/ohm/ - electronics general

[Anonymous No.1961504]

Solder paste is was too expensive edition

100% brand new from factory guaranteed work thread >>1957408

>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.

>Project ideas:
http://adafruit.com
http://instructables.com/tag/type-id/category-technology/
http://makezine.com/category/electronics/
Don't ask, roll:
https://github.com/Rocheez/4chan-electronics-challenges/blob/master/list-of-challenges.png.png (embed) (embed)

>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
Horowitz and Hill, The Art of Electronics

>Design/verification tools:
LTSpice
MicroCap
falstad.com/circuit/circuitjs.html
NI Multisim
CircuitLab
iCircuit for Macs
KiCAD (PCB layout software, v5+ recommended)
Logisim (Evolution)

>Components/equipment:
Mouser, Digi-Key, Arrow, Newark, LCSC (global)
RS Components (Europe)
eBay/AliExpress sellers, for component assortments/sample kits (caveat emptor)
Local independent electronics distributors
ladyada.net/library/procure/hobbyist.html

>Related YouTube channels:
mjlorton
w2aew
jkgamm041
eevblog
EcProjects
greatscottlab
Photonvids
sdgelectronics
BigClive
Ben Eater

>Li+/LiPo batteries
Read this first:http://www.elteconline.com/download/pdf/SAFT-RIC-LI-ION-Safety-Recommendations.pdf

>I have junk, what do?
Shitcan it

[Anonymous No.1961515]

>>1961504
>.png .png embed embed embed
Unfortunate OP.

[Anonymous No.1961525]

>>1961515
Cry me a river.
There are children starving in Africa right now, who don't even own a single multimeter.

[Anonymous No.1961528]

>>1961525
I don't care. The OP sucks.

[Anonymous No.1961576]

Following up on my previous posts. I'm looking for some new tools to get to improve my soldering. I am looking for helping hands to hold board and wires in place while soldering, something with a sturdy base and padded clips, and I'm also looking for a good light/magnifier combo. A kind anon last thread recommended panavice for board vices, could anyone recommend items for holding wires in place when soldering, or good light/magnifier combos? I was almost just thinking of getting some kind of elderly person's reading magnfier/lamp combo like what my grandmother had in her later years, just not sure and I like to ask folks who do it what they use. Thanks for any replies.

[Anonymous No.1961590]

when i print a footprint from kicad on my printer the size is like 10% off but if i say mill it, or generate gerbers and send it to chinks the size matches perfectly
i have the print settings in kicad set 1:1 so i wonder how to fix this shit, because it's annoying if can't try out the sizes on paper and such

[Anonymous No.1961646]

>>1961590
possibly ppi mismatch
I just export to pdf and print afterwards

[Anonymous No.1961647]

>>1961646
i tried doing that and got same result

[Anonymous No.1961656]

>>1961590
>>1961647
Have you any page margins enabled? The default settings often add some and shrink the document.

[Anonymous No.1961672]

>>1961656
no, i checked all that and margins are set to 100 and content scaling is turned off

[Anonymous No.1961748]

>>1961590
Change the printer setting (the hardware, not the kicad dialog) to "actual size" sounds like it may be printing "fit to page"

[Anonymous No.1961790]

>>1961748
I checked all of that shit but i just can't figure it out, all scaling etc is turned off, paper is a4, but it still prints wrong.
The annoying thing is that on screen the size is correct, so it's something somewhere in the printer driver or something, i'll have to try the pritner at work to see if it also fucks up the size

[Anonymous No.1961968]

still PID-heater anon from previous general,
the circuit is done, now i was only looking better at my IGBT and considering i'm driving a 100W load i want a heatsink on that pricy 20$ component (and to make sure i don't just burn down my enclosure)
it's driving 12V 10A (a bit less, more like 8 but let's keep some safe margin) and i can't find on-resistance or stuff like that on the datasheet to calculate how much it will dissipate of those 100w.
It's a G4BC30FD in TO-220 package, and i have a couple of 50°C/W heatsinks for that package...do i need something bigger or these components have so little resistance that it doesn't matter and i can just use that and be good? please help

[Anonymous No.1961971]

>>1961968
forgot the link to the datasheet i'm a big R
http://www.farnell.com/datasheets/1916241.pdf

[Anonymous No.1962003]

>>1961968
Have you even tried to turn the circuit on yet? Just looking at the datasheet, the 5v your Arduino puts out won't be enough to trigger the gate for anywhere near enough current to run the heater. You need more voltage on the gate to get 10 amps from collector to emitter.
As for the heatsink, your situation may be easier to bolt on a large heatsink, and monitor the temperature as you run it. It's designed to handle a ton of current, so I wouldn't be worried about it burning up, so long as you start out with a decent heatsink and keep an eye on it.

[Anonymous No.1962020]

Anybody know where I can get IDC header style cables that aren't ribbon cables?
I need something with a bit more current carrying capability than a ribbon, so individual wires exactly like what's used in pic related, but I need to keep the regular pin header form factor.
Bonus if I can get them premade from somewhere like digikey.
I don't even know what the technical name for such a configuration is to search correctly.

[Anonymous No.1962021]

>>1962020
Forgot pic like the retard I am.

[Anonymous No.1962026]

>>1962003
Actually no, i should receive the PTC module tomorrow and i kinda wanted to try on a bread-board First with a lower load Just to make sure everything works correctly (i did write firmware so i have to check that too, not only the hardware, a piece of led strip should do the trick)
I think the only big heatsink i have Is a HUGE One where 4 big 15A BJTs where bolted on, can't really use It and nothing to cut It with...i'll see if i can recover something Better than the Little TO-220 One i was thinking about using.
As for the turn on voltage what i did understand Is that the whole package Is a BJT and a MOSFET together, so i don't have to worry about the voltage as long as Is somewhere near 5/6v and not more than 20v but it's the First time i read and try to use IBGTs so i'm not sure, i Guess the led strip test Will be good to test if it's a complete turn-on or not, otherwise i Guess i can Just Place a small BC337 to drive 12v to the gate

[Anonymous No.1962060]

recommended resource to learn rf principles?

[Anonymous No.1962077]

>>1961525
at least copypaste the OP into a text document for speed baking instead

>>1961590
Really depends on how you send it to your printer. I think the method I ended up using was saving it as a vector image svg, then opening it in one of my web browsers, then printing it from there. Sending it from an image editor or file-viewer gave me a similar issue to what you're describing.

But there's got to be software out there designed for this. The "bigprint" software that Mattias Wandel uses to make to-scale templates to glue onto plywood might work for this, though it is designed for a much larger scale and might not have the ability to dump out shittons of ink like you need for an inkjet transparency photomask.

[Anonymous No.1962082]

Can anyone point me in the right direction with how to wire an on off switch in my circuit? I'm DIYing an electric bike and I figured I want an on/off switch. Problem is, turns out there's not much space so I can't use a large one, a small one would get melted by the current, which is around 15A right now, but I'm looking to increase it later.
This got me thinking, in general, what's the canonical way of wiring an on/off switch? A relay? Some kind of mosfet? Do keep in mind I'm a brainlet who never went to electronics school, so if you'd link an appropriate video or article, I'd be grateful.

[Anonymous No.1962139]

>>1962082
Basically, use a MOSFET or IGBT and a tiny switch to energise it. A common IRLZ44N is rated to 22mΩ when on (10V Vgs), meaning no more than 33mW of power. Even without a heat-sink, that will be fine with a TO-220 package stuffed somewhere since the junction-to-ambient thermal resistance is 62K/W. At 25C ambient, that's running up at 55C. The transistor is rated to 175C.
And there are much better transistors out there that do better than 10 times less power than that.

[Anonymous No.1962165]

the following circuit only works if i put my thumb on the lead on the capacitor on the left that connects to a resistor a diode AND bjts base. i can modulate the frequency by pressure applied. its the led blinker/ frequency generator with variable frequency but consistent duty cycle circuit. i adjusted it to be 60 hrz to 220 hrz and should be about 50% duty cycle regardless of frequency

i just soldlered it together. and even resoldered it right there.am i earth ground. is this magic? am i a jedi now? if i change the pressure on the lead with my thumb it changes the frequency not the potentiometer

[Anonymous No.1962172]

>>1962139
anon that's 5W at 15A/22mohms. probably closer to 7W at temperature. would need a heatsink for that specific tranny.

[Anonymous No.1962173]

>>1962165
sounds like stray capacitance, also check your cap and resistor values

[Anonymous No.1962182]

>>1962172
Oh it's P = I^2/*R, whoopsie

[Anonymous No.1962216]

>>1961968
> i can't find on-resistance or stuff like that on the datasheet to calculate how much it will dissipate of those 100w.
Figures 2 and 5.

[Anonymous No.1962236]

>>1962173
i fixed it . i figured if my thumb adjusts the stupid thing so it works then i just needed to tie on a cap or a resistor to that point and then connect soem where else.

100k ohms from the positive rail to that cap lead works but it was boosting the frequency to khz range so a 47 nf cap on the other cap mirrored position to the same point

as far as i can tell it makes a rc circuit connected to the previously listed one and it comes down to 75hz which is fine for running a transformer. collectors tied to 2 fets not shown and the fets manage the power connected to the positive rail through a center taped transformer

so the final looks like pic related. im still pretty sure im a jedi or the source of all things electrical

[Anonymous No.1962239]

>>1962139
I see. Thanks! Can i just splice the hot wire and fit the mosfet in between, following with the same + source but through a tiny switch to the third leg? (after figuring out the order of course)
Also would a motherboard mosfet work? I don't have the part number right now, or are they typically rated for 12v and below and I shouldn't even bother with the motherboard one?

[Anonymous No.1962250]

>>1961968
Don't really know what your design is, but I'm assuming it's either DC or low switching speed since you mentioned a heater.

The IGBT will drop about 0.5v at 10A of current. That means 5 watts (pic related). According to the datasheet the junction to ambient thermal resistance is 80°c/w. With no heatsink, it will hit a junction temperature of 425°c assuming an ambient temperature of 25°c. 50°c/w heatsinks aren't going to be good enough either.

Why are you using a 600V IGBT for a 12V application? That's a really inappropriate transistor choice as you can see from the high voltage drop across it. You could get a high current, low RDS(on) MOSFET for around $1.

https://www.digikey.com/en/products/detail/infineon-technologies/IRFB7545PBF/4772483

This one has an RDS(on) of 9mohm at a junction temperature of 125°c. That's less than 1 watt of dissipation at 10A of current. You can get away without a heatsink if you use this transistor.

[Anonymous No.1962251]

>>1962250
Fuck typo. It's actually 1.5V drop across the IGBT. It's actually 3x worse than what I said before.

[Anonymous No.1962260]

>>1962026
Sorry to make multiple posts like this but I'm apparently bad at following threads. How hard you drive a transistor determines how much it turns on. There is no rule of thumb like "5v or 6v is good enough" because every transistor is different. You have to look at the curves in the datasheet like pic related. If you don't drive your transistor into it's fully on state, it will only allow some current through, thus dropping a large voltage across itself. This is actually where it dissipates the most heat. You can end up overheating and killing your transistors really fast by doing this. And since transistors often fail short, you can end up overheating other things too.

[Anonymous No.1962296]

led and 220Ω resistor, name a more iconic duo

[PID-heater anon No.1962311]

Thanks for all the comments guys, basically i was Just looking at what i have at hand right now since i didn't really want to order stuff for such a simple circuit but i Guess i really forgot most of my electronics past now.
>>1962260
Well i have a 2N3055 in TO-3 package, what about that? Big package for big Powers and It should be rated for 15A

[Anonymous No.1962320]

Beginner trying to learn computer/electronic repair. Can you recommend me a cheap-ish multi-meter? I'm on a budget but around 50 eurobucks should be fine. I have access to German Amazon and Aliexpress.

[Anonymous No.1962323]

>>1962320
Either buy a Fluke or stop posting here immediately.

[Anonymous No.1962327]

>>1962323
If I buy one on Ali for cheap will they chink me and send me a fake?

[Anonymous No.1962329]

>>1962311
>2N3055 in TO-3 package

that transistor, along with the required heat sink will be way larger than a 15A capable switch.
for small size, gotta stick with mosfets.

[Anonymous No.1962334]

>>1962329
ye i'm just gonna buy the one you reccomended, i can just drop it in or should i add a small BJT to switch the 12V on it's gate to make sure it's fully conducting?

[Anonymous No.1962335]

>>1961504
>Solder paste is was too expensive edition
A friend recommended me plain old rosin and it's cheap and amazing even for lead free soldering. Liquid rosin is even easier to use and it's easy to make (rosin + alcohol).

[Anonymous No.1962341]

>>1962327
Look at fluke 17b+ on ali.

[Anonymous No.1962346]

>>1962334
You should be able to just drop in a BJT to switch the IGBT, but make sure your logic is correct.
If using a single NPN BJT to drive the IGBT, common low-side wiring will make it act like an inverter logic gate, thus a "1" from the arduino will drive the BJT to saturation, grounding the IGBT input, making it stay open.

