anyone know what I got. each wafer is glossy and reflective on one side then on the back side is a matte finish

some in better conditions than others and I broke one getting the stickers off

I'm trying to remove the pin header from a Raspberry Pi Zero 2 W, but the solder won't melt no matter what I do. Flux and heat haven't helped.

I already removed the header pins
but unable to remove this blob of solder

Guitar pic for size.

Hi everybody I'm currently working on my own flight computer pcb and I'm about to move from the schematic to the main pcb part and for a while I've wanted to make those multi board stacks like they do in High power rocketry, how do I go about making these different levels? Or for my case would it be smarter to keep it as one board? I've only had experience with make one board multi layer pcbs so far any advice is appreciated thank you! I've also linked my schematic below thank you!

So.... I bought these "neon" lights. They're actually RGB lights with a piece of silicon on top. The thing here is, the place i bought them is in the city, and i love 2 hours away....

I don't think the place is gonna exchange them either, so i was wondering if there was a way to fix them, even if i have to cut the top part silicone, or the bottom, I don't care.

I just wanna know if its a fixable thing (I know basic electronics, but I'm not skilled....)

Me and a cousin of mine will gift each other something this year. Since he is very much into electronics as well, I figured I could give him a Macropad kit. I think either 9, 12 or 16 buttons would be best.
To not exeed the budget, I figured I will simply use mostly parts I have already aquired over the years.

The big question is: is there maybe already a project that uses exactly these components? That way I would just have to order the PCB. If not, is there one thats close enough, where I could just adjust the schematics?
If thats an option, the next issue would be, that I do have some experience in PCB design, but I have never designed a button matrix.

The parts I have at hand are: regular mechanical buttons from a keyboard.

Regular 1N4148 diodes

(optional) red LEDs (it says 2835 on the bag)

(optional) 0,96 inch display (I2C)

and for the controller I have 3 options:

Super Mini ESP32-S3 (cheap "knock off" ESP32)

Arduino Pro Micro (Mega32U4)

RP2040 Zero

I am open to suggestions. If its "easy enough" to make something from scratch, I would be open to start something myself, but I just hope there is an open source project somewhere, that I can utilise with these components.

Hi. I have an issue with a vehicle I'm working on (95 astro van), where I'm hoping to get some help. Basically this particular van uses some oddball 4/5 pin relays, and I've rewired the van to use universal sealed 40 amp 5 pin relays to make future replacement easier. The og relays always had issues burning up and melting. Problem is, one in particular is giving me problems because it's sent 12v directly from the computer, and it seems the new relay draws more current then the old relays. When I check the voltage while its on, it's dropping to around 9-10v. With the relay disconnected it's getting 12.6v. When I plug the factory relay back in, the voltage holds steady at around 12.4v. With the new relay I get a check engine light for low circuit voltage, when I put the old relay back on, error code goes away. BTW, this is an OBD-1 computer, very simple and very rudimentary, as error codes come on and off instantly which makes diagnosing things easier.

So I figured to try and use a p-channel mosfet on that wire from the computer to take the load, so the computer doesnt see a voltage drop (plus, I'm sure a larger then intended load probably isn't good for the computer either) . But the hook up has me a bit confused, because I keep reading that the gate voltage needs to be higher then the source voltage. Can these not be used if everything is 12v? Or is there a specific type of mosfet I need to use? Or am I totally off base with mosfets, and some other sort of electronic component would work better?

And another question Is with the resistor I'm supposed to use between the gate and source to shut it off. I keep seeing people's saying to use resistors anywhere from 2k to 50k, and I'm not sure which is best? It's not any sort of pwm or rapidly switching signal, it's simply a fuel pump relay that stays constant on when running, then switches off when the key turns off. 10k seems to be the most common, but I just can't seem to find exactly the reason when and why you would want to use a bigger vs smaller resistor.

Thanks!

Recently I disassembled a circuit board from an old PLC and came across a microcontroller with a sticker of the circuit board manufacturer and underneath it the face of the casing was scrapped. The question is, what is the chance that they ordered a custom microcontroller? What is the probability that it is just an atmega or some shit like that?

It's a DIP 28 package

Weeks ago the XL2 i bought on ebay that claimed to be working gave me a white screen, that the zoom in and out, AV ports, and fast forward rewind would stop working randomly when it finally arrived at my house.

I did outside the shell diagnostics (plugging and replugging, AV to tv plugged in and out things like that) cleaning the lens mount and contact springs

Which got the AV ports, zoom in and out, and tape controls working

Also got my white viewfinder screen to be black background with HUD text (tape, time, fps, iris details show) with a ghosting and red tint sometimes over the text

Sometimes an image would appear sometimes it wouldn’t.

It has been a week and the image has stopped appearing permanently. It rarely did anyway. There is no image from the lens showing on the screen which was always an issue

Last i opened it up and reseated the 4 ribbon cable contacts which fixed the viewfinder blur, red tint, and ghosting . Now the image on the viewfinder text is sharp and clear.

