing one interface for all sort of microprocessors so it is an overhead and more limited than what your processor actually supports
So it's like Java?

I've never really got into embedded system stuff before, I remember people talking about a butterfly chip and coding in c or machine code, is that a better approach?

[Anonymous No.2782150]

>>2782126
>is arduino a good platform to start learning on or not?

absolutely it is
in the same way Microsoft Flight Simulator is a good way to learn how to fly jets

[Anonymous No.2782151]

>>2782143
Different Anon, but I strongly believe that it's best to learn C and assembly language for whatever platform you choose. That will give you a strong foundation that will serve you well, even if you move to other platforms. This topic is a target for endless arguments as you will soon witness, no doubt.

[Anonymous No.2782210]

>>2782150
What a babe, I wish I had a girlfriend like that to shag

[Anonymous No.2782213]

>>2782150
>in the same way Microsoft Flight Simulator is a good way to learn how to fly jets
What about flying microlites?

[Anonymous No.2782215]

>>2782210
She's holding the cockstick all wrong, clutching it to her bosom like a babby.

[Anonymous No.2782233]

>>2782215
You sure know how to hold a stick huh

[Anonymous No.2782234]

>>2782091
One reason is all the checks for which MCU it is, and the conversion from "pin number" to the correct port and that port's pin. But all that should be precalculated at compile time, so I don't really get why it takes so long.

>>2782140
Yeah, with G or D (idk which), but it doesn't work that well.

[Anonymous No.2782244]

>>2782126
Yes.
You can buy a 2$ thing from Ali that you can program right away via USB or you can nigger rig an Atmega microcontroller on a breakout and provide a crystal, voltage regulator and USB interface yourself.
The result is exactly the same.
My advice is to go for the 2$ and ignore all the gentooman tier elitists.

[Anonymous No.2782246]

>>2782244
there is a middle ground where you buy a dev board and not use arduino environment.

[Anonymous No.2782247]

>>2782246
There is also the context correct ground where you don't push your elitist views onto clueless fucks.
If he has to ask, he has no clue and the entire arduino ecosystem will serve him well until he hits the limits of what is possible with those. At that point he no longer has to ask.
Your non-contribution has been noted, your (You) has been delivered, now you can fuck off back to /mcg/.

[Anonymous No.2782257]

I made the prototype of this board and when I try to draw the PCB I basically had to rewire everything to make lines work. Now I have to redo my prototype and update my code using this PCB and hope that I didn't screw things up

[Anonymous No.2782268]

>>2782257
>had to rewire everything

yo traces too fat
more svelte traces would allow for denser routing so you could better stick to the original

[Anonymous No.2782273]

>>2782234
>all the checks for which MCU it is
i don't believe you, nobody's that retarded

[Anonymous No.2782274]

Hi, I am trying to slim down the AirTag to make it less bulky and fit into a credit card shape, so I can put it in my wallet. I'm aiming for less than 2mm in thickness if possible. I'm considering creating a separate PCB for the antennas, so they aren't stacked on top of the PCB like in the AirTag, which should slim it down more. I would replace the CR2032 battery with two parallel CR2016 batteries, which should give me about the same battery life. My main concern is the 8GHz antenna's curved shape on the AirTag, and I don't know how much that affects the range at such high frequencies. I am currently in my first year of electrical engineering, so my knowledge is limited. I'm still waiting for my AirTags to arrive so I can start testing. Any advice?

[Anonymous No.2782276]

>>2782268
I don't think track widths are an issue, it is just you can't cross over lines in 2d obviously, while my prototype was in breadboard with wires

I wanted to make tracks a bit thick so less room for error while I am milling this thing

[Anonymous No.2782277]

>>2782246
or just buy an arduino and not use the arduino environment. are you retarded?

[Anonymous No.2782278]

>>2782277
arduino is a dev board anon

[Anonymous No.2782281]

>>2782278
no shit. why exclude one dev board just because it's popular?

[Anonymous No.2782282]

>>2782281
I didn't exclude arduinos, reading comprehension?

[Anonymous No.2782288]

>>2782276
>you can't cross over lines in 2d obviously

you can, sorta
when you use thin traces, it allows for the possibility of running traces in between pads
meaning you can sneak traces thru otherwise blocked paths

of course, this is all academic if you're milling

[Anonymous No.2782301]

>>2782037
Okay that's good to know, but what's the alternative?

[Anonymous No.2782312]

>>2782301
>alternative

there's only a few hundred to choose from
STM32 seems to be a rising star
it has a good beat, and you can dance to it

https://en.wikipedia.org/wiki/List_of_common_microcontrollers

[Anonymous No.2782325]

>>2782091
One example is analogread takes time and is blocking until you get the real. Meanwhile using your MC's api you can do other stuff while analog read process is ongoing

you can read/write multiple values at once normally using registers

arduino also maps pins for some reason. To make it more generic I guess

[Anonymous No.2782331]

>>2782312
I think you misunderstood
I have 0 knowledge of electronics
I don't even know what to do with that information

[Anonymous No.2782333]

>>2782301
Look up some circuits that use 555 timers and try to build them yourself on a breadboard. That will at least give you some fundamental lessons before you move on to Arduinos.

Or don't. It's really your call, Anon. There is no single path to follow.

[Anonymous No.2782341]

>>2782331
>I have 0 knowledge of electronics

oh, ok.
well, you can spend a lot of time watching introductory videos and reading all the books in the top post
but easiest is to sell your soul to the devil and gain all the requisite knowledge that way
just like Tesla, Maxwell, von Neumann, Gates, etc did

[Anonymous No.2782342]

Hi, what's a good way to ijntuitiuvely understand capacitance?
What's actually happening at the very lowest levels?

[Anonymous No.2782345]

>>2782342
Two metal plates separated by dielectric material. One is positively charged (anode), the other is negative (cathode). The distance between them determines voltage rating, and the thickness, length and height of the plates determines capacitance. In a circuit they act as a reservoir of voltage to even out fluctuations (ripple) when they are in parallel to a load, and in series to a load, DC is blocked and AC is passed. They commonly act as filters (frequency) in conjunction with inductors and resistors. There's more to it than that, but that's my understanding.

[Anonymous No.2782347]

>>2782331
It’s project dependant. What did you want to do with an Arduino in the first place? If you don’t have a project, find one and use that as a launching point for learning the theory. Go ahead and buy a nano or uno along with a bunch of other components like transistors and op-amps. They’re useful, but not the end-all be-all of electronics. If an arduino programmed with arduino code is enough for a project, then there’s nothing wrong with using it besides the missed opportunity to learn how to do that task more properly. Which would be a useful experience for when arduino code on an arduino won’t cut the mustard.

[Anonymous No.2782348]

>>2782345
No, all of that part I think I understand understand, what I don't get is how the two plates are interacting at single level because everything must be in a capacitive relationship with everything else but attenuated by surface area, separation and composition, but I want to understand what this specific field is.
I think I'll try asking someone on /sci/ but I'm probably just really overthinking the problem, I was trying to mentally visualise the process of an LC oscilation and got stuck wondering if capacitors discharge themselves because the removal of the potential difference meant that like charges collected on the plates were in repulsion or whether it was something else.

[Anonymous No.2782358]

>>2782348
When one plate builds up enough charge, electrons jump to the other plate through the electrolyte. More distance between plates needs a higher charge to jump. Capacitors (as well as other charged materials) leak over time. In a circuit, resistors are sometimes used to bleed off charge from the anode. It's the electric field fluctuating in relation to change of voltage.

[Anonymous No.2782359]

>>2782348
Yes, everything is capacitively coupled where it isn’t shielded by another conductor (e.g. coaxial wire). And yes, the excess charges in the plates of the capacitor do repel each other, causing them to produce electrical current when those charges have a place to flow. Don’t fuss too much about having a technically correct understanding of capacitors, so long as you understand their characteristic equation I = C*dV/dt, and have a qualitative intuition for how they’ll influence a circuit, that’s all that matters.

Alpha Phoenix did a neat few videos on electricity flowing in a wire recently, I recommend them.

[Anonymous No.2782379]

Tried on SQTDDTOT, didn't get an answer.
Trying here now:
>>2782077

[Anonymous No.2782381]

>>2782379
post pics
Could be the bushing or the bearing.

[Anonymous No.2782383]

>>2782381
It's late night here and I'll only be back there on monday.
Without the screw, everything is centred as far as I can tell and the axle spins freely. Only that screw is out of centre.

[Anonymous No.2782385]

>>2782383
Are the threads perpendicular to the axle? Is the screw large? Is the fan or prop damaged? What is the RPM of the motor at full speed? You could try using some Loctite or epoxy putty to fill any void to reduce play in the threaded hole to test, but I still think the bushing and/or bearing is damaged. No way to tell for sure just going by a description of the problem.

[Anonymous No.2782386]

>>2782347
I just want to learn electronics

[Anonymous No.2782387]

>>2782386
Read and tinker with broken stuff. That's the old school way.

[Help me find this IC No.2782388]

Im trying to find information on an IC with 4S501 74203 H2031 written on it, i can only find taobao and aliexpress links with no information on them. any help is greatly appreciated

[Anonymous No.2782392]

>>2782388
Maybe LT1913. A pic of the surrounding circuit would help. Even better, a pic of the whole board.

[Anonymous No.2782395]

>>2782385
No, the threads are parallel with the axle. It's right in the centre and holds a large exhauster fan. The fan itself is fine. The small fan on the back that cools the engine is completely gone. There's small pieces of if stuck in the housing, that's all that's left. 1710 RPM.

[Anonymous No.2782400]

>>2782388
What’s the circuit context? What components are nearby, where bypass caps are, what pins have thicker traces, what nodes are obviously connected to power rails, etc. There’s an SM74203 boost converter IC by NatSemi.

[Anonymous No.2782401]

>>2782395
You said there's no vibration without a load, so it's possible that the the axle is okay, but the fact that there's shrapnel in the housing doesn't sound good. You'll have to disassemble it to know for sure.

[Anonymous No.2782404]

>>2782401
By the housing I meant this:
(found some pics on phone, will post more)

[Anonymous No.2782406]

>>2782404
This is from before I got a new screw. Even with the old bent screw, is kind of hard to see it bent on the pic.