[Anonymous No.1962347]

I have a question about surge protection that you guys are probably knowledgable about.
So I bought a house and the cabling is an old piece of shit without grounding and I've had a surge in the past. See image related of a varistor in my heater that blew up and had to be replaced (thankfully it works). I'm planning to install grounding in my house and also install surge protection and a modern breaker thing at the inlet from the electrical company. Until that is done though, I would like to protect some of my more expensive electrical things like computer, tv, router etc. from surges that may occur again. I've found out about these surge protector plugs that you can buy pretty cheap and was thinking about getting some to place between wall socket and power strip.

I'm planning to get one of these from Brennstuhl but the Schuko plug variant. bigclivedotcom has taken it apart and reverse engineered it so you can check the schematic if you like:
https://www.youtube.com/watch?v=wIQYbs09vGg
1. Will the surge protection in such devices work even without ground? I assume that they should.
2. Does the PSU's of my computer already protect against this or can a surge fuck up my computer too?
3. Do you recommend something else instead or is this a good idea?

[Anonymous No.1962352]

>>1962020
>>1962021
"IDC male plug" should get you started. You may need to get an unwired plug and run the correct gauge wire yourself between plugs.

[Anonymous No.1962362]

>>1962327
15b, 17b, 18b are real fluke models, made exclusively for china market.
They are being exported by many sellers, and no fakes are known.
17b+ is the sweet spot.

[Anonymous No.1962399]

>>1962334
>should i add a small BJT to switch the 12V

there is zero difference if the gate current is coming straight from a switch, or if it's coming from a BJT that itself is fed by a switch. furthermore, NOT having an extra transistor ensures the circuit draws zero current when idle.

[Anonymous No.1962409]

>>1962347
>Will the surge protection in such devices work even without ground?

a typical surge protector will have MOVs running from live to ground, and live to neutral. so you're only using half of those, but your still protected. however, these are not magic: if the surge has a lot of energy behind it, it will kill the MOVs, then kill your equipment. solution: use an infinite number of MOVs.

>Does the PSU's of my computer already protect against this or can a surge fuck up my computer too?

typical computer supply will include 1 or 2 small MOVs, more if it costs more. usually this is not adequate, and you should add external ones, usually located inside power bars. but you can never have enough.

>Do you recommend something else instead or is this a good idea?

once again, more is better.

[Anonymous No.1962429]

>>1962409
Thanks, fren.

[Anonymous No.1962441]

>>1962409
You seem to be knowledgeable about surge protection. Do you know how surge protectors "know" when they no longer provide protection, and turn the LED off, but still provide power?

The reason I ask, and please tell me if this is a bad idea, but I'd like to provide whole-house surge protection by MOVs at the main panel; they don't make a device specifically for my box, and if I can do this, I'd like to be able to monitor the condition. MOVs are so cheap that replacing them once a year, or whenever, would be fine.

[Anonymous No.1962449]

>>1962441
>Do you know how surge protectors "know" when they no longer provide protection,

MOVs are completely dumb devices, they know nothing. to make the circuit self-aware, you use fuses that can remember over-current or over-heating events. i.e. they blow, and thus remember blowing.

[Anonymous No.1962451]

>>1962441
Look for MOVs with 3 pins. They generally have integrated protection (thermal, fuse) with pin to allow external device.

[Anonymous No.1962453]

>>1962449
>>1962451
thx

[Anonymous No.1962456]

>>1962441

as for mucking around inside your fusebox, i'd say most jurisdictions would look unkindly on that unless you're a licensed sparky. insurance companies likewise.

[Anonymous No.1962457]

>>1962456
true. I'm an EE so I think I can do it safely. (famous last words)

[Anonymous No.1962464]

>>1962441

here's a bit of propaganda from Littelfuse showing the diff outcomes when you have a simple MOV, a MOV with an external fuse, and a MOV with an internal fuse (made by Littelfuse, of course).

[Anonymous No.1962481]

can you recommend a cheap reflow oven?
i only need to reflow shit like once a month so something really cheap that still works well

[Anonymous No.1962484]

>>1962481
Toaster oven with diy controller?

[Anonymous No.1962545]

>>1962334
Hey it's me again. If you're looking to drive this transistor from a 5v arduino pin, you're going to want to have an extra driving transistor so that it's driven at 12V. Same goes for if you decide to use the IGBT. Just make sure it's got a lot of heat sink if you do.

>>1962399
There is a difference if the gate voltage is 5v or 12v. 5v will not allow the transistor to conduct as well which will dissipate more heat.

[Anonymous No.1962582]

>>1962545
>There is a difference if the gate voltage is 5v or 12v

that's a logic fail. if the voltage is too low to turn on the FET, then it's gonna be too low whether there's a switch or switch+transistor providing said voltage.
similarly, if the voltage is adequate, it's gonna be adequate in both cases.

[Anonymous No.1962584]

>>1962545
>from a 5v arduino pin,

there's no arduino. the dude is just trying to avoid a large or expensive 15A switch.

>>1962545
>There is a difference if the gate voltage is 5v or 12v

that's a logic fail. if the voltage is too low to turn on the FET, then it's gonna be too low whether there's a switch or switch+transistor providing said voltage.
similarly, if the voltage is adequate, it's gonna be adequate in both cases.

[Anonymous No.1962612]

I have a number of motors which I want to be able to switch on just by pressing a momentary push button for each one.
I was going to do a circuit like pic related, this should cause the relay to latch right? (My motor being driven through the two unwired contacts on the relay.

I would however also to be able to break the latch when a limit switch is reached.
Obviously the easiest thing would be to have normally closed limit switch where I have the red circle in my picture.
Unfortunately the limit switches installed only have normally open contacts.
Is there a simple way to unlatch the circuit with a normally open switch (I can have either ground or VCC to the limit switch).

Obviously I know there are set reset relays and much easier ways to do this but I wanted to get this done before Monday and I'm working with what I have at hand.

So I have plenty of BJTs, resistors, caps, diodes of various values

[Anonymous No.1962666]

>>1962612

cut line between A and B and add limit switch circuit in between. transistor is normally on, when switch hits limit, relay loses power, so the latch goes off.
only problem is, WHAT THEN? the circuit becomes stuck, unless you add another switch to reverse direction of motor.

[Anonymous No.1962689]

>>1962612
>>1962666
Use multiple soft latch circuits, the first powering the motor, the n/o limit switch turning the first latch off and second latch on for the next part of the circuit.

[Anonymous No.1962694]

>>1962666
Actually, only one of them is driving a motor, the other 3 are solenoids.
It's basically for remote control of a big circuit breaker.
The motor winds the spring so it never has to reverse.
Solenoids are for an interlock, closing the breaker and opening the breaker

[Anonymous No.1962760]

>>1962584
>that's a logic fail
In the case that the transistor is used as a logic level shifter from the arduino it makes sense. That isn’t the case, but you already provided a rebuttal for that alone.

[Anonymous No.1962766]

why doesn't this circuit 0V out the 2nd op amp if the + input it is negative?

[Anonymous No.1962773]

>>1961504
What is the definitive reading list to get into electronics? The principles part seems too short.

[Anonymous No.1962776]

This schematic is for the question "design a system that has an output of 1 when the input has been 0 for exactly seven clock times"
Two questions here.
1. If X = 1, would the CLR activate and clear everything? I see it going through an inverter so so I should add another inverter right under it so that it would become 1 and then activate?
2. Why did they decide to AND the clock and the complement of X? I can't seem to understand why the person decided to make it leading edge rather than trailing.

[Anonymous No.1962887]

>>1962766
You’re feeding the second op-amp an input voltage below its negative supply rail. Of course it’s not going to work how you expect it to.

>>1962776
1: should clear everything if it’s a global clear, but behaviour will depend on whether it’s a synchronous or asynchronous clear.
2: leading edge is more conventional, and there are timing reasons for choosing either.

[Anonymous No.1962892]

>>1962887
>1: should clear everything if it’s a global clear, but behaviour will depend on whether it’s a synchronous or asynchronous clear.
Gotcha, didn't know that there was a synchronous and an asynchronous clear or even a global one, just means that I need to study more! Just to be sure, do you think I should add a NOT just before clear so that a 1 gets put inside when x=1?
2: leading edge is more conventional, and there are timing reasons for choosing either.
Oooh, I didn't know that leading was the more conventional one. Do you know why they and'ed the clock with X' though? I've never seen that before...

[Anonymous No.1962896]

>>1962887
>You’re feeding the second op-amp an input voltage below its negative supply rail. Of course it’s not going to work how you expect it to.
why?

[Anonymous No.1962908]

Why aren't there coil and transformer winding people like there are making custom pcb's?

[Anonymous No.1962937]

>>1962908
People wind their own Tesla coils and toroidal transformers all the time.

[Anonymous No.1962939]

>>1962937
no i think he means you order one according to specs and you pic coil form and what type of primary and in both cases proportions

and the answer is probably the cores and cost of wire. where as pcbs are cheap to make tons of especially the flex pcbs. its like 9/10ths plastic

[Anonymous No.1962950]

>>1962939
Dont believe it.
where as pcbs are cheap to make tons of especially the flex pcbs. its like 9/10ths plastic

Dont see why any of this is a reason why custom coils arnt more available.

[Anonymous No.1962955]

>>1962766
look up "op amp unity gain buffer," you need negative feedback for op amps

[Anonymous No.1962967]

How dumb is this idea: I have a bunch of used Brita filters and a need for a fume extraction/filtering unit. The filters are full of activated charcoal granules.

What if I dumped the charcoal into a void between two particle filters (mesh, HEPA filter material, whatever) and then forced air through the package using desktop fans?

[Anonymous No.1962968]

Repost since last thread ended.

I plan to rig up a solar-powered aircon system using 2ndhand car components in my summer break (I'm a mechanic and can get this shit cheap), my electronics knowledge starts and ends with cars and 12 volt systems.

Presumably I can get an off-the-shelf system to handle charging the car batteries with the solar panels, but I want to be able to have the system turn on when the interior temperature of the shed reaches a set point, and also have a way to prevent draining the batteries too much; Would running it with an arduino or something be worthwhile, or are there simpler options?

[Anonymous No.1962969]

>>1962967
Okay ish

Desktop fans might not have enough static pressure do this efficiently

[Anonymous No.1962971]

>>1962967
No way cause the filters are already used.

[Anonymous No.1962972]

>>1962939
Pretty sure flex PCBs are more expensive than FR4 PCBs.

>>1962950
Because PCBs use a series of very standardised thicknesses and are easy to laminate together like that. Making custom shaped ferrite cores is more difficult, and it also requires professional magnetism simulation to make in the first place.

The actual manufacturing process is winding copper around a core, which is not a parallelisable task like PCB photomasking and etching is. Twice the wire = twice the time, compared to an etch bath or exposure taking a fixed amount of time and can be done as batches of dozens of boards at once without needing dozens of machines. Also winding tricky toroidal cores might require some pretty complicated machinery.

Conventional E-I and bobbin cores are easy to wind and easy to assemble, and come in a series of standard sizes, so should be easy to manufacture with custom turns. But for inductors these already exist in every inductance you’d ever want, and possibly the same for transformers too. I’m imagining that product designers will mostly be buying off the shelf magnetics except for when they really need custom magnetic cores too. There’s a relatively large freedom when selecting an inductor or transformer, so long as the turns ratio and inductances are close enough to what you initially designed for, the slight differences can be compensated by changing the cheaper surrounding parts (transistor selection, capacitor size, reference voltage, etc.). Only if you’re right up against the edge of one of your parts will you need a specific magnetic device, which is a sign of bad design. Or if you need something so far away from what already exists, in which case you need to rethink your design or hope you’ve got sufficient volumes to justify expensive custom magnetics.

[Anonymous No.1962974]

>>1962896
Look at an internal transistor diagram of how an op-amp is constructed. Something simple like a 741. It should be fairly obvious that an input voltage outside of the rails won’t result in proper behaviour. As the other guy says, op-amps are designed to be used with negative feedback, while comparators are the equivalent part that doesn’t use negative feedback and only output Vcc or Vee.

[Anonymous No.1962978]

>>1962972
Based maker of coils.
Dont care about the coils just transformers.
So we kneed more companies that do winding!

[Anonymous No.1962981]

>>1962978
Sneed's Core & Coil

[Anonymous No.1962987]

>>1962981
So that would be down at sneeds boil?

[Anonymous No.1962988]

>>1962987
Well tha was when he was part part of the doyle.

[Anonymous No.1963010]

>>1961504
i wasnt going to post this but if some one wanted to make a 60 hz - 2 khz oscillator to drive a transformer with 2 n channel fets or a signal driver that goes even higher the following adjustment makes it adjustable and if you put a pizo electric buzzer on 1 emitter of a bjt you can hear the difference as you crank it up

if the cap is tied to the 3rd pin of the potentiometer it is adjustable again. the original circuit required two 470k resistors which i dont have also the original circuit was not balanced for 330n caps ect

[Anonymous No.1963017]

>>1963010
looks complicated. Have you tried something like this?
>R2 is a 150ohm in series with a 5k rheostat
>C1 is 3.3uF

[Anonymous No.1963026]

>>1962239
You need to get a MOSFET that's rated a bit above the current and voltage you need. If you're running a 12V system, then get a 15V or higher FET. The thermal calculations are as I did earlier, and should be identical anyhow for any TO-220 package. As the other anon pointed out, you'll want something significantly below 20mΩ (5mΩ at most) if you want to cram it somewhere without a heat-sink. If you're willing to scrounge about on octopart or wherever then finding such a MOSFET will be a piece of cake, but if your primary component source is ebay I'm not sure where to start.
Just getting a cheaper transistor like the IRLZ44N and whacking a heat-sink on it is also an option.

