/diy/ - Do It Yourself

first for polar phasors

what do I need to learn to be able to make an induction cooktop?

>>1989685
>if I keep the maximum charging voltage to let's say 1S batt to 4.1v
You want the charge current to taper off significantly once you're at that point, and it means you lose probably over 10% of your capacity.
>inverter
You probably don't need one, unless you're powering something that runs off a transformer or has an AC motor. Many appliances are stupid enough that having AC isn't important (e.g. a resistive heater, a blender with a universal motor) or are smart enough to run on a range of voltages (anything with an SMPS), in either case having a ~100VDC boost converter should work just fine.

>>1989955
nice

>>1989983
self-resonant shit

>>1989983
A 101 course on electronics. MIT 6.002x teaches the basics.
>a whole course? i'm not doing that
Okay skip ahead to https://www.onsemi.com/pub/Collateral/AND9166-D.PDF

So I updated my OTA VCA and powered it with a dual supply. I tied the negative feedback resistor from the output to the ground instead of the inverting input and added a resistor in series with the potentiometer on the I(bias) pin. I also switched the signal input from a DC square wave to an AC triangle wave produced by my oscillator. Still not getting an output though. I'm getting more LM13700s mailed to me so I'll be able to see if it's an IC problem (e.g. sunk too much current into I(bias)) or a design problem.

So I updated my OTA VCA and powered it with a dual supply. I tied the negative feedback resistor from the output to the ground instead of the inverting input and added a resistor in series with the potentiometer on the I(bias) pin. I also switched the signal input from a DC square wave to an AC triangle wave produced by my oscillator. Still not getting an output though. I'm getting more LM13700s mailed to me so I'll be able to see if it's an IC problem (e.g. sunk too much current into I(bias)) or a design problem.

>>1990042
cool
you building a eurorack module or something?

>>1990085
Yeah, I'm planning on building a basic dual VCA but the VCA itself can also be part of other modules (e.g. filters, percussion etc.). I guess the OTA isn't often used because there's not much in the way of guides regarding its use.

>>1990042
It's a design problem. The op amp will always try to bring the output (5 & 1) high if the inputs (4 & 3) are mismatched. Because the output is pegged to the 12V rail, there's no feedback. Also not sure why you're bleeding to ground from 5 through a resistor, it's not doing any filtering and the op amp doesn't store charge?

>>1990109
What are you planning to do for the faceplate? I've started working on building some eurorack stuff and I got a small polycarbonate sheet that I'm gonna try cutting and detailing into useable modules.

>>1990231
Not the one you're replying to, but I've been having fiberglass faceplates manufactured by the same PCB company making my boards. That's getting fairly common now. If you get creative with the copper and solder-resist layers you can get the entire thing HASL coated and looking like metal.

>>1990193
The LM13700 is an operational transconductance amplifier (OTA). They're supposed to be used open-loop (without feedback). The 1K to ground converts the output current to a voltage (although that value seems a bit low; the datasheet examples use 10K or 30K).

The basic principle is that the output current is equal to I_abc*(Vp-Vm)/Vref (Vref ~= 50mV). So if you use it to drive a fixed resistance, the overall gain is I_abc*R_out*(Vp-Vm)/Vref, i.e. the voltage gain is proportional to I_abc.

Compared to a conventional op-amp, an OTA has a predictable (and controllable) open-loop gain. The main downside is that the biasing can be somewhat finicky if you want high linearity (low distortion).

>>1990262
This one is just a prototype so I cut some corners. Final version will have black-solder mask over the tan sections. I'll also sand it down a little and apply an enamel coating.

>>1990262
>>1990271
Shit that looks pretty good. I had heard of pcb faceplates, but I had heard they were crappy.
>analog video synth
You're the video synth guy! I'm your biggest fans lmao.
Are you gonna be selling or open sourcing those?

>>1990321
I'm going to be selling it as a DIY kit really soon. It's all through-hole components so amateurs can solder it. I'm not keeping the schematics secret but I think I'll hold onto the microcontroller source code. I don't want it to be too easy to clone.

What is this round crimp terminals? Someone cut the cord of an Electrolux EW500F washing machines. 220v/50Hz

>>1990346

>>1990338
That's so cool.
My brother has low functioning autism and is obsessed with making weird sounds with various phone/tablet apps. He also obsesses over the minute visual effects of videos on a VCR.
One of my goals is to make him a device of some sort that adds video/audio effects to his game console and VCR outputs. He'd fucking shit himself.

>>1990351
Look up "dirty video mixers" It's a super simple circuit that makes aesthetic glitch effects.

https://www.youtube.com/watch?v=FNp4Te2BnwU

>>1990351
There was an anon on here that made a NES light gun into an instrument that played different notes by shooting the screen, and the notes were determined by a shifting psychedlic rainbow pattern.

I don't believe it actually used an NES, I think it was a rasbpi or something.

>>1990369
>>1990369
That was me. I did three different light gun video synth projects. None of them used a NES , RPI, or microcontroller. I was pushing myself to get better at hardware back then so it was all opamps and logic gate chips.


https://www.youtube.com/watch?v=tJvaH2gRwj8
https://www.youtube.com/watch?v=BhoqS5sP0P4
https://www.youtube.com/watch?v=TMScn4Sus94

>>1990267
> I know a lot of things but still cant make sound with my circuit.
K.

>>1990390
s-shut up

Anyone know what any of these components could have come from?

>>1990420
garbage can

>>1990338

holy shit anon i love you, I've been wanting to start developing some of my own video gear but had no clue where to start

fucking based

>>1990420
Thats pretty broad desu, anything to go by?

>>1990231
I just buy guillotined aluminium, drill holes, sand it, spraypaint it, apply some detailing (knob function etc.) with a coloured sharpie then give it a lacquer cover. I don't really care about super precision or really fancy faceplates. I did try to buy a sheet and cut my own plates out of it but buying it already cut to size was way better than my wonky attempts.

>>1990420
Is that a load-cell?

>>1990231
>>1990509
Once I get into my laser PCB workflow (covering blank PCB in etch resistant paint, lasering off where I want it to etch) I'll likely do a similar thing for faceplates. Might etch the faceplate and melt some black wax into it like Clickspring.

>>1989993
>You probably don't need one, unless you're powering something that runs off a transformer or has an AC motor.
yea, I'll be powering at least one refrigerator so I have no choice but to use an inverter.
>You want the charge current to taper off significantly once you're at that point, and it means you lose probably over 10% of your capacity
I know, but at least I got battery longevity tradeoff of it. Maybe I should put a bidirectional ampmeter near the battery so I would know if there is a load or not so I could adjust the charging current accordingly?

>>1990351
>My brother has low functioning autism and is obsessed with making weird sounds with various phone/tablet apps

Can you please record these and share them. I feel this is the purest form of art.

>>1990509
I'm thinking of buying some 1.5" (40mm) aluminum strips, 1/16" (1.5mm) thick, cutting with a hacksaw, then drilling. IDk wtf I'm doing though. Terrible idea?

>>1990615
I bought 50x100x2mm panels for $4 a pop which was more expensive than if I made them myself but trying to hacksaw a straight line is a bitch, especially when you're sawing deeper than your hacksaw frame. A circular saw would definitely be a better tool but I'd rather pay slightly extra to avoid hassle.

>>1990649
Hmm jlcpcb's $2 deal is for 100x100mm boards, right?
split them in half, at 5pairs minimum +$8 shipping that's $1 per faceplate

>Mims III, Getting Started in Electronics
>hand written
can't tts like i usually do b/c im retarded

>>1990698
(I use tts so much I've forgotten how to read)

>>1990563
I've thought about that. He doesn't save them or anything as that's beyond his capabilities, so I'd have to put a recording device in his room or on his tablet and collect weeks of audio. There are some good bits, but it'd be a lot of work and it'd be hard to do without invading his privacy.
As sort of an example though, one of his favorite things to do is record the klasky csupo logo (https://youtu.be/90U0dYQDft0)) and slow it down. So there'll be periods where he listens to,
>"klaaassskkkyyyy csssuuupppooohhhh, brbrbrbrbrbrbrbrbrbrbrbrbr quuaacckk quaaaccck"
on repeat while giggling to himself lol.
There was one time where he recorded a woman laughing and slowed it down and down-pitched and distorted it and it just sounded like some straight demonic shit. It was metal as fuck.
>>1990383
>>1990369
damn that's aesthetic

>>1990346
>>1990349
Looks like a pin that goes into a molex housing for quick connect/disconnect.
Think of the old power connectors on IDE drives inside computers. You can crimp on the wire, then push it into the plastic housing. If you look close, you can see little tabs coming off of them to help hold them in the housing.
I think those are the female ends, but I could be wrong.

How would you guys go about denoising a very sensitive setup, which is grounded to full extent, situated inside of a full-metal Faraday cage with grounded chain visor space and on a pressurised air table? Trying to restore a setup which is meant to measure nA, pA and even fA differences, but somehow both the line noise and some sort of high frequency noise (10-50 kHz) tends to appear. I tried connecting all of the things to the same socket, and correction using a line corrector humbug, but it seems to still come up with 5-10 pA of noise, which is way too much for what I'm trying to measure.

>>1990042
Turned out the problem was that the input signal needs an amplitude <100mV. A voltage divider was enough to get it working. Added a CV input and now it's ready for the board.

>>1990698
It doesn't help that it's all on lined paper and a bad scan. It's a good book though.

>>1990549
There are refrigerators designed to run off DC, for RVs and boats and the like.
Ideally, you’d be monitoring input current from the solars, output current to the load, and current into/out of the battery. More data = more better.

>>1990765
What’s the power supply? Are any capacitors potentially microphonic? Are all inductors toroidal? Are any metal pieces (potentiometer knobs, chassis, etc.) left floating? Is there any noisy equipment nearby?