[Anonymous No.2782407]

>>2782406
That's all I've got for now, could take more pics on Monday.

[Anonymous No.2782409]

>>2782404
The broken cooling fan will definitely cause vibration because it's unbalanced at the end of the shaft.
>>2782406
>>2782407
The threads are definitely crooked. You could attempt to tap new threads and use a larger screw, but it's probably not the main problem. I still say bushing/bearing(s).

[Anonymous No.2782413]

>>2782409
None of the broken cooling fan bits is still in the axle, so it just hands down in there when I run it on the bench. I need to replace it but the screws are rusted to shit, put some deruster in them for the weekend (probably has evaporated by now but whatever, might have done its job by now). I'll open it and check the bearings on monday. The screws for it are also rusted and on the same situation as the previously mentioned ones.
Also tips for removing rusty and stripped screws?

[Anonymous No.2782417]

>>2782413
>tips for removing rusty and stripped screws
Penetrating oil, blowtorch, and cutting new slots in the screw heads. If those fail, drill them out.

[Anonymous No.2782445]

>>2782273
You're probably right, I'd expect that stuff to be defined in the m328p.h file or whatever the IDE imports implicitly.

>>2782386
But WHY do you want to learn electronics? Is there anything in particular you want to make? Or be able to fix?

There's a lot of different core fields, such as:
>power (power supplies, both linear and switching, and strange resonant topologies)
>audio (amps, synths, effects pedals)
>radio (antennas, transmitters, receivers)
>instrumentation (precision sensing and datalogging)
>electromechanical (jukeboxes, cassette players)
>discrete logic (retro computers and little else)
>unconventional bullshit (circuit bending)
There's also instrumental fields:
>embedded (programming MCUs)
>DSP (analogue circuits, but digital)
>control theory (feedback loops)
>PCB fabrication (routing or etching)
>enclosure fabrication (3D printing or otherwise)
That don't really make up projects unto themselves, but will help you on your way to making a project come together.
If there's any of those that seem particularly interesting, there's some YouTube channels I can recommend. Like Moritz Klein and Lantertronics for audio. Or W2AEW for radio.

Even if you don't know what you want to specialise in now, keep it in mind. As you learn the basics of the things I outlined above, you'll decide for yourself if they're appealing or not. At most stages of a project, you can choose to either diy something or try to use something ready-made for the job (e.g. diy or buy a buck converter, make or get made a circuit board). Microcontroller programming is one thing that is required somewhat often and isn't easily outsourced, so in that respect it is one of the more valuable things to learn.

There's also the matter of copying a project vs designing it from scratch. Starting off you'll likely just be copying projects, but you should be trying to understand how they work as you go. My first project was the Elektrosluch, it was fun.

[Anonymous No.2782465]

>>2782041
thanks, don't have a proper multimeter to measure, but if it lasts another year or two I would be happy

>>2782124
yeah think I will try that, just need the figure out what contraption to use to squeeze

[Anonymous No.2782473]

have you ever used solder mask?

i think i scratched my pcb too much so some contacts got shorted that should not be, so im thinking of appliyng solder mask to fix it. is that wrong

[Anonymous No.2782480]

>>2782445
I mean, if you're asking me about my end game, I want to be able to make my own simple computer
Like this
https://www.youtube.com/watch?v=n_eEDAQWMdY

[Anonymous No.2782503]

>>2782473
I use it for diy PCBs, but in your case you're basically just using it as UV-cure glue for re-insulating the board. If it's conductive now, it will be conductive when you gloop all over it. More important than insulating it is mechanically removing any pieces of metal that are shorting those contacts together, be that solder, copper, or a component itself. Then you can gloop over it, if you see it as necessary.

>>2782480
Here's the order I'd approach things:
>reading circuit diagrams
>an intuition for how current flows in a circuit with voltage sources
>a basic understanding of bypass capacitors
>a basic understanding of digital logic
>an understanding of propagation delay in synchronous digital circuits
>nontrivial circuit design
>board design
>programming

I highly recommend Ben Eater's videos in general.

[Anonymous No.2782533]

Any demo of penetrating one of these tubular USB devices with the least damage done?
I probably have a bad or under-specced cap in one. The ethernet upload LED flashes regularly with increasing frequency over time but works well enough otherwise. Feels sketchy having it use like this though.

>>2782473
solder mask only protects the traces from coming into contact with the elements. If the traces are shorted or broken applying solder mask wont fix anything.
MrSolderFix demonstrates trace repairing among other things very well. His content is gold worth if you try yourself instead of just letting a professional do it for you.

[Anonymous No.2782538]

>>2782533
never mind, just found the other tard hanging out here https://www.youtube.com/watch?v=kToXDWeON1E

[Anonymous No.2782592]

>>2782465
>what contraption to use to squeeze
Mini needle nose pliers would be perfect.

[Anonymous No.2782593]

>>2782473
You can use nail polish.

[Anonymous No.2782596]

>>2782533
>bad or under-specced cap
>ethernet upload LED flashes regularly with increasing frequency over time
No, that's not it. It should just stay off until there's a signal. There's a tiny cap for each of the tx/rx leds on the ground side.
There's a bigger cap for both the anodes on the other side of the board.
Then there's the signal coming from a shy chip's (XT25F08B-S) pin 7 and 8 through a couple of resistors (R123, R126). Those are also connected to the 40 pin ethernet chip (RTL8153B) pin 33.
There's a resistor left out (R127) between pin 5 of the mystery XT chip and R126.

Also some via's with unknown connections for now.

[Anonymous No.2782613]

just curious, has anyone ever tried reviewing / cleaning up the links in the OP? stuff changes you know. if nobody is up to it, i will do it one day so please don't complain. but not now. nah. maybe next week. i mean some time. in the future. i promise.

[Anonymous No.2782622]

>>2782596
>XT25F08B-S
>http://www.chipsourcetek.com › ...PDF
>Quad IO Serial NOR Flash Datasheet - 矽源特科技ChipSourceTek
...
>RTL8153B
>pin 33
DVDD33 (Digital VDD 3.3V)
The datasheet also states that the behavior of the LEDs is programmed so the TX LED blinking might simply be a programming issue?
I'll assume so to keep using it with less worry about the other end of the ethernet cable.

[Anonymous No.2782623]

>>2782622
Remember to probe the pins once you have your scope to be sure.

[Anonymous No.2782692]

I have a box fan with the usual 3 discrete speed settings. I want a better control of its speed, but I remember reading somewhere that I shouldn't use PWM like you do on PC fans. What's the right way of controlling what I assume is a shaded pole motor?

[Anonymous No.2782696]

>>2782692
You can cut down on the voltage.
Also pwm works fine to some degree, but’s not great.
In either case, the fan should be started at the full AC voltage, current and frequencyand then dialed down after it has been started.
Also ideally, you’d want a stall detector which can happen at very low speeds.
So, ideally, you’re looking at a variable voltage/frequency pure-sine VFD with the ability to detect the winding’s back EMF.

[Anonymous No.2782731]

>>2782692
>better control of its speed

a standard dimmer will work absolutely fine but add a bit of hum at speeds below max
(the tiny ikea types not recommended as they dont give much range of adjustment)
if hum is annoying, a more expensive speed fan controller will do the job

[Anonymous No.2782735]

How long can I put off learning soldering with breadboards? Can I learn the basics with just them?

[Anonymous No.2782743]

>>2782735
soldering is really really easy to learn though? just get good at desoldering parts scavenged from old circuits

[Anonymous No.2782748]

>>2782735
Save yourself the headache of breadboards. It's easier to solder stuff than to check and recheck connections a billion times only for something to move a bloody micrometre and open the circuit as you go to power it.

[Anonymous No.2782753]

>>2782735
They allow you to easily swap components for experimentation, saving a lot of time in the process, however it's crucial to buy good quality brands as these posts >>2778960
>>2779006 allude to.

These Anons are also right >>2782743 >>2782748. Learn to solder/desolder and understand the shortcomings of breadboards to minimize frustration and maximize productivity. Build your circuit so you know it'll work. Tweak it to your liking, but don't over complicate things because you'll be tearing it apart eventually. Keep it simple.

[Anonymous No.2782758]

>>2782753
>>2782748
>>2782743
I don't have any sort of garage or anything to solder in, just my room and 7 roommates. If I have to run some sort of loud fan to suck up solder smoke that leaves behind a bad smell then I might piss them off

[Anonymous No.2782759]

>>2782758
I live alone but it's just a small single room and a bathroom (I hate this place). And I can solder just fine, I do it by the window and I'm not a pussy to worry about a small amount of vapour.
Solder vapour is only a hazard to the gooks who spend their whole lives in a sweatshop making apple garbage and huffing the magical smoke.

[Anonymous No.2782760]

>>2782758
Do you have a bathroom with an exhaust fan? You could solder while you're on the shitter instead of reading Field & Stream. lmao

[Anonymous No.2782765]

>>2782759
Does soldering make a lot of noise?

[Anonymous No.2782766]

>>2782765
Zero noise.
The iron is just a resistance heating up, there's nothing there to make any noise.

[Anonymous No.2782767]

>>2782765
soldering doesn't but the fan can

[Anonymous No.2782778]

>>2782767
>>2782766
Do I need to wear a mask or something? What sort of fans should I use?

[Anonymous No.2782779]

>>2782778

[Anonymous No.2782784]

>>2782778
I make sure to do it with no pants for maximum performance. Depending on how good your eyes are a magnifying glass be useful but not necessary.
I don't use a fan.

[Anonymous No.2782787]

>>2782779
Can it run Asteroids?

[Anonymous No.2782789]

>read What Nyquist Didn't Say
>seems pretty obvious, whatever, i got it
>one month later
>need to design a filter for an adc
>

[Anonymous No.2782790]

>>2782735
in addition to what others said, breadboarding is only good for a quick test of a couple of elements, like maybe check the voltage, measure current, or check if a transistor is ok etc, but even then it won't be accurate so it is ok for basic tests. it is ok if you are just learning ohms law and such. but it gets exponentially more frustrating as you add more parts and connections. so never prototype any real projects on a breadboard. even the shittiest solder job is infinitely better than anything you can do with a breadboard. especially if you are into measuring things as part of debugging your project. you will get random results and it will be infuriating.