The actual wiring is simple; put the N-channel MOSFET with its source at BAT-, and drain at ESC-. Has to be on the low side because of how MOSFETs work (P-channels are worse), unless you want to shove an isolated DC-DC converter or charge pump in somewhere, which is not advisable. Then use a switch to feed it the recommended gate voltage. If you're running a 12V system then you can almost certainly just use the battery for this directly. Else, you'll need a zener or L7912 or whatever. Might draw a circuit diagram in the morning if you need it.

No clue what a mobo FET is like, but it might be good.

>>1962260
>There is no rule of thumb like "5v or 6v is good enough" because every transistor is different
My rule is "shove as much fucking current into the gate until it's near its maximum recommended gate voltage". To that end I'll use darlington totem poles and 2.5A gate driver ICs. 12V is usually a good voltage in any case, even for logic level MOSFETs.

[Anonymous No.1963027]

>>1963017
i would but i would 1 have to buy a 555 timer and 2 gamble it all on if you just gave me a bad pin out. like 6 years ago some bullshit happened and i became aware of bad pin outs on 555 timer circuits being handed out so i stay away. if i knew you irl i would try it but nobody i ever knew cared about circuits

[Anonymous No.1963028]

>>1963027
>like 6 years ago some bullshit happened and i became aware of bad pin outs on 555 timer circuits being handed out
Read the fucking datasheet you bongoloid

[Anonymous No.1963033]

>>1962978
There are companies that do this. But it’s a limited run prototyping service aimed at corporate customers that don’t care about extravagant prototyping fees. The only reasons PCB manufacturing has gotten so cheap is that it’s easy to put one-off boards next to larger production runs, because PCB manufacturing is inherently cheaper, and because the volumes are orders of magnitude higher. The volumes could be higher if there was no alternative, but there are plenty of off-the-shelf magnetics to fit basically any project. PCBs on the other hand can’t just be bought to fit a project at all, the only alternative is prototyping with home-etch/mill setups or stuff like manhattan. Which just aren’t practical for high-pitch components.

[Anonymous No.1963036]

>>1963028
no the datasheets accessed by americans are not the same its why japan closed off access to part of their internet segment because of a influx of americans trying to use their servers to learn basic shit for circuits

the mountain of bad data goes farther than pinterest troll circuits. it goes all the way to bad datasheets and entire websites locked with wrong dates so you have to change your clock to the wrong month and year just to access it. pinouts for lots of shit is wrong on datasheets. found it at least 5 times for bjts alone because i harvest parts from dead appliances and power supplies. fucking TO-92 could be anything. ebc, ecb, bce but what it says and what it is might be different even with the right manufacturer. 555 timer shit can be wrong on all accounts and they even started doing this to exclusively white households in retaliation for non whites getting the wrong data

white supremacist ruined it for every one in america now and being in europe must be nice since you guys sued google

[Anonymous No.1963044]

looks like we have our very own schizo now

[Anonymous No.1963059]

>>1963044
well ignorance is bliss or your one of the people who think ensuring more wont ever use a 555 timer by recirculating bad pinouts is good since they will stop selling it within 5 years probably since its not being made anymore

but if you had ever watched youtube vids on circuits you find a 1 off reference to this problem about every 20 videos or so practically

https://medium.com/@srcbot/datasheets-are-fake-an-inductor-case-928556155fba

its not the parameters alone like a ior fet saying its good for 20 amps but cant handle 5 its also pinouts and the 555 tier one is well known i electronic circles as are the 2 websites with wrong dates run by the kkk

[Anonymous No.1963063]

>>1963059
Get the datasheet of the Texas Instruments official website. Cross reference it with ones from Diodes Inc. and Fairchild or whoever. Test it immediately. I've used NE555s dozens of times and it's worked every single one of those. Either you got incredibly unlucky, or you're a schizo convinced that your circuit HAS to be correct and thousands of EEs are wrong instead.

And that whole article reads like an advertisement for sourcingbot. A 15% tolerance is shitty, but perfectly fine for low-spec DC DC converters and the like. 10% tolerances are common on bottom-of-the-barrel resistors. Need tighter tolerances, buy better characterised parts in the first place. Manufacturing tolerance variations are a far shot from completely messing up the pinout of a component.

>kkk
I'm not even going near that rabbit hole, though it could be interesting for a laugh. Basically, only trust information that's either been confirmed by others before you (i.e. arduino forums or eevblog forums) or from reputable companies' official documents. While this is difficult to do with noname chinese knockoff parts (that I've never had problems with), with something as old and tested as an NE555 it's a piece of cake. As well as datasheets, you should check out application notes. These companies are trying to sell you their products, it's in their interest to give you plenty of information on how they can be used, any incorrect information would be bad for business.

[Anonymous No.1963166]

>>1963026
Aha, thank you, now I know exactly what to do. And it looks like the mobo MOSFET will work. Rated for 35V, 4 milliohms. Saved me from being very confused why it doesn't work, as mynfirst idea would be to wire it high-side. I'll stick a heatsink on it just in case since it's pretty small on its own.

[Anonymous No.1963181]

>>1962968
yeah, you can use something like an arduino uno, a realy and one temperature sensor, it would be completely trivial to do
also any solar battery charger has input for solar panel, battery and output, so if the battery is drained too much it custs it off, even shit cheep ones have it so you don't need to handle it yourself, but arduino can easily monitor battery voltage too if you use a simple voltage divider to bring 13V down to 5V and use analog pin on the tarduino.
Car batteries are shit though, they are designed for high current and floating charge usage, where they are kept at say 90% charge or more all the time and deliver short burts of current.
For solar panels you will want to use deep cycle batteries like RVs use, the absolute top tier are of course AGM batteries

[Anonymous No.1963187]

Gonna try tempering chocolate as a part of a christmas gift. I'll use a rice cooker as a double boiler, with an arduino + temperature sensor switching a mechanical relay to follow a temperature gradient. The response speed of the system should be slow enough that the relay is only switching once every few seconds, so I think it should be ok.
Any questions?

[Anonymous No.1963189]

>>1963187
why not make something actually useful instead of diabetes delivery device?
Like for example a ventilator for when they get kissed by coronachan

[Anonymous No.1963224]

>>1962968
Simplest option would be to get an off the shelf thermostat module for 12V (alibay/amazon) and just wire that up. Many solar chargers (but not all) have a set of output terminals for DC loads that will switch off when the battery gets too low.

But if you know some basic electronics or are willing to learn, a more /ohm/ way of accomplishing the same is pretty simple. You'd need a comparator circuit with hysteresis (important) that would be hooked up to an analog temperature sensor, with its output switching the ac on and off; and another comparator connected to battery voltage and a reference voltage, controlling a solid state relay for disconnecting the load. This is all textbook circuits that one can look up in application notes or have guys with Indian accents explain on Youtube.

Parts: Thermistor (temp sensor), potentiometer, LM339 quad comparator, 78L05 voltage regulator, solid state relay, handful of resistors, veroboard/stripboard to mount components on.

Or an Arduino like >>1963181 said if you like programming more than soldering.

[Anonymous No.1963232]

which solder do i need

[Anonymous No.1963258]

>>1963232

this one

[Anonymous No.1963262]

>>1963232

this one. in .02-inch diameter.

[Anonymous No.1963265]

>>1963232
Any with aprox 37% lead, 63% tin.
Avoid chinese solder. Dont even think to buy it.

[Anonymous No.1963297]

>>1963265
why? chinks are very eco friendly actually.
even their leaded soldered is completely lead free

[Anonymous No.1963324]

>tranny base current dilates collector-emitter current

[Anonymous No.1963349]

>>1963324
i'd put my emitter in a tranny collector iykwisf

[Anonymous No.1963352]

Having never used them before, I want to buy some inductors to mess around with and ideally also build some lc oscillators with. What henry value should I get? Also, do the toroid versions differ in function from the ones that more closely resemble film resistors?

[Anonymous No.1963370]

>>1963297
>even their leaded soldered is completely lead free
Um... No. It is zinc-lead-aluminium alloy by looks of it, and by how mushy it is when you melt it.

[Anonymous No.1963376]

>haha let's make the pin spacings 1.8mm so it just barely doesn't fit any 2.5mm pin headers, or breadboards, or perf boards, or dupont cables or anything else
god damn assholes.
whatever, i made myself this gorgeous breakout board, so now it's time for some wireless fun
i want to try out long range transmissions for a long time now, but never gotten around to do it
i just hope the pcb copper won't fuck with the antenna

[Anonymous No.1963436]

just had an idea
>digitally selectable variable capacitor
>have array of addressable capacitors, sort of like an array of LEDs
>microcontroller sends signal to /PLA/ROM/whatever to select any number of these capacitors in either parallel or series
>the selected capacitors are then joined to form one "capacitor" with a specific capacitance
all because I don't want to buy and wait for a variable capacitor
I feel like this is infeasible and pointless but it still sounds like a fun project

[Anonymous No.1963454]

>>1963436
it would probably be easier to solder them to a board and have manual switches or a central dip switch but your idea actually sounds kind of interesting. i would steal it but im 90% sure tesla has a patent on the monster capacitor array and its distribution system for the cars

[Anonymous No.1963517]

>>1963436
They got em on ebay/amazon
"Programmable capacitor, 1nF-9999nF"

[Anonymous No.1963532]

>>1963517
fuck, I thought I was being clever

[Anonymous No.1963536]

I'm working on a project where I have two separate pairs of IR transmitters-receivers exchange data. The problem is that I'm noticing that the emitters interfere with each other.
Does anyone know what the best way of placing the emitter and transmitter would be? I'm thinking of putting the emitter in front of the receiver right now

[Anonymous No.1963545]

anybody here have experience with audio cable soldering? Does the type of solder make a difference? I'm aware that non-lead solders are harder to work with but I want the best results possible.

[Anonymous No.1963560]

>>1961504
So this is my first ever wiring. I always wanted to build a guitar, and so I’m starting with a strat loosely based on Alex Lifesons sportscaster.

Anyway, I can get sound out of it but I am failing to get a good ground no matter what. I took the wired pick guard from another strat that works and it also has ground problems when hooked up to my input/ground.

I have one ground to the bridge claw thing, and one at the input. Currently have it in a mess of taped together cables while trying to troubleshoot.

Only thing I did different from the diagram was the ground on my volume was not directly soldered to itself - I used a wire because I tried that once and I think I had too much heat and burned away the metal.

Can anyone point me in the right direction?

[Anonymous No.1963569]

>>1963560
Be nice. It’s my first time ever using a soldering iron. Started wiring the switch first. I may just get a new one and do it all over again as I’m improving slowly.

[Anonymous No.1963577]

>>1963560
Replace the 1/4" jack and cable to the amp.

[Anonymous No.1963580]

>>1963577
I tried another jack and cable.

[Anonymous No.1963588]

>>1963189
>he still has covid 19 in his country
lmao

>>1963376
>i just hope the pcb copper won't fuck with the antenna
It might, I'd remove the ground plane near the antenna or stick the antenna vertical.

[Anonymous No.1963590]

>>1963580
Take a pic of the spring claw ground point.

[Anonymous No.1963605]

>>1963590
I initially had it on the hook on the bottom, and realized from looking at the other one they did it on that little hook.

[Anonymous No.1963609]

>>1963605
If the wiring checks out then clean the selector switch and volume/tone pots with contact cleaner. The only other thing it could be is the pickups.

[Anonymous No.1963610]

>>1963036
You need to take your meds before posting.

[Anonymous No.1963622]

>>1963609
If it does the same thing on another set up pick guard, I would think that would rule out the pickups and switch? I just redid the ground wires entirely and problem persists. I think the wiring checks out, but one thing is I went ahead and played it with the bad ground, and the bill lawrence has different phasing, I think? It was tinny but swapping the ground and hot wire made it open up. Is there more I need to do?

[Anonymous No.1963634]

>>1963622
Maybe you wired the pickups out of phase?

[Anonymous No.1963735]

Trying to figure out if these diodes will handle 12v 1a and the internet is fucking useless. The only markings are SI and 57-27

[Anonymous No.1963750]

>>1963376
1.8mm * sqrt(2) = 2.54mm
yur sposed to mount it diagonally

[Anonymous No.1964004]

>thermocouples are expensive
why :( i just wanna measure the oil fry pan temp

[Anonymous No.1964053]

>>1963750
oh that's clever

also HAHAHAHAHAHA lmao at the anon who made a PCB

>>1964004
they're like $5 mate

[Anonymous No.1964062]

>>1963735
i have never seen a normal diode that cant handle atleast 300v 1a. is its a signal/zener diode looking one. those are literally the only times i have seen a weak one that dies at 18v 1a

[Anonymous No.1964087]

>>1963735
Really?
57-27 1N2071 1N4005 600 PIV 1A Rectifier

[Anonymous No.1964094]

>>1964062
>i have never seen a normal diode that cant handle atleast 300v 1a
Never seen a 1N4148?

