I saw my project mentioned in another thread, so I figured I'd make a post.

I've been snagging those Victrola/Crosley/etc. suitcase record players from Goodwills lately and converting them into guitar practice amps and speaker cabinets. Basically gut the entire thing and build all of the internals from scratch.

These are a pretty basic preamp circuit with a TPA3110 stereo power amp. One channel of the power amp goes to the internal 6" speaker, and there's a 30w@4 ohms output on the back for an external cabinet. The top three-way switch selects the output. I didn't want to have to worry about calculating impedance and deciding whether to go with series or parallel connections, so the switch is: internal only, mute, external only.

These are the first two prototypes; I'll probably rip out the felt stuff in the lids and put some kind of logo or something.

I've amassed 10 of these over the past few weeks, so I'll be building some to try to sell locally before Christmas, and I'll probably give away a couple to friends.

I've also found a few actual vintage travel record players and wooden suitcases that I'll do something similar with.

Based on electrode consumption observations, the total energy output is projected to reach 100Wh.

​

Hi everyone,

I recently repaired my laptop hinge using a bolt 🔩. The repair is working, but the problem is that the **end of the bolt protrudes approximately 1 inch from the back of the laptop screen**.

It doesn't look very good aesthetically, so I'm looking for some ideas to cover or hide the protruding part and make the repair look cleaner.

I'm mainly looking for a **DIY touch-up solution** that doesn't look ugly and, if possible, doesn't require replacing the screen's back cover.

Some ideas I have considered are covering it with a small piece of plastic, using some kind of cap, or making a small cover around it. However, I'm not sure what would look best or be practical.

**What would you recommend for hiding the protruding bolt?** Has anyone done a similar laptop hinge repair and found a neat way to cover it?

Any suggestions or DIY ideas would be appreciated. Thanks!

I made a small heater from Nichrome wire on an aluminium plate. 50 Ohms resistance.

It only gets to about 40 C with a 24 V supply, so I want to get a 48 V supply, but be able to control the current or voltage to limit the heat, as the power goes from about 12.5 W to almost 50 W.

I'm only looking to get to somewhere between 50 and 60 C.

I have a small mesh tent that is see-through for eyes, but an IR camera has problem seeing through. I don't think there is a way for me to paint it with some paint to meke the mesh not appear white on the camera. So I had an idea - I could put a small IR light inside of the tent to make the inside more visible to the camera sitting outside. But since the tent is zipped up I can't conveniently run a cable into it. So I'm wondering - are there any convenient ways of powering a small USB light through the fabric? The best solution I found so far was using some magsafe QI charger and receiver. I haven't tried it yet, I wonder if there are any more convenient options out there...

Has anyone ran a USB power through fabric?

From finding the right low voltage components to building a custom thermometer or experimenting with miniature potentiometers, DIY electronics always brings new challenges and creative ideas!

What are you building lately, and have you discovered any useful components or clever solutions worth sharing? I'd love to hear about your projects and learn from your experiences!

One thing I wish more beginners learned early is to get the circuit working before worrying about making the project look finished.

It's tempting to assemble everything, glue the components into a case, and clean up the wiring afterward. But when something stops working, troubleshooting becomes much harder if you can't easily reach the connections or remove a component without damaging the build.

I'd much rather have an ugly prototype held together with tape or a temporary enclosure that works reliably than a beautiful project that fails because one wire came loose. Once the electronics are tested and the code behaves as expected, then it's worth spending time on the enclosure, cable management, and finishing touches.

I also think simple first projects deserve more credit. Helping a child build something that lights up or responds to a button can teach more practical skills than immediately attempting a complicated macro pad with a dozen features.

Get it working first, make it reliable second, and make it pretty last. That approach saves time, money, and a lot of frustration with DIY electronics.

I've been working on an open-hardware idea: sending power (and eventually data) through a solid steel wall with no holes, using a pair of ~40 kHz piezo transducers bonded on both sides. The theory, the driver/receiver schematics and the simulation side are written up, but I can't set up a bench myself right now because I'm in the middle of moving.

Lab systems for this exist (RPI, CEA-Leti, TDK), but I haven't found an open, reproducible garage build with published numbers on a thin steel plate.