[Anonymous No.2782794]

>>2782789
he also wrote that paper in about the most confusing way possible full of strawmen just to make you even more confused while reading it

[Anonymous No.2782795]

What sottering station should I buy?

[Anonymous No.2782796]

>>2782795
fx888d just shut up and buy it

[Anonymous No.2782797]

>>2782790
So what about PCBs then. Am I going to have to learn how to make them or something?

[Anonymous No.2782799]

>>2782789
isn't that why CD ROMs are sampled at 44kHz, instead of the 36kHz you could theoretically get away with?

[Anonymous No.2782800]

>>2782797
just solder your parts point-to-point or Manhattan style over a ground plane for more serious prototypes. don't bother with PCB's unless you're starting a small business

[Anonymous No.2782801]

>>2782796
i know it is a great station but i hate the gay colors. absolutely abhorrent. vile really. yellow and blue? what is this, a nintendo cube? a Toys-R-us trinket?

[Anonymous No.2782804]

>>2782797
No. Use perf boards. These are good
And buy some single strand wire. Same idea as a breadboard but way more reliable.

[Anonymous No.2782806]

>>2782804
wait, so what's the difference between this and a pcb?

[Anonymous No.2782807]

>>2782806
look up what a pcb is

[Anonymous No.2782808]

>>2782806
Literally google PCB.

[Anonymous No.2782809]

>>2782807
>>2782808
pozzed colon buster

[Anonymous No.2782811]

>>2782806
these are a headache to route, and a nightmare to desolder if you fuck up. don't bother with them, use a ground plane based method.

[Anonymous No.2782812]

>>2782801
The station is rock solid, but the colors are revenge for Nagasaki and Hiroshima.

[Anonymous No.2782813]

>>2782811
>headache to route
When you're getting used to it, maybe.
>nightmare to desolder
Nope.

[Anonymous No.2782814]

Serious question, how hard would it be to replace the case of a fx888d? It has such great reviews but it may as well be a pink Barbie doll. That's how embarrassing it is to own it. Would it be possible to disassemble it and spray paint the case and make it look professional like a Weller station?

[Anonymous No.2782815]

>>2782814
>Would it be possible to disassemble it and spray paint the case and make it look professional like a Weller station?
Sure. Why not? Give it a light sanding, spraypaint, and clearcoat. The keypad you're stuck with unless you have one made for you, or you have the means to make it yourself.

[Anonymous No.2782817]

>>2782814
they're easy to disassemble and it would be easy to spraypaint the frame

i took mine apart to add a parasitic buck converter to drive a spare pc fan as a ghetto fume extractor, sadly it worked for a day and then the buck fried somehow

[Anonymous No.2782820]

>>2782814
just color it with sharpie if it bothers you that much

[Anonymous No.2782821]

>>2782613
I rewrote it a year or so ago. Anything in particular standing out as outdated? It’s a strange OP because that guy’s GitHub link contains almost everything, so what isn’t included by it is what is left to write beneath that link. I should probably go and fork that repo and clean it up. Any suggestions are welcome. I’m new to GitHub but I can probably figure out merging pull requests.

>>2782795
Do you have another iron to fix any problems with your future station? If so and you don’t mind getting your hands dirty, get a chinky station. They sell cartridge tips for like $2 each and they somehow just work for years.

[Anonymous No.2782823]

>>2781474
>>2781493
>>2781494
what kind of wire do you use that can hold its shape so well like that?

[Anonymous No.2782824]

>>2782808
>>2782807
So PCB basically has the wires inside, but can only be used for one circuit?

[Anonymous No.2782825]

>>2782824
yes
it's practically free to get a custom pcb made and they aren't hard to design, the trouble is waiting for them to show up

[Anonymous No.2782827]

>>2782823
Tin-plated copper, solid core.

[Anonymous No.2782828]

>>2782814
>it may as well be a pink Barbie doll.
what is your autism? it's fucking blue and yellow

[Anonymous No.2782829]

>>2782821
>Do you have another iron to fix any problems with your future station? If so and you don’t mind getting your hands dirty, get a chinky station. They sell cartridge tips for like $2 each and they somehow just work for years.

I don't entirely understand what you are suggesting. Buying a cheap station and cheap tips? And then what? Getting my hands dirty with what, modding or fixing it?

>cartridge tips for like $2
What is a "cartridge" ? I know separate tips are available but I had a bad experience with cheap shitty tips. They get oxidized quickly and are hard to clean up. I had to sand them lightly but that could damage them. I loved my old Weller tips but the pencil fell apart. Such shitty quality.

[Anonymous No.2782831]

>>2782828
Yea solid trannie colors. I may transition next year then I will buy it.

[Anonymous No.2782832]

>>2782831
May as well, if you're interested in electronics and not sports or sex then you're already halfway trooned

[Anonymous No.2782835]

>>2782832
Wait. Troons like to compete in wahmen's sports and they like any sex they can get, whether consensual or not. Plus sports ihas been DEI'd for a long time. It's niggers all the way down.

[Anonymous No.2782836]

>>2782824
A typical evolution: a breadboard to learn the basics (1 week), then perfboards to make simple projects (1 months to 5 years) then you graduate to PCBs and make your own dedicated custom boards per project. But you still prototype them on a perfboard before ordering a PCB. PCBs made in china are dirt cheap but take 2-3 weeks to arrive here so you want to make sure your circuit works before ordering it.

[Anonymous No.2782838]

>>2782832
That explains why fx888d is so popular.

[Anonymous No.2782843]

>>2782835
Hobby electronics is probably the second most troon'd thing after computer science. Fran Blanche is one of the biggest voices in the community and she's a heckin valid transgirl. I don't remember what's up with adafruit but I'm sure it's trooned.

[Anonymous No.2782844]

>>2782835
Sports is the only field where you don't need DEI. It happens naturally (but you cannot say that). Just ask Mike Cuban. He is a big fan of DEI. (but won't hire 5'3 chinese power forwards).

[Anonymous No.2782846]

>>2782838
Just get a peencel then. lol
>>2782843
You watch too much jewtube. Troon shit is pushed by political hacks who happen to be the most unpopular people on Earth. Believe what you want. Doesn't matter anyway.

[Anonymous No.2782850]

>>2782846
I like my OEM pencil which is why I am not ready to troon out just yet.

[Anonymous No.2782851]

>>2782850
The FX888D has extra girth so it can double as a dilator in a pinch

[Anonymous No.2782853]

>>2782851
Or you could build your own dilator as a first project done with a FX888D. I don't know how it works but there must be some electronics in it. Like a microcontroller powered dilator?

[Anonymous No.2782854]

>>2782844
DEI forces unqualified people into high-paid careers in every field you can think of. Why not make the NBA more huwhite and chinky? It would be in keeping with installing nigger CEOs into giant corporations for the purpose of destroying them.
>>2782850
You equate blue and yellow to trannies for some odd reason. I think you're actually a troon yourself. Wave that peencel flag!

[Anonymous No.2782856]

>>2782829
Well you see, I bought a KSGER T12 OLED station 3 years ago, and it’s been great. But the build quality has been called into question by strangers on the internet who don’t like the smallish isolation gaps and lack of a grounded case. And a few months ago, my main P-ch MOSFET died short circuit and resulted in my tip getting up above 500C, it was glowing. I took it apart, desoldered the old FET, and screwed a TO-220 FET to the case connected by wires, which should be able to handle far more power. I also modded it with a barrel jack on the back so I can run it off a LiPo or car battery or whatever. That overcooked tip still works fine, as do all the other shapes tips I bought over the years. But I can’t exactly recommend it to someone getting started. The models that use an external power supply are probably more reliable.

It uses cartridge tips, meaning the element and tip and thermocouple are all in the tip, which itself can be hot-swapped if you’ve got something to grab the hot tip with. This means there’s lower thermal resistance between the temp sensor and the tip, ensuring faster and more accurate thermal performance. Probably. I can desolder D2PAKs with them so something’s working right. Conventionally these tips cost way more than seperate tips that you just slot over the element and screw down with a collet, which is still true, but damn 936 tips are like 20c each at this point so that isn’t saying much.
If dodgy chinky tips are your concern, you can always use name-brand Hakko tips with your station, but you do pay for them.

This T12 station is similar to portable irons like the Pinecil, TS100/TS101, TS80/TS80P, etc. The Aixun T3A is an even more powerful station, but idk maybe I should make my own instead.

[Anonymous No.2782861]

So things I'm going to buy next paycheck
>Soldering Iron
>Helping hands
>Wide clippers and strippers
>Solder
>Flux
>Breadboards and perfboards
>components
What am I missing?

[Anonymous No.2782864]

>>2782861
>next paycheck
Maybe you should build up some savings so you don't have to wait for a specific time of month to buy things

[Anonymous No.2782867]

>>2782856
That sounds awesome. I honestly always thought about some REAL project like buying some cheap crappy device for the sake of the case and controls and improving it or possibly completely gutting it and build your own but keep the original enclosure instead of making your own. A power supply would be a good example of a project like that.

[Anonymous No.2782868]

>>2782861
Forget the helping hands. Use Blu-tack instead. Get an articulating ring lamp with a magnifying glass.

[Anonymous No.2782869]

>>2782864
I moved out this week and had to pay a bond so I had no spending money and I'm not dipping into my savings for a hobby I have experience with

[Anonymous No.2782876]

>>2782861
Wrapping wire. If you want to go the perfboard route, buy both single strand and multi strand wire. Single strand is easier to tin, but it is more brittle so it works well when you connect two points on the perfboard and it is not moving. But if you want to make an external connection, like maybe to a pot, use multi stranded wire since it is more flexible and doesn't break easily. Buy different sizes, from 30AWG to say 24AWG. Teflon/silicone wire on ali is really cheap and it is a high temp so it won't shrink when you tin it which can be frustrating as a beginner.

example: 200C wire
https://www.aliexpress.us/item/3256806216876597.html

[Anonymous No.2782880]

>>2782876
Is Aliexpress the best place to buy components? Its going to be annoying waiting 3 weeks for everything to come.

[Anonymous No.2782881]

>>2782880
that and lcsc

[Anonymous No.2782882]

Also what sort of components do I buy? Should I just buy 100 of everything?