[Anonymous No.1964125]

>>1961504
I seemed to misplaced my desoldering braid and now its missing. Is there any good alternative for a desoldering braid?

[Anonymous No.1964130]

>>1964125
make all prototypes surface mount/skywire

[Anonymous No.1964139]

Are there any modern equivalents to Heathkits?
My dad used to be really into them when he was younger, and so it would be great to get a really nice electronic kit for him.
Guy has a full lab, so no limits due to skill. lol

[Anonymous No.1964143]

>>1964094
no. 1n4007 is so common there is no excuse for anything else in the 1a range to exist if its a genric diode. dead serious 4/6 diodes i remove from boards of random appliances are 1n4007. its 1kv 1a .

i bought two 100 piece packs of it and retrieved like 2 dozen. ones from boards are nicer because they have thicker leads so passive flow amps is higher than the thread like thin lead ones i bought

everything else i find is like 600v 3a or 300v 5a

[Anonymous No.1964171]

>>1963750
>diagonally
i can't, or it won't fit in the case, obviously if i could do it like that i wouldn't bother with cutting a hole in the pcb

[Anonymous No.1964173]

>>1964125
There's no alternative to good braid. Don't get the cheap stuff, there's a real difference. Solder suckers are pretty shit but are more useful than braid for THTs, while braid is definitely better for SMDs. There's also vacuum pumps (or maybe compressed air) based solutions, but they're not too hobbyist friendly. Canned air would cool the joint down too much, but I've heard of people blowing through a straw to clear out a plated through-hole.

>>1964143
Better not be using 1N400X as small signal diodes though, they're slow as fuck and have somewhat high capacitance.
Even for smps uses they're slow, had to buy a UF4007 for my geiger counter psu because a 1N4007 didn't cut it. They're basically only good for rectifying AC at 50/60Hz.

The 1N4148 is a small-signal 0.2A diode btw, and a very common one at that.

[Anonymous No.1964174]

https://www.youtube.com/watch?v=mBFWDeOGicM&t=3s

[Anonymous No.1964179]

>>1964139
kiwi co maybe

[Anonymous No.1964180]

>>1964173
i already specified not signal or zener diodes... but regardless its kind of like switch speeds on zvs circuits. did you know that a 1n4007 can be used for a zvs and as long as im not trying to do mhz or higher range it means fuck all. hell power transistors switch fast enough for a zvs and the data sheet means nothing. any time you see a 2ns rise time or similar its for telecom crap . you can make a inverter for 50kv with power fets or bjts that does 400khz

[Anonymous No.1964246]

tarduino user here, say I want to send a signal over 433.42Mhz rf without using a micro controller(ideally i want a battery powered remote), what type of ICs would i need. The specifics dictate ASK/OOK modulation, manchester encoding and a "Symbol Width" of 1208us. One thing in particular that is confusing me is that this symbol width does not seem to have any correlation with the frequency of the clock on the rf transmitter. Aditionally that the protocol requires a wide range of microsecond intervals also seemingly unrelated to the 443.42Mhz clock (30415 us,). Every encoder ive looked up doesnt seem to have a way for me to program the specific signals and timings I would need.

[Anonymous No.1964252]

>>1964125
Strip the insulation off of a length of coax cable like RG-58, separate the inner conductor from the braided shield wires and cut it away, coat the braid with flux and gently heat so it wicks it up and the excess drips away, then use it.

[Anonymous No.1964254]

>>1964139
>modern equivalents to Heathkits?

not in terms complex projects, like doing your own oscilloscope, but for simpler projects, there's this.

[Anonymous No.1964262]

>>1964246
Change the receiver instead.

[Anonymous No.1964268]

>>1964262
Unfortunately that is not an option, signal is for multiple motorised blinds that already have a controller. The idea was to save the $150 dollars for another remote by making my own and challenge myself by not using a micro controller. I’ll do some more research but if I can’t figure it out I’ll just have to use one.

[Anonymous No.1964271]

>>1964268
Use your phone to connect to a micro's web server and toggle the original remote with a gpio pin.

[Anonymous No.1964283]

>>1964271
Yea that’s the plan if I can’t find an ic or combination of ics that would be able send pre programmed signals with those precise timings based on which button is pressed(pretty much a tv remote but rf)

[Anonymous No.1964291]

>>1964246
>I want to send a signal over 433.42Mhz
433.42MHz is the "carrier", and all you need is a radio that allows you to put a signal into that carrier using ASK or OOK.
One way would indeed be to just enable/disable the radio and thus do OOK.
>1208us symbol width.
Put your arduino back into the drawer it belongs.
While it might be possible to pull it off with a shitty AVR8, this is a task that justifies the use of a more capable microcontroller (stm32) or an FPGA.
Probably best to keep it at stm32 if you're not familiar with an HDL.

[Anonymous No.1964300]

>>1964283
Those exist.
Modules like this one use them:
https://www.aliexpress.com/item/4000336212097.html
(unfortunately no visible IC markings on the photos)

[Anonymous No.1964320]

>>1964300
>>1964291
>>1964271
Thanks for the help guys, looks like ill have to actually do some proper reading before I try and tackle this problem.

[Anonymous No.1964329]

>>1964291
>this is a task that justifies the use of a more capable microcontroller
I don't see why. If you're just replaying hardcoded signals it should be fine to just
>toggle gpio
>sleep x microseconds
>toggle gpio
>sleep y microseconds
>...
and 1208us is 1.2ms which can be easily done by even a crappy microcontroller (which is probably what's used in the commercial remote)

[Anonymous No.1964333]

>>1964329
I knew somebody would reply in this form. That's why I wrote:
>While it might be possible to pull it off with a shitty AVR8
And indeed, you can pull it off. Especially easy if you write your code in assembly.
But on a better microcontroller, you can do it effortlessly.

[Anonymous No.1964353]

is there something in electronics I can utilize to generate HIGHs and LOWs randomly?
Perhaps by the rotational diceration of a 4 pole permanent magnet in a magnetic field of an AC electric magnet switching on and off in determined intervalls? Just an idea lol...

8bit MCU solutions are welcome too.

[Anonymous No.1964354]

what is the best way to solder the tiny legs on sot micros?
do i just go one by one putting tiny drops of solder on each legs, or do i kind of smush solder on all legs and then send john wick after any solder bridges?

[Anonymous No.1964360]

>>1964354
Youtube has a bunch of vids of soldering these which you can check.

[Anonymous No.1964367]

>>1964353
>generate HIGHs and LOWs randomly?

if you google it, you should find various circuits based on
- noise generated by a reversed p-n junction
- noise generated by radioactive sources, like in a smoke detector
- randomness of wind speed + direction (or stock market prices if you're internet capable)
- circuit using shift registers, or counters and XOR gates (pseudo random number generator)
- other stuff i dont remember

[Anonymous No.1964372]

>>1964367
oh right
thanks!

[Anonymous No.1964394]

I want to make my own solar battery charger.

I have a PV cell that outputs about 8.2 V in direct sunlight, and I can draw about 200mA directly from its leads. I had planned on using a TP4056 board to charge a 18650 lithium battery. The TP4056 board says it accepts 5V as input. Does that mean I can't use my PV cell, or that I need to drop the voltage down to 5V? Can I just use a different board that accepts 8.2V? I'm well within the limit for current.

[Anonymous No.1964408]

>>1964394
the cheapest solution may be to get a buck converter module, probably <$2 on ebay/ali.

[Anonymous No.1964425]

alright guys i got sent here from /g/
i need a few replacement capacitors for a motherboard that had some snapped off
pic related, not sure what the capacitance is
it says K3 X on the bottom

[Anonymous No.1964427]

>>1964246
>manchester encoding
Is self clocked. The "symbol width" 1208us is probably more of a minimum or a target. I'd aim for slighly more, say, 1.3us.

[Anonymous No.1964447]

>>1964425
Probably 27uF.

[Anonymous No.1964457]

>>1964447
Thanks
What makes you think that, btw? Prior experience with other similar sized capacitors with the same voltage?

[Anonymous No.1964458]

I want to start making logic now by starting with something basic like making a down counter that starts counting down from the 10 minute mark to 0, would I need to manually fill out the truth table with 6 bits (then copy it 9 times) or is there a better shortcut for it?
My process would be:
1) Truth table with 6 bits with D flipflop output that counts from 0-59
2) Karnaugh map
3) convert Karnaugh to d-flipflop equations
4) repeat 9x more times for 10 minutes
Is there a way to shorten step 1 (I know there are already IC's made to do stuff like this but I want to start getting my hands wet).

[Anonymous No.1964459]

>>1964457
Yes.

[Anonymous No.1964460]

>>1964425
>>1964447
this, 27uF 25VDC whatever diameter original is.
Though this seems a bit low for motherboards considering power requirements but this depends where these capacitors are and what they power

[Anonymous No.1964462]

>>1964408
Thank you.

[Anonymous No.1964466]

>>1964457
>What makes you think that, btw?

just a joke, mate. i have no idea what i'm talking about except that i know 27uF is not a standard value, and likely has never manufactured, and that black dick tastes best.

[Anonymous No.1964467]

>>1964466
https://www.chinahao.com/product/543576494221/

[Anonymous No.1964475]

>>1964460
Near the top right of the motherboard, just above the socket

[Anonymous No.1964476]

>>1964459
>>1964460
>>1964467
Thanks again, guys, this is really helpful

[Anonymous No.1964478]

>>1964460
>>1964467
>>1964475
>solid state
Then it looks like polymer caps
Considering their placement near some rather beefy inductors it makes sense due to their low resistance
Possible alternatives (though a bit higher voltage) are somewhat plenty
>mou.sr/3lj7MCR

[Anonymous No.1964482]

>>1964478
Great, mouser has a Canuck website too!
Is 35v still safe to use?

[Anonymous No.1964483]

>>1964476
You should replace all of the chink caps with Jap caps while you're at it.

[Anonymous No.1964486]

>>1964482
>Is 35v still safe to use?
If there's enough room for the larger size cap then yes.

[Anonymous No.1964491]

>>1964486
Perfect
Any specific brands? Should I just grab these Panasonics? https://www.mouser.ca/ProductDetail/Panasonic/EEH-ZA1V270V?qs=sGAEpiMZZMvR1wrj203KOPF7SW6v7ybR5mPd3ia8Gb%2FZX58NAXjj4Q%3D%3D

[Anonymous No.1964496]

>>1964491
Panasonic is fine, but double check the dimensions and make sure they'll fit the footprint on your motherboard.

[Anonymous No.1964536]

>>1964180
>i already specified not signal or zener diodes
You said "normal diodes". I'd say 1N4148s are pretty normal. I think what you meant to say was "power diodes".

[Anonymous No.1964706]

This thermal fuse for my tenant's dryer failed the continuity test. Stoked to make use of my multimeter outside of an /o/ application. Hoping to simply replace this and fix the dryer.

[Anonymous No.1964721]

>>1964333
What’s the limiting factor? Sounds like I could fit that in only half the progmem on a nano without much difficulty, and that’s using the tarduino environment.

>>1964353
LFSR is what audio circuits tended to use for noise generation. There’s some interesting algebra behind them, though they are dead simple to implement without knowing anything. Might be able to get a lower part count with amplifying thermal noise, but those might be finicky.

[Anonymous No.1964725]

>>1964721
The limiting factor is just effort.
avr8 are slow trash, although honestly polling (if the controller doesn't have to do anything else in async manner) wouldn't be hard.
This sort of thing is nice to do with interrupts. Actually, you might be able to make it work without polling. It being over 1ms,.. it could be done with an ISR on a timer.
But my point is, stm32 are dirt cheap and so fast that running this physical protocol would easily be negligible to the point of invisible in terms of CPU time.
Fuck, you can get a black pill with a stm32f103 at ~$1 on the usual chink site.

[Anonymous No.1964776]

>>1964725
>The limiting factor is just effort
What effort? The effort of setting the dropdown in the dweenie IDE to arduino instead of stm32?
>Fuck, you can get a black pill with a stm32f103 at ~$1 on the usual chink site.
No, you can get a black pill with some weird and probably buggy counterfeit chip for $1 on the usual chink site.
A remote seems to me the ideal application for something like a padauk since just about anything should work and you can shave as many pennies as possible. But for a one-off you might as well use whatever's handy. That's assuming it's just a remote and doesn't need to do other stuff.

[Anonymous No.1964786]

>>1964536
>you better not use a 1n4007 as a small signal diode

again isaid not signal or zener

if it doesnt follow the rule of higher voltage lower current on the sliding scale of 1kv 1a at high and low being 300v 5a then its a nonstandard diode and not common grandpa. they dont make 12v 500ma diodes anymore and havent for like 4 decades. old new stock ran out what 5 years ago

[Anonymous No.1964825]

>>1964353
This probably isn't a good solution, but I read it the other night and thought it was interesting
https://electricdruid.net/tr-909-noise-generator/

[Anonymous No.1964829]

Whew, that pic got a smirk out of me OP

[Anonymous No.1964865]

>>1964776
>No, you can get a black pill with some weird and probably buggy counterfeit chip for $1 on the usual chink site.
I've got one. It looks like this:
** Blinky Test **
** Keir Fraser <[e-mail]>
** https://github.com/keirf/Greaseweazle
Serial = whatever
Flash Size = 64kB
Device ID = 0x0000
Revision = 0x0000
Testing I2C1... OK
Testing I2C2... OK
Testing SPI1... OK
Testing SPI2... OK
Testing TIM1... OK
Testing TIM2... OK
Testing TIM3... OK
Testing TIM4... OK
DMA Test #1... OK
DMA Test #2... OK
DMA Test #3... OK
DMA Test #4... OK
Testing 64kB Flash... OK
Enable TIM4 IRQ... .OK
Testing 20kB SRAM (endless loop).....