>>1990861
the power supply is general uk power line, there is a potential risk of microphony, but i wiped everything with demineralised water earlier this week. there is sadly a plenty of noisy equipment in surrounding floors, and i can see when they start it, but even if nothing is on, still getting high bandwitdh noise fucking up my signal. I already forced two floors above and two floors below to turn of their radioactive measurement shit/frying chemicals procedures, but it led to about 0 change

>>1990861
just to clarify again; nothing left floating, and even in 'we do not have it on' situation. there is a noise. I genuinely can't vouch for the fuckers, as they also 'did not touch the centrifuge' despite being caught on camera. but the sample is in patented faraday cage, so the noise should not go nearly as far

>>1990867
sorry centrifuge is outside of the cage; inside the cage we have a microscope, four laser diodes, a weird 9-valve perfusion system and an organ bath with bunch of cells, complimented with a set of four electrodes and micromanipulators to move them to the right spot.

>>1990870
everything grounded as fuck to the amp which feeds to computer

>>1990765
Just some miscellaneous thoughts on noise... my bible for noise problems is the book "electromagnetic compatibility engineering."
If I had the time and budget, what I'd do is to have everything electrically floating and dc powered from a battery bank, and cut power at the breaker to every plug and light in the room to be extra sure. Once everything is electrically floating, check for noise when everything is ungrounded, and then again when it is grounded.
Check all your assumptions, like that ground is actually ground, make sure the faraday cage isn't damaged, that the line conditioner isn't faulty, that you and other people aren't carrying mobile devices in the room (try coming in after midnight), that other equipment hasn't just failed from simpy being power cycled over the holidays.
Try injecting noise at various parts of the system to see if shows up in your test equipment.
My first guess when hearing 10-50khz is the problem is from a switching power supply. Computer or monitor. Start slapping chokes on everything that carries power?

>>1990765
I remember reading that the human body can act as a capacitor with electrical sources in a room (IE mains, communication signals), so maybe make sure you're grounded yourself when handling it.

I'm probably retarded but who knows

>>1990864
>the power supply is general uk power line
What, it's running off 240VAC? Surely there's an AC-DC power supply in there somewhere.

I'd have a much tighter shielding box around only the ammeter itself. Even some grounded tin foil might be sufficient. Faraday cages are pretty shit at dealing with something as low as 50Hz IIRC.

Happy New Year, everyone.
Yesterday, one of my neighbors put out a TV that was apparently broken. I took it for myself last night and put it in my yard so that I could take it apart and salvage any capacitors, voltage regulators, etc. on the New Year's weekend. It rained late last night and this morning, though, and it got pretty wet. The top is open, too, so there's no doubt that everything inside got soaked. It's dry now, though. How much of the stuff inside still works? Should I just trash the whole thing? I don't want to test every single IC and capacitor in there one by one.

ts100 came in the mail today
it melt stuff good
it heat really fast

>>1990999
Remove all PCBs, submerge them in isopropyl alcohol for a few minutes, air dry for 24 hours. Trash the rest of it.

>One resistor short
>Most online component shops away until the 4th
>Have to wait at least a week
Goddamnit.

>>1990765

>I tried connecting all of the things to the same socket
Was this an attempt to eliminate potential ground loops? Have you re-checked the circuit for loop paths connecting to ground? That might be the source of your line noise

>>1991005
Thanks anon, I'll do that. The boards themselves don't look as bad as I thought they would (especially the brown one, which I was most interested in).

>>1991003
I received my pinecil, but still haven't tested it. I'll give it a go soon, as I need to solder some devboard headers.

>>1990999
>>1991025
You can probably just let it sit (in dry air) for a week and it should be just fine. A sealed big rubbish bag with a jar of calcium chloride in the bottom makes a good dryroom for drying out things that might have an affinity to water, such as some particularly hygroscopic foam lining for my rollerblades' inners. Might want to clean out some of the contacts afterwards though.
I'd see about troubleshooting it before salvaging it, getting a replacement logic or power supply board could well leave you with a more valuable end-product than just scrapping it for parts.

That brown PSU board could be a reasonably good PSU board for a project or two, though if it is a CCFL driver as well then you're gonna have some high voltage shit to deal with, for better or worse.

>>1990420

2 toy dc motors, one geared. the yellow thingy is a heater, like for hand warmers. dunno what the PCB is.

>>1990756
>I think those are the female ends, but I could be wrong.

does it look like a cunt? yes, so it's female.
and i can confirm those are Molex pins, as used on PC power supplies.

>>1991025

people tend to exaggerate about water damage. as you can see, in the short term, the only things you have to worry about are steel bits which rust. as for the rest, unless it's been weeks, you can just put the PCB in font of a fan for 15 minutes per side, and it'll be good as new.

>>1991028
>pinecil
wtf I paid 80 cad for mine and pinecil is only 30 bucks?

>>1991102
>cad
You got the incel peencel.

>>1991108
i got chinked eh
30 bucks sounds like a meme

>>1989950
rollin

>>1991102
I've mentioned pinecil here and elsewhere (e.g. csg) every now and again.
Too bad you somehow ended up paying extra buck for a ts100.

>>1991152
I am experienced coper and seether

>>1991161
Yeah, I am no stranger to coping and seething either.
But I love my irons (pinecil and ts80).

i-i am very happy with my t12 station t-thanks

>>1991211
It's alright stutter anon.
At least we can solder, unlike those guys in /g/.

I found 2 presumably broken vacuum cleaners on the side of the road. I don't know anything about electronics/machines and thought that opening them up would help me learn a bit.
What are some useful parts that I should keep when I'm done butchering the vacuums?

>>1991241
That's a good way to get bed bugs.

>>1991247
Huh? I'll be doing opening them up on my workbench.

>>1991252
You underestimate those fuckers.

>>1991258
What should I do to prevent them? They're currently in my wagon.
It's summer here, if that helps.

>>1991241
The motors, any capacitors or transformers, switches, possibly high W resistors
Make sure all capacitors are discharged so you don't kys tho

>>1991269
>>1991241
In fact just take pics of any circuit boards and electronics you find inside and well help you out

>>1991269
>Make sure all capacitors are discharged so you don't kys tho
How do I do that? Push the on button?

>>1991270
Thanks man. Wasn't going to do it today but I guess I'll get started.

>>1991271
Take some metal piece with an insulated handle like a screw driver and touch it to both terminals of the capacitor

>>1991269
>Make sure all capacitors are discharged

It's a vacuum cleaner not a CRT television, microwave oven, or xenon camera flash. There shouldn't be any dangerous capacitors in there.

>>1991264
>What should I do to prevent them? They're currently in my wagon.

stick in black garbage bags and leave in sun for a couple of days.
"Interestingly, bed bug eggs must be exposed to 118°F for 90 minutes to reach 100% mortality."

>How do I do that? Push the on button?

dont listen to idiots going on about charged caps. not a chance in a trillion you'll come across one in a vacuum cleaner.

Sorry for the quality, the Huawei program won't install so I had to use my regular phone.
>>1991273
Alright, will do.

>>1991275
I'll stick the other one in a bag. They've been outside for a few days now and in my car for several hours on a 29° day already. When I took the first one apart there were a few small insects and a tiny spider. If they were alive does that mean bed bugs would be?

>>1991282
I would say you could use all of that, but most useful would be the yellow capacitor, the jumpers, and the what I asumme is a triac (black 3 terminal thing) with the heat sink
Does it have any model number on it?

>>1991298
Not that I know what to do with any of it but is the rusted capictor really usable?
>Does it have any model number on it?
The heat sink? I can't read it.
How can I remove the top so it's just a motor?

>>1991282
That looks rusty or something. Dead simple circuit though. Arguably you could repair that circuit and have a working vacuum cleaner (or two) to use or flick on trademe, or you could take the PCBs themselves and use them as dimmer circuits for generic appliances like lamps and such. Though given their state I'd probably lean towards salvaging parts. Especially that heat-sink, actually. The larger cap might make for a good capacitive dropper circuit.

>>1991302
Capacitors (at least potted-box and dipped types) are basically hermetically sealed, they should be fine unless they're obviously cracked.
As for the motor, it should be possible to remove that shroud, destructively or not, but whether the fan will be easily removable from the shaft is another matter entirely. Perhaps only if you've got a proper bearing-pusher. Dedicated blower motors aren't an awful thing to have around, for things like a diy forced-air furnace and the like. Check the brushes however, that model seems to have air blowing directly past the commutator and windings, improper filtration could have led to dust ingress and subsequent abrasion of the commutator-bars or brushes.

If you can read the part number on that TRIAC/transistor/etc. you could find a datasheet for it easily, which would help. Not quite visible on your image.

>>1991323
Thanks for the help. The plastic housing for this vacuum is pretty fucked so I just through it out. Maybe the dimmer for some ricey furniture or something.
I do a bit of welding and I could use the exhaust function to remove the fumes rather than using a fan to blow them away. Would fumes affect a motor? Surely not.
It was wrapped in some sponge but it was covering the model number so I took it off.
I managed to salvage the on/off switch, dimmer, and the retractable cord.

>this should be easy
>tin wire
>melt a bit of solder in the metal tube
>heat tube and wire
>waiting for solder to melt
>not melting
>metal tube melts plastic

Hakko set a 750, using lead free, why am I so bad at this

>>1990861
>There are refrigerators designed to run off DC, for RVs and boats and the like.
I want to power my current AC refrigerator in my cabin
>Ideally, you’d be monitoring input current from the solars, output current to the load, and current into/out of the battery. More data = more better.
alright I'll use 3 sensors. another question, if I vary the duty cycle of the switch to decrease charging current, that means the voltage also got decreased, correct?

>>1991339
>using lead free
kek

Happy new year, you arses.