[Anonymous No.2782883]

>>2782880
Entirely up to you.
Ali is cheap but it takes longer. Try Amazon or ebay too. Or any local suppliers. But that could be expensive. I always buy wire on Ali since I have enough and I am never in a hurry.

[Anonymous No.2782885]

>>2782880
Digikey and Mouser for silicon.
>but it costs too much
Buying fake shit does too.

[Anonymous No.2782887]

>>2782882
That also depends on many things and is entirely up to you. You can buy "100 of everything" which could be cheaper or more expensive depending on the components. For example if you need to buy a bunch of resistors, you can buy a kit of like 1000 pcs and 20-50 different values. That would be a bit more expensive and it will take longer if you buy on Ali or ebay. Or you could buy specific values on LCSC and it could be somewhat cheaper since 100pcs could cost about 10 cents. You won't get this kind of prices on Ali.

[Anonymous No.2782892]

Does anyone use multiple soldering stations? I was thinking instead of changing tips all the time I could just alternate between two different stations. If people buy 10 guitars and 20 rifles, why not buy multiple stations?

[Anonymous No.2782895]

>>2782882
None.
Get old appliances for free or dirt cheap on the internet. Craigslist, boomerbook marketplace, sidewalk or whatever your people do in your country. Doesn't matter if they work or not. Take them apart to see how the circuit works and how it's wired and all that then use the boards to train desoldering. You can take off every single component in there, including the stuff you'd normally pass.
In the end you'll have learned how to solder, learned about circuits, learned or at least got some idea of how those appliances work and also made a little pile of spare parts you can use for your own projects.
Also if you give up, you haven't spent anything.

[Anonymous No.2782896]

>>2782895
And test the components as you take them off and figure out a way to sort and store them that works for you.
Do that as soon as possible so you don't end up with a pile of stuff you'll sort later™...

[Anonymous No.2782897]

>>2782892
>Does anyone use multiple soldering stations?
Yes. I have a couple of old Weller stations, cheap Home Depot shit irons, and a Hakko for stuff I care about. I'm always on the lookout for big boi stations that are broken, like JBC, Metcal, and Pace.

[Anonymous No.2782899]

>>2782887
How do I know what I need to buy
I'm a complete beginner

[Anonymous No.2782900]

>>2782899
Dude, you're overthinking this. You're not building a lab. Pick a few projects and buy multiples of the components you'll use. You'll acquire more than you need over time.

[Anonymous No.2782901]

>>2782899
Depends on what do you want to do?
If you just want to learn the basics, buy some through hole resistors, capacitors, LEDs. Maybe some 555s. And batteries and battery holders.

[Anonymous No.2782903]

>>2782817
> failed
No flyback diode to squash and back-emf from the fan coils.
Every DC supply should have a reverse biased schottky diode across the outputs and one forward biased leading to the output terminal just in case. Also maybe a .1μF ceramic across them to help filter out any high frequency crap from arcing or what have you. Obviously, a full fledged low pass filter would be great, too.

[Anonymous No.2782904]

>>2782901
Batteries? I thought power supplies were better
>>2782900
Maybe I should just get some sort of starter kit then? What about this?
https://www.jaycar.co.nz/duinotech-arduino-compatible-uno-starter-kit/p/XC3902

[Anonymous No.2782905]

>>2782904
>Maybe I should just get some sort of starter kit then?
Yes, but not that one. It's way overpriced.

[Anonymous No.2782906]

>>2782899
Toolbox fallicy.
Pick a project you want to make.
My only suggestion is when you buy the parts, buy more than one. It’s a standard practice, because sometimes they are bad, or go bad and burn out because mistakes happen.
Before long, you have a bunch of extra parts when you need them for the next project.

[Anonymous No.2782907]

>>2782882
buy 10-20 each of every 1/4 watt resistor in the E6 series from 10 ohm to 10megaohm, and 50+ each of the 1k, 10k, 100k, and 1megaohm resistors.

do the same for ceramic capacitors from 10pF to 100nF, and for electrolytic capacitors from 0.1uF to 100uF.

also buy a couple dozen 2n3904 NPN transistors, 2n3906 PNP transistors, some 1n4048 (fast) diodes, some 1n1007 (power) diodes, and a bunch of LM358 (pulls to 0) op-amps and TL072 (are they still expensive?) op amps. and keep a good, cheap-shipping supplier on hand in case you need anything else.

Should cost around $50 in total

[Anonymous No.2782911]

>>2782903
it was a probably sane design, i think i just didn't leave enough headroom on the buck ic's max rating
inputs went to the fx888d tranny, output ports soldered directly onto a headphone jack that i stuck into a hole i drilled in the hakko

[Anonymous No.2782914]

>>2782904
Arduino sounds like a huge distraction if you are a beginner. Do you want to learn electronics or coding?

[Anonymous No.2782916]

>>2782905
Keep in mind those are NZD. It's like 50 USD

[Anonymous No.2782922]

>>2782907
Good list. I can’t argue with that. I’d add…
IRFZ44Ns
LM317s
2N7000
TIP31 and TIP32

[Anonymous No.2782923]

>>2782867
Get the one with the narrow blue handle.

>>2782885
LCSC is perfectly fine for silicon. You have the option of buying name brand, or buying knockoffs with datasheets, and can easily distinguish the two.

>>2782892
Tip changes take like 10 seconds total, including heat-up time.

>>2782904
Oh, a fellow kiwi. Jaycar also have packs of resistors and capacitors, but all their stuff is pretty pricy. If you don’t mind the wait, buy from AliExpress.
t. works at jaycar

[Anonymous No.2782924]

So if you put a clamp meter over the whole power wire you won't get an accurate reading because there's two wires inside going in opposite direction and cancelling each other's field....
What if I'm measuring from a tri-phase wire?

[Anonymous No.2782929]

>>2782923
I got a good paying job now; I don't mind paying extra for convenience
>Jaycar also have packs of resistors and capacitors
How do I know the difference between them? Do I need all of them?

[Anonymous No.2782947]

>>2782929
There’s both metal film and carbon film packs. Metal films are all I’d bother with, which means RR0680 if you absolutely want a resistor pack. It’s not that big, so you’ll probably buy a bunch of 1k, 10k, etc common values either way. You really don’t need a lot of resistor values outside those round numbers unless you’re messing with op-amps or LM317s and want precise resistor ratios. Digital circuits use nothing but 10k resistors and 100nF caps for the most part.

[Anonymous No.2782958]

>>2782924
Are you familiar with Kirchhoff's current law?

[Anonymous No.2782959]

>>2782958
Kind of, but with the clamp I'm measuring it indirectly. Doesn't that make a difference?

[Anonymous No.2782960]

>>2782959
Doesn't matter. Current in = current out, regardless of how many wires are going in or out.
Ampere's circuital law states that the total magnetic field going around a closed curve is proportional to the total current flowing through a surface bounded by that closed curve. So if the net current equals zero, the measured magnetic field equals zero. And a current clamp measures that magnetic field.

[Anonymous No.2782962]

man i wish kicad had some way of defining star grounding points

[Anonymous No.2782965]

>>2782960
I see it.

[Anonymous No.2783023]

>>2782899
>>2782900
This. Also make sure to save the original part numbers of you have to look up the specifications in the future.

[Anonymous No.2783079]

>>2782960
Also does that mean that if there are 3 wires and I clamp the meter around 2 of them, the reading I'll get is the same as if I were to clamp only the third wire by itself?

[Anonymous No.2783080]

I have a USB PD board connected to a PWM controller then powering a fan. When I turn the PWM controller pot on a small amount - the power will cut out sometimes. I think this is because of the low current the fan is pulling, the PD chip has a lower current limit, like a powerbank.

How would you fix this? Wire in an LED? A resistor? A decoupling capacitor?

[Anonymous No.2783111]

My second pcb, getting better at this. This time I trusted the tool and line widths are perfect, in my previous PCB I tried manually adjusting the depth because I felt like it was cutting too little

It would be a lot easier if I had a single side PCB, so I don't have to deal with the side I don't really use. I think I still needed to isolate the pads even though they won't be connected to anything

Only fuck up was my alignment hole didn't go through to the sacrificial board (I think I forgot to update cut Z or something) so I had to manually align it, but it turned out fine

I will use one of these joystick in my project but they are a pain to use in breadboard. So I made this, it just reposition pins in a way that I can insert to a breadboard.

[Anonymous No.2783120]

>>2783111
oh shit, I noticed a mistake lol. this gap is too small, it was supposed to be 2x2.54 mm to fit the middle of a breadboard. But I can fix it during the soldering I think

I was designing the PCB yesterday but initially I used the wrong component (there are different types of those joysticks apparently and I used a larger one). When I switch it to a smaller one (actually I created a new symbol), I didn't check the gap. fml

[Anonymous No.2783121]

Are you supposed to get proper readings on voltage regulators without a load? Reason for asking is because I assembled a PSU for eurorack (modular synth) with +5V and +/-12V but I'm getting -16V on the negative rail when measuring with my multimeter.

[Anonymous No.2783123]

>>2783121
Regulator is an L7912ACV if it matters btw.

[Anonymous No.2783146]

Is the NCV tester enough to find wires inside walls before drilling?

[Anonymous No.2783148]

>>2783121
>Are you supposed to get proper readings on voltage regulators without a load?
Usually not. Attach a load to the -12V rail and test again.

[Anonymous No.2783161]

>>2783123
>Regulator is an L7912ACV

these will give you -12V with or without load
my guess is you wired it wrong
the positive ones are in-gnd-out
but the neg ones are gnd-in-out

[Anonymous No.2783165]

I can't find probe leads for multimeter with alligator clips in here, so I thought about cutting the leads and adding banana connectors to be able to switch between the normal leads and ones with alligators.
My question is how much would that affect the accuracy of the meter and if there's any specific type of wire I should use to make the new leads with aligator or if I can just use some random braided wire I have lying around here?

[Anonymous No.2783170]

>>2783165
>just use some random braided wire

you need extra thick insulation on wires and alligator clips for high-voltages
just get these so you dont die
or dont so we can laugh at your funeral

[Anonymous No.2783174]

>>2783170
Do they work on all types of leads? Mine look like this, it's the cheapest chink shit possible.