I'm looking for someone who'd find this a fun weekend experiment: two transducers on a 3 mm steel plate, a driver near resonance, a rectifier and a load on the far side. Then measure DC power delivered vs. input, and grab a couple of scope captures. Even a negative result with real numbers is useful.

The test protocol and what counts as a complete result are in this issue: https://github.com/zeloras/through-metal-link/issues/5

Happy to answer questions about the coupling, matching, or transducer choice in the comments.

Can anybody recommend a USB-C to C charge module for 18650s with an unregulated output?

Ages ago, I bought a bunch of TP 4057 modules for this exact purpose. But it turns out they are tp4056 and I already burnt one out by plugging into USBC. I don’t want to modify resistors or anything like that, I just buy something off of flea Bay or Amazon

I have this Roku remote I bought on Aliexpress and for the most part it works but the channel buttons don't all work. Netflix, Hulu work and YouTube works but goes to Spotify. I'm curious if I could buy another micro controller chip, program it the right way and have working buttons. I'm as they would call it a noob!

​

​The homing signal board on my Xiaomi Mi Robot Vacuum-Mop 2 Pro (MJST1SHW) charging dock is damaged, and the vacuum can no longer detect the dock to return for charging. Finding a standalone replacement dock on the second-hand market isn't working out, as sellers are pricing them almost as high as a complete used setup.

​I’m currently trying to build a replacement beacon using an Arduino/ESP32. I set up two IR LEDs for the left and two for the right, modulated at 38kHz. However, the vacuum doesn't respond to the custom beacons at all during its docking routine.

​Does anyone have experience generating these specific homing signals? I would greatly appreciate any insights into the correct IR protocol, pulse timings, or data payloads required to get the vacuum to recognize the dock.

I need it to be this specific length, but the tactile feel doesn't seem right.

This is a transistor OR gate which gives an output of HIGH (1) when at least one input is HIGH (1). It gives a LOW (0) output only when both inputs are LOW (0). Correction to the above circuit: We need an additional transistor inverter at the output of this circuit with a little bit modification so that it converts NOR gate to OR gate.

I know nothing about electronics but this looks pretty simple? It just lights two separate bulbs about the size of a lentil. Can I reattach this and make it work again some how? I don’t have time to order another set and spider noir won’t have the same vibe if the goggles don’t glow :-(

(Ps I don’t have any soldering equipment or anything like that, but I have glue and sheer willpower if that’s helpful)

I'm working on a music toy project with the following requirements:

- Built in speaker/buzzer (doesn't have to be good, just beeps and boops is enough)

- Portable (battery powered, and can fit in pocket, no extra cables required to use)

- At least 4 buttons in a grid (but preferably not more than 12 buttons or so, then it gets too big)

- Programmable so I can assign sound to the buttons etc.

I got excited when I came across the Adafruit Macropad RP2040 because it looks absolutely perfect, but unfortunately it can't be powered on its own.

I'll eventually try to build it totally from scratch, but as I'm a beginner (i just have some soldering experience from working on drones) I'd rather buy a kit or something pre-made that I can just repurpose or hack

Are there any products or kits out there that might be a good starting point?

Thanks!

There's something satisfying about building or fixing something with your own hands, whether it's helping your kid complete their first electronics project, finding a clever use for a tiny battery-powered light, or fighting with super glue that refuses to cooperate! 😂 Sometimes the simplest projects turn into the biggest learning experiences.

What's the most fun DIY electronics project you've worked on recently, or the most frustrating problem you've had to solve? Share your creations, clever fixes, and hard-earned lessons. Let's inspire each other to keep tinkering!

I have doing a college project. My project is "Automatic Night Light Sensor". It consists of 470 Ohm Resistor (for LED), 100K Resistor (for some voltage diff thing), BC547 (NPN Transistor), LDR (8 or 12mm), LED. But as per my observation, the bought resistor called "100K" was actually 12K.

The issue: The LED stays lit even if there is light or darkness.

Help me troubleshoot this. I might need to submit this tomorrow! 😢

The main reference was: https://www.build-electronic-circuits.com/night-light-circuit/

(Circuit diagram in link)(https://www.reddit.com/media?url=https%3A%2F%2Fi.redd.it%2F16luv5gbk1yh1.png)