>>1991339
Don't you have to crimp the wire then stick it in?

If i am getting brownouts when my chip is connected to usb power on my computer, is it safe to take an isolated 5V power supply and hook it to the + and - on of the USB cable?

>>1991386
Connected to your chip? Yeah. If you're using an arduino or something then you should buy a barrel jack and connect its wires to your power supply (less fiddly). Try placing a high value capacitor between + and - rails or a smaller capacitor between the v+ and v- of your chip.

>>1989950
Aight I'm a beginner and I just did my first soldering. I think I managed to fuck up the soldering tip by oxidizing it in the process though. Now it won't melt/stick to solder. So I should always keep solder on the tip and just wipe before soldering? Or should I wipe / re-add solder on the tip before soldering. Would using a bit of fine sandpaper be a good idea at this point? I read somewhere that it fucks up the tip but at this point the tip is basically useless anyways.

>>1991339
>lead free
found your problem

>>1991395
>Now it won't melt/stick to solder.
You used shitty chinese solder. Don't sandpaper the tip ffs

>>1991339
Besides the whiskers problem and how much harder it makes soldering in general, lead-free melts at a much higher temperature, which makes what happened to you very likely.

>>1991339
Lead builds character

I'm surprised this shit works (at least the saw wave), what a fucking nightmare.
What is the cheapest way I can get into double sided pcb etching?

>>1991571
laserjet printer and photo etching. You can get kits for cheap; The printer is probably the most expensive part.

>>1991576
>>1991571
He probably meant ordering proper PCBs made.
It's cheap these days, and you get quality that puts any home-etched board to shame.

>>1990501
>>1990521
>>1991067
I found it in my brothers drawers. Found in an altoids can along with a bloated battery that I throw outside. Led to believe that they're all from the same device cause of the wires.

I saw a voltage divider in an AC circuit but instead of the non-wiper pins being + & ground or - & ground, they were + and -. How would that work? If the two rails are +-12v would it provide a voltage range of 0-24v?

>>1991633
wireless vibrator? lmao

>>1991571
>What is the cheapest way I can get into double sided pcb etching?
cheapest? by don't.
Just use chinks,you can get like $5 double sideds with silk screen and everything for like $5 bucks without any work

>>1991339
Is that a name-brand XT-60? I've heard that no-brand ones are made of shitty plastic that melts at a lower temperature, hence why the guys over at /diy/rcg recommended that I get name-brand (Amass in this case) connectors. I also use leaded solder. Instead of tinning the wire first, I prefer to wipe some solder paste inside the solder cups, insert un-tinned wire, and jam the soldering iron set to 350C with a big (T12-K) tip, and feed in as much solder wire as possible. Sometimes the large tip causes the sides of the plastic to get a bit melty, but so long as the extra cable shield will still fit on it's not usually an issue.

>>1991395
Just wipe off the tip with copper wool. If you don't have any, quickly wiping with some ordinary facial tissues works pretty well. Then get some soldering flux. Do not sandpaper the tip.

>>1991571
Double-sided is a pain for hobbyists because PCB design software assumes you've got plated-through-holes. Soldering both sides of an IC is possible, but makes it impossible to desolder and doesn't apply to IC sockets or other flush parts. Vias are somewhat easy, just using solid-core wire and the right-size drill and maybe some hammering, but drilling is a whole exercise in itself. Those carbide PCB drills break easy, at least if you're not using a drill-press. Not to mention having to align the two sides. I'd personally recommend single-sided etching with jumpers for this reason. Bonus points for SMTing everything, picrel. That said, the flexibility of a 2-sided board is hard to beat, so it might be worth trying anyhow.

And look to using PCB fab-houses, which may or may not be viable, depending on whether you live in a place with horrible import duties.

>>1991696
>Is that a name-brand XT-60?
I doubt it - I just ordered off ebay. I'll pay attention to this.

Thanks for the practical advice. This is close to what I tried to do. It seemed flawless in my head, but the execution was seriously fucked. I'm at 399 C - is this too high? Is the flux necessary for it to melt on it's own, or is that just for it to bond properly?

When I put the solder against the tip alone, it takes several seconds ( 5+ ) to go liquid. Maybe the solder is too thick:?


>>1991443
>>1991369

I know it's easier to use. Have young kids around the house. Not worth the risk. inb4
>lead isn't bad for you, I've been using it for 20 years and hardly anyone notices my mild retardation or anger issues

>>1991380
Crimp it before I put it in? Or crimp it after I put the wire in? I thought that I should maybe crimp it, but the semi-circle isn't conducive to that. ( no pun intended )

>>1989950
i have a module i am using with my arduino that i want to be able to switch the power on and off, to reduce power consumption. easy way would be to use a relay, but they are too big. how can i do this with a transistor?

>>1991774
Did you figure out how much power the module draws first?
Because if within i/o pin max current, it would make a transistor pointless.
Also, the typical transistors is wasteful for just on-off.

>>1991751
>399C
300C will still melt the brand-name plastic on mine (bought Amass brand from aliexpress, they're not much more expensive than nobrands). The higher your temperature, the faster you'll be able to get in and get out. The joint didn't form because you didn't have good thermal contact to both the cup and the wire. Might be difficult if you've got a conical tip, but a screwdriver tip or similar can make thermal contact with both at the same time. I find having half a mm thick layer of (fresh) molten solder on my tip helps improve thermal contact greatly.

>>1991774
A field-effect transistor is what you're after, a MOSFET in particular. Something like pic-related.

>>1991774
Can you just have the transistor drain & source as a switch or is that too much voltage drop for you?

>>1991774
soft latch switch
https://www.youtube.com/watch?v=Foc9R0dC2iI

It's crazy you guys know so much. I am a junior at a college getting a degree in Electrical Engineering but the type of stuff you all talk about just blows me out of the water.

>>1991797
To be fair, I'm astoundingly good at sounding like I know what I'm talking about when I actually don't.

>>1991797
I have my degree and half the anons here still seem to know more than I do

>>1991797
Maybe you're just retarded.
>>1991811
You, too.

>>1991816
I am very retarded, I'm surprised I even graduated

>>1991819
We were all retards once, Anon. Nobody gets smarter as they age, just a bit less retarded.

>>1991816
No need to be a dick. I still have like 2 more years to do in my degree.

>>1991386
>is it safe to take an isolated 5V power supply and hook it to the + and - on of the USB cable?

if you mean replacing one 5V source for a better one, that's cool, but if you mean putting 2 diff supplies in parallel, then there's a chance one or both will die.

>>1991834
I was being an ass, not a dick. A dick would tell you to sneed, cope & dilate.

How do I build ram?
I've never soldered before

>>1991875
Yeah fair

>>1991875
yeah I guess you're use to being the bottom huh

>>1991880
Whoa, buddy. Cool it with the antisemitism.

>>1991878
Define "I want to build RAM". You're not going to be building ram sticks if that's what you're after.

>>1991878
Buy a bunch of transistors, make flip flops, multiplexers, and some other shit idk

>>1991889
>>1991897
Why can't I build ram sticks.

>>1991898
because you need to ask how to build ram sticks
Look up how computer memory is actually built

>>1991898
>"Why can't I, a person with no materials or prior experience, build an end product cheaper and better than ones mass manufactured in factories."
Doing it for the fun of it is a different story but given that a 16gb ram stick is ~$30 don't believe that you can beat it.

>>1991898
You can. Get some sticks of dead wood and write "ram" on them.
Then stick it up your ass, faget. Happy new year.

>>1991898
This: >>1991909
The semiconductor processes required to make a single transistor, let alone a few billion of them only a dozen nanometres from one another, is out of reach for almost all hobbyists even with the most advanced knowledge and tools. There are one or two guys on youtube making logic gates and such in their own lab however, but not something I'd recommend unless you're particularly enthusiastic and learned.

If you don't mind how much RAM you have (like 1k-1MB) and don't mind using MCUs, then I guess you could probably chuck an MCU on a PCB alongside a RAM IC and maybe have it work on whatever kind of PCIE/etc. slot that computers use. An MCU might not even be necessary if the data format is correct. Then again, maybe they have a lower limit and it's basically impossible without 250MB or something.

Though judging by the way you asked the question, I can only assume that your knowledge of basic electronics, let alone digital logic or embedded software or computer architecture, is virtually nonexistent.
Ben Eater's Youtube channel is a reasonable way to get into digital electronics design.

>>1990420
a vibrator

>>1991571
that reminds me of my favorite image to troll /ohm/

>>1992012

I've been getting onto the arcade hobby, and I want to repair monitor chassis. Seems that they're definitely advanced, but not much in depth knowledge required.
For older boards, mostly discrete components like caps, resistors and some transistors. Newer models have digital ICs. Sometimes there are schematics, sometimes not. I can't follow them all that much either way.
Since most are minimum 20 years old anyway, it it worth just literally testing everything? Any tips or reading for testing aforementioned components? I'm a noob and only really change obviously bad components (scorched or leaky). Any way to know they're working without hooking up to a tube?

>>1990420
>>1991642
I'm not doubting you but what is the foil for exactly and what is the motor with the cylinder head? I googled the serial codes for the board and big cylinder thing LRF. The golden thing with the 2 leads is the remote or is it an insied component?

>>1991776
>>1991784
>>1991784
>>1991783
I want to switch a SIM7000a module on and off. It maxes at 3 amp 5v. I want to be able to turn it on and off using the digital io pin on an arduino.

Would this mosfet work for that? It looks a bit overkill.
https://www.sparkfun.com/products/10213
I would just need to put a small resistor between my arduino and it.

>>1992028
>It maxes at 3 amp 5v.
Ok, definitely not directly from an i/o pin.
The transistor you linked seems massively overkill.
You can buy capable transistors at a few cents on your local electronics store.

