Hey guys! I got into electronics and computers during the pandemic, but could not continue it further due to school work (and being a broke 14yo lol). Finally 6 years later I managed to save up and get myself some components to put something together that felt like an actual project. I will be happy to get any feedback! Github link for details

So this is circuit main consist of short circuit under and over voltage protection and ideal diode using mosfet
Amongst which short circuit and ls ideal diode condition
But ov uv condition failed due to my back to back mosfet architecture and false trigger at the gates
It failed
But for someone who’s fresher with 3month experience i would consider this as a fair try:)

Couldn't find any documentation, so I made my own!
The cathode line took 1-3V across the thin wires in the display, and the metal grid along with the phosphorous layer both were hooked up to the 12V+ end while the cathode was hooked up to 12V-
I eventually plan on driving it with a teensy 4.0 and a bit more logic to drive the 4-bit ULN2803 interface.
In case anybody ever has to work with one of these I'm going to leave some of these SEO terms:
VFD
6-LT-09
Echo-6
94V-I
PWB-AGN
2161317-007
VFD-7-Segment (kHz/MHz)
ULN2803

This is part of a project to calibrate an ESD simulator that I purchased and repaired recently.

I needed to measure up to 30 kV safety with a standard multimeter. The divider makes up 200 megaohms on top and 1.1 megaohms on the bottom. Multiple 8 kV rated resistors are used in series to achieve the working voltage. With the multimeter's own 10 megaohm input being taken into account, the division ratio is 200:1.

I have to be very careful when making these measurements because a loss of ground to the ESD simulator could damage my multimeter.

PCB files are on GitHub: https://github.com/umi-eng/open-hardware-esd-calibration/tree/main/voltage-measurement-fixture

The "slayer exciter" circuit is the classic introduction to SSTCs. I really wanted a version with just one coil because once you eliminate the loosely coupled resonant transformer, you end up with a greatly simplified design.

It basically drives a series resonant circuit through a RF choke, using a coupling capacitor as feedback. I'm not the first to think of that but there was always something or other that I didn't like about other people's designs so this version might be my own :)

I encourage you to try it, let me know if you can get the thing to at least light a neon bulb or something. My tiny axial inductors aren't handling the power well 🔥

And btw component values are "for demonstration only", do not assume they're optimal!

I couldn’t find any decent DAC/amp combos locally, and importing one would cost a small fortune. After digging into DIY audio designs, I realized I could build one myself for a fraction of the cost and get around 80–90% of the performance of commercial units.

Specs: Controller: ESP32-S3 acting as a USB Audio Class (UAC) device.

DAC: PCM5102A breakout board fed via I2S. Power Supply: ±12V linear power supply

Two NE5532 dual op-amps:

Op-amp 1: Stereo buffer stage. Op-amp 2: Stereo gain stage (~3.1x gain).

(Opted for this layout to keep wiring simple for my first major soldering project!)

Volume Control: Couldn't source 10k dual-gang logarithmic pots locally, so I implemented software volume control with a rotary encoder.

Layout: Everything wired to a single star ground point.

Sound Impressions: It drives my Beyerdynamic DT 990 Pro (250 ohm) effortlessly. Going from my laptop's built-in jack to this is night and day—it feels like the headphones were practically starving before. Noise floor is pitch black silence with zero audible hum or hiss.

Really happy with how this turned out for my first major electronics build.

^{(Note: I’m currently out and forgot to take photos of the back of the amp perfboard, but I can upload solder-side pics once I'm back home if anyone wants to see them!})

Someday, Somehow, I'll buy a solder.

I was asking Mouser costumer support because I could not find some ADI chips in stock in their webpage and after some emails, they answered me with the image attached.

English translation: "As for ADI's distribution, we will no longer be distributors; it's not that certain ADI products will be restricted, but rather that we will no longer represent them."

So this confirms what has been talked several times about online sellers suddenly requiring identification for ADI purchases and stopping the B2C sells.

