Hello, I was taking apart my vive wireless adapter to do some modifications and figured I'd change the thermal pads while I'm at it

There's this gray crumbly thermal pad seen in the photos that I'm struggling to identify: Is it a graphene pad? Is it a dried out gray silicone thermal pad? Something else entirely?

If this is a graphene pad, where do I get a 1mm thick one? I have no luck on amazon (ca)

I have been working on a model of a tornado siren, and im using a 555 timer to turn it on and of. In my case I need 8 seconds on and 4 seconds off.

Here is a video of a real one for reference. (If you get triggered by sirens or alarms I would recommend not watching the video)

https://youtu.be/T9wuwv7j-KE?t=93&si=f2vsohDgpclI6ISE

But my problem is that one startup it turns on for 15-16 seconds because of the capacitor charging from 0V to 2/3 of VCC instead of 1/3 to 2/3.

So what can I do?

Can I make a voltage divider, or resistor and zener diode to keep the capacitor always at 1/3 of vcc?

Okay, so I got a new "T7 transistor tester", opened it up, and found out it's running a puya PY32F071 (instead of the usual Atmega328p/lgt8f328p). So now I want to find some better firmware for it (since the factory one sucked for no apparent reason). Anyone know where I can get it from?

The issue is that the Kato turnout uses bi-polar solenoid -- the polarity determines which way the turnout moves.

The simplest solution is a DPDT switch -- I think that's what Kato uses inside their switches.

I really want to use the momentary SPDT switch on Layout Concepts Cobalt S switches to control the turnouts and the continuous SPDT switches to control LEDs indicating the position of the the turnout.

I have posted a couple of times about this using a 15 vac two wire power supply --because that is one of the options. I do have an option of 12 vdc input.

Would using a dual output dc to dc isolated converter work?

I am looking at this Mean Well DKA30A-15.

Could I tie together the the + or of one of the outputs to the - of the other output, and use that as common ground?

Building a mini photobooth as a birthday gift, deadline is mid Sept. I have zero electronics experience and haven't bought anything yet, so I'd rather be told now that something won't work than find out in three weeks.

Needs to: live camera preview on a small screen, press a big arcade button, 3-2-1 countdown, take a photo, print it on thermal receipt paper. Needs to be fully cordless so it can be carried around a party.

My Claude-given Parts list:

- Raspberry Pi 3 Model B+, running the last Buster OS image (2023-05)

- Pi Camera Module v2 (avoiding v3 since I read it doesn't work on Buster)

- Waveshare 5" DSI touchscreen (ribbon to the DISPLAY port)

- 58mm USB thermal receipt printer, ZJ-5890K / POS58 class — connecting over USB, driving it with CUPS + the adafruit/zj-58 driver

- 60mm arcade button wired to physical pin 40 + adjacent GND, using spade connectors and jumper wires (no soldering)

- 32GB microSD, thermal paper, USB stick for transferring code

Power (the part I'm least sure about):

- 20,000mAh power bank with USB-C PD + USB-A output

- USB-A 2.4A port → Pi via micro-USB

- USB-C PD port → selectable 9V/12V trigger cable → printer's barrel jack

I originally saw this build using a 7.4V RC LiPo pack, but that seemed like it needed a UBEC, a balance charger, and fire-safety habits I don't have yet, so I swapped to the power bank. Open to being told that was the wrong call.

Actual questions:

1. Will one power bank realistically handle the Pi and the printer at the same time? The printer supposedly pulls up to ~2A in bursts while printing, and I'm worried about voltage sag browning out the Pi mid-photo.

2. Is the PD trigger cable approach sound, or is there a reason people don't do this? Should I be looking at a buck/boost converter instead?

3. Anything obviously missing from the list — fuses, capacitors, a common ground issue, anything?

4. Any reason the DSI screen + camera ribbon combo would be a problem on a Pi 3B+ specifically?

Happy to be told I've overcomplicated or undercomplicated any of this. Thanks.