Passing blinky means that if it's a fake, it's a damn well made one so it wouldn't matter.

[Anonymous No.1964867]

>>1964776
>>1964865
To add to that, I also have some f4 and l0 based similar devboards, they did cost a little more but still under $5.

[Anonymous No.1964893]

>>1964865
How do you test those? I got an extra cheap bluepill on the way.

Also no clue what the difference between a bluepill and blackpill are.

[Anonymous No.1964896]

>>1964893
The serial output had the url... but I'll link more relevant page:
https://github.com/keirf/Greaseweazle/wiki/STM32-Fakes

[Anonymous No.1965049]

More of a general question here but what's everyone's pcb design flow? I feel like I'm wasting too much time on custom parts and general part searching while working on the schematic, then making changes on the layout when I realize I overlooked something. How do people bang out a board in one day?

[Anonymous No.1965050]

i want to blink two alternating leds, but I want them 180 out of phase. I want the blinking really slow, like .1Hz (it's for a decoration so just a gentle pulse would be nice). sine wave would be nice but even triangle would be good enough

is there a good way to achieve this? i originally tried with a 555 but couldn't think of an easy way to have the pwm get modulated by the base .1Hz signal; then I jumped to arduino but that really seems like overkill and increases power consumption. I was hoping to run it off a watch cell but it's increasingly seeming like that can't happen.

[Anonymous No.1965052]

>>1965049
>draw up schematic in kicad
>annotate, then go choose footprint
>search value and package size i need from mouser/lcsc, pick cheapest one that fits voltage tolerance
>generate bom, send to order parts
>draw pcb

connectors are the only thing i stress over; most other things are easy enough to find drop in replacements

[Anonymous No.1965054]

>>1965050
Not really sure what pwm has to do with it but I think a 555 astable vibrator configuration will work just fine, just use the proper R and C values, maybe a pot to adjust duty cycle down the line

[Anonymous No.1965055]

>>1965054
And some kind of integrator circuit on the output my b

[Anonymous No.1965059]

>>1965052
So you really only worry about matching the footprint rather than having an exact custom part that can be referenced via the schematic?

[Anonymous No.1965061]

>>1965050
>.1hz gentle pulse
I'd get comfortable with microcontrollers because of the reduced parts count. Everything can be done with a single 8 pin avr and its internal rc oscillater and no external timing components. And it'll be pretty low power.
If you really want you can use a dual or quad 555 chip to have a high frequency timer modulated by a .1hz sawtooth, check the 555 data sheets they'll explain how to do pwm. A flipflop could be used to alternate between the two leds.

[Anonymous No.1965063]

>>1965059
oh now i see what you are saying. yes, absolutely, i make symbols for ICs not in my libraries, but even then you just link them with the footprint (for example QFN-44 or TQFP-44 or whatever you wnat to use). you don't need to draw the footprint, they're all standardized just make sure you set it as the one you want to use. for generic things like resistor/cap/diode i just use the generic R / C / D component and then jsut assign the footprint i intend to use. I keep all my datasheets in my project folder for the parts i end up buying in the case i need to reference some specific parameters

[Anonymous No.1965068]

>>1965054
i wanted pwm for low power draw since it's LEDs I was thinking high freq could help with battery consumption

>>1965061
OK, that's what I was starting to lean towards, maybe it's not really that overkill. guess I need a qfn socket for my programmer though or figure out how ISP works

[Anonymous No.1965069]

>>1965059
not sure what cad you're using but see pic rel:
you can set symbol (representation on schematic) and footprint (representation on layout) separately so you never need to draw up both and they definitely don't need to be part-specific, they just need to match the one you intend to use (or the one you pick after you're done drawing the schematic, can be done before or after)

[Anonymous No.1965087]

>>1965050
Pretty sure you can do that with three comparators and an op-amp. Use one comparator and an op-amp to make a slow triangle-wave schmitt trigger + integrator oscillator (gonna want a somewhat high quiescent current so like a 10k resistor with a massive cap in order to get that time constant). Then use another comparator to make a fast oscillator (1kHz or whatever), and feed the 1kHz square and the 0.1Hz triangle into each input of the final comparator. Use transistors on that to power the LEDs. Use high-side switching for one LED and low-side for the other, that should provide you with the phase difference. If you want you can use a log filter (series resistor then antiparallel diodes to 0V) to make it more sinusoidal.
Depending on the LED powers, you could arguably replace the PWM driving with just linear driving.

Should be relatively easy to make this in LTSpice or Falstad or whatever.

If you need good battery life, then it may be a struggle to get the oscillator running true. But if you were considering using a 555, you'd be up shit creek because those fuckers draw a bunch of power.

[Anonymous No.1965123]

i hate solder paste, not only it's incredibly expensive, it's almost impossible to buy here but even if you refrigerate it it still only lasts like 6 months
this is fucking gay as fuck, i want to use solder paste for soldering smds because stencils make it so super easy, but just getting and storing the paste is such a hassle it's making me want to kys

[Anonymous No.1965127]

>>1965123
if you're doing that much assembly why not get it done at the boardhouse?

[Anonymous No.1965128]

>>1965050
its a stripped down version of the russian circuit i posted earlier which is adjustable. every one circulates the fixed version. the adjustable one is running a transformer at low frequency. the led blinker can be tinkered with in falstad to get the right resistor values for low low frequency

[Anonymous No.1965129]

>>1965127
i'm not, i only assemble one board once in a while so having chinks do it is not worth it and since i don't do it often it takes me a long time to use up one packaging of paste which is why it ends up expiring in the end
and i just hate soldering smds by hand in regular solder, just slapping them on with tweezers and popping them into a reflow oven is comfy as fuck

[Anonymous No.1965130]

>>1965050
just use the led blinker circuit if you dont want to use a 555 timer. 2 leds supported and auto opposite on of cycles. you could use it to drive a transformer if you didnt mind it not being adjustable after you solder it together

google led blinker circuit. 4 resistors 2 caps 2 bjts 2 leds

[Anonymous No.1965172]

>>1965050
>arduino but that really seems like overkill and increases power consumption. I
actually you are just retarded and probably using like arduino mega or some shit to do it
Use some avr chip like attiny13, it only uses about 1ma of current and if you put it into deep sleep and only wake it up to toggle the leds it like microamps only. (and it works with arduino ide) Plus it's same size as the 555. And doesn't need any bloat like caps.
There is absolutely NO EXCUSE to be an analog cuck in 2020.
NO
EXCUSE

[Anonymous No.1965181]

>>1965172
to adjust the attiny you have to change the code. for 555 timer its more outdated because they dont make it anymore and even the clone is no longer in production . so you can count the time it will be around on 1 hand in years

as long as humans exist they will make resistors, capacitors, diodes and transistors. the ics will come and go and dead diagrams with parts nobody can buy will probably litter google. but in 100 years a person could make the analog one if humans still existed. your 555 timer wont even be recognized . same for the attiny

[Anonymous No.1965201]

>>1965181
wow this cope is so massive it's collapsing space and time around it

i'm so sorry you became an irelevant analog boomer, but that is just how the cookie crumbles, either advance your skills along with the trade, or fade into obscurity

simple as.

[Anonymous No.1965213]

I see you guys have retards even here
I'm sorry

[Anonymous No.1965237]

>>1965213
It all started with some guy who did not know what reactive power was.. then we were suddenly here.

[Anonymous No.1965240]

>>1965049
>find pictures of the components on aliexpress
>save each one as .jpgs until they are no longer recognizable
>put all of them in paint
>connect them with red,blue and black lines in paint
>post it on /ohm/ and complain it does not work
>>1964776
>counterfeit IC meme again
>>1964706
landlords should be killed

[Anonymous No.1965254]

Sorry for the dumb question but how in the frick frack pattywhack do I build a light that changes color based on a physical adjuster and NOT a remote control? Amazon is full of the type of stuff that is remote controlled and I want a freaking slider to adjust my colors. Thanks homies

[Anonymous No.1965260]

>>1965254
You could use a micro & potentiometer to control RGB LEDs with PWM.

[Anonymous No.1965314]

>>1965254

get a 3-color LED and put a pot in series with each color, so you can vary each color from 0 to 100% . you need a series resistor on each pot to establish the max current you will allow. typ. 200 ohms at 5V. as for the pots. prob around 5K to make sure they go completely off.

[Anonymous No.1965457]

Are dim VFDs servicable?
My 2003 Sony receiver has an incredibly bright VFD after frequent use over 17 years yet the 2013 Sony receiver i got last year is so dim in the daylight i cant see it a foot away.

[Anonymous No.1965479]

>>1965457
forgot to add i have the schematic if that helps

[Anonymous No.1965486]

>>1965457
forgot to add, i have the schematic

[Anonymous No.1965497]

>>1963560
>>1963569
>>1963605

Too much heat on your iron for one. If this is your first time that's excusable, but your wires are quite sloppy.

I see burns on your wiring from the pickups to your switch. That's the first place I'd look. Like one anon said, I'd redo the switch and clean it up. The other guard may have issues when you removed it.

[Anonymous No.1965503]

can i solder tiny smds like qfp with these two tips?
in videos i have seen they always use tiny flat tips so it seems like i'm fucked and have to order C1 from the chinkville?

[Anonymous No.1965537]

Any PIC masters here feel like taking on a dedicated but frustrated apprentice? I'm working on a project but I've hit a wall (my background is not in electronics)

[Anonymous No.1965559]

>>1965537
>PIC
Here's your problem.
PIC is the past, inferior in every way, and a relative PITA to work with.

[Anonymous No.1965566]

>>1965559
it's all I know

I'm open to working on other architectures though esp if I can work in C++, Rust, something new and refreshing

[Anonymous No.1965573]

>>1965566
>new and refreshing
From PIC perspective, almost everything is.
>open to working on other architectures
stm32, gd32v would be my main suggestions. Check out the stm32 intro stuff at stm32-base.org. gd32v is a chinese copy which swapped the cpu with a risc-v core.
To get some cheap devboards, see >>>/g/78844377

[Anonymous No.1965586]

>>1965573
thanks for pointing me in this direction

I guess I meant new and refreshing in terms of embedded programming languages. I suppose you normally work with STM32 in C?

[Anonymous No.1965591]

>>1965586
I'm relatively new to stm32 myself. Before, I used PIC and AVR8. Considering price and capabilities of stm32, these two do not make any sense anymore.
It's been mostly a side thing, as I am focusing on FPGAs (verilog) now that there's an open fpga stack. See icesugar on that list. If you end up feeling like trying that out, also get the nanoDLA.

[Anonymous No.1965602]

Is using a cheap switching regulator like pic related followed by a LDO linear regulator a good idea if you want a cleaner output? I was just learning about switching regulators & how they work with a PWM signal and the inductor and it seemed to me that the inductor would resist changes in load, so they'd be great for eg a fan, but maybe not so great for eg a raspberry pi where the load changes suddenly

[Anonymous No.1965603]

>>1965591
right on, I'm currently working with 8bit pics. The 18F family. My main wall is working with the I2C module. Probably because I'm new to reading datasheets. I wish there was more (any) example code, it's so hard to find online

[Anonymous No.1965608]

>>1965603
Yeah... that sort of thing is trivial to do in any modern microcontroller.
PIC is mostly dead these days, community wise. Most people I know who ever used them, including myself (PIC12/PIC18), did everything in asm because there's no open source c compiler for the architecture.
I never used i2c with these, so I don't think I can help either.
I don't how simple (or not) your project is... if it's something simple, you might be able to get away with one of the arduino devboards linked, and the arduino IDE/SDK. The likes of i2c are trivial there.
When most devboards are $1 to $5 range, it's really not worth the pain to use PICs.

[Anonymous No.1965685]

>>1965254
Single quad comparator IC. Use one comparator to make some semblance of a triangle wave (Schmitt trigger oscillator), then use the other three to ride off that T-wave with pots to adjust their trigger position. Put three transistors on the three comparator outputs. Needs a bunch of passives (9-14 resistors, 2 capacitors). A micro might be a better way, but isn’t as fun.

>>1965314
Ew

>>1965457
I think that’s damage to the VFD itself (possibly from overdriving). You can measure the voltages on it while it’s running to see if it’s being underdriven compared to what the datasheet recommends, but I doubt it.

>>1965602
Yes, but LDOs aren’t wonderful at dealing with high-frequency transients, compared to mains ripple. You may want to consider a capacitance multiplier as well/instead, or maybe an LC filter topology. There’s a reason many audio circuits still use mains transformers.