Trying to solder for the first time after watching some tutorials. My material doesn't melt like in the videos. It melts for a second then immediately shrinks and hardens.
Is the soldering irons max temp too cold or is the solder shit?

>>1992039
Solder really doesn't need to be molten for more than a fraction of a second. It sounds like you might be holding the iron to the solder not the component, so you end up with just a useless little ball of solder not stuck to anything.

>>1990338
I'm bored. Somebody ask me how my circuits work please.

>>1992044
how did you learn about electronics and making circuits? i know nothing

>>1992041
I tried holding it to the wire(trying to splice wires as practice) and the solder never melted so I tried to be direct and it did melt but turned into a ball. 15 minutes of trial and error with out getting any nearer.

>>1991783
I just have a standard cone tip - i'll look into that. I saw a video of someone connecting these, and going to try it their way. Basically the same, but no real attempt to get the wire far down into the tube.

>>1992047
I have a computer engineering degree so I knew the basics, but that's mostly digital electronics and programing. I wanted to get better at practical analog and have been teaching myself for five years. I found video synths were a good way to do it because I can really self-motivate with visual projects.

>>1992051
What's the wire like? You might be struggling because it's enamel coated, or because it's too think for the iron to heat up properly.

I got my $600 trumpbux in the mail and want to build an electronics lab. I have 300 more to go, does this look about right so far?

>>1992060
It's 3mm with the coating, the copper coloured wire is similar in thickness to small LED wires. I've exposed the wire, of course.

>>1992070
>conical tip
Get a screwdriver tip instead.
>that dmm
never heard of it, better be truerms
>solid core wire
get yellow too
>no scope
>no function generator
For a scope, you should consider looking about for 2nd hand (analog) scopes in your area. For a function generator, there are some reasonably cheap single-board MCU-based f-gens tout there. Might want to consider getting a cheap logic analyser too.

Also get some parts, like op-amps and comparators, grab-bag of resistors, ceramic and electrolytic caps.
Needle-nose pliers also, and/or tweezers (I like the 45° ones).

>>1992070
You can get higher quality parts for less money...hakko is good but for other benchtop tools I would look at ebay used auctions to score an analog scope, freq generator, and dc power supply. Depending on your area you could find quality scopes for $50 used, generators/power supplies around $80 each. Give or take an extra 20 for shipping but then you got something durable. Look at name brands like tektronix or hewlett or leader. It'll take some time but you don't need to source everything at once. Be smart about your spenditure

Get a nice pair of wire cutters and tweezers. Your flush cutters are ok. You'll want more than one breadboard, look at various sizes. Some can connect to each other via side tabs. Your hakko will come with a cleaning station so forget the tip cleaner. You also don't need a special tinner, you already have solder. Get some thick and thin lead rosin core solder, you don't want to waste time using thin solder for large plated holes and vice versa.

Reserve $100 for a nice fluke multimeter, then you won't need to replace it. Desoldering pump is garbage, get some thick solder wick and rosin flux in a can for all your desoldering needs. You can use the flux for soldering prep too. Flux pens are a personal preference thing.

Lastly are the multi use stuff which include solid core and stranded wire with various awg (20-22 is good for breadboarding), and all your components. I don't like component kits, however I do recommend you get a random variety of passives. You can get huge packs on aliexpress for cheap. While you're at it get a cheap saleae logic analyzer clone for digital purposes. For your actual components, make a schematic first then order the components you will use but order more than you will use to 1. have spares 2. pay less per unit and 3. build up to a collection. I also recommend a heat gun, heat shrink, and electrical tape.

>>1992051
Sounds like poor thermal conductivity. Make sure the wires are tightly wound together

>>1992027
>The golden thing with the 2 leads is the remote or is it an insied component?

already told you, it's a heating element. it provides gentle heat, a few watts, not vaping type heat.

>>1992044
I know for music synth, there are a bunch of common modules - vco, vcf, eg, lfo, vca
What are the most common modules for video synth? The bread and butter?
Also, do you ever use tempco or is heat drift a desired effect?

>>1992130
There's a VGA to NTSC/PAL converter chip that's really popular. When I look at other people's video synths it's usually that with VCOs,VCAs, etc feeding into it's RGB inputs. These are the same circuits used in analog audio but with opamps fast enough for video. Other people like making modules that deliberately corrupt video signals for glitch effects. Camera-TV feedback loops are also super popular.

>> do you ever use tempco or is heat drift a desired effect?
Heat drift isn't a big issue if you plan out your circuits well. It would be an issue if there were lots of free wheeling high frequency oscillators, but I have everything tied together in a way that keeps things synchronized to video frame rate and the color subcarrier.

>>1989950
in-circuit cap testing, can i use one those chink ebay thingies that work as lcr and esr and much more ?

Only kinda electronics related but I need a connector with at least 16 terminals and is really small, while being reasonably easy to source.
So far I've only found the Micro HDMI connector. Any suggestions?

>>1992141
>VGA to NTSC/PAL
Not him, but I bought some LM1881s, is that what you're talking about? For use with my oscope and its blanking input.
Something that actually converts RGB to cromacity or whatever it was called would be useful though, if I wanted to mess about with a proper color TV. Assuming it didn't have a VGA input.
>opamps fast enough for video
Any recs?
>I have everything tied together in a way that keeps things synchronized to video frame rate and the color subcarrier
Good idea on that front. Async circuits irk me.
>vid related
That sort of pattern looks to be created frame-by-frame, as opposed to line-by-line. Unless there's some funny non-integer clock division and/or LFSR shit going on there. How much of that is out of a video card/computer and how much of it is made from your effects racks?
Do you ever make actual framebuffers in RAM ICs or MCUs?

Also have you dabbled in any vector images? I've been wanting to make some form of vector display for a while now.

>>1992148
Maybe for an input filter cap, possibly for a bypass cap, but almost certainly not for a small-signal cap in a more complex topology. And you'll never be getting a good ESR reading. Out-of-circuit testing is the way to go unless you really can't avoid it.

>>1992169
What are you intending to connect?

>>1992175
Speaker drivers inside an IEM. Up to 6 of them so more like 12 terminals actually.
Space is very limited. Also I haven't thought of impedance, should be low as well.

>>1992178
USB Type C has enough conductors.

>>1992183
No it doesn't. Nevermind.

>>1991851
excuse me what?
NO. if the power sources are isolated from each other then nothing bad will happen, since pretty much all power sources contain diodes to prevent backfeeding

>>1992171
This is the NTSC to PAL converter chip I was talking about:
https://www.digikey.ca/en/products/detail/analog-devices-inc/AD725ARZ/699489

> That sort of pattern looks to be created frame-by-frame
It was created by pointing a camera at a TV with a video synth adding patterns in between.

> Also have you dabbled in any vector images?
Yes. Any random sine waves into a vectorscope makes a pretty spirograph pattern so I got bored of it quickly. Color raster video is a lot more technically challenging. I did build this entirely analog vector to raster converter. It's low res but a working proof of concept.

>>1992188
>AD725
saved (;
>pointing a camera at a TV with a video synth
I see, so those patterns are the kinda weird shit you can get with a time delay. I wonder how fast these BBDs of mine will run...
>random sine waves into a vectorscope
I was thinking more along the lines of plotting out a series of X-Y points and having the thing trace lines through them. Pretty sure some sort of "2-channel voltage sequencer", something that switches through a series of potentiometer voltage pairs, would do the points, and a low-pass filter after it would draw lines (or curves) between the points to some approximation. Maybe with some more work it would be possible to draw smooth lines between each coordinate.
>entirely analog vector to raster converter
Now THAT is interesting. Low resolution means low temporal resolution, right? Since spacial resolution is analog, at least in the X direction. I've no clue where to start with something like that, would you mind parting with a block diagram or circuit diagram or whatever you've got lying about? I would want to make something with comparable resolution to a thin scope trace, not that I'd know how such a vector trace would look on a color CRT.

>>1992028
> I would just need to put a small resistor between my arduino and it.
Er, no. You can't put the FET on the low side to switch power. And if you put it on the high side, the source pin will be at 5V and the gate will need to be several volts above that (i.e. you need a level shifter and a voltage multiplier). You could use a p-type FET, but they're a lot less common, particularly for logic-level (i.e. |Vgs_thresh|<5V).

Use a relay.

>>1992210
>You can't put the FET on the low side to switch power
There is literally nothing wrong with that
>level shifter
Actually not entirely out of the question, if the leakage current is low enough you could arguably use a common single-capacitor boostrap. I wouldn't though.
>You could use a p-type FET, but they're a lot less common, particularly for logic-level
If even a single fitting such transistor can be ordered on digikey, then it doesn't matter how common it is. Heck, daeev probably has part recs in his video: >>1991788.
>relay
poopoo quiescent current, unless it's latching, which are even rarer than logic-level pfets

I wanted to add an antenna to a project. I was going to get the traditional collapsible one because I thought it would have a better range but I also see the stubby black ones that are more common now. Has anyone found the black ones to fare better?

>>1992221
Antennae length is chosen based on the wavelength of the signals they receive. You don't just pick it at random and hope for the best.

>>1992225
I stick my finger in the coax socket and pick up FM

>>1992225
I should have clarified that I meant radio waves. Commercial RF must have a degree of leniency given that many radios had collapsible antennas. I guess the stubby ones are used for other wavelengths so I'll go with the former.

How do I build 128mb of ram for my fpga

>>1992250
Very carefully.

>>1992250
rectangle

>>1992250
you need like 128 mini ferrite beads then you got a weave wire through all of them like a grid and then have another line for read and it is destructive memory so accessing it erases it when its read. not suggested for ram but you wana build some shit and nobody here can give you a circuit diagram for modern ram so you gotta use antiquated tech like 1970s destructive ram

>>1992273
>>1992264
>>1992262
Why are you guys like this
I just want to play neo geo games... Someone told me I could build the ram

>>1992283
iirc you don't want much ram on your fpga, it's a waste of space. You'd want to store it on an external chip
I just made that up though

>>1992283
Dodge builds the Ram.