[Anonymous No.2783175]

Eric Dollard, is he right about Steinmetz's work on electricity?

[Anonymous No.2783192]

So I have three months to make a tube amp for guitars. I've neither handled tubes, made an amp, nor played guitar before.

Any tips?
I intend to follow the following schematics for it, what do you think?
https://robrobinette.com/How_The_5E3_Deluxe_Works.htm
I also found a yt video of someone building it so that helps.

>>2777077
Nice numbers

[Anonymous No.2783193]

>>2783148
Will do that tomorrow. Don't have the time to assemble the load today.

>>2783161
Hm. It's at least wired correctly. I'll se if I solder bridge somewhere.

[Anonymous No.2783198]

>>2783192
>Any tips?
Take your time and think things through as you go along. If you get stumped, stop and ask questions. It's probably best to start with audio as it's pretty straightforward. Have you found a source for tubes? Buy extras of everything.
>>2783193
You can use a resistor as a load. Try 1k.

[Anonymous No.2783212]

>>2783148
> usually not (give the right voltage without load)
A regulator should give you the right voltage even when unloaded.
Wall-warts, however, will not… they’d be way-over unless you load them down. Now usually you need a few volts over (or under, in your case) to get the 78/79 regulators to work right.
You want to make sure undar a 1A load that the PSU doesn't dip below the voltage ceiling (or floor) that your regulator functions properly at.

[Anonymous No.2783214]

>>2783198
>You can use a resistor as a load. Try 1k.
Managed to find my dupont cables and hooked the PSU up to a 1k. Got a solid -19.5V now. Thanks for the suggestion! Had no idea you couldn't/shouldn't measure without a load, I've always gotten good readings from doing that before.

[Anonymous No.2783216]

>>2783212
>Wall-warts, however, will not
Oh, that explains it. Appreciate the info.

[Anonymous No.2783223]

>>2783214
>-19.5V
Oops, meant -11.5V

[Anonymous No.2783268]

Some faggot was going on about cleaning up the OP in a new thread. Now's your chance, coz we're dying on page 9.

[Anonymous No.2783275]

It is such a slow general but I noticed that it always ALWAYS hits the bump limit eventually. It is like in real life. Time seems to pass slowly but next thing you know you are ten years older. And how do you know that? Just check the file with the notes you took on a project that you were so excited to work on but never finished. Check the timestamp. I bet it was 10 years ago.

[Anonymous No.2783276]

Also imagine being on page 9 of your life.
The good thing is you don't know it is page 9.
But sometimes you could be on page 6 and the mods being gods nuke the thread if you know what I mean. You never know. Enjoy the present!
I am on my 6th beer today.

[Anonymous No.2783282]

>>2782533
im trying to remove connectivity between two solder pads (the dmm beeps loudly when i test between them) and i have been looking at the pcb for anything indicating that they are connected and there is not anything obvious, no loose solder. could it be internally shorted, like in the holes?

[Anonymous No.2783322]

I can either buy 30 50x70mm perfboards or 10 70x90mm perfboards for the same price. In area, 30 small ones is almost twice as much. Is 50x70mm too small to be useful? I can easily cut the larger one to make smaller ones but going the other way around isn't as simple.

[Anonymous No.2783326]

>>2783322
they cost a penny so just buy both

[Anonymous No.2783327]

>>2783326
Let's say I'll only buy one.
They're not as dirt cheap in my country, still cheap but not just "a penny".

[Anonymous No.2783328]

>>2783322
Post pic of this “perf board” you speak of.
You can always cut the bigger one. Score it with A knife and snap it. This has always been the way.

[Anonymous No.2783329]

>>2783282
>could it be internally shorted, like in the holes?

sure, could be a 4-layer board with a connection on a hidden inner layer
could be a coil across the pads, or a low-value resistor
or a shorted cap/chip/transistor
first thing is use ohms scale to differentiate between a short and a small resistance
if there's some resistance, apply power and use IR cam, or alcohol, or tip of you tongue, to find any heat

[Anonymous No.2783330]

>>2783328
I think I'll go for the larger ones, even if I get less of them. I'm just not sure. It's quite the difference in area.

[Anonymous No.2783346]

This is a stupid question but my brain is working at like 2% right now. How is wattage measured for batteries? A dyson cordless vacuum claims it has a 500w battery but ebikes also have 500w batteries. The ebike probably delivers the 500w continuosly for an hour while the dyson probably dumps the entire battery in under 8 minutes. Would this mean the dyson battery has a 62.5 watt hour battery and the ebike has a 500 watt hour battery? Efficiencies aside the wattage probably corresponds to motor size too? About a 60w motor for the dyson and 500w motor for the ebike?

[Anonymous No.2783347]

>>2783346
Watt is J/s, if the energy is just sitting there the wattage is zero because energy isn't going anywhere.
Batteries store charge, which is measured in Coulombs.
How much energy that charge carry depends on the potential difference, which is measured in Volts, or J/C.
How fast the battery discharges depends on how fast that charge can move from one side to the other, that's the current in C/s.
Multiplying voltage and current you get the power, in J/s. But note that current only exists when the circuit is closed and that charge is going places, so the battery all lonely by itself doesn't have any wattage.
>watt hour
Cursed unit which actually means charge, in coulombs.

[Anonymous No.2783348]

>>2783330
Picrel is the standardest of standard.
It’s the stuff you want.

[Anonymous No.2783349]

>>2783346
>>2783347
Let me summarize, and say, yeah, you’re on the right track if the voltages is the same.
Some motors are more efficient than others.

[Anonymous No.2783350]

>>2783348
Can't find exactly that in here. Other than my pic related I have the green ones with the solder mask. largest size is 100x100mm.
For cost, those I posted are the cheapest.

[Anonymous No.2783354]

>>2783350
Well, keep looking. In the meantime just get the biggest one with the most square cm per peso and cut them down, because we’ve been doing that forever.
Also, I have some of these things, I’ve never once used the edge card tabs for anything, It’s no edge card standard that I’ve ever seen. I’d cut those off too.

[Anonymous No.2783356]

>>2783347
>>2783349
Should I be calculating in J/s to get a better idea on energy density? Im trying to calculate how much energy batteries hold. Im thinking that the dyson battery probably has 5940 total watts put into it and the ebike battery has 30,000 watts put into it.

[Anonymous No.2783365]

>>2783356
You get the potential difference (the voltage) across the battery, then connect it to a load and measure current. Leave that on until the battery discharges while measuring how long that takes. Then you do:
>voltage x current x time (in seconds)
That will give you how much charge (in Coulombs) that battery holds. If you want energy density you divide that charge by the volume of the battery. You could also divide the charge by the weight of the battery and that gives you its specific energy, which is sometimes called energy density too.

[Anonymous No.2783375]

>>2783346
You guys over complicate things. No need to delve in Joules and coulombs.
What is your end goal? Are you comparing the two batteries, which of the two has more capacity? Battery capacity is typically measured in Amp Hours. You can derive Watt hours from that since you know the voltage.
That's all there is to that. You can then figure out how long each battery can last at a certain current, or a certain power (knowing the voltage).

[Anonymous No.2783376]

>>2783365
what if im trying to see the energy density between 50lbs of hot sand vs a battery? I wouldn't be able to get the charge from the sand.

[Anonymous No.2783380]

>>2783375
Im just trying to find out what types of things hold how much power. Like how much energy is stored in a gallon of liquid nitrogen vs a car battery. The vacuum was just to get an idea because I can see that this dyson vacuum has a 500w motor and drains to empty in like 8 minutes. So 500 watts x 8 minutes is how much energy it stores roughly. Not trying to account for resistance or motor efficiencies. Just trying to get somewhat close.

[Anonymous No.2783382]

>>2783376
>50lbs of hot sand
Mass of sand (in grams) x specific heat capacity x temperature difference (in relation to ambient

[Anonymous No.2783384]

>>2783380
>hold how much power.
You mean energy.

I don't know where 500 watts is coming from but for example a 3V battery might have a capacity of 1000mA x hour. That means it can source 1A for an hour. 1000mA.hour at 3V = 3W.h. 3W*3600 = 10800 J. That's how much energy it stores.

[Anonymous No.2783405]

>>2783365
>>voltage x current x time (in seconds)
>That will give you how much charge (in Coulombs) that battery holds
Wrong, you multiplied by voltage so it gives you a result in joules.
Personally I just use Ah and Wh because cells are already measured in those, and the units are more convenient. Factor of 3600 if you absolutely need C or J, idk maybe you want to see how much something will heat up or whatever.

>>2783375
I recommend comparing Wh instead of Ah. Maybe for 12V lead acid typical situations you can ignore voltages, but for lithium ion battery packs you can’t take it for granted. 2S, 3S, 4S, 5S, and 6S are all pretty common. 18650s are around 10Wh each.

[Anonymous No.2783408]

>>2783384
So thats 3 watts x 3600 seconds = 10800 joules

So a 21.6v 5000 mah vacuum battery would be 180W.h or 180w x 3600 would = 648,000J

If I wanted to do something like take1 liter of water from room temperature to boiling it would look like this 1000g*4,184J/(g*°C)*80°C= 334 720 Joules

So the battery would have almost twice the energy of 1 liter of boiling water?

>>2783382
1000 grams x .703 x delta T of sand from ambient to 500f (240c delta) = 168,720 joules

So 1000 grams of sand at 500f has half the energy of 1000 grams of boiling water and 1000 grams of boiling water has about half the energy of a 500 gram battery.

That would mean the battery is almost 4x more energy dense than the water and almost 8x the sand. The sand could have a much higher delta T though and could hold 1,195,100 joules which would put it at roughly the same energy density to the lithium battery if not accounting for lost energy.

Thats what im getting basically. I think im on the right track

[Anonymous No.2783413]

>>2783408
boooooooring

[Anonymous No.2783416]

>>2783408
checked graphite too and below its melting point where it turns to gas 1000 grams would hold about 2,541,000 joules of energy

Assuming you can turn that heat back to electricity then graphite seems like it would be pretty good for grid storage. Cheap and dense

[Anonymous No.2783418]

>>2783408
21.6 x 5000 = 108w not 180
21.6 x 5 x 3600 = 388.8k

[Anonymous No.2783428]

>>2783416
Do you have any plans to getting that energy back out of the graphite or sand or whatever? Unless you plan on using it for heating something, you’re looking at an inefficient and complex process to turn it into electricity or work.

