Background:

I have a smaller computer I use as a server, its small form factor so has a limited power supply and space for storage

I've salvaged an 8 drive bay from another computer and intend to sit them under the server and run the data cables for the hard drives back to the server.

as for power I intend to get a small psu to supply the drives with stable 12v and 5v to spin them up. I intend to trigger the secondary psu with a relay tied to something in the main server, maybe a fan header.

*Question: what do i have to do (if anything) to make sure those two power supplies do not affect each other or do something like send excessive voltage down the data cables between the machines. *

from my research it seems like simply plugging the psu into the same grounded circuit in my house may be enough (i'm in Australia so all our wiring is grounded back to the main board)

I have also seen a suggestion that I could ground both chassis together.

I would like to add phone charging (more power than basic USB 5V) to my cargo bike with a 36V battery. I can find a lot of 12/24 V charging modules for cars and trucks, I can find this 10-30V module (pictured), but nothing for something like 42 V input voltage that can occur on a 36V battery. I can add a step-down converter in front of it, but I wonder if I can make it simpler and smaller. Thanks.

The boat isn't really hiding. It's me. So I am building a sonar lighthouse: a beacon under the hull and a handheld unit that points at it.

An hour of zigzagging around the reefs hunting lobsters disorients me, and that is not fixed by a compass.

Electromagnetic radiation doesn't travel underwater, so radio and GPS are out. That leaves sonar, or a long leash on me.

Simple idea. But building it requires a lot of skills and knowledge I don't have. Yet.

Let's get started.

The analog receiver design is my greatest weakness, so I am tackling that first. My high level idea is shown abstractly above. I know how to make that LED bar. That's all.

What else?

Transducers: I know absolutely nothing about them. Don't even know what I don't know.

Schematics: I am using KiCad which I hate, but the devil you know and all that. It is needed for PCB, simulations, and documentation of details.

An analog circuit: Never knew enough to qualify as rusty. This is where I really fall flat on my face, but I'm gaining speed. This is the next post I think.

Simulator: SPICE, which I used from the 80's thru 2000 on microprocessors. Rusty, should be fine.

Housings: Have 3D printer and plenty of experience there, that'll be fun.

PCB: never made one, no idea how, but looking forward to learning much, as it seems great fun.

Firmware: Code lives on ESP32-S3, same as my thread machine. These I know well.

Software: Arduino IDE and Arduino C++, very competent there too.

Tools/equipment/chips/etc purchases: My true area of expertise, I've practiced for years, am very active.

If anyone sees me going full steam into a brick wall, I'd love to hear it.

Next time I'll talk about my circuit and how I think it should work. Not how it does work. How I think it should work. That's the difference between saying JLaw is dating me and JLaw should be dating me.

Follow if you want to know when I post updates.

Thanks.

Hi, I have two old electric toothbrushes. One is a weak motor at 26k RPM and the other is a strong one with 96k RPM. I tried using the 96k strong motor toothbrush (after sanitizing it) to clean my shoes but either the bristles were too soft or the RPM wasn’t strong enough because it didn’t clean as well as me just wiping it with a rag.

How can I repurpose these two electric toothbrushes? Im new to DIY

Please tell me what I’m doing wrong.

I am trying to connect a 12v dc bilge pump to a longer cord to pump out surface water collecting on my pool.

The pump has two settings: switched manual and automatic mode. Zoom in on the manual and you’ll see brown wire is positive for auto function. Brown with white stripe has been isolated. I have 12.4V at the end of the 2 core cord.

I’ve tried a waterproof crimped butt connector connecting brown to positive and black to black but the pump will not work. To troubleshoot I removed the butt connectors, tested connection and checked polarity. It’s fine (I think) but double check my working.

The 240v AC to 12v DC is working fine. Steady 12.4V DC to the lead. 5A in-line fuse in tact.

What am I doing wrong? I figured it would be black to black, brown to red and good to go?

I'm trying to find a way to have power from an outlet power my Smart Lock. E34 I know back in the day people had this double A battery thing you could buy. I was hoping if someone is also thinking about doing a dummy battery so that we can plug it into the wall.

I am trying to build a custom cyberdeck using a rasberry pi, but have no idea how to design a case. Could anyone help?

I have an Ender 3 V3 KE and am using PETG.

My parts list (Am pretty sure its compatible but if not please let me know):

https://docs.google.com/spreadsheets/d/1VTqKV0g0OBa-KC8KjaraNMoa1YKqMowC5PlBn9xWoqw/edit?usp=sharing

I am trying to build a cyberdeck that has a dpad, a, b, x, y, start, select, menu, l1, l2, l3, r1, r2, r3, (https://www.thingiverse.com/thing:2406507 for shoulder buttons), all the io on the top left or right side, cabling routes, screw/standoff holes, mic grill, speaker grill, camera hole, vents for the fan, the keyboard/trackpad to be magnetically attachable to the back, and for it to look simewhat similar to the GameBoy (buttons on bottom, screen on top).

Thank you

Following penguintutor's tutorial on connecting lcd display to microbit. Will these work? It needs a 5v power sipply, and i dont have a board. If it does work, what pins do i hook up to? Also, how would i solder those? Thanks

I am trying to help a teacher with a science project in their classroom.

The goal is to use a DC motor, driven by a mock wind turbine fan, to power a small LED. I have tried a few different DC motors and still having trouble generating enough voltage to power the LED.