As for their response rate, the output capacitor buffers that. You can assume that the switching controller can react in a couple of PWM cycles’ time, which probably means just a couple or maybe dozen of microseconds. So long as the capacitor has minimal voltage droop after that time period it should be fine on that front. Not like a raspi will probably care about 100mV of ripple anyhow.

[Anonymous No.1965691]

>>1965685
well i must have awful luck, i buy a receiver for the first time in 16 years and i get one that has a burned VFD

[Anonymous No.1965695]

>>1962296
Kek maybe this trio is in the same league?

[Anonymous No.1965717]

Im trying to lower hissing noise on my amp.
I only know how to solder.

where the hell is signal gnd?

[Anonymous No.1965726]

>>1965717
It's one of the traces from the red RCA jack that leads to the potentiometer. Set your meter to continuity test and touch one probe to the outside of the RCA jack and the other to one of the two points. Whichever beeps is signal ground.

[Anonymous No.1965734]

>>1965726
so if its signal gnd to pwr gnd, it's connecting a wire from RCA jack gnd to DC barrel jack gnd?

would you also think its a good idea to ground the banana terminals too?

[Anonymous No.1965738]

>>1965734
Ground is also called common because all components are connected to the same plane on one side (excepting HV and RF which have their own isolated ground reference). The banana terminals are already grounded on the board in your pic.

[Anonymous No.1965747]

>>1965738
>Ground is also called common because all components are connected to the same plane on one side
im assuming thats something like gnd to chassis?

does it make a difference if the power supply doesnt even have ground, if im connecting to pwr gnd?

thanks my guy

[Anonymous No.1965750]

>>1965747
Everything has a ground in a complete circuit or else it wouldn't function. If you look closely at the board you'll see that the traces are surrounded by copper, which is the ground plane. All of the components on the board including the connectors have one side grounded to that plane at some point in the circuit.

[Anonymous No.1965766]

>>1965691
Check the caps near the VFD driver IC.

[Anonymous No.1965776]

This is probably a dumb question and I'm really sorry. How do I input the flipflop outputs into the 7-segment display? The 7 segment display only accepts 7 inputs (excluding the decimal point) and I only have 3 flipflop outputs. Am I supposed to do another truthtable where I convert each number (0,1,2,3,4,5,6,7) into their abcdefg forms...?

[Anonymous No.1965782]

>>1965776
multiplexing

[Anonymous No.1965790]

>>1965717
Looks like a differential class-D amp. Each output jack has two pins, and both go to an LC output filter. If you grounded either you’d get either a lower amplitude output, more distortion, or a lot of heat. So is refrain from extra grounding. What frequency is the buzzing? It can’t be the class-D’s PWM frequency, but it might be some harmonic of it. I’d add more capacitors across the power rails and possibly as a part of the LC filters too.

Though I suspect the noise is coming from your PSU. Shitty SMPSs tend to be too noisy for audio applications, replace it with a decent laptop brick, and if that doesn’t work, use an audio power supply or transformer-based power supply. Might be able to bodge a good power supply with the existing one and a linear regulator and/or LC filter and/or capacitance multiplier, maybe.

>>1965738
What the fuck no they’re not already grounded. They’re differential.

>>1965776
Yes. Or use an existing BCD-to-7-segment decoder, which logisim probably already has. There are 74LS and 4000 series 7-segment decoders on the market, fyi.

[Anonymous No.1965798]

>>1965782
Yeah I forgot mux exist, completely my bad there. I have to incorporate this somewhere in my overall design. Thank you!
>>1965790
>Yes. Or use an existing BCD-to-7-segment decoder, which logisim probably already has. There are 74LS and 4000 series 7-segment decoders on the market, fyi.
Thank you! For now I just want to do something basic but I'll look into the 74LS and 4000, pretty excited at how much there is.

[Anonymous No.1965805]

What does the R mean in electronic markings, I understand that it's a decimal point but it's used both for resistors & inductors... does it have a special meaning?

[Anonymous No.1965806]

Does connecting two signals, each with 1k output impedance count as a mixer?
Would it be possible to use this simple, yet linear, mixer in analog computing?

[Anonymous No.1965823]

>>1965049
After idea and concept, the first thing I do is come up with the bill of materials.
The schematic, layout, and other details are then decided based on what parts are available and cheap.
Once I know most of the parts I'm going to use, then I do topology and layout.
Sometimes there's no avoiding going back and making changes on the schematic to make the layout and routing easier, e.g: changing pin assignments on a microcontroller.
Component values don't need to be decided before spinning the board, of course.
I usually put some extra pads in, e.g: extra filter capacitance, options for different types of connectors, test points aplenty, and superimposing through-hole and SMT footprints for easier prototyping.

[Anonymous No.1965831]

>>1965805
R is much more legible on laser-etched or silk-screened ICs. It likely started with resistors hence the R, but spread to inductors. At least, I’ve never seen 4L7 or whatever.

>>1965806
That’s a passive summer. Usually a “mixer” refers to multiplication of signals. Passive summers and summing amplifiers are comparatively trivial. Mixers are nasty circuits requiring OTAs or JFETs or Vactrols or whatever. A somewhat easy way to go is two logarithmic amplifiers, a summing amplifier, then an exponential amplifier. Easy to hit the rails though, probably drifts a bunch too.

[Anonymous No.1965832]

>>1961504
Gentlemen, can I drive effectively this MOSFET at around 100kHz with a simple 555 or do I really need a driver?

[Anonymous No.1965838]

>>1965790
>What frequency is the buzzing?
not too sure how to answer, but it's those low hissing noise when nothing is playing.

I recently added the signal gnd to power gnd and it did lower the hiss a lil, but added a hum when volume is half way up.

>Though I suspect the noise is coming from your PSU

its two prong so i'm assuming it doesnt have a gnd?

[Anonymous No.1965840]

>>1965832
Gate charge Q_gate = I_gate * T, where T is the time it takes to charge the gate at constant current. For the gate charge, fund the point on the corresponding graph on the FET’s data sheet referring to the voltage you’re driving it with. Note that an NE555 will drive its output at Vcc - ~1.7V, so you’re shit out of luck if that puts it below your V_gate_threshold. For the current, see the short current output current of the NE555. Then multiply the resulting time by 2 or so, since it won’t be constant current but tapering off.

[Anonymous No.1965843]

>>1965832
you don't need a driver at 100kHz given that the 555 has a fairly strong output. you can do the math but i wouldn't bother unless you're pushing the specs and switching large voltages and currents.

[Anonymous No.1965850]

>>1965838
>not too sure how to answer
Record it with a microphone and analyse it with audacity.
>signal ground to power ground
Could you point out where those are on the PCB? It’s possible that it did fix your problem, and the hum is just mains him resulting from an ungrounded appliance. Grounding the thing (wrap a wire around a faucet or other grounded appliance) or strategically adding capacitors (and inductors) might solve the problem completely.

>doesn’t have a ground
That won’t help, but it won’t be the whole problem. There will be noise on the output of the PSU regardless of what it’s from, just don’t know if it’s sufficient to cause the hissing. I’d you have the ability, run it on a car battery or transformer-based power supply. Else, add a bunch of power supply filtration capacitors.

Of course, being able to use an oscilloscope would be preferable.

>>1965843
>he doesn’t know about the decreased output voltage
If he’s running 5V then that puts the output at ~3.3V which is below the maximum V_gs_threshold of 4V. A quick totem-pole ain’t fixing that, don’t think a pull-up works either.

[Anonymous No.1965855]

>>1965850
>that puts the output at ~3.3V
only for a microsecond or so while it's charging the gate. if you care to approximate the output droop as a resistance then it's around 20 ohms, which isn't bad at all and is only around an order of magnitude higher than good gate driver ICs intended to switch fat 600V fets with big gate charges at 400kHz. the higher rdson at 5V drive is going to swamp the losses from the extra switching time at 100kHz.

[Anonymous No.1965856]

>>1965850
>Record it with a microphone
recorded on max power

[Anonymous No.1965868]

>>1965840
So I'm getting that it will take 150ns for an NE555P to switch the IRFU220. If I am using a Vcc of 12 that puts me around 10 volts ouput form the 555. 10 volts gives me a gate charge of 15nC. The 555 can max output 225mA, I rounded down to 200mA.

If a 100kHz signal has a period of 10µs, then 2% of the period is being spent just trying to turn the MOSFET on. Is this acceptable?

>>1965843
>i wouldn't bother unless you're pushing the specs and switching large voltages and currents.
I will be switching large voltages. This is for a boost converter with an output of (hopefully) around 100V.

Thank you fellas for your replies.

[Anonymous No.1965883]

>>1965486
>>1965766
it will be about $2 for all the caps, but hopefully the IC isnt bad, that would run me $10-12

[Anonymous No.1965927]

>>1965855
Read the datasheet. It has a typical high-level output voltage of 3.3V at Vcc=5V, and 13.3V at Vcc=15V. It's basically two diode drops, not a resistive thing, which would scale linearly with Vcc instead of remaining unchanged.

Pic related, even at 1mA or less, the voltage drop is flattening out at 1.4V or so.

[Anonymous No.1965930]

>>1965927
wait what the fuck my 555s don't drop this much and i'm definitely not buying >cmos

[Anonymous No.1966005]

>>1965856
How close was the mic? The SNR isn't great, was that measured with or without the bodge? The hissing is coming from the speakers, not the coils, right?

Started to trace the GNDs of the board, and I think I came to the conclusion that you connected two already-connected nodes.
But I found this (picrel). What the shit is this gap between the two GND planes for, if they're connected at the bit solder hole/pad anyhow?

[Anonymous No.1966069]

>>1965927
Maybe Anon should install a heater resistor under his 555 to heat it up to 125 ℃, to optimize its MOSFET driving performance.

[Anonymous No.1966074]

Doing a project where I'll analyze air and water for certain contaminants with some different sensors. Will need to pass a certain amount of air through water in one of the steps. Do you guys have any idea on what I can do to achieve this? Thinking aquarium pumps is the easiest solution.

[Anonymous No.1966077]

>>1966074
I made a turbidity sensor with PVC pipes once, it worked in a lake/river. are you working in a open setting or a lab setting? the default is using peristaltic pumps I guess.

[Anonymous No.1966083]

>>1966074
Peristaltic are the go-to for non-invasive/non-contaminating pumps. They're not that fast, but should be fast enough for the sensor so long as the reservoir's mixing doesn't solely depend on the pump. Aquarium pumps won't be that much faster, but they should be fine anyhow since they're arguably good enough for fish to live in.
I'm interested in what kind of sensors you can use to monitor water quality though, aside from optical ones.

>>1966077
If it's in a closed system, he'd not want any electrolytic reactions happening with the sensor, which may or may not have been a possibility with your turbidity sensor. Can't remember. Do they pass AC through two capacitive plates or something like that?

[Anonymous No.1966084]

>>1966083
the turbidity sensor was just one led and two receivers, there were other sensors but not water related.
>I'm interested in what kind of sensors you can use to monitor water quality though, aside from optical ones.
Induction salinity meter (did that one as well once in another project). There are capacitive and resistive ones as well but they are subject to fowling and water reactions.

[Anonymous No.1966086]

i'm starting to recognize components

[Anonymous No.1966087]

>>1966084
>one led and two receivers
That makes sense. Don't suppose there's any differential measurement to be made easily, with two different LED colors, is there? Like a pulse oximeter.
>Induction salinity meter
Interesting, gonna look into those ones
>There are capacitive and resistive ones as well but they are subject to fowling and water reactions
Resistive yes, but capacitive ones can have a thin insulating barrier on the plates.

>>1966086
gratz, now remember the SMD codes

[Anonymous No.1966089]

>>1966087
the reaction might happen with salts in the water, giving skewed results. Also it was unsuitable to my project because
>diy
>biological fouling
>Don't suppose there's any differential measurement to be made easily, with two different LED colors, is there?
no. One straight in the optical path and one perpendicular to it to get the scattered light

[Anonymous No.1966090]

I read on https://www.raspberrypi.org/forums/viewtopic.php?t=233421
>For short runs I'd probably use a GPIO pin (buffered, of course).
Can anyone explain what buffered means, or even better how that would be implemented? Eg could you do it with a cheap mosfet/transistor?

[Anonymous No.1966104]

look how fucked this equation is wtf. how am i supposed to use this shit.

[Anonymous No.1966110]

>>1966104
>does not want to learn logarithms
never gonna make

[Anonymous No.1966112]

>>1966110
tell me what log nothing is

[Anonymous No.1966118]

>>1965868
For a boost converter in discontinuous conduction mode, it's the switch-off time that's relevant. The current at switch-on is zero and the rate of increase is limited by the inductor, so it's low throughout the switch-on period. The switch-off occurs at peak current. As Rds increases, the current remains unchanged (inductive load) until the output diode conducts and you start charging the output capacitor. So you're looking at up to I_peak*V_out being dissipated during the switch-off interval. Note that this can be significantly more than the power being converted, which is (1/2)*I_peak*V_in.

IOW: fast switch-off times are important for boost converters. Losses during the switch-off are the main reason that simple boost converters aren't used with high step-up ratios and high power (for that, isolated topologies using a step-up transformer are more common). Continuous-conduction mode reduces the issue somewhat, as peak current is closer to average current (power dissipation is proportional to current squared). The downsides are that you also have to worry about switch-on times and that continuous-conduction is much harder to control (you can't just use hysteresis; typically you use PID control with feed-forward to control the inductor current with a simpler inner control loop to maintain the desired current).