Make an iron flow battery instead. Or maybe one of those liquid metal batteries.

[Anonymous No.2783434]

>>2783418
Good fucking catch. I fucked up on my math. Thank you. I guess this is why everything always reverts to steam
>>2783428
Looking at it as heat energy. Turning it back to electricity is the expensive part.

[Anonymous No.2783470]

How do you guys not die of boredom working on this ugly garbage?

Genuine question I don't understand how anyone could have electronics as a hobby instead of a job.

[Anonymous No.2783474]

>>2783470
You could say the same about any hobby or job. People have their interests and they don't always coincide with your own. Why don't you like my favorite color or music or food?

[Anonymous No.2783485]

>>2783474
What do you get out of electronics hobbyism? Do you make anything practical that you, and perhaps loved ones, are proud of? Or is it mostly unimpressive toys?

[Anonymous No.2783487]

>>2783485
I make losers like you seethe by existing ;)

[Anonymous No.2783489]

>>2783485
I started out fixing computers and musical instruments long ago. Then I did a lot of restorations of old and valuable items which netted me enough money to do more complicated and interesting things. Now I mostly build weapons and weapons systems, offensive and defensive (don't ask). Every once in a while family and friends bring me things that they would like fixed, but that happens less often these days.

So what do you do as a hobby? Ever built anything yourself?

[Anonymous No.2783490]

>>2783485
I’m frequently designing and building things that don't exist, and in that sense electronics is just a means to an end, like 3D printing and chemistry are to me.

On the other hand, I like the feeling of being able to make whatever I set my mind to, which is why I’m putting effort into being able to make my own PCBs even though it isn’t that practical in a world with JLC. I want to build an EDM milling machine too, then I can make shit from metal.

Also I studied physics, and electronics is the only part of that I found a practical outlet for, unless I want to build an optics bench and fuck around with lasers.

[Anonymous No.2783491]

>>2783487
Projecting hard now, pajeet. How's it feel being women-repellet?

[Anonymous No.2783497]

>>2783489
>So what do you do as a hobby
Music (Guitar, stringed instruments), cooking, coffee brewing, sport (track, martial arts) and on occasion computer programming though motivation has wanned.

Each of these has utility to myself and others without a lack of beauty and spirit.

Seems like electronics, which I feel I'm forced to learn these days, is sorely lacking in the latter despite its undeniable usefulness at scale.

[Anonymous No.2783499]

>>2783491
keep pumping your net worth into crypto buddy, I'm sure it'll moon someday :)

[Anonymous No.2783500]

>>2783490
>Also I studied physics, and electronics is the only part of that I found a practical outlet
Loved and studied Physics too. E&M is such a treat if you're a math buff like me, but getting practical drains the fun from it too bee on-ust

[Anonymous No.2783503]

>>2783497
>without a lack of beauty and spirit.
You see a pile of junk, whereas I see potential to perform magic and make some extra money on the side in the process. That's beautiful to me. To each his own.
Goodnight, Anon. It's getting late.

[Anonymous No.2783512]

>>2783503
>potential to perform magic and make some extra money on the side in the process.
It is magic. I suppose that view would make it tolerable, but it doesn't "feel" magical. A firework exploding a pattern, QR Code art, or making olive oil are more in line with real-life parallels to magic.

G'night to you and thanks for the answers.

[Anonymous No.2783540]

>>2783329
i dont have an IR camera. it is literally just two solder pads with holes next to each other that visibly dont connect to each other.

[Anonymous No.2783556]

Wanna repair a fried HDD PCB into which I accidentally plugged a 19v laptop adaptor.
This white thing measures around 1.5k I assume it's not a resistor, but just a fall protection or something like that.

[Anonymous No.2783559]

Closest thing I found resembling a fuse. It shows no continuity. What does the code "XH" mean?

[Anonymous No.2783561]

[Anonymous No.2783569]

>>2783556
>a fried HDD PCB into which I accidentally plugged a 19v laptop adaptor
I'd want to look up the datasheets of each IC on the board. See if they were taking the 12V directly, or if they were running on a lower voltage. For the ones that would be running on 12V, especially the motor drivers and voltage regulators, check if they can handle a higher voltage. That should tell you what broke. There's other components like TVS diodes and such that could have died and protected your circuit too, but I wouldn't be too hopeful. Worst case scenario, the overvoltage fault propagated all the way through every damn IC on the board, it's not uncommon for LDOs to have a maximum voltage of 15V. I've had one of them die and fry the rest of my circuit before.

Sucks that there's no silkscreen.

>mystery component
Trace the nearby board and see if the other components tell you what it's likely to be. Run that 5-pin chip through the SMD codebooks and see what you come up with. Looks like a SOT-23-5, but check the scale to be sure.
There's another of it on the opposite corner of the board by the looks of things. Yeah I'd guess they're they're acceleration sensors or similar.

I bet you'd have to get special HDDs for the ISS that don't stop spinning in microgravity.

>>2783559
Does the similar one to the right have continuity? The fact that it's in series with power traces suggests it probably should have continuity, especially considering the only via before it is a single one, and the vias after it are in a group of four for high-current. It also looks like a fuse. Check where those vias go, judging by the pinout of a sata power cable those three pins are your +12V lines so with any luck that's the only fault. The ones on the right with the other fuse are +5V. Look it up in the SMD codebooks, but I'm not hopeful about getting an amps rating like that. Maybe other HDDs have better documentation that you can reference.

[Anonymous No.2783597]

>>2783268
Uhh, it's not gonna be done right away. The thread after next one should have the new OP with any luck, but i'm a procrastinating shitbag who is kinda busy lately so no promises. There's quite a lot of things I want to add to the github, I'm not sure what should be in the OP, probably just the main advice and most important links. Here's the repo:
https://github.com/74HC14/ohmOP/
Feel free to do pull requests for blocks of text or make issues for guideline suggestions or whatever.
I decided not to fork the Awesome Electronics repo, because it's massive and has a bunch of shit that I don't really care about. Also the CC0 license is less based than the MIT license or the Unlicense.

[Anonymous No.2783601]

>>2783569
It's a multi layer board, so I can't really see where the traces lead. But the original enclosure was conceived for 12V with a standard barrel plug.

[Anonymous No.2783602]

>>2783597
The right fuse is not blown, so that makes sense. Maybe there is the chance the fuse saved the rest of the circuitry from blowing up.

[Anonymous No.2783604]

* the right fuse being the 5V line, I guess

[Anonymous No.2783607]

>>2783601
>It's a multi layer board, so I can't really see where the traces lead
Are the relevant vias blind? Yeah probably can't easily trace them if there's internal signal traces.
>the original enclosure was conceived for 12V with a standard barrel plug
Did it also have a 12V to 5V converter inside the enclosure? If so, check that's not dead too. I don't know what happens if you power an HDD from 12V but not 5V, as would be the case if it took its 5V from a USB cable and that USB cable was unplugged.

>>2783602
>Maybe there is the chance the fuse saved the rest of the circuitry from blowing up
Some of those big 2-pin packages after the fuse could well be TVS diodes, so I'd be somewhat hopeful.

[Anonymous No.2783609]

>>2783607
>TVS diodes
The diode behind the left hand fuse is indeed connected in parallel to the supply it seems. The via leads directly to the ground plane.

[Anonymous No.2783630]

At 12v it says 570mA. Which would be the roughly appropriate value?

[Anonymous No.2783632]

>>2783630
https://de.rs-online.com/web/c/?searchTerm=sicherung+smd+0603

[Anonymous No.2783647]

>>2780898
How did you manage to get the schematics.

[Anonymous No.2783672]

>>2783647
elektrotanya.com

[Anonymous No.2783713]

>>2783630
I thought I'd pick this fuse rated at 750mA nominally. Is this right or is there some high inrush current with hard drives that I should pick a higher value?
https://www.mouser.de/ProductDetail/Littelfuse/0438.750WRA?qs=wd5RIQLrsJizrClqzRejlA%3D%3D
Or can I use this resettable fuse?
https://de.rs-online.com/web/p/ruckstellende-sicherungen/6927639?gb=s

[Anonymous No.2783715]

IS THIS THREAD DED?

[Anonymous No.2783723]

>>2783715
Just about. You wanna make the new thread?

[Anonymous No.2783745]

What’s the upper limit for 555 timers. Can’t seem to get more than a couple minutes with a 2200uf cap and 1Mohm resistor. Adding more resistor makes 555 get hot.

[Anonymous No.2783797]

>>2783745
>upper limit for 555 timers

i've used the monostable for half hour
dont remember the cap, but resistor was 22M

>adding more resistor makes 555 get hot

makes no sense
it means you screwed something up
too low a resistor on pin 7 can cause overheating, but there's no such thing as too high

>>2783556
>This white thing measures around 1.5k

that's a fall detector.
it shuts off the HDD if it detects it's falling

[Anonymous No.2783816]

>>2783797
>resistor on pin 7
That’ll do it. Thanks anon.

[Anonymous No.2783820]

>>2783745
You can also use another 555 timer to effectively double the length of time (it’s got a flip-flop in it).
The 556 has two 555 timers in it.
>>2783797
> but resistor was 22M
Reasonable to assume that doubling the resistance will double the length of time. There are a bunch of other tricks you can use too. Some of the app notes cover them. 10 MΩ resistors are commonplace, btw.

[Anonymous No.2783824]

>>2783713
> resettable fuse
You don’t want the drive (SSD or spinning platter) o power itself down. It’s likely to use the most current when writing, which is the worst possible time to loose power.
Why are you trying to fuse protect a hard drive, they already have TVMs and fuses on them already.

[Anonymous No.2783828]

>>2783556
>>2783561
Piezo shock sensors, not fuses.

[Anonymous No.2783829]

>>2783824
Because I'm replacing the input fuse.

