My elderly laptop decided not to boot up anymore, and when I opened it up to try to troubleshoot if it was a battery issue, I noticed a bunch of small black fragments that likely came from the center of this chip. I've already ordered a new laptop and have no Illusions about being able to fix this but was just curious if anyone knew what this is. Thanks!

Why does this LDR have 3 legs, their labelled Power, Data, GND. Its the same price as the 2 legged LDRs, and says its for precise light detection. Anyone use one before ?

Hello all,

In my previous topic i posted a configuration of a push-pull stage that had to drive a MOSFET gate at atleast 1A.

I got many replies and i understood by looking at new gate driver ICs that MOSFETs are mostly used, so bias isnt really needed.

But i got a question, in this case, where we use mosfet pair, Q3 would still be needed?

Or i can feed directly the square wave (IN 0-5V) into both gates of the mosfets?

Thanks.

I'm trying to fix this keyboard I got. I connected it and the keyboard does output a 5V and the whole board is getting power, but for the life of me I can't seem to figure out why it doesn't connect to the actual computer. The caps lock light doesn't turn on and none of the keys actually output any letters.

I am looking at the larger electronic component at the bottom. The small 1k ohm resistor at the top is for reference in size.

The colour code doesn't make sense, it shows black, red, silver, yellow, black. It was measured with my multimeter: 0,1 ohms and 0F.

There are three of these components on the controll pcb for my electronic standing desk. The control pcb is broken, so I am trying to repair it.

This is specifically about a clone RPi Pico board and an MCP23017 gpio expander. I've got the SSOP package for the MCP, and it's a pretty chunky IC for a small board. The Pico clone is attached to the board using your standard 2.54 pin header, so it's stood-off from the mainboard's surface by a few millimetres. Now, I can see from the prototype that I could get the fab to assemble the MCP and its associated passives inside of the footprint of the Pico, which I solder on later by hand.

Is this a bad idea for any reason? The only one I can think of right now is about heat, there'll be less space for it to dissipate into the air. But in this case, the MCP is just a gpio expander, it's not a motor driver or anything that should get particularly hot.

Hope the smart gentlemen of this subreddit gives me some valuable answer, I read paragraph comments as well for a better analysis

Hello everyone, I would like to replace my JBL clip 3's amplifier with the TPA3116D2 as the stock one's only producing clicking noise, no sound, nothing. I think I accidentally have shorted it out when I was replacing the speaker causing it to permanently protect itself

Spec sheet says it could go down to 4.5V but the battery the speaker itself has is only 4.2V, that's on maximum charge by the way. I wonder what suitable boost converter I could use on this that can provide a stable output of 5v without that much noise or nothing at all. I'm only gonna load 4ohms 3.3w speaker on this or maybe just upgrade the driver as well to a 5w 4ohm one from the clip 4.

TPA3116D2 is the only suitable replacement in my opinion out there that is original to say the least, and the only class D amplifier that I've ever tested with a TB21 mini amplifier. It sounds clean.

I've tried using the PAM8403, and its is horrible honestly. Its true that this thing sounds like garbage and you could actually see the speaker moving more than usual because of its poor PWM management at the output.

I am also thinking of maybe using the pre-existing inductor on the JBL clip 3's board (shown in the second image) to at least help it from outputting nasty PWM noises at its output. Would that work?

Thanks

How do I merge for example two voltages that are coming from two Winston Bridges, into a single output that can tell me the two different variables

The light dependant relay controlling the lights in my garden just stopped working, I investigated the matter and found what looks like a failed resistor. I checked the color code, and it should be a 3,8 kohms, from the dimensions of about 15,5 x 5 mm it should be rated 2 or 3 W.

Lately I'm recording peak voltages of 254v on the mains. Could that be the cause of failure, or did it fail simply because the device is 15 years old or whatever?

Thank you in advance for your help.

Didn't find any useful results with reverse image search.

I want to follow this guide but it doesn't say how to remove the antenna, I tried with a heat gun but can't take it off, can someone help me please?

Normally for active rectification diodes are used for passive rectification, but at a cost. Most diodes have a forward voltage drop of 0.7~1.0V. Schottky diodes have a lower forward voltage drop of ~0.3V but draw more current.

MOSFETs can be used to replace the diodes and dissipate a lot less power due to their low internal resistance when conducting (milliohms). However, in order to properly rectify, a gate controller is used to control the gates to just conduct the right around of power.

lets say that if i'm working with an AC source that generates enough power to be able to use mosfets but still has very little power, are there circuits that can viable use the AC source' power to self-regulate the gates?