[Anonymous No.1966119]

my sleep deprivation and insomnia are going to put me in an early grave but it's giving me weird and neat ideas in the mean time

I'm probably fundamentally misunderstanding something here.
if we can use fourier transforms to isolate signals of a certain frequency, why is it that we can't do full duplex communication on a single wire just by frequency shifting one of the (AM) signals and then filtering out the respective signals on either end

[Anonymous No.1966120]

>>1966119
in the same vein, if we have, say, a digital signal divvied up into one-byte chunks, what's stopping us from boosting our throughput by assigning each bit its own frequency and then transmitting it via AM, allowing parallel transmission

[Anonymous No.1966126]

So im trying to fix my pre-lit christmas tree.
In this video, this guy says that all christmas bulbs have shunts, so that when one bulb burns out, the circuit isnt broken

Thats fine, but he also says that shunts can fail.
Ok thats fine too.
But then he pulls out some christmas tree light tool that fixes "broken" shunts by sending a small shock through the lights.

At 10:00
https://youtu.be/EzbQCRkZKck?t=595

In that particular video it doesnt work, but there are other videos that clicking the trigger a few times miraculously brings them back to life.
Does anyone know what is actually going on, and why that would fix the circuit? It doesnt make sense to me.

[Anonymous No.1966134]

>>1966077
Cheers, will look into those pumps. It will be in a lab setting initially.

>>1966083
Thank you for the details. I'm testing out some ways to make certain compounds more (or less) detectable using optical spectrometry.

[Anonymous No.1966139]

anyone here uses stm32 chips? mainly the f10x and f40x series?
I am trying to find out if they work standalone with any extra components or not, but can't find anything concrete.
Some sources say you must use a bunch of decoupling caps, other ones also say you need a crystal, so i don't know.

[Anonymous No.1966146]

>>1966119
>>1966120
uhm.... imagine if we could transmit such thing by air uhm.......................................... I will call it "The radio" because of how rad it sounds

[Anonymous No.1966152]

>>1966146
well duh, but I was referring specifically to signals transmitted over wires

[Anonymous No.1966153]

>>1966139
It might run stable enough without decoupling caps but that depends on your board design, power supply, how it's clocked, etc..

It has an internal oscillator so you don't necessarily need an external quartz but it's gonna run slower and less accurate (there are tricks you can use like run time calibration using mains frequency to improve it (AN2868)).

Check out ST's application notes like https://www.st.com/resource/en/application_note/cd00164185-getting-started-with-stm32f10xxx-hardware-development-stmicroelectronics.pdf

[Anonymous No.1966154]

>>1966153
well i want it to be stable enough to do stuff like communicate over i2c and spi.
If just a few caps is what it takes to make it stable i guess i can add them.
But if the power supply is a battery wont the caps be kind of pointless? since battery power is completely clean without any ripples

[Anonymous No.1966156]

>>1966154
>battery power is completely clean without any ripples
that's what Big Battery wants you to think

[Anonymous No.1966160]

>>1966154
The MCU is gonna do some high speed switching. That introduces noise in your clean power.

[Anonymous No.1966161]

>>1966152
https://en.wikipedia.org/wiki/Frequency-division_multiplexing

[Anonymous No.1966176]

>>1966160
>>1966156
So i am looking at some guides and they always recommend two caps instead of just one, why is that?

[Anonymous No.1966182]

>>1966120
>assigning each bit its own frequency and then transmitting it via AM, allowing parallel transmission

if you mean using each bit to modulate a carrier signal, something like FSK, then these carrier signals would be a higher frequencies than the bitstream. this implies that the cable (and the whole transmit/receive system) is able to carry frequencies higher than the bitstream. if so, you just increase the speed of the bitstream and you've accomplished the same speed boost without adding any complexity.

[Anonymous No.1966186]

>>1966176
>two caps instead of just one, why is that?

it's a conspiracy by the Big Cap industry. the ''reasoning'' they use is that the big cap is good for cleaning low frequencies, while the lil fella kills the high frequencies. if you believe that, you probably also believe Biden won.

[Anonymous No.1966188]

>>1966186
wrong, the big cap is called a bank cap and it smoothes out any dips in voltage with the smol cap filters out emi

[Anonymous No.1966189]

>>1966176
>two cap

Lel, i don't think so, get ready to hate your life unless you own a PnP

[Anonymous No.1966191]

>>1966188
>any dips in voltage

a dip in voltage, also known as ripple, is the same as a low-frequency event.

[Anonymous No.1966193]

>>1966188
>any dips in voltage

a dip in voltage, also known as ripple, is the same as low-frequency noise.

[Anonymous No.1966208]

my (non-autoranging) multimeter is acting weird.
When I turn it on, it latches onto a random number, no matter what function I turn the dial to. It does, however, move the decimal point with the range so there's that I guess. Sometimes it will intermittently turn off while turning the dial and it will re-initialize to another random number, but otherwise it's the same.

The battery is fresh. Any ideas?

[Anonymous No.1966211]

>>1966208
Check the battery terminals, the rotary switch, the probe connectors & probes.

[Anonymous No.1966216]

>>1966208
checking chips for continuity, what appears to be an SMD transistor has continuity between what seems like the collector and emitter. I think that means it's goofed. Still trying to find the datasheet online to see if it's not some anomalous depletion mode mosfet

>>1966211
Checked, and they're all good. It does it whether or not the probes are inserted.

[Anonymous No.1966217]

This is the mainboard from an A0 scanner.

Something is wrong with is, as the scanned files are gibberish rather than an actual scanned image of the physical document (will post another picture). this could have also caused the sudden death of my pc's motherboard. As I was troubleshooting it, I had it connected via USB to my PC (ethernet wouldn't work for some reason). 4-5 hours into the process, my PC suddenly died as I had just pressed scan on the software that was running on my PC. I have verified that my PSU works, and I'm pretty sure my motherboard died and have oredered a replacement one. All of the USB devices that were plugged in still work.

Is there anything I can look for while I am waiting for a repair quote for this PCB? Will it even be possible for a professional repair man to fix it?

[Anonymous No.1966218]

>>1966217
Could this pos have caused my motherboard to die? Is there any way to check if it's leaking voltage or sending back voltage to the host device? Wouldn't it have simply killed just the port that it was connected to rather than the motherboard itself?

pic is the scanned file

[Anonymous No.1966224]

>>1966208
Just grab a 17b+ on aliexpress.

[Anonymous No.1966228]

>>1964458
I may be misunderstanding what you mean, but why would you need to go through Karnaugh maps at all?
59 is 111011, which can be matched with a 5-input AND gate; by looking at the bit patterns for 58, 57, 56 etc it's obvious that those five bits do not get set until 59 has been reached.
You can then use the output of the AND gate to reset the 0-59 counter and simultaneously increase a second counter, counting from 0-9. Same principle applies there, but you match the value 1001.

Or, since you specifically mention counting down, you can also load your FFs with the value 111100 (60) at the start, count down and just look for all zeroes. (And counting down is of course just counting up with values inverted)

If you can find it, try to get your hands on "The TTL Cookbook". I know there is a PDF version around somewhere. It's old, but full of real-world tricks from the days when you really had to minimize the number of ICs. Look into selector logic for example.

[Anonymous No.1966233]

Hey /ohm/, a while back people mentioned some formerly commercial circuit simulation package that had recently become free. It had a large library of real-world components and seemed like something worth checking out.
I can't remember the name and have no idea what to search for. Anyone know what I'm talking about?

[Anonymous No.1966240]

>>1966233
Probably Micro-Cap:
http://www.spectrum-soft.com/download/download.shtm

[Anonymous No.1966242]

>>1966240
what does this offer that LTSpice doesn't?

[Anonymous No.1966244]

>>1966240
That's probably it yeah, thanks. I can find archived threads now that seem familiar.

>>1966242
More components/better models I think.

[Anonymous No.1966247]

>>1966216
what are the chances that, if I yoink a random transistor off of another PCB and swap it in with the broken one, that it will work

[Anonymous No.1966267]

>>1966247
>what are the chances
random

[Anonymous No.1966280]

>>1966126
Well I went and bought the tool, and it fixed my lights in within a few clicks.
It actually fixed several lights I thought were completely dead.

I still dont understand how it works, or how a shunt would suddenly be fixed with a jolt of electricity

[Anonymous No.1966298]

>>1966119
We can, it's called frequency multiplexing.

>>1966120
Look into the Shannon-Hartley theorem. The maximum bitrate you can obtain is proportional to the width of the frequency band you're taking up.

>>1966126
>>1966280
https://en.wikipedia.org/wiki/Antifuse

>>1966134
A prism + ccd is the cheapest way to make a spectrometer that isn't just a bunch of different colour LEDs.

>>1966216
>an SMD transistor has continuity between what seems like the collector and emitter
The diode-check mode will detect a diode between base and emitter. If you're assuming the middle pin to be the base, you're probably wrong. Do some out-of-board testing on known components instead of fucking about on some mystical PCB.

[Anonymous No.1966300]

I've been thinking for a long time about making an analog video switch, but I don't know exactly where to start. I have some experience with electronics, have access to most tools I could want but I know shit about the frequencies involved and have never undertaken such a project. I'd appreciate some pointers (experiences, reading material, relevant ICs etc) as well as general thoughts.

Requirements:
6-7 composite inputs
3-4 composite outputs
2-3 component inputs
1 component output
Composite output and component Y must share the same output lead/RCA plug
Must also switch stereo audio in/out for all sources

Some thoughts:
Independently switching the composite outputs (send composite input 1 to output 2 while sending input 3 to output 1, for example) would be nice but also looks to me like it would drastically increase complexity. Alternately, having one "monitor" output and ganging the other outputs together would be a decent solution
I'd like to keep the video and audio switching physically separated (within reason) as I'm somewhat paranoid about noise. The setup would among other things be used for digitizing videotapes and I prioritize signal integrity over cost/ease
Control via Arduino just because it's easy and extendable
LEDs on front to indicate which source is routed where (this I know is trivial)
Might throw in S-video in/out while I'm at it although I don't have anything using it atm
Considering using SCART for the main/monitor output to handle all the different types of output. Having SCART on all the inputs would be nice I guess, but they are rather expensive, take up a bunch of space, and I just don't see the need for having all the inputs supporting all types of signal coming any time soon
A switchable processor loop for composite video would be nice


Any and all input appreciated

[Anonymous No.1966302]

>>1966300
I'd say use FPGA

[Anonymous No.1966320]

Any idea how I can make a logic circuit out of this?
The crux is that while T1 is high and T2 becomes high too, M2 is supposed to stay low and vice versa

[Anonymous No.1966324]

>>1966280
> how a shunt would suddenly be fixed with a jolt of electricity

i'd guess there are 2 contacts that are touching but not conducting coz of oxidization, and a zap of current welds them together.

if you have too many shunts in place, the voltage each bulb receives can get too high, and more and more bulbs blow, which causes a cascade that kills them all.

[Anonymous No.1966326]

>>1966302
For an analog signal? No he should just use a bunch of analog switches and 1-of-N encoders like the old days.

>>1966320
Draw a timing diagram, and/or show the full truth table if there aren't any transitions.

>>1966324
https://en.wikipedia.org/wiki/Antifuse

[Anonymous No.1966337]

>>1966320
>>1966326
This is how it's supposed to look like

[Anonymous No.1966361]

>>1966320
>>1966337
tinyurl.com y5453q3a
I made a quick falstad thing

[Anonymous No.1966365]

>>1966361
crap I got something wrong
I dont have time to fix it now

[Anonymous No.1966371]

AVR ADC guru needed. I use an AVR to sense water flow in a pipe. Two stainless steel screws in the pipe conduct when water is present. Pic related shows 24 hours of samples. Some of the time when there is no water, the signal is noisy, but this never happens when water is in the pipe.

There is a connector between the sensor circuit and the AVR pins which might be the cause. At about 8:30 am in the plot I plugged/unplugged it a few times and it might have cleared the noise, and it might have simply gone away on its on. The question is, does a bad connection make sense based on the circuit and the plot? Why would it never show noise when water is flowing, which I believe acts like a 20k ohm resistance, so there is some current flowing in that path, but the current in the connector pins to the AVR is not affected by this.

My understanding is that the ADC is like a very high impedance, but it has capacitors that are charged which requires a bit of current for each reading. Why would the circuit work correctly when the voltage doing that is low (about 1 volt) compared to high, which is about 5 volts?

This circuit has been in operation for over a year, and the noise comes and goes and does not correspond to anything I am aware of, like rainfall. But until today the noise was bearable, like that between 9 and 12 on the left end of the plot. The threshold to determine if water is flowing is the red line, so today there were some false spikes when the noise barely made it to that line, meaning I need to fix it.

[Anonymous No.1966377]

the retard in change of naming these should be fired
it actually happens that people order CB chips from chinks and get C8 chips because they look very similar, seriously whats next? a line of chips named
O8B01 and 0B8Ol?

[Anonymous No.1966392]

>>1966371
>Two stainless steel screws in the pipe conduct when water is present.
Are the electrodes in bad shape? Maybe galvanic corrosion.