[Anonymous No.2783831]

>>2783120
What kind of CNC rig are you using, if it's something you have on your desk at home?
I've become almost as interested in PCB manufacturing as the electronics as I find it requiring to big investments and steps for a small producer.
Currently thinking about potting enameled wire in epoxy and having SMD solder points lasered on copper tape to be placed before pouring the epoxy.
Would make it possible to manufacture boards even with BGA footprints at home. Also double component sides. Also internal grounding planes.
But of course it's not for mass production!

[Anonymous No.2783846]

>>2783831
>BGA
A socket on a breakout board probably exists, picrel is one for programming at least.
Prototyping with enameled wire is already practiced:
http://davr.org/pics/wiring5.jpeg
Neat work!

[Anonymous No.2783847]

>>2783831
I have a vevor cnc 3018 but all 3018 looks the same. It is pretty much the cheapest one out there

I don't trust myself with laser desu, that is why I went for a regular drill version. I am putting a bit of neutral oil to keep the dust down, seems to be working well. I made a ghetto box cover to avoid splashes but it is not really splashing much

[Anonymous No.2783859]

>>2783831
Ticking away the moments that make up a dull day, you fritter and waste the hours in an offhand way.

[Anonymous No.2783873]

>>2783745
You can get a binary counter IC like picrel to exponentially slow your clock pulses to almost nothing
It's how real time clocks work; a 32.768kHz crystal oscillator gets divided, divided, divided down to a steady 1Hz pulse.

[Anonymous No.2783951]

I want to switch solenoids and then recover the energy back out of them. Like for a coilgun, or for a micropower electromechanical system like a clock escapement. I think I’d need something like an H-bridge, I can ditch two of the FETs for diodes instead but they’re not brilliant for efficiency. Switching the transistors at the same time, one high-side, also would be a pain in a high current situation. Should be trivial for low-power applications where complimentary FETs or BJTs are all you need. Anyone done this before?

[Anonymous No.2783954]

>>2783829
> replacing the fuse
Until you find out how it blew, you should temporarily replace it with a current limiting resistor. No? If you have a thermal camera, that might help too.

[Anonymous No.2783960]

>>2783831
> potted wire in epoxy
They do this for mass production.
After potting, they simply use a flycutter to level the top which partially cuts off the wires left close to the surface leaving “pads” for soldering.
At home, you can use drywall fiberglass tape to reinforce it, and just sand the surface if you dont have a flycutter.

[Anonymous No.2783963]

>>2783951
> get the energy back out of them
This has been done before in electric cars. What they do is attach a generator to the electric motor, and once it starts to turn the generator powers the motor, and, in turn, the motor turns the generator, for infinite power. I don’t want to go into too much detail because of disappeared by oil cartel.

[Anonymous No.2783964]

>>2783873
My alarm clock uses an AC output wall-wart adapter, because the 60 Hz is zero-cross detected, and it does a ÷60 on it to get the 1 Hz.
No timer or inaccurate crystal required.
The power company keeps it adjusted so it stays correct over time.
Your microwave oven clock works the same way, no 555 timer needed.

[Anonymous No.2783967]

>>2783963
lmao
You just reminded me of this guy: https://www.youtube.com/watch?v=pPYCKySAePQ
and this guy: https://youtu.be/ovo6zwv6DX4?t=84

[Anonymous No.2783984]

>>2783954
It blew because he connected 19V to it. Read before offering boilerplate advice.

[Anonymous No.2783996]

>>2783984
Thanks, pedantic non-contributing annoyer. I followed it back to >>2783630 where the reply chain was broken.

Why don’t you clip out and organize the chain linking each one back properly and post it on your onlyfans page since you’ve got nothing else to do.

Also, the advice stands unless you’re positive nothing else fried.

[Anonymous No.2784023]

>>2783996
>the reply chain was broken
I apologise.

[Anonymous No.2784034]

>>2783996
>the advice stands unless you’re positive nothing else fried
The likely cause is a TVS diode which is connected in parallel to the power supply and conducts as soon as a certain voltage is exceeded, thus tripping the fuse.

[Anonymous No.2784036]

new op paste:
https://github.com/74HC14/ohmOP/blob/main/paste.txt

[Anonymous No.2784037]

>>2783497
How is this not beautiful?

[Anonymous No.2784039]

>>2783497

[Anonymous No.2784040]

>>2784039
i wish my pcbs were this shiny

[Anonymous No.2784042]

>>2784034
So back to (My) original quesion.
WHAT WOULD BE FUSE VALUE TO PICK IF THE DRIVE HAS THE AFOREMENTIONED SPECIFICATIONS >>2783630
Can I use a resettable fuse perhaps https://www.mouser.de/ProductDetail/Littelfuse/0438.750WRA?qs=wd5RIQLrsJizrClqzRejlA%3D%3D or picrelated?

[Anonymous No.2784050]

>>2784034
Yes, but it’s not a certainty that nothing else caught the overvoltage. My supply of TVS diodes and 12/5 V failover regulators comes entirely from old hard drives my company discarded, hundreds of them.
However, I’m not sure why the TVS is in there in the first place since under normal circumstances it’s very hard to overvoltage one of these due to the connectors. You kind of have to work at it.
I know of lots of other expensive retail electronics with the bog standard 2.1mm DC jack, some with sleeve positive, and no TVM or reverse polarity protection. But that’s where you need it. Not hard drives. Besides, most drives have regulators in them (the ones I have) so you’d think they’d be a bit tolerant of overvoltage.

[Anonymous No.2784078]

>>2784042
Resettable fuses don't trip nearly as quickly, check the datasheets to see if the trip time is significantly faster than the effective lifespan of the TVS diode if you really want to give it a try. Personally I'd just go with a normal fuse, those things last the life of the device without tripping unless someone overvolts them, which presumably you won't ever be doing again. Some coloured heat-shrink over your 2.1x5.5mm jacks would be a better investment.

As for value selection, I'd try with that 750mA. But those SMD fuses blow pretty fast, so I'd probably buy a 1A and 1.5A while you're at it in case the inrush current is significant. Maybe they make ones that blow quicker or slower. Measuring the input capacitance will tell you the energy storage of the capacitors via E = 0.5*C*V^2, which is equal to the energy dissipated in the series resistance. Not sure what percentage of that ESR the fuse will be though.

>>2784050
The main ICs that run off 12V are the voltage converters and (I assume) the motor drivers. Shouldn't be too tedious to check which ICs will be running at 12V and check their datasheets. 15V and 16V are common maximum voltages for ICs and capacitors. I'd generally assume that a laptop power brick won't be able to push enough current into the TVS diodes to get over 15V even for a moment, but it depends on the brick's output capacitance.

[Anonymous No.2784096]

thread should last another 9 hours at least, i'll make a new one once i wake up and it hits page 10

[Anonymous No.2784098]

>>2784078
ok. I picked the next highest value. I'll just hope for the best.

[Anonymous No.2784104]

Why is electronics and CAD related software still so windows centric?
In real software, half of all devs are on Linux.

[Anonymous No.2784105]

>>2784104
Because software developers know next-to-nothing about business and industry. What's your explanation for people who want to force their opinions down everyone's throats?

[Anonymous No.2784106]

>>2784104
CAD has always been Windows centric. All major corporations really don't want you to poke in their software, so any remote association to FOSS is a big no no.

[Anonymous No.2784108]

>>2784105
You're stuck in the past, where everyone thought Linux was for hobbyists. Big business and the software industry turned towards Linux.

[Anonymous No.2784110]

>>2784108
You're delusional. Were you born with a penis and think you're a woman now? lol

[Anonymous No.2784111]

>>2784110
It's what a stackoverflow survey showed. Practically all server software runs on Linux.

[Anonymous No.2784112]

>>2784111
Right, the web mostly runs on linux. That doesn't equate to "big business" running linux. When people sit at their workstation, they're running Windows or iOS.
From wikipedia:
>For desktop computers and laptops, Microsoft Windows is the most used at 72.99%, followed by Apple's macOS at 16.13%, and Google's ChromeOS at 1.76%, and desktop Linux at 3.77%. Since ChromeOS is a Linux based OS, it can be added to the total desktop Linux share bringing it to 5.53%. 0.01% is FreeBSD and the remaining 5.32% is likely obscure Linux distributions. Furthermore, it is important to mention that the data source uses page views and not unique users for evaluation, for this reason, this data must be considered with caution.[3]
People at work aren't using their phones for CAD and spreadsheets.

[Anonymous No.2784114]

>>2784112
>iOS
macOS

[Anonymous No.2784119]

>>2784112
bt macOS is a freebsd fork?

[Anonymous No.2784120]

>>2784119
It's a closed-source OS for over 2 decades, and it's a UNIX "fork" if you can call it that.

[Anonymous No.2784126]

>>2784104
>In real software, half of all devs are on Linux.
Transgender Linux usere aren't the ones working on process planning and physical product design. Most of those people have never even touched a micrometer in their lives. It's not because "industry" isn't ready for optimal tools, but rather because people need shit that somebody WILL be responsible for. They don't want to use Mac OS X because there aren't enough tools on Mac OS X for actual engineers, and they don't want to use open source shit unless it's more than 100% proven to work correctly. In engineering, you can't let two lines of code written by a dumb contributor on Github fuck up shit in a way that'll somehow lead to unpredictable behavior. Literally everything has to be factored in and be predictable. There can be no hidden variables, no abstractions being left explained away, nothing of that sort. That's why actual engineers use computer software made by German, Japanese, and American companies with an extremely high reputation for quality and reliability, as opposed to using something sketchy made by a group of students and hobbyist trannygrammers from Bangladesh and Kazakhstan who contributed to a gay Github repo in between their dilation sessions.

[Anonymous No.2784127]

>>2784126
And all the idnians flooding into microsoft make you think it'll retain its quality reputation?

[Anonymous No.2784128]

>>2784126
>Transgender Linux usere aren't the ones working on process planning and physical product design.
At our small company, we use Linux for everything, except the PCs that are for running Altium and Solidworks. None of us is trans.
>In engineering, you can't let two lines of code written by a dumb contributor on Github fuck up shit in a way that'll somehow lead to unpredictable behavior.
Yeah, they'll just buy dubious garbage, and when it fails they'll either sue the company they bought it from or put the responsibility on them. If you want to know what thew modern engineer is worth, look at Boeing.
>That's why actual engineers use computer software made by German, Japanese, and American companies with an extremely high reputation for quality and reliability, as opposed to using something sketchy made by a group of students and hobbyist trannygrammers from Bangladesh and Kazakhstan who contributed to a gay Github repo in between their dilation sessions.
Now you're just shitposting. India is "big" in software because large companies outsource there, not because it's somehow associated with open source. Do you work for Boeing by any chance?