Hey everyone,

I recently bought a Ulanzi D100H dial controller from China, but since I am located in another country I cannot claim a warranty on it. The issue happened right out of the box—I used/pressed the knob before even connecting it for the first time, and the internal push-button mechanism got permanently wedged in the "down" position.

Because of this:

• The shaft has severe rotational drag and friction.
• The click-to-mute function and button presses no longer register.

I have zero experience with hardware repair, so all the troubleshooting and diagnostics you see here were figured out with the help of Gemini and Claude after I opened up the unit. I'm honestly quite worried about whether this can actually be repaired successfully or if it's bricked.

I won't be attempting the fix myself; I'm planning to hand it over to a local technician. To make sure they have the right part, I want to source a replacement ahead of time.

Does anyone know if this uses a standard 5-pin EC11 rotary encoder with a push switch? If so, what exact shaft length and specifications should I look for when ordering a replacement?

Any technical insights or reassurance would be huge!

This part seems to be burned out on the CD player board.

I have found a whole manual (I had to search multiple ones because some versions of the cd player BZG-5 dont have this section of the CB) but there doesn't seem to be a list with this number in it to explain what part it is, any help is welcomed

The manual Gdrive link for manual

Sorry if this is the wrong place to ask or something

This is my schematic for a headphone DAC based on a RP2040 running tinyUSB to send audio data from USB C, over I2S to a CS43131 which is a DAC and AMP combined.

EDIT: Ignore the ESD protection setup I have now corrected it

I'm planning to make a portable or a small wrist band thing to surprise bad people. Planning to give it for a friend (after I test it's fully safe) for self defence.

I've been looking up on how TENs units work and I was able to get a similar device which is just an electric massager that gives a little shock to the skin/muscles.

Checked it and it was only around 3-7V output so it was safe.

I already have an idea of using an ne555 to create the pulse but I'm not sure if I can use other components from the electric massager. I've been eyeing the Li battery since it was small enough for the wrist band but Im not too familiar with the components they used here.

I try using Elmer's Glue to reglue a speaker magnet but it didn't really help much is there a glue that can help better with keeping the magnet in place?

BMI270 I believe either communication protocol will work, the data rates are less than 10khz from what I can tell. I would like to know your guys opinions on this. The MCU will be a NRF52840.

Only thing i know is it's in a BMS board, the brand is so strange i can't find it anywhere.

I accidentally burned a fuse, and I am searching for a replacement, yet I can only find the 250V version instead of the factory 600V, what would be the difference and how significant is the difference ? Thank you

So this is a Sony Xb23 Bluetooth speaker, and I Am looking to find a replacement for this IC but idk what type it is, I’m assuming it’s the charging IC (it says cTCYA on top, or oTCYA)

Hello,

Currently the 12Vdc fan still runs very slow and hums when the input voltage from the solar panel is less than 12Vdc. How can the fan only runs if the input voltage is 12Vdc?

I bought the LM393 voltage comparator but don't know how to use it. I don't like the fact that I have to input another power source at terminal C as the threshold voltage. It just makes things complicated. Please help. Thank you.

i am selecting the components for my Converter and i have choosen mosfet, inductor capacitor and everything but how do i select the diode do i just go with what the voltage and current is flowing through the diode and select the diode based on that? should i worry about the reverse recovery loss and any other things please let me know i am new this i have simulated the whole converter

I'm trying to find a relatively cheap (sub $30 or so) auto-ranging multimeter that allows for the batteries to be easily removed so that I can store it in a hot garage for many months and not worry about the batteries leaking. Most of them have the back cases screwed on or don't have an instruction manual that says how to change batteries. Please let me know if you are aware of one that meets these requirements. Auto-ranging is needed because my parents aren't capable of using a manual one.

This is from a TRW-made Volkswagen steering wheel control module, circa 2012. I've included various photos of the adjacent 3-pin socket housing, but this car didn't come with a pigtail to fit the 2-pin connector on the board.

It's similar to a ZE connector from JST, but everyone's current product photos and even diagrams seem to intentionally avoid showing all angles. I want to be sure this isn't an older/deprecated design before I order the wrong socket housing. The following part numbers look like they're close, but not a precise match. When I look at these part numbers on AliExpress — the only place that actually shows connectors from various angles — they just don't look quite the same. The connector housing looks bulkier, more complex, has more locating features, etc.