Hi I wasn't able to fly my rc planes for a while due to corona and I forgot to recharge them and now they are 0.1-0.4v under voltage.
Now my charger doesn't want to charge them it just says ''low voltage''. Can I revive them or did I just kill 100$ in battery's

>>1992273
>ferrite beads

this is not as far-fetched as it sounds. in the 80's i built a 128Meg upgrade to my TRS-80 coco using bubble memory.

"Sharp used bubble memory in their PC 5000 series, a laptop-like portable computer from 1983. Nicolet used bubble memory modules for saving waveforms in their Model 3091 oscilloscope, as did HP who offered a $1595 bubble memory option that extended the memory on their model 3561A digital signal analyzer. GRiD Systems Corporation used it in their early laptops."

>>1992315

what you wanna do is give it a bit of juice from a non-intelligent charger to get it up a few tenths of a volt, then finish charging using smart charger.

if you have a current-limited supply, use that, or just a series resistor and a multimeter to measure current. just maybe 100mA so you dont wreck anything.

>>1992316
Can you explain how bubble memory works to an idiot? I tried to figure it out once but was lost. I understand it's sort of like a hard disk or VHS tape, but it's not physically moving; the magnetic bits are being pushed around solid material by other electromagnets somehow.

>>1992324

i'd be more than glad to explain; it works like this: https://en.wikipedia.org/wiki/Bubble_memory

>>1992323
Ok the only other charger I have is a airsoft ni-mh charger, is it ok to use it on a lithium battery or is it a no-go?

>>1992332
srry forgot pic, I don't have any resistors laying around but 250mah is still pretty low

>>1992326
>>1992328
Talk about tripping over yourselves.

>>1992333

nah, too much voltage. if you dont have a resistor, find something that does the same job. i just pulled a 10W 120V bulb, like an xmas bulb, and it measures 131 ohms. that would limit current to around 36mA which is super safe.

>>1992332
>is it ok to use it on a lithium battery
No, it's not ok. You can make your own battery packs with single 18650 cells and a spot welder built from a microwave oven transformer. Got any old laptop battery packs?

>>1992335
What is the maximum voltage I can put on a 4s?

>>1992337
I need these light 100g battery's so my planes fly 110+km/ph. with a homemade 18650 pack it would weight 180g and my speed would be 60-80km/ph.

>>1992342
>a 4s?

oh, it'a a 4S. that's 14.8V - 16.8V, so your 8.4V charger aint gonna cut it. you'd need, say, a 19V laptop charger and a 25W 120V light bulb in series.

>>1992342
>I need these light 100g battery's
Would 14650s do the job?

>>1992348
*14500

>>1992044
How good do opamps need to be to work for this? From what I can tell you usually need up to 6MHz of bandwidth for video signals. Would the ne5532 work? What parameters do you use to judge whether or not an opamp will work for video synthesis?

>>1992328
>i'd be more than glad to explain

Additional information you might find interesting.

>>1992044
>>1992352
Also, where did you find information about video synthesis directly? Are there any good textbooks that go over common circuits and how they function?

>>1992352
>Would the ne5532 work?

ever heard of datasheets?
"The NE5532, NE5532A, SA5532, and SA5532A devices have a 10-MHz unity-gain bandwidth."

so, at 6 Mhz, it can provide at most a gain of less than two.

>good textbooks that go over common circuits and how they function?

there's less than 72 people in the entire planet interested in this topic. so no textbooks. you gotta figure it all out using your headbone.

>>1992332
>>1992333
>>1992335

another tactic that should work: instead of using a dumb charger, tell your smart charger that you're actually charging 14 series ni-mhs, and limit current to 100mA. that should boost the voltage and get you past the Low Voltage warning so you charge as normal.

>>1992364
thank you, this saved me some time instead of putting a light bulb in series with my laptop charger.

>>1992349
Oh thx I did not know they made high-drain lithium battery's this small size

>>1992352
I've been using TL974s. They're really cheap for how fast they are. However they have this oddity where the output is rail-to-rail, but the inputs can't be within 0.7v of the rails. When using audio OP-amps like LM324s you'll see big distortions on even simple things like a ramp wave across a scanline. Trying to handle the 3.57MHz chroma subcarrier is completely impossible.

>>1992355
This is the best website I know of for explaining how analog composite video signals work.

https://www.maximintegrated.com/en/design/technical-documents/tutorials/7/734.html

I started out doing microcontroller projects with pixely video outputs. There are many example projects like that online. Once I understood how the signals worked I started figuring out how to make patterns with analog circuits instead of code. There isn't a book or tutorial for that. Once you know what analog circuits do on a scope and understand how that translates to a TV screen you can do some interesting stuff.

>>1992371
They come in many sizes. For example, a 18650 cell is 18mm in diameter and 65mm tall.

>>1992022
Check out these channels. Plenty of examples to learn from.

>Joe's Classic Arcade Games
https://www.youtube.com/user/LyonsArcade/videos

>Arcade Jason
https://www.youtube.com/channel/UCODLTJtRV-jYvmTx9YScCVQ/videos

I can't be this stupid
>Buy Radio Shack LEDs a decade ago
>Open them up today for lulz
>None of them work
>in before voltage
I tried on the rated C batteries and AA batteries (1.8V), and tried 4v out of desperation.
Could they actually all be bad?

>>1992461
>9800mAh
>No resistor
>"Why does my LED not work?"

I have a 100 amp panel that keeps tripping. I literally just need 20 more amps or something without buying a new panel?

Can't I just upgrade the main breaker or something?

What do?

>>1992461
you need to put a 50-80 ohm resistor in series or they fry instantly

>>1992461
You may have them connected backwards

I had an idea for a digitally selectable component bank so that you can get a near-arbitrary component value by combining a bunch of different components in parallel or series. I've used resistors in the drawing, but I want it to work with capacitors and inductors as well. (this is supposed to be for a digitally tuneable radio antenna so I can change the resonant frequency without needing a variable capacitor)

Working out the design, it looks like I'm going to need a shitload of select pins. I don't think multiplexing would work (unless I attach some sort of hysteresis/capacitance to the gates) since that would essentially just be a variable load as the transistors turn on/off, which would fuck with the radio application.
And that's just for the serial transistor select. I still need to figure out how to combine the parallel and serial circuits so it's just one circuit with parallel/serial being selectable via another set of transistors (even more select pins)

does anyone more experienced than me have any insights into what I can do? Improvements?

Does this look like a particular existing tube type?

>>1992490
Your schematic resembled a digital to analog converter which is already a thing.

>Digitally tuneable radio antenna
Use a RC filter except the R is an OTA with a configurable Ibias.

>>1992490
Fine tuning, or multiple bands?

>>1992462
>>1992483
Why do we still get these questions lmao this is like LEDs 101

>>1992490
It's called a decade box. Maybe a CPLD would fit here.

>>1992505
Ideally both, I could just have a component bank for gross tuning between different bands, and a second fine-tuning bank

>>1992500
The antenna I plan on using uses an LC filter (tuned LC loop antenna). Maybe I can use one of those goofy op-amps-as-an-inductor circuits. I still want to pursue this idea though.

>>1992510
the idea is to use some kind of FPGA or RAM/EEPROM as the interstitial logic

>>1992462
>>1992483
Even with a AAA battery? That's what I used first

>>1992514
I believe that LC is better than RC when it comes to more powerful signals but I don't know what sort of power a radio signal has given the distance they travel.

>>1992516
Yeah. You're sending too much current through the LED. Even basic LED tutorials throw a resistor on the LED to limit current.

>need humidity to be accurate to +/- 3%
Anyone know if I can find any decent sensors for arduino that will match this and actually be accurate.

Dht11 was like 30% off

>>1992524
Go on a parts supply site and filter. Otherwise, apply statistical methods to your data (averaging, standard deviation etc.).

>>1992230
what frequency radio waves

>>1992250
Find a 128MB RAM IC that's fast enough, or maybe use a computer RAM stick and see if you can interface with it.

>>1992250
https://www.mouser.com/Semiconductors/Memory-ICs/SRAM/_/N-4bzpt?P=1z0sr05

I have an old mp3 player that the lithium ion battery has gone in. It has a weird proprietary battery pack, but I took it apart and it is just a lithium ion battery with a control board soldered on. Do i just need to match the voltage for a replacement cell? Will this experiment burn down the neighborhood?

>>1992555
Yes, match the voltage.

>>1992558
Is that all though? Like are there other parameters that I need to match for it to charge properly?

>>1992345
>oh, it'a a 4S. that's 14.8V - 16.8V, so your 8.4V charger aint gonna cut it
Depends on what the current voltage is and when the B6AC will accept it.

>>1992354
that's meant to be utter bullshit, right?

>>1992490
Interesting design, but I suspect an R2R ladder is superior. Also there'd be current from the blue path flowing into the 2k resistor to the red path.
A simple parallel array of capacitors with JFETs on each one should work for a selectable capacitor bank.

>>1992500
It's often best to have the tuned circuit (LC circuit) before the input amplifier, otherwise you might get clipping distortion from an unwanted signal that's more powerful than your desired signal. I'd use a varactor-based tuned circuit.

>>1992516
A yellow LED is ~2V. Any lower than that it won't turn on at all, which is the case with a 1.5V AAA. Much more than 20mA and they die after a short while, though they're visible at below 1mA. A lithium ion battery has a voltage high enough that it will just shove as much current as it wants through the LED, overheating the die immediately. Arguably you'd be fine with two AAAs in series, as their ESR can be high enough that the current won't exceed 20mA. If they're shitty AAAs.
But you should use resistors instead.