[Anonymous No.2784138]

>>2784104
People always want to blame someone else when things go wrong and companies are run by people. That's why OSS is not loved by decision makers. Because they can't blame and sue a bunch of anonymous nerds who made the software. They want to point the finger at a big company say you did it, fix my problem.

[Anonymous No.2784139]

>>2784128
>look at Boeing
Boeing fired their competent white male engineers for refusing the fake vaccine. The rest died from the fake vaccine and were replaced by shit piles, like many other industries.
> India is "big" in software because large companies outsource there
India sucks at everything (pootube "engineers" are proof). The whole country is made of poo and the decision to give away US industry was political (greed), not based on competence. Take a look at the world you live in now and compare it to the pre-Nigbama world. If you're honest with yourself you know why everything sucks.

[Anonymous No.2784145]

>>2784139
>retard going full /pol/cuck
Not worth my time.

[Anonymous No.2784149]

>>2784145
You cut your dick off. lol

[Anonymous No.2784151]

>650 posts
/ohm/ has set a new record.

[Anonymous No.2784154]

>>2784151
>652 ;^)
I found RaspberryPi cameras for 2€ a piece on chink express. Any cool project ideas? My idea is something like an AI that recognizes black people. Though I have to find ways on how to use that data.

[Anonymous No.2784156]

>>2784154
I think machine vision doesn't detect nogs, so you'd have to do gorilla detection. Remember the "self-driving" cars that wanted to drive over them, and the uproar from the social media fags? lmao

[Anonymous No.2784177]

>>2784154
Make it a hidden cam then and let it shout NIGGER NIGGER NIGGER.

[Anonymous No.2784179]

>>2784106
> always windows
Hello, zoomer. You’ve apparently missed MicroStation in your “I feel lucky” education. The opposite is actually true.

[Anonymous No.2784182]

>>2784179
In fairness to that Anon, he said "Windows centric" not "Windows only". What was the last version of Microstation to run on another OS? Honest question.

[Anonymous No.2784186]

>>2784177
>tweaking the output of a siren to be closer to niiiiiiiiiggeeeeeeeeer niiiiiiiiiggeeeeeeeeer

[Anonymous No.2784190]

>>2784179
>Zoomer
I'm no boomer, but I know for a fact that all professional CAD softwares jumped on windows as fast as they could. I'm aware there was CAD way before there was Windows, but by the late '90s Windows was the main platform. Shit like CATIA and NX date way back, and I recall they still release for UNIX, probably because they have to scale up to handle massive projects and staying on Windows for that is probably suicide. All other today's industry standard softwares born from the 90s onwards, like Solidworks and Inventor, is Windows only.

[Anonymous No.2784230]

>>2784190
There are still commercial enterprise grade unix systems in operation at a number of companies.

[Anonymous No.2784235]

baking now

[Anonymous No.2784242]

NEW THREAD >>2784240

NEW THREAD >>2784240

NEW THREAD >>2784240

[Anonymous No.2784301]

fuck it, lets push her to 700
What's the weirdest way you've wired a transistor?

[Anonymous No.2784303]

>>2784301
Glued to the top of an optoisolator, lead clipped from the base with a vertical SMD resistor deadbugged between them.

[Anonymous No.2784307]

>>2784301
What is the theoretical voltage limit to a CW multiplier?

[Anonymous No.2784311]

>>2777077
Does anyone here have experience with CC1101? From what I know, it is possible to make a circuit for multiple frequencies with a single chip but I couldn't find any reliable information about it. People either mention writing to internal registers or changing capacitors/chokes. Which solution is correct? I would like to control the frequency with a microcontroller in the similar way that flipper zero does it. Are there any examples I can take advantage of?

[Anonymous No.2784315]

>>2784307
whatever the breakdown point is I don't want to be anywhere near the thing

[Anonymous No.2784319]

>>2784315
https://www.youtube.com/watch?v=ooPlDbRXzAc
AAAAAAAAAAA

[Anonymous No.2784325]

>>2784319
https://www.youtube.com/watch?v=QAAngb2XeOc

[Anonymous No.2784332]

>>2784325
https://www.youtube.com/watch?v=r782JNmhgQY

[Anonymous No.2784335]

>>2784307
Breakdown voltage of whatever is surrounding the components. You can even use vegetable oil to insulate, but you'd better be damn sure about your sealing or you'll make a fucking mess. Trust me, I know.

[Anonymous No.2784337]

>>2784332
This fuckin guy. Holy shit.
https://www.youtube.com/watch?v=WavTP2Viovo

[Anonymous No.2784339]

>>2784319
just a little fizzle

[Anonymous No.2784342]

>>2784335
>vegetable oil
Sounds like a good firestarter. haha

[Anonymous No.2784344]

>>2784339
Would you zap your nuts with it? For science.

[Anonymous No.2784345]

>>2784342
I've read a paper that basically said that's a fine alternative to mineral oil, as long as the water content is very low. Could have been bullshit tho, can't know, I shelved the project after the oil spill.

[Anonymous No.2784346]

>>2784345
I don't know either, but it seems like it could be an extra hazard. Glad you survived.

[Anonymous No.2784347]

>>2784344
hazel or brazil?

[Anonymous No.2784348]

Pole pig? Wtf
https://www.youtube.com/watch?v=4hXVT120QO

[Anonymous No.2784350]

>>2784347
nigger toes!

[Anonymous No.2784351]

>>2784348
oops
https://www.youtube.com/watch?v=4hXVT120QO8

[Anonymous No.2784356]

>>2784337
>>2784351
>Sidor Sidorovic
this guy won't live too long I imagine....

[Anonymous No.2784360]

>>2784356
I was thinking the same, but his last video is a week old. Maybe he has plates in his skull.

[Anonymous No.2784363]

>>2784360
The lightning god hasn't claimed his soul quite yet.
I wonder if he'd do the old flying a kite in a thunderstorm trick?

[Anonymous No.2784366]

>>2784363
I wouldn't doubt it.
https://www.youtube.com/watch?v=Crs41lPeZRI
Dude is nuttier than a squirrel turd.

[Anonymous No.2784369]

>>2784366
Have you seen his hands anywhere? Is he the skinny type slav maniac or the fat type slav maniac?

[Anonymous No.2784371]

>>2784369
He's a bit larger than average from the looks of it.
https://www.youtube.com/watch?v=OeFL1gCsfME

[Anonymous No.2784372]

>>2784371
That's his buddy though?
rural slav land is a crazy place

[Anonymous No.2784373]

>>2784372
No, his buddy is filming.
https://www.youtube.com/watch?v=BOZTIjfeGQo

[Anonymous No.2784376]

>>2784373
Truly fascinating creatures.
I remember their life expectancy is somewhat low.

[Anonymous No.2784379]

>>2784376
Maybe he's a medical equipment technician. I dunno.
>I remember their life expectancy is somewhat low.
Yeah, living a hard life would make me welcome death just to get me out of this place!

[Anonymous No.2784383]

>>2784379
Good night friend, try not to blow your house up anytime soon ya hear.
Hopefully we meet again in some future thread I've had this idea I wanted to test out on a few motor windings could be jumpy..

[Anonymous No.2784384]

>>2784383
Goodnight, Anon. Keep one hand in your pocket. lol

[Anonymous No.2784387]

Almost there to post 700!

[Anonymous No.2784389]

>>2784387
Random circuit post

[Anonymous No.2784392]

>>2784389

[Anonymous No.2784394]

[Anonymous No.2784395]

ooh, low-leakage diode using a reversed bjt

[Anonymous No.2784396]

[Anonymous No.2784400]

woo
post 700

[Anonymous No.2784401]

[Anonymous No.2784402]

Mods have to make this thread a sticky now.

[Anonymous No.2784408]

702

[Anonymous No.2784409]

>>2784408
Most popular thread in /diy/ history? Has to be.

[Anonymous No.2784414]

He's missing both thumbs. Wonder how it happened.
https://www.youtube.com/watch?v=CzylbkS1ZSk

[Anonymous No.2784415]

>>2784414
and a couple of other fingers too. Damn.

[Anonymous No.2784523]

>>2779726
I paid $3.50, including shipping and tax, for 5 boards last week. Cry.

[Anonymous No.2784526]

>>2779645
>>2779726
>>2784523
Shit's that cheap now? Maybe I should try it myself.

[Anonymous No.2784541]

>>2784392
It’s hard to trust a circuit where the guy can’t draw a coil correctly.

[Anonymous No.2784544]

>>2784541
It's labeled though. Can you read words?

[Anonymous No.2784545]

>>2784541
look at his resistors, he's from euroland, forgive him for being born unto sin

[Anonymous No.2784547]

>>2784545

[Anonymous No.2784554]

>>2784545
OMG! Is that why they draw resistors that way? Because they can’t draw coils properly! It all makes sense now.
I feel like an etymologist now. And you’re the co-discoverer, anon.
Paper forthcoming.

[Anonymous No.2784603]

713

[Anonymous No.2784636]

[Anonymous No.2784645]

rejoice, we are free

[Anonymous No.2784730]

Why are we here? Just to suffer?

[Anonymous No.2784731]

>>2784730
Can we get to 1000 posts?

[Anonymous No.2784732]

>>2784731
No. we'd need a bigger resistor.

[Anonymous No.2784733]

>>2784732

[Anonymous No.2784735]

>>2784733
Bigger.

[Anonymous No.2784741]

>>2784735
Check out this space-age crematory.

[Anonymous No.2784746]

>>2784741
lets get 12 of these babys up and glowing and we should be good to go.

[Anonymous No.2784796]

>>2784735

[Anonymous No.2784834]

I'm planning to build a solar charger for 12v lead acid.
Is this valid way to make one?

[Anonymous No.2784835]

>>2784834
I am planning to have very low current charging capability, just to keep the battery topped up for occasional use.

[Anonymous No.2784839]

lpbp