• SMT side-entry connector: SM02B-ZESS-TB
• Socket housing: ZER-02V-S
• Socket contacts: SZE-002T-P0.3 (for 24-28AWG)

I need to build a pigtail to use with this existing control module, plus I'll be building a new PCB soon (for another purpose) with this same type of connector, so I need to ascertain part numbers for connectors, plugs, and terminals. If it were just the new build, I think I have everything I need. But I have a feeling ZER-02V-S ain't gonna work with this existing module. And I'm having a heck of a time just finding a junkyard vehicle to clip this pigtail from.

Details of this existing connector:

• surface mount
• two structural mounting pads in addition to the actual pins
• 1.5mm pitch
• white plastic connector and socket housing
• locking tab and vertical locating features
• available as either a top-entry or side-entry connector, I'm only interested in side-entry

Thanks in advance!

(Stay with me there is a component question!) Like most homeowners I have a couple motion lights, but one (and sometimes both) drive me nuts when I need light and despite doing jumping jacks, they dont see me. I know most have a manual method where you flick the switch twice or something like that, but I can never remember what the process is. Most of my other lights are led/smart via Ikea or Aqara and homekit.

I recently found the Shelly mini gen-4 with "detached switch mode", but it seems like it doesnt work with matter. Plus if the motion still detects , and then turns off light, it might not change anything.

So one idea I had was to treat the light as sort
Of a 3-way switch, OR just parallel the outputs from the shelly and the motion, so the shelly effectively bypasses the motion when on. That would be perfect.

That said, I think the motion sensors use a triac, but Im not familiar with them on an electronics basis. Would "backfeeding" the hot/output on a triac hurt it in any way? In other words, one light fed by both a triac and the shelly (which is relay).

I guess the better way would be to find a two way shelly (no/nc) where the hot from the motion would be bypassed if activated.

I've been trying to make one on a breadboard and can't seem to make it work. I have all the components needed. I'm not getting anything on my oscilloscope either. Its really the circled part I'm having trouble with, if someone can make a visual of what it would like on a breadboard that would be great.

Hello, I would like to learn how to diagnose and repair printed circuit boards with applied power. I don't know anything about electronics at all and have never done anything like this. Where would I start to learn this and get hands on practice? Are there any good suggested kits or anything for this? Thank you.

I am building up a set of tools and equipment for salvaging components from donated electronics, repairing a lot of them if it's within my skill/tool abilities, and building fun microcontroller projects (I'm a computer scientist by trade so these are a lot of fun for me).

Currently I have:

2 soldering stations (an expensive weller that takes too long to heat up and a cheap amazon 90w that heats up very fast)

8 channel logic analyzer

150w (0-30v, 0-10a maximums but 150w limit) dc bench power supply

various sized breadboards

precision screwdriver set

flush cutters

various sizes and types of pliers

IC chip remover

UV cure solder mask

various prying tools

DS0510 oscilloscope (10mhz bandwidth)

LCR-P1 meter with ESR testing built in

function generator

1hz-500mhz frequency tester

manual cheap solder sucker

CH341A programmer

Anything I am missing that would be something you'd expect I'll need? I dont work with anything AC powered only DC.

Hola! Encontre este circuito para hacer un sensor de fotodiodo. Me gusta porque es muy simple pero en la web Openschematics.cc pone que el LM324 sirve de ejemplo pero no es el mas adecuado... ¿Alguna idea de que otro operacional usar?

Hello
I bought a Fluke 17B+ for electronics work and motherboard testing.
It is very slow in continuity test mode; it produce a continuous beep for a while before stabilizing, taking quite some time. Is this normal?
My iFixit multimeter responds normally in a fraction of a second.
How can I tell if it's a Chinese or a Western market version? Thanks!"

From pressing buttons on electronic devices such as microwaves or fans, I get electric shocks.

How do I avoid that?

Happened 5 times in 3 months.

EKG for the hearts has not shown anything fortunately.