>>1992562
Make sure you charge it under the right lunar phase. I remember that time my high voltage capacitor blew under a gibbous.

>>1992562
You don't want to put a novelty-size battery on it because it will take forever to charge, but it won't explode or anything.

>>1983954
The thing that makes me anxious is, I read that low ESR decoupling caps can cause linear voltage regulators to oscillate, so the "bad" electrolytics are actually recommended sometimes, or at least used to be. There's also the non-linearity where capacitance drops when a DC bias is applied.
But I suppose I could add a small resistance of a few ohms in series with the ceramic caps to make sure the oscillation problem doesn't happen

>>1992578
>the non-linearity where capacitance drops when a DC bias is applied
I should clarify that this refers to the cheap, high-C ceramics, of course

If you had some magical 3D printer that could print motors that aren't limited by current manufacturing processes, is there anything you would change about the shape of the windings or the motor itself to improve performance?

>>1992589
http://www.superpower-inc.com/content/hts-motors-and-generators

>>1992592
I meant more about the way they're designed, as opposed to the materials. What's the optimal shape for a motor?

>>1992601
It depends on what kind of work the motor is supposed to do. Sometimes you want high speed, other times high torque. Maybe you want the precision of a stepper motor. Probably a better question for a mechanical engineer.

>>1992563
>that's meant to be utter bullshit, right?

Nope. The rest of the book is 100% serious. The part where a diode turns into an integrated circuit had me in tears when I first read it.

I'm trying to repair a flashlight (Stanley sl3hs), so I took it apart and inside was a 18650 showing nearly 0 volts, so I replaced it with a different 18650 (this one is also old, had 2.3V), which briefly let me turn on the light but it went out. I tried letting it charge but the voltage only went down by about 20mV in half an hour, even though the light was off.

Now my question is, could this be a battery issue, or did something go wrong in the circuit? There's obviously some parasitic drain but it seems very large, and I'm not sure what to check.

Do you guys know if there is an IC that could generate PWM square wave at about 100-500 KHz and you can adjust the pulse width?

>>1992631
forget where I saw it, but there's a high speed 555 out there. Like a 9555 or some other derivative name

>>1992631
ATtiny is good for this kind of thing.

>>1992631
ah, here it is. ICM7555, LMC555 go to 500kHz and 3MHz respectively. No idea what they cost.

>>1992638
>ATTiny
Which ATTiny?

>>1992640
>ICM7555
>LMC555
holy crap, these are under 2$ each. Which do you think is better?

>>1992646
ATTiny45/85 will do fine. I'm sure you could get away with something smaller, but 45/85 is versatile and example code is easy to find for countless projects.

>>1992654
>ATTiny45/85
I'll also look into those as well as the CMOS 555s

I'm having a bit of a blonde moment. If I have two inputs that each go through a potentiometer and resistor into a common line:
>inA ->10k pot -> 10k resistor ->out <-10k resistor <-10k pot <- inB
then I can just remove one of the resistors, right?
>inA -> 10K pot -> x <- 10k pot <- inB; x->10k resistor - >out
They're all feeding into a summing op amp so I don't need to worry about interference.

>>1992354
>>1992623
>germanium crystal
>the same crystal was used to produce the silicon chip, or microprocessor
>was a few mm square, with hundreds of thousands of magnetic "bubbles"
It's absolutely awful. I assume the image is in that format due to someone in the past taking the piss? Or did you find it?

>>1992692
Draw a diagram. What are the resistors even for when you have potentiometers?

>>1992696
Two input signals with pots acting as attenuators. I feel like I can just have both feed into the one 10k resistor rather than two separate resistors but I wanted to double check before I soldered it on the stripboard.

>>1992713
So the resistors are just a minimum resistance stop for the pots? Then yeah you could have the two pots go together then have the resistance after that. Not that I understand why you're adding 12V to your signal.

>>1992718
Both feed into a transimpedance converter which provides a current source for an OTA-based amplifier. The 12V is a base voltage that can be manipulated to provide a base voltage level. The external voltage signal can be used to modulate the voltage on top of the baseline.

But thanks, I was running low on 10K resistors and eliminating one will help until I get more delivered.

Looking for the VU meters symbol on this. they dont function anymore and I need to trace it back to see where the problem lies. its an early 70s receiver, should be two of them somewhere

>>1992496
looks like a typical vacuum tube from a tube amp, but the base doesn't look standard

>>1992763
I want to punch your schematic in the balls.

>>1992763
VU1 and VU2, right hand side, down and to the left of T15/T16, which in turn are to the left of the Ext.Sp. and Line Out sockets (J7/J8/J9/J10).

>>1992855
its a shitty schematic but a nice early 70s all wood/metal receiver. the VUs used to work fine until i had it off for a year or two and now they dont register at all

>>1992857
thanks. i assume the VUs receive all audio (FM,tape,phono etc) passing through it?

>>1992713

having series resistors acts as a safety. if, for example, both pots are at the leftmost position, then you have 12V going directly into your input jack without anything to limit current.

>>1992862
also interesting that Line out and the ext sps are both passed through the EQ and VOL. On this unit the ext sp outs are 1/8" phone jacks while the line out is rca. but running line out is still controlled by the volume and treble/bass sliders

>>1992763
>>1992857
this unit is a clusterfuck inside with no clearance for anything i might just cut my losses on the VUs, any advice for what on the chain could be causing the VUs to not work?

My led monitor won't turn on. Before I disconnected it or a blackout happened and there was no sleep led, then i switched cables and I got sleep led indicator back and it would function. Another blackout / I hit the surge protector switch I one again switched cabled and to get to turn on. Eventually It didn't work and I waited and it worked. Now it won't work. I opened it up, and none the caps look fucked and nothing looks burnt. What are the options.

>>1992922

looks like the meters are driven by the external speaker-out signal, just rectified by a diode each. not much can go wrong: diode dead or meter needle stuck.

since you have access to the speaker-out signal, you can bypass the internal circuitry and wire your own diode/meter combo. (or replace VUs with digital equivalent, if you're keen)

>>1992962

you keep talking about switching cables and it coming back from the dead. i dunno what cable you're talking about, but there's certainly a possibility that the connector in question is loose or dirty.

and you're no TV technician, so that's pretty much the only level of repair you're suited to diagnose.

>>1992737
>The 12V is a base voltage that can be manipulated to provide a base voltage level
Sounds like you might be better off with something like this:

With your circuit, the amplitude of the signal would change as a function of the DC bias. Though I don't know how a transimpedance converter works.

>>1992763
>>1992922
Could be VR5/VR6, if they're manually adjustable from the outside its possible that their tracks got worn down, or have dust or oil or something stuck in them. D13/D14, since they're old-timey germanium diodes, coulda cooked. Should be fine to replace them with schottkys, though I'd look in-depth to see if others are doing the same. I'd also scour the circuit for other germanium diodes, I think they have somewhat of a tendency of not lasting too long.
If you are testing those parts anyhow, might as well measure continuity on the VU meters.

>>1992962
Check for a blown fuse, MOV, suppression-cap, etc. Ceramic fuses look identical whether they're blown or not, so measure the things.

>>1992962
mostly caps, check them one by one, could also be diode, MOV, or fuse

Noob here. Why doesn't this light up when I touch both wires to the part that has a + and - on it? I connected 4 button batteries, each are 3v and the LED requires 12v. There's a dimmer(not sure what it's called) inbetween.
I also tried connecting an old car door light bulb and it didn't light up. I added a fifth battery now but that didn't change anything.

>>1993204
I can barely make out your circuit. Are your batteries new? Get a multimeter and see the voltage output.

>>1993204
>inb4 you are connecting it backwards

>>1993212
I don't have that stuff. It's a set of batteries, wire, led, wire, dimmer, wire to battery. That order.

>>1993218
It takes like 2 seconds to switch them around. I'm holding the wires and just touching the exposed metal part.

>>1993204

the leds will work from 12V directly, so remove the dimmer as one potential source of problems.

no voltmeter? no problem: touch wires to your tongue to test if you get a good strong tingle.

should be obvious, but are you touching the 2 contacts at either end, or one wire at each end? the first way is the right way.

forget about car lamps, they need like 50 times more current than those tiny batteries can provide.

>>1993223
4 batteries in series = 4*3v = 12v. If a battery is old, then 3*3v + 2.2v !=12. Basic fucking math.

>>1993223
>>1993226
Also, 4 batteries in series with xmAh each will output xmAh; 4 in parallel output 4xmAh.

>>1993225
I'll remove the dimmer and test it.
I'm touching the 2 that are right next to each other.

>>1993226
>>1993228
Can I add more batteries without destroying the LED?

>>1993230
>Can I add more batteries without destroying the LED?

those tiny batteries have a very high internal resistance. no way can they hurt your LEDs coz they put out such little current. put as many as you want in series.

>>1993230
Depends on how much current the LEDs take. If you have 8 3.3v then wire up two parallel stacks of four batteries wired in series.

https://www.instructables.com/How-to-Wire-Batteries-in-Series-or-in-Parallel/

>>1993225
Didn't work. I'm now connecting directly to an individual LED.

>>1993232
Alright. I'm going to try 7.

>>1993236
They're standard LED strips. They're all facing the same direction so that would be a series, right?

>>1993243
The batteries were too weak. I have 30v worth of batteries now and I can only get 1 LED to light up.
Thanks lads.

Can you guys identify this connector on a L shaped USB type c cable? It’s the first time i see it and i wonder if it’s a cable I should avoid. It comes with a keyboard I want to buy

>>1993281
Also do you guys know any method or software I can use to check the polling rate of a keyboard?

>>1992555
Nice trips sam

if i have linear regulator that is fixed at 3.3V with 1.2V voltage drop and i supply say only 3.5V to it will i get nothing on the output or 2.1V?