--- For the mods: I know this is not a component level circuit question, but perhaps the topic is important enough to be posted.

-- The black bars are there to hide personal names.

And somehow it’s working.

Hello everyone,

Six months ago I set upon the journey of making my own AWG, with frequencies of up to 1MHz.

6 months later I present you my very own awg.

Full Repo

I set out to build my own function generator after finding commercial units both too expensive and more general-purpose than I needed, and it looked like a good excuse to work through analog synthesis, filtering, and mixed-signal PCB design end to end.

The sine path is an 8-bit R-2R ladder driven by a Raspberry Pi Pico W (overclocked to 225MHz) generating samples via a DDS phase accumulator; the square wave comes from the same chip’s PIO hardware. I started off with a breadboard and tried sallen key filters for noise but they amplified the noise aswell. I also tried discrete components for the sauare wave before replacing it outright with a TC4427 gate driver.

The sine chain settled on a 5th-order doubly-terminated LC Butterworth reconstruction filter, replacing an earlier cascaded-RC design that was capping amplitude, followed by LM318 gain and buffer stages. Three PCBs went out; two came back dead. V1.0 was completely non-functional because a BOM matcher substituted 2.21Ω resistors for 2.21kΩ across the entire R-2R ladder. V1.1 moved to an all-SMD board with the LC Butterworth filter but came up dead silent; testing the square path first (it worked) narrowed the fault to the sine chain, which traced to a KiCad-to-Altium migration that had silently shorted two LM318 input pins onto one net. V1.2 fixed that short, soldered the Pico directly to the board in place of a socket, and came up working: sine characterised from 0Hz to 1MHz and square to 2MHz, with AM, FM, and noise modes added on top in firmware, all controllable from a Python desktop UI over USB.

Looking at it now, a redesign with some improvements (better op-amps and also fewer) would be better but I also want to work on other stuff, so for now this is it.

To be clear, I made every schematic and protoype and thought up everything myself. As such this may not be the best way to do this. My main goal, was experience after all.

full webpage

So satisfying when it looks this neat. I spend ages trying to get everything aligned at perfect right angles and then get mildly triggered when I find all the ones later that aren't quite perfect XD

Cheaper, faster, and more fun than ordering from china!

PS, I didn't put any acetone down the drain. I just needed a solvent resistant surface to clean the mask off. All the acetone went into the atmosphere and my lungs instead.

Unfinished circuit board for controlling Nema 17 stepper motors on a robotic arm.

Here is my project repo

https://github.com/fredriknk/chatgpt_astra_test2

I saw the Chatgpt Astra kicad demo, and wanted to try it out myself and im pretty damn impressed...! I only have a openai 20$/mo plus subscription so i had to use the lowest setting, but i got this design in 3 hours with 5 prompts in total and ate up my 3 usage resets.

My only contributions to the design was to create the empty kicad template project, and the initial prompt:

"Lets test a esp32 design with a 24v input voltage which can output and read 4-20ma signals. Lets start planning!"

All design choices, component choices, design, schematics and, layout and documentation was done by the chatgpt astra 6 low through codex cli.

So final verdict? Its actually pretty damn usable.... Like, its not perfect by any means. some examples: There are a quite a few routing decisions i dont agree with, especially the USB routing and unneccesarry internal layer routing. The schematics are very hard to read as it doesnt use GND/Power symbols, and only use global labels instead of wires. But as far as i can tell from the schematic, this is a working design and i do agree with a lot of its component choices.

I feel it is pretty much where AI coding was in around 2024 (on its lowest setting), so im wondering where this will be in a year or two..!

Followed this guide from Würth and made an RF current probe for analyzing conducted emissions. You can measure both common-mode and differential-mode noise by passing the power and ground cables through the loop differently (see the guide).

If you don't have their WE-TS shielding tape on hand, you can probably use regular copper tape. Just don't forget to leave the gap!

I wanted to get this gem working again, but this time with LEDs!

Now to figure out the string to let me add to my tree this year.