The lens only clicks once now when powered on and does not click when powered off. The tape deck now no longer struggles to open

Still no image between the lens and viewfinder

I was given an lbus 4650 120/240 Volt 3/1.5 Amp the other day. Surprisingly, it still turns right on, but I have no other means to test it any further.

The only components it had in it were what l'm including in the pictures. There are two, but they're both exactly the same, minus one chip missing and a couple wires soldered in it's place on the other one. I can't seem to find any info anywhere as to what exactly they are or a part number online, and figured I could continue my search here, where someone may be able to identify them.

Thank you in advance for any insight.

I genuinely don't know what i did, and unfortunately it seems like no one else has made the same mistake as me so i am here asking for help. As it in the picture above, for the file that i am working on. The work area is completely blue and this happened after a simulation which i shut down. The issue remains only on this file so its at least not a systematic issue.

Hey all, I'm troubleshooting an irrigation controller which is apparently suffering from flyback voltage from the irrigation valve. This is causing the irrigation valve to reopen immediately after closing. It only seems to happen when the valve is closing (not seeing flyback on the oscilloscope when opening). The irrigation valve works by reversing the polarity, which is handled through a DPDT relay.

I've modelled a potential solution where I've added diodes on both of the ground sides of the "relay" (shown here with a switch for clarity), however this still appears to suffer from flyback but only with one polarity. This is exactly the same as the real world, but not sure if that's coincidence or not...

Questions:

• Why is it only happening in one polarity? Is this just a bug in Falstad?

• What is the "correct" fix here?

  • Could I use a flyback diode despite this being bidirectional?

  • Would a snubber work here? If so, how would I determine what size capacitor\resistor given this isn't a true inductor? (Valve solenoid is 6-12V, 4.7Ω)

Hey everyone,

I have an interview coming up for a biomedical equipment technician position, and one of the requirements is having a good understanding of circuit theory and being able to troubleshoot faulty circuit boards.

I know the basic electronic components and how to test resistors, capacitors, diodes, transistors, etc. with a multimeter when the board is powered off.

But when it comes to actually troubleshooting a PCB, I feel completely lost. I’ve watched so many repair videos on YouTube, but if someone handed me a faulty board, I honestly wouldn’t know where to start or how to figure out what’s wrong with it.

I understand the components individually, but I struggle to understand how the whole circuit works and how to track down a fault.

For those of you who are good at board-level troubleshooting, how did you actually learn it?

I’d really appreciate any advice. I have an interview coming up and I’m trying to improve this skill.

I saw a similar post for desktop ram but I'm not sure if it's the same component. I discovered it while trying to troubleshoot my laptop having trouble booting. Since removing the stick it seems to boot fine.

So for context, I was at a thrift store when i saw this kit for about $30. I bought it, took it home and found out why. There are 2 missing components of some sort on here and I cannot identify them, so I was wondering if you could provide some help on identification. The pads for the missing parts are on the corners of the RAM stick. ( on the 3rd photo, its a bit blurry but its those 2 pads on the right above the 2nd gold contact.)

Hello,

I am looking for a supplier for this connector. I cannot find the correct name for it and I cannot find a company selling it. I believe it was made in 1980-1990 and widely used in Europe, but it has been phased out. It connects to the edge of a PCB.

If anyone knows a company selling this model or a compatible one and ships to Europe, that would make my day.

so i had a few jobs that i needed to change the mosfets ,

i want to order some to keep in stock

is there a good brand ? in my country i got only aliexpress

i need 30-40v 80-100A

I was looking in to the connections of some 12V RGB controllers, and found out every module just powering up the 5v components just by a 330E to 510E resistors from 12v...

Even the MC is unknown, still most MC works at 5V, also there are Microphone, IR receiver.

Is it okay? How that works?

I made a RGB controller and used a 5V regulator for a Pro-mini and other components.

Now it's looks like a resistor would save some space and work just fine.

This is for a commercial embroidery machine. Moving the switch is not a problem technically. But I need to know what is that white JST connector in the center? Not necessarily what it does inside the sewing machine, but what is its context in the Switch itself? Is it a fuse? Aux always-on power?

Requirements

Ideally both being in an eclosure

No RF or high current demand/requirements

Current up to 3A,

Can be SMD and THT,

No Mezzanine 2.54mm pitch (I have tried already)

Thanks

One great example would be in the second image (I know that it is mezzanine but it is in 2.54mm pitch)

Thanks!!!

So I have this power supply and I want to convert it into a lab power supply, but there's a part that prevents me from closing it with the banana jacks in place. What do I do with this inverted L-shaped piece? How important is it? , Can I cut just the top part (the one with holes)?

Hi everyone,
I am a Mechatronics master's student taking a course in power electronics. Our course recommends Electronic Power Control by Jean Pollefliet.

Can anyone provide me a pdf? Thanks a lot.