>>1993333
You need input voltage to be above a certain threshold for the regulator. Check the datasheet for specifics, but assume 4.5-5V minimum for stable 3.3V output from the regulator.

>>1993335
i don't really need stable 3.3, i am fine with less i am just wondering if the supply voltage is less than the ldo regulator (ams1777) needs to output 3.3, if it will simply malfunction and give me nothing or if it will give me
3v3 minus whatever voltage below the minimum supply voltage needed for 3v3 i am supplying

>>1993337
It depends on the type of regulator. Some won't give any output at all, some will output unstable voltage, some will overheat from oscillation.

>>1993337
One way to find out, eh?

>>1993281
>>1993282
ask /g/
also it doesn't look common or easy to replace, so I'd avoid it

>>1993281
It's a proprietary USB cable.

I feel like a retard right now
what do they mean by a "FET Switch" in this context? Like, what would I be wiring things up to?

Does the reference signal go to the gate? Is the RC lowpass side the source side of the N-channel Mosfet? What would I be wiring to the other side then?

>>1994051
They're talking about an analog switch IC. For example a CD4051. The reference signal controls which position the switch is in. You can built these with discrete FETs but it's a lot trickier.

>>1994051
That's a really weird way to make a phase detector. Normally you'd run the input and reference into a XOR gate and lowpass the output. I don't see any advantage to the way this one works.

>>1994080
it came directly from The Holy Book TAoE itself, I'm just trying to figure out how to implement it in falstad before I breadboard it myself.

Do you have an example schematic for the kind you're describing?

Also, is a phase detector the same thing as a phase comparator? It sounds like it

>>1994080
XOR phase detectors are not used in practice. Only in textbooks. Actual phase detectors like you find in PLLs use analog multipliers.

>>1994150
Do you have any idea how expensive analog multiplier chips are? For consumer electronics applications where you need to phase lock or decode phase modulation everybody uses a XOR gate or a slightly more complicated circuit that goes to push,pull,Hi-Z based on the phase difference. Look at the phase comparator circuits in a CD4046.

man I just want to build baby's first phase locked loop

>>1991241
I took apart the second vacuum and this is the motor. Not sure which is better to use. >>1991302
How do I hook it up without killing myself? Do I just wear rubber gloves? Also, does it need a capicitor to start? I remember seeing something like that was needed for certain motors. My end goal is to either create an exhaust system or some sort of respiratory gear to mitigate the affects from welding fumes.
I'm from Aus, apparently we have more power in out home outlets. Not sure if that matters.

>>1994181
>Do I just wear rubber gloves?

yes, if you're stimulating your prostate. no if you're wiring a motor.
you assemble it while unpowered, then move away, shield eyes, crouch, so your crotch is protected, then plug in the power cord.

>Also, does it need a capicitor to start?

first rule of intelligent tinkering is you disconnect things as necessary to remove from the case, but make note of how things are wired so that you can then reconnect everything as it was originally. doing it this way means never having to ask clueless questions on the internet.

>>1994167
>Do you have any idea how expensive analog multiplier chips are
Well they're not that expensive, but they're not that good either. A pair of ring modulators should work for most RF stuff. The bigger hurdle is requiring basically perfectly sinusoidal inputs for both signals, and the result still has some of the issues of an XOR solution.
>or a slightly more complicated circuit that goes to push,pull,Hi-Z based on the phase difference
It's more complicated than that, they use "phase frequency detectors". A standard XOR phase detector can lock on harmonics, to get more range than f-2f (in practice more like f-1.5f) you need something that actively pulls the feedback voltage as a function of frequency, as well as phase. It's what the 4046's 2nd phase comparator does.

On that note, can anyone tell me how the fuck to do this? Best I've come up with is a standard phase comparator, with a synchronous envelope follower after the low-pass just to keep things as flat as possible. Then I have the two signals also go into low-pass filters, then into envelope followers, then into log amplifiers, then both into one differential amplifier, which turns on a PNP or NPN transistor on either side of the envelope follower's output if the frequency difference is too great. Tuning it would be a bitch, but I'm pretty sure it would function. Still, sounds rather shit compared to something using a digital method with FFs or counters or shift registers or whatever.

>>1994173
An NE555 astable oscillator makes a passable VCO, the uneven duty-cycle isn't an issue. XOR + LPF makes an acceptable phase comparator, but don't expect it to lock properly outside 1.5 times the VCO's base frequency. It's fun to watch it lock onto harmonics or fail to lock properly at all. I made a blog post about PLLs and that circuit if you're interested in more.

>>1994181
It's brushed, no cap needed but I wound't be surprised if there's a suppression cap across the windings.

>>1994215
Alright, thanks. There's a small capicitor in the pcb so I thought it could be for starting up the motor.

>>1994167
>do you have any idea how expensive analog multiplers are
Yes. Good thing PLLs have the analog multipliers built into the IC instead of needing to build them with discrete external Analog Devices ICs.

>CD4046
wow a cheap as shit PLL that can only multiply up to 20-30MHz uses XOR phase detectors. Color me shocked.
If you knew anything about electronics you'd realize good PLLs used in RF and instrumentation like spectrum analyzers doesn't use XOR phase detectors.

>>1992631
Setting arbitrary pwm frequencies on an attiny requires modifying the timer registers yourself. If you don't want to deal with that, I suggest getting a teensy. You'll save yourself a lot of time.

>>1994221
>instrumentation like spectrum analyzers doesn't use XOR phase detectors.

I specifically said consumer electronics frequently use XOR phase comparators. This was in response to whoever incorrectly said that's only used in textbooks not real life. Your expensive lab equipment is one of very few places you'll find phase detection done with analog multipliers.

>>1994215
>sounds rather shit compared to something using a digital method with FFs or counters or shift registers or whatever.

This approach causes too much jitter for most applications. The frequency output of a digital counter can only be integer divisions of its source clock. To stay phase locked to some external frequency it needs to jump back and forth between the two frequencies it can do on either side of it.

>>1994221
>PLLs have the analog multipliers built into the IC
Sorry, but where are the monolithic PLL ICs you're referring to? Besides the CD4046 there's like 1 or 2 others I've seen, with similar specs. For actual professional use, I'm pretty sure people use individual phase comparators and VCOs, be they made from just one IC each or made from a bunch of discrete components.
In the case of a monolithic FM radio receiver IC, they almost certainly use a digital phase-frequency detector.

>>1994241
>To stay phase locked to some external frequency it needs to jump back and forth between the two frequencies it can do on either side of it
The input to the VCO is always going to be an analog value. The output of a digital circuit fulfilling such a role will output PWM that guides the VCO to the correct output. Regardless of the frequency of the PWM signal, with a low-pass filter and a synchronous envelope follower, and maybe some extra filtration afterwards, the output should be more than smooth enough for most cases. If the frequency jumps about too much even then, you can just set the VCO to ~16 times the desired output frequency and divide away those irregularities, assuming you're not up against some semiconductor frequency limitations.

Resources on using OLEDs and other display tech? And Cameras?

>>1994245
i just hope that adafruit or hackaday has an article on whatever part i'm using

>>1989834
>12 dollars for a battery
>https://www.adafruit.com/product/2011

the same type of battery is $10 on ebay/amazon/etc and with ada I don't have as much housefire risk

their shipping cost is insane though, so I was thinking I'd make up for it by buying a couple and adding some extras I've been needing like heatshrink

Newbie here. How difficult would it be to add a headphone out to one of these?

>>1994268
Does it already have a speaker? If so, not hard.

>>1994270
Yeah it does, a small one so I could run it through an amp afterwards to boost it. Thanks anon. Will purchase and fuck around with it

>>1994302
A circuit capable of driving a small speaker is already more than powerful enough for headphones. If anything you're going to need to put a resistor in series to reduce the amplitude.

>>1994268
>>1994270
>>1994302
>>1994309

I had one of those, it doesn't have a speaker, its a piezo buzzer. It doesn't make sound that can be run straight to headphones.

>>1994324
Only if it's an active buzzer. A passive buzzer still receives an oscillating signal. The only way to find out would be to test.

>>1994324
>>1994330
Interesting. I'll buy one and take it apart and see what I can do with it. Its for music production so either way it'll be good to know. Thanks for the insight guys.

>>1994227
>I suggest getting a teensy
Teensy is strangely expensive in my cunt, I'll go for STM32 if I have to go for large uC route.

Hi. Noob here.

Looking to build a PoE PCB. Am quite new to embedded - have fucked around with communications including ethernet a little bit. I'm basically looking for a PoE block diagram to copy and learn from but everything I find is either too specific or generally questionable. I don't really mind the PHY chip used. I'm working with a PIC MCU right now. If anyone could point me in the right direction it would be greatly appreciated.

>>1994580
PoE is usually 24 or 48VDC, you need a proper power supply to step that down to logic level. You might be able to find dedicated 48V-5V or whatever solder-in modules, which would make your life easier. I’d recommend feeding the switching output through a linear regulator though, for ripple rejection purposes.

Then there’s the matter of data transfer over Ethernet, which is a rabbit hole in itself.

>>1994580
Have a look at some of what TI has to offer:
https://www.ti.com/power-management/power-over-ethernet-poe/powered-devices/products.html
Even if you don't use any of these chips, the datasheets will give you a lot of good information.

i'll ask here i guess since apparently they don't know shit in /rcg/
>>>1994594
would this work? if not why

>>1994884
You need a way to manipulate flight control surfaces (ailerons, elevator, rudder, etc.) which the drone's flight controller isn't set up to do. You'd need to modify the drone's firmware or build your own flight controller.

>>1994899
I didn't think of that
would you consider modifying the firmware beginner friendly?

>>1994913
Not at all beginner friendly. That doesn't mean you shouldn't try, but it's gonna take real effort and a lot of time.