[Anonymous No.1966405]

>>1966392
They're not great; per the circuit, they are always energized with the same polarity, so one has a dark appearance and the other is clean. I toyed with the idea of adding circuitry to reverse the excitation each time, but since it works I'd rather avoid adding components. The basic circuit has been in operation about 15 years, but the connector that I suspect was only added a year or two ago so it would be easy to quick-change the AVR box, which also senses a lot of other things.

However, relative to your point, it doesn't seem that that would make the noise come and go during the "off" periods, and never appear during the "on" periods, right?

I will eventually "fix" it by replacing the AVR box, the circuit shown, or the wiring that connects all that to the pipe which is about 30 feet away, protected by a conduit. It annoys me that I can't come up with a theory to explain the intermittent behavior. The only clue is that it never happens when water is present, only when there's no flow.

[Anonymous No.1966411]

>>1966392
>>1966405
Ok, I might have missed your point. The connection to the screws is well protected and is solid, and was changed a few months ago when the cable developed a fault. The noise was the same before and after, in that it comes and goes. But today it went wild.

[Anonymous No.1966412]

n00b question here

which of these is live, the left or the right wire? there isn't a white cladding on either. the right wire has fringes on the side whereas the left has the mfg info printed and a smooth side.
>look up the mfg data
haven't found shit

[Anonymous No.1966414]

>>1966412
forgot image

[Anonymous No.1966418]

>>1966412
the hot wire is the more narrow prong on a plug if they are both the same then one on the left when looking at the plug straight on.

also why is it no one can google here? just google plug polarity BOOM done.

[Anonymous No.1966419]

>>1966412
>which of these is live, the left or the right wire?
you have not given enough info. is the wire already hooked up to something? if no then pick one. if yes then it gets complicated but basically the hot wire goes to the fuse or switch.

[Anonymous No.1966421]

>>1966418
this helped, thanks
>>1966419
other end is a plug but I've got it figured out

[Anonymous No.1966458]

>>1966320
>>1966337
OK here is a fixed and simplified falstad simulation of what I am trying to achieve
the outputs M1 and M2 are missing obviously

tinyurl com y3qzdqdl

[Anonymous No.1966476]

Hear me out bros, I'm trying to make this counter that counts down from the hundreds but I ran into an issue. I'm using 12 d-flipflops, with 4 each controlling a single seven-segment display.
So I have 3 seven-segment displays which represent the hundreds, the tens, and the singles individually. I have it so that when the singles go to 0, the tens goes down by 1 and when the tens hit 0, the hundred goes down by 1.
However, when the hundreds go down by 1, the tens number doesn't go down to 9 but stays at 0.
I know this is probably hard to read so I'll try to say it in another way.
500 -> 409 -> 408... -> 401 -> 490 -> 499.... -> 400 -> 309.. -> 301 -> 390.
The D flipflops are wired so that they start at 0 and the next number starts at 9 -> 8... -> 1

[Anonymous No.1966484]

>>1966476
Nevermind I think I figured out where I went wrong, the tens start at 0 and they only go down by 1 when the singles hit 1 and is about to hit 0. I changed it so that they go down by 1 immediately when the singles go from 0 to 9!!
Holy fuck I'm dumb as fuck. Good thing the thread is about to die...

[Anonymous No.1966500]

>>1966414
Usually the smooth wire is the hot, ribbed is the neutral. But this is not always respected.

[Anonymous No.1966517]

>>1966371
Use a smaller resistor, like a 10k. Not like there’s any fuzz on the other side, so there won’t be any downside besides galvanic issues.

[Sally Struthers No.1966567]

>>1961525
> For years I’ve helped children. I’m Sally Struthers and I’m asking you to help poor toolless children in Africa.
> For just the cost of shipping, we can send one marginally functional multimeter
> to a poor child Today. Won't you please help?

[Anonymous No.1966570]

>>1966517
>so there won’t be any downside besides galvanic issues.

or sewer rats fucking in the pipes.

besides the lower resistor, a cap across might help to attenuate the spurious alien RF transmissions. every unshielded cable should have a cap.

[Anonymous No.1966595]

>>1966570
Oh yeah, a cap is a good idea for certain. 100nF should be more than sufficient.

A low enough resistor value (and a power supply that can handle it) or a massive enough capacitor will take care of the rats too.

[Anonymous No.1966606]

Is there any danger with connecting a CR123A battery bank directly to a buck voltage regulator? Im using a TPS62050. I'm planning on putting one pair in series and one pair in circuit for max capacity at 6V. Do I need an additional protection circuit?

[Anonymous No.1966607]

>>1966606
I meant one pair series one pair parallel

[Anonymous No.1966643]

>>1966606
>>1966607
Why not each pair in series, then both pairs in parallel? How are you charging the batteries? Does your buck converter have overvoltage/overcurrent/short/reverse polarity protections? Should you fuse the battery+ inline with the buck input? What other ways can you limit current from the batteries?

[Anonymous No.1966667]

I'm trying to make a counter where as soon as it counts up to 4, it just stops and starts another counter, is there a way to go about doing that?

[Anonymous No.1966680]

>>1965503
I use that BC2 style tip for everything smd.

[Anonymous No.1966681]

>>1966643
>Why not each pair in series, then both pairs in parallel?
yeah I'll do it that way
>How are you charging the batteries?
planning on using primary cells
>Does your buck converter have overvoltage/overcurrent/short/reverse polarity protections?
It lists Overtemperature and Overcurrent Protected on datasheet. I can't find any other information. What would you do for reasonable safety?

[Anonymous No.1966706]

>>1966681
>What would you do for reasonable safety?

they're small but capable of 1.5A, so you need to take a minimum of care. and that involves making sure when you parallel things, the 2 batteries (or 2 series circuits) are both at approx the same charge level, and are of the same brand, and same age. this is to prevent the strong ones from dumping their seed into the weak ones, and getting all hot and bothered doing it.

[Anonymous No.1966714]

>>1966706
the usage will be routine, cells will be same brand and age. Would it be overcomplicating things to add other components for safety since this converter has overcurrent, overtemperature?

[Anonymous No.1966722]

>>1966714
>overcomplicating

yes it would. maybe just add a fuse on the batteries in case of catastrophic failure.
they're small batteries, so even shorting them is just gonna produce a little heat. some people purposely short 9V batteries to use as hand warmers.

[Anonymous No.1966793]

>>1966722
thanks. I'll start researching fuses and try to add one in. This is the first time I've built something

[Anonymous No.1966820]

What are some cheap and easy guitar effects to make that you guys can recommend for me? Just for initial testing, I'll get into more complicated and polished designs once I get into making a custom modular-synth platform.

So far I've got:
>octave up
>sustain (with vactrol)
>tunable distortion/overdrive

I don't have any access to variable pedals, so the effects have to be set-and-forget. So no Wah. Autowah is difficult.

Also not sure if I should have a gain stage after the guitar, since all of these will be intended to be cascadable. I'll have to read into what kind of voltage levels and impedances a guitar outputs directly, and what kind of SNR to expect. I'll start every effect with a buffering step of some kind, so don't worry about that.

[Anonymous No.1966842]

>>1966820
Looks like an octave-down effect is pretty easy too. As in using the frequency divided square wave to toggle the polarity of the initial waveform, not just feeding the square wave back into the passthrough.

[Anonymous No.1966877]

>>1966820
Octave up is hard to do without digital filters.
>phaser
>vibrato
>distortion (fuzz face is the easiest)

[Anonymous No.1966885]

>>1966877
>Octave up is hard to do without digital filters
Just doing a simple full wave rectification. Doesn't just double all the harmonics, adds a bunch of new ones in too, especially even harmonics. Also adds negative harmonics if you're playing multiple notes at once, which sounds edgy.

>phaser
I've got all the shit to make one relatively easily with vactrols, but it's quite a lot of parts. Might do so, but probably won't.

>vibrato
A periodic variation in frequency, doesn't sound easy to do at all. Requires mixing (multiplying) the input signal with an oscillator whose frequency is varying. And probably filtering one sideband off too, somehow.
That or using an oscillator whose frequency is varying to feed the clock input of a BBD, which I actually have some of. At least I think that will work.

A tremolo on the other hand, piss easy with a vactrol VCO and an oscillator to vary it.

>distortion
Doing that with my tuneable overdrive. I'm using op-amps for hard clipping, but with an option to switch in anti-parallel diodes for soft clipping. Op-amp circuits are easier to design and debug so I'll be sticking to them, as opposed to the older style of transistor effects. I've already tested this circuit before so I know what I'm doing.

[Anonymous No.1966887]

>>1966885
yeah I bunched the vibrato and tremolo. tremolo is much easier.
>I've got all the shit to make one relatively easily with vactrols, but it's quite a lot of parts. Might do so, but probably won't.
I made mine with 2 home made vactrols. (led with LDR and heatsrink)

>Doesn't just double all the harmonics, adds a bunch of new ones in too, especially even harmonics. Also adds negative harmonics if you're playing multiple notes at once,
yeah it sound like shit tho.
You could do a mechanical reverb. If you use Piezos for sending and receiving it will sound like garbage but will be easy to make I guess.

[Anonymous No.1966888]

>>1966887
And if you can buy PT2399 ICs then it is easier to make a proper reverb.

[Anonymous No.1966892]

>>1966887
4 vactrols*

[Anonymous No.1966894]

>>1966887
>I made mine with 2 home made vactrols
Just a two stage phaser? What does it sound like? All the circuits I see use like 8 stages.

> it sound like shit tho
The demo I saw was pretty cool. By FesZ Electronics on YouTube.

>>1966888
>ADC and DAC
Might as well just slap a cheap MCU and do any DSP I want. For that sort of thing I plan on using my BBD ICs as far as I can. MN3207s (with MN3102 drivers) in case you're wondering.

[Anonymous No.1966896]

>>1966894
If you have BBDs then you do not need the PT2399...

[Anonymous No.1966945]

>>1966567
man how come i never see coupons like that for flukes?

[Anonymous No.1966956]

>>1966877
>Octave up is hard to do
just mix a signal with itself, innit?
maybe you'd need an all pass filter -> multiple mixers per band to keep it clean

[Anonymous No.1966960]

>>1966956
without expensive mixer IC or DSP usually people just pass it through a rectifier bridge.

[Anonymous No.1966965]

>>1966960
it's just a gilbert cell, innit? can't be hard to make

[Anonymous No.1966977]

>>1966965
it actually is.

[Anonymous No.1967031]

>>1966517
>>1966570
>>1966595

Thanks for the ideas. Definitely should have a cap. Reducing the resistor from 100k to 10k should shift my signal range from 1v..5v to about 3.4v..5v, but if the noise goes away I can deal with that. Also ordered rat traps.

[Anonymous No.1967041]

>>1966570
>, a cap across
Across what

[Anonymous No.1967053]

>>1967041
butt cheeks

[Anonymous No.1967199]

i want to stock on some chips from chink before the retarded import laws hit, is lcsc the best store in chinkland for this?

[Anonymous No.1967205]

>>1967199
find a aliexpress seller which has the most variety and order everything from him so it comes in a singel package(or a couple guys).

[Anonymous No.1967211]

>>1967205
i use ali alot but not micros, there are too many scammers there, some of the huge stores are fine, but those only have small chip selection and mostly sell dev boards
i still cry every time i look at my bag of 20 chips that have Attiny85 printed on them and also attiny85 pricetag on them, but as i found out are actually attiny13.
Paying few bucks extra to make sure i am getting the top shelf insectoid silicon is fine.
I looked at a big chip seller in my country and those jew cunts are selling the same chip for literally over 3 times more. And you fucking know it was made in the exactly same insect hive.

[Anonymous No.1967219]

>>1967211
>I want to buy chips
Specify then that you want uCs before asking your question. And buy from vendors with good ratings, read the comments. I have managed to get refunds 100% I was scammed on ali, and it was super fast.
LCSC is good too I guess.

[Anonymous No.1967234]

>>1967219
>And buy from vendors with good ratings, read the comments
I have ordered literally hundreds of things from ali, i am a fucking ali expert. But sometimes only sellers with no orders offer the item, or they only have like 5 ratings with no comments so that is all useless.
Even if the seller has say 30 5 star ratings and nothing else i can still be a scam because idiots who buy there rate it 5 start when the package arrives and before they try the chip and find out it's fake and you cannot lower start count on ali, only increase.
So sometimes i just have to take the risk since no reputable stores sell the part i want, and so far i was only scammed once and couldn't get a refund because i only found out a month later

[Anonymous No.1967257]

>>1966300
>I don't know exactly where to start.

well, i'd start at the thrift store (or kijiji, ebay, etc). since everyone is converting to HDMI, you can find lots of items like this going for around $3. (i bought 3 myself, as general purpose signal switches, not necessarily for video.)

[Anonymous No.1967285]

>>1967283
>>1967283
>>1967283
>>1967283
NEW THREAD

[Anonymous No.1967497]

>>1967199
>before the retarded import laws hit
What? Is this in burgenland?

[Anonymous No.1967964]

>>1967497
Cuckistan union
https://ec.europa.eu/taxation_customs/business/vat/modernising-vat-cross-border-ecommerce_en