I have the motor attached to my drill and I am only able to generate 0.9V

Am I missing something or can someone recommend a cheap DC motor that I can use?

I appreciate it, and I know the kids will too!

I'm currently interested in using a Raspberry Pi Zero 2 W that I found to create a small AV recorder/maybe playback device, and I need to connect a few devices to the GPIO pins. However, I have no clue what I'm doing! Not to mention I'm not entirely sure where to start in confidently navigating this project, outside of basic troubleshooting/component research.

If you have some resources that I could study (reading,video, or otherwise) to help understand how to use the GPIO pins on my Raspberry Pi, as well as any vital background knowledge that might keep me from frying anything, I would love to see them!

Thanks!!!!

I've got bins and drawers full of components and I could never remember where anything was. I knew I had the part, just not which drawer, so I'd end up tearing through half of them looking for one thing.

So I made an app for it. You take a photo of a part or a bin, and later you can find it again by photo or by scanning a QR sticker on the bin.

It's free, no ads, just me working on it. Android only right now and still in testing.

If anyone wants to try it out I could use some feedback, mostly whether the photo search actually finds the right stuff. Comment or DM me and I'll send you the link.

1) https://groups.google.com/g/skew-testers
2) https://play.google.com/apps/testing/com.skew.app

Knocked my ~6-year-old 43” Samsung Smart TV over while cleaning a few nights ago and the screen landed on a pointy corner of the table.

I‘d like to offer it up for free to anyone in my area who salvages them for parts to do…whatever (repair? diy stuff? art? crazy meth-fueled inventions?) with.

What can I do to prepare it for use by complete strangers? It was connected to several streaming services when I broke it. The last thing I want is for some rando to access my Prime account and buy a bunch of bullshit or get my credit/debit/bank/personal info off of it.

While developing our Makerfabs Nomad Terminal, we wanted to improve GPS performance without increasing the overall size of this compact LoRa handheld device.

Our first design used a passive ceramic GPS antenna mounted on the PCB, underneath the display and close to the battery. The initial test results were:TTFF: 8.2 seconds; ~15 visible satellites after 1 minute

For the next revision, we switched to an active ceramic antenna with LNA and repositioned it above the PCB, with a better orientation toward the sky.

Test Results

The optimized design reduced Time to First Fix (TTFF) by ~37% while significantly increasing the number of visible satellites.

For compact GPS/GNSS devices, antenna performance isn't just about the antenna itself. Placement, orientation, PCB layout, battery/display interference, and surrounding components all need to be considered.

For those working with GPS/GNSS on compact embedded devices: what antenna types or layout techniques have given you the biggest improvement in real-world performance? We would really like to learn more from your experience.

Frankly, I know absolutely nothing about electronics. I have this SimpleHuman lighting mirror that I absolutely love, it stopped working under 2 years from purchase. Apparently it’s a common issue and keeps happening. It’s been discontinued since, and I can’t find anything of the same quality.

I can easily just replace the battery like they show in the video here. It looks fairly simple, but I was thinking why not have the mirror turn into “plug in only” then I won’t have to keep replacing the battery. Especially since I have to pay a hunk of money for shipping alone.

Is this even possible? And, is it a project easy to tackle by a first timer?

I have a guitar pedal I'm selling, but the 3 position switch has a broken knob. Pulled the pedal apart but it looks like the switch has 10 pins. Anyone know what these are called? I'm having a hard time finding a replacement.

USB3 Flash device. BGA152 is fitted onto a two‑layer PCB. Only the D0‑D7 signal traces are length‑matched. Surprisingly, it works properly.

I'm brand new to electronics, only have a basic understanding of circuits and stuff (I mean in the sense of components wired up, not boards) but i wanna make the barrels on a prop minigun im making spin, and I dont really know whats the best solution for that.

What iv come to the conclusion of so far is a brushless DC motor, connected to an electronic speed controler, which is in turn connected to a pulse width modulator and a battery. I ideally wanna make something that on a button press (pulling the trigger) it starts to spool the motor up to the speed i want, and then on letting go of the trigger, spool down too. I figured this is good at avoiding wear, especially if its a small motor pushing hard, but also would look cooler than trying to instantly snap to full speed and full stop.

I know some sort of Arduino would probably be involved but im honestly out of my depths with that kinda knowledge, how to wire it all up, and hell even what size of motor i would need for the weight its trying to spin.

The barrel cluster is about 700 ish grams, and I was planning on having a large internal diameter bearing for it to rest inside the receiver so there wont be much friction for the motor to push against and its not having to support much weight either. honestly I didnt know where to look or ask for this kinda help so if anyone also knows a more appropriate place or resources id be hugely thankful.

I am doing a project which needs an outdoor component. the voltage / current flowing is less than 30V 1A. to connect to the outdoor component, I need a waterproof connector. what connector should I be looking for? googling for 4 pin waterproof connectors brings up large weatherproof connectors which are rated for 250V - 5A. I am looking for something like SD1604 connector but that is too large for the application. Also the connector might be exposed to sunlight as well.

I have tried basically like 8 different dimmers that rated from 2a to 5a and all of them end up same way. They stop responding to the remote or button and stay at full power. I am plugging them into a heated glove that draws max 1.5a at 12v. I am really not sure what else to try. I thought the 5a one would work since I am draw below it's max by a lot. I am open to any suggestions or products you guys can recommend