>>1994922
i'll give it a try, thanks for answering

>>1994927
YW. Good luck!

>>1994913
>>1994884
Now sure what kinds of motors the drone uses but you could try building your own flight controller using a small controller like an arduino nano or pi zero
Still not super easy but I think that would be more beginner friendly than modifying the existing control circuitry. Plus you could customize it more if you were to add extra features

>>1994884
>>1994899
Well, it would be pretty shitty, but arguably you could mount the drone motors in a similar configuration, e.g. one above each wing and one below each wing, but pointing forwards. That would give you rudimentary pitch,yaw,roll control without needing servos. Might even be able to use the stock flight controller too, assuming it’s not trying to use altitude or an accelerometer or magnetometer or whatever as feedback. Accelerometer might still work if tipped 90 degrees, maybe.

As for “I’ve got 4 motors, some servos, a plane body, but no controller or FC”, that’s a question that rcg should be most suited to answering.

>>1994783
>>1994800

thank you

>ordered three lots of modules from the same store on ali
>one on 11.11
>one a week after
>a third a week after that
>the third lot just arrived now
>the other two are still in transit
wew, got my stlink before my bluepill
also got some polyimide tape, a DAC, those blue usb cables, and a BT5.0 receiver board with integrated amp

>>1995060
Based and stm32pilled.
>bluepill
Not black pill? Unironically?
>a DAC
Which?

>>1995060
>mfw the tape says "Koptan"

>>1995090
>Not black pill? Unironically?
I still don't know the difference, what I ordered was titled:
>STM32F103C8T6 ARM STM32 Minimum System Development Board Module
No mention of either "pill". I ordered "green jade" colour, which I suspect will be blue, though maybe it's black and the "khaki" is blue.
Are there differences in STM32 boards I should worry about? Besides the whole counterfeit chip thing that I'm probably buying into.
>Which?
MCP4725. 12 bits, I2C, 0V-5V range, 2µs/V. Hopefully I'll use it with an MCU of some sort alongside my spare ADS1115 for audio DSP. Hope they'll all run on the same voltage.

>>1995106
>>STM32F103C8T6 ARM STM32 Minimum System Development Board Module
https://stm32-base.org/boards/STM32F103C8T6-Blue-Pill
https://stm32-base.org/boards/STM32F103C8T6-Black-Pill
The pinouts are different and you should be able to tell which one you have.
Other than that, you'll find that the differences are minimal.

>>1995106
>Besides the whole counterfeit chip thing that I'm probably buying into.
Try the Blinky test from GreaseWeazle
https://github.com/keirf/Greaseweazle/wiki/STM32-Fakes
I hope you're fine.
My blackpill (bought from link) passes blinky: https://www.aliexpress.com/item/4000103610226.html
>MPC...
If it's actual Microchip, it'll be fine and easy to work with. That's the deal with Microchip.
The sole exception I am aware of is the PIC family, which is obsolete or worse than the alternatives, and should be generally avoided.

>>1995112
>Try the Blinky test from GreaseWeazle
I planned on doing this, but I was just assuming it will be a counterfeit, I heard that most of the F103s on ali are. IIRC they function the same for 90% of what I'll ever do, though the more nuanced USB shit might be an issue. DIY USB peripherals are cool shit, I want to see more projects with them. Considering some people actually buy $20 preprogrammed PIC24s for their joysticks instead of getting a badusb or memepill.

>If it's actual Microchip, it'll be fine and easy to work with. That's the deal with Microchip
I hope so. The glitch ripple is a little alarming though, 50LSBs at the most. I want to look into designing a resistor ladder DAC that works off Gray code instead of linear binary, but I'm pretty sure it will either be a massive pain with different resistances and a bunch of reference voltages, or just not work at all.

>>1995109
>he doesn't just buy a slightly more expensive but superior F411 instead
cringe and bluepilled

>>1995142
Being devboard Anon, I have F411, and also L052.

I'm ultra retarded and neither googling nor books help. How do I know how to connect power source with schematics like pic related? Okay, grounds go to -, but where to hook up +?

>>1995142
>>1995145
Is there an easy to digest summary of the differences between the common STM32s? I care more about added/improved features like onboard timers and USBs and I2C channels, and DAC/ADC resolutions, as opposed to things like RAM and PROGMEM and EEPROM space. They're already large enough for basically embedded project I could think of.

>>1995166
Op-amp circuits like this are designed for a split-supply. i.e. GND is halfway between V+ and V-, which go to the op-amp's Vcc/+ and Vee/- pins respectively. Commonly used is ±12V, though ±5V or even ±2.5V could work (used by some synth racks apparently). You can either make a split-rail ground by connecting a unity-gain-buffer op-amp circuit to a 10k/10k voltage divider (should be self explanatory) maybe with some capacitors, or you could replace resistors to GND with a resistor to V+ and V- each. Capacitors can just go to V- or V+ without too much worry, they block DC after all.

For an example, compare the common "comparator oscillator" circuit's split-supply and single-supply variants. Note that in single-supply circuits, the GND symbol means V- more than it does any kind of signal GND.

>>1995166
>neither googling nor books help.

you're a bad, bad googler. a few minutes after searching '' op-amp coolbook'' you'll realize that 90% of op-amp circuits are wired thusly.

pic from https://www.nutsvolts.com/magazine/article/op-amp-cookbook

how do i solder this shit?
leg by leg manually, or should i try my luck with a heat gun?
i purchased a cheapo hot air station but i am too scared to use it because i know i will just desolder and blow away everything around the chip footprint while soldering it

>>1995247
It's easier than you're making it out to be. Use flux and keep a desoldering wick handy. Line up the chip legs with the pads on the board and tack one in place, then solder the rest.

>>1995247

if only there existed a web site with over a billion how-to-solder-SMD videos.
we might call it youtube, if it existed.

>>1995267
would make more sense to call it smdtube then

>>1995247
Like a man

How far can I get cobbling together reference designs?

I'm sort of confused about connecting this PHY to a a magjack and implementing PoE as a whole. All of the parts I see have a pinout similar to pic related but where the fuck is the power? It's Power over Ethernet, not just a magjack with data on it. Am I missing something?

>>1995329
forgot pic

so i deflowered my hot air gun and turns out that shit is super easy,
i just plopped some solder on and it magically went onto the pads i literally just placed the chip on once it was hot enough to melt the solder and that was it
i just hope i didn't cook the insides of that chip

>>1995337

>>1995112
>The sole exception I am aware of is the PIC family, which is obsolete or worse than the alternatives, and should be generally avoided.

Maybe the PICs from the 80's and 90's
They have PIC32's now that are built on ARM architecture.
>>1995106
>12 bits, I2C
>audio DSP
I wouldn't put too much effort into it. If you want to play with audio, get a DAC that supports I2S or basic PCM style input. I'd suggest at least 16-bits, but that isn't 100% necessary.

>>1995187
F411 has FPU, 12-bit 2.4MSPS 16ch ADC, full speed USB2.0 device/host/OTG controller, and 100MHz CPU freq

>>1995337
FUCK
it did burn, fucking fragile piece of shit, i held the air gun on it for only about 20s at merely 330C

god fucking damn it, good think a bought a full tape of these cunts

lads, is it possible to sense the current of a 100KHz PWM signal with ACS712? If it is, do I need a low pass filter at the output of it or could I just do an averaging or rolling average in the software of a uC? Thanks before.

>>1995329
I dunno man, when I opened up my TP-Link PoE module there is literally not a single electronic component in it, just bald PCB with traces connecting the data lines between input port and output port and power and ground to the output port from the power jack.

>>1995372
20 seconds? Jesus dude, what kind of solder are you using?
Don't hold the nozzle so close, and kinda swirl it around, don't just point it right at the chip.

>>1995384
Sounds like a passive injector/receiver. Whatever is getting connected to the power port has a buck converter on the lines.

>>1995397
it's regular leaded solder and this was the first time in my life i hot air soldering SO GET THE FUCK OF MY BACK YOU BULLY

also, i'm not sure if it's really burned, it's weird, i can see this output on a scope from the digital pin on the micro, and since it's a digital pin it should not be possible for those peaks to be anything else than 5V each, but at the same time if the micro really is burned, then how am i getting any output at all?

ti's a mystery

i guess the only option i have is to desolder it and put it into a programmer and check if it can still be programmed or not

>>1995384

makes sense. data + power = PoE
there's no safety protocols implemented, but we're not noobs who need to be coddled.

>>1995329
>>1995333
You should read up some more on PoE. There are different modes.

Other than Analog's DSPs are there any out there with an easy no programming config tool?

>>1995401
>since it's a digital pin it should not be possible for those peaks to be anything else than 5V each
Depends on what else is on the board, what type of probes you're using, how calibrated your scope is, ect...
The slew rate looks bad on those waves, but I can see a pattern, so its most likely something corrupting the wave between the micro and your screen.

NEW THREAD >>1995422
>>1995422 NEW THREAD
NEW THREAD >>1995422
>>1995422 NEW THREAD

>>1995187
>Is there an easy to digest summary of the differences between the common STM32s?
There's a summary here:
https://stm32-base.org/guides/getting-started

>>1995353
>They have PIC32's now that are built on ARM architecture.
I'm aware, but they're not competitive to offerings by others, or even their own samd chips.
>I'd suggest at least 16-bits,
Audio's usually done by oversampling at a lower bit depth. Audio's also hell. There's open source implementations to look at (nwavguy's ODAC) if you want to learn.

>>1995247
>>1995266
What I worked out to do is get some solder on at least two corners on the PCB, then put down some flux, then the device with tweezers to hold it in place. Tip of the iron to get the corner pins tacked down. Then flux over the remaining pins, and solder them one at a time. Clean it all up with alcohol and/or flux remover and you're done.