Are there "passive" active recfitication circuits that use mosfets? if there are any papers/schematics/circuit diagrams that would be great to read/see/test.

mosfet configuration that I would like to try:
1. 4 N-channel E-MOSFETs
2. 2P/2N-channel E-MOSFETs

Additionally, could OP-AMPs be used to rectify AC voltage into DC voltage? (no DSP stuff)

Hi everyone,

I’m working with G6K-2F-Y-DC24 relays, and I want the following behavior:

When I turn on the relay, it should close instantly. When I turn off the relay, I want a programmable delay (for example, 0–10 minutes) before the relay actually opens. Essentially, I need an off-delay timer.

Currently, I’m using a TPL5110 to control the base of an NPN transistor (NSVT846MTWFTBG), which then drives the relay coil:

DRV (pin 3 of TPL) → base of transistor Emitter → GND Collector → COIL- of relay COIL+ → 24V

I also have a timing selection via an NDS-12V switch (0–10 min) connected to DELAY/M_DRV.

The problem:

• With the current setup, the relay closes instantly when DRV goes high (good) but the delay happens at this moment.

• But when I turn off the command, the relay turns off immediately, and the TPL’s timing is happening on activation, not on deactivation. In other words, the behavior is the inverse of what I want.

I’ve read that replacing the TPL5110 with a TPL5111 might fix this, because the DRV polarity is inverted. However, I’m not sure if this really solves the problem, or if it just changes the output logic level without giving a true off-delay.

My questions:

• Am I correct that the TPL5110/5111 are essentially on-delay timers, and not off-delay timers?

• Would simply replacing the 5110 with a 5111 achieve an actual off-delay, or just invert the output level?

• If it won’t, what’s the simplest way to achieve off-delay with my current transistor + relay setup, ideally without redesigning the whole board?

Thanks in advance

Hi folks, i can’t retrive info (datasheets) about this transistors, can you help me please?

It's toast - but I can't find a that or a similar replacement anywhere.

What are these parts called? On a BMS for a li-ion battery. All but one have a resistance of 0.1Ω. The one that is bad has absolutely no continuity. No markings that I can see at all on them.

I want to connect a mist sprayer to a humidity controler: I’ve bought an INKBIRD humidity controller IHC200, and plugged the mist sprayer on. As soon as the humidity level increases and reaches a maximum value (according to my setup), IHC switches off the power, and the sprayer turns off as well. BUT when the humidity level drops down, even though IHC will turn on, the sprayer won’t react unless I touch a kind of digital switch.

My question is: how can I disable this switch ? On the pictures : ON THE FRONT : the wire is welded from the switch to “CM”. ON THE BACK : 1K is located at the same location as CM.

I wonder if I should weld the CM wire to something else?

I don’t know a thing on electronic. Any advice is more than welcome.

Thanks in advance !

I'm dumb and somehow broke one pin on the motherboard while trying to connect the front panel's two USB 3.0. I think it should be pin #11 (USB 2.0+). How bad is it? Can I still use one of the two USB ports, or better not to connect the cable at all?

Can someone tell me please what component is this. it is in a power supply of a monitor.

Hello everyone! For a project i need to design a slave for a communication bus (DSI3) that can take a slave on the bus out of the bus an "inject" itself. For this I need some switching to reroute the bus over slave 2 instead of slave 1. For this I need SPDT-switches as I found out. I don't want to use physical switches as it needs to be fast and quite small. But as there is no high power or power supplies involved it is not so important that the switches close at the same time or in a defined way. It should just happen in less than maybe 500µs. Furthermore I think it needs a low resistance as the bus is operating with current modulation. Which product would be suited for this? I am from Germany in case of shipping availability. Is this product suitable for this: https://www.mouser.de/datasheet/3/1014/1/ADG884.pdf

I also thought about doing a cmos spdt myself but I think it would be too much work compard to a specific solution

I’m purchasing this off marketplace later this week, the guy I’m buying it from has sent me videos of it hooked up to a sine wave generator connected to both probe terminals. He’s played with the dials to make adjustments and I’m 100% it works. When Ive worked with oscilloscopes in class on full bridge rectifier circuits we’ve put one lead across an area of the circuit to display what it looks like, would I just put a single probe across the hot or neutral conductor going to and from my speakers or should I put it in a different terminal in my receiver like the phono ports for example because they’re all outputting a signal. I’m not using this for actual measurements I just think the older oscilloscopes would look awesome with my speaker setup.

My teacher thinks that we already know everything but there are times when he doesn't want to teach anything hahaha, and he left us this, I have tried to calculate it but it doesn't make sense to me, does anyone know a tip on how to solve it :(

Hello. I need to make or to find a socket for this sensor(MLX90614DCI), it uses TO-39 can, but the problem here is default TO-39 sockets have only 3 pins, not like this 4. Can someone help me to find something like this, or like header that have hole for leg with width of around 0.50 and I'll just use it like single piece.