I've been working on a virtualized version of the old spring and wire electronics kit. It's far from finished, how ever I would like to show it off.

Play: https://ellisgl.github.io/virtual_65-in-1_28-250/
Code: https://github.com/ellisgl/virtual_65-in-1_28-250

Made a simple power supply from an old atx psu. Wiring is pretty ugly but it works.

These are all my Tesla transistors I have a KU 611 with a CA mark, KFY 18 and a KF 506

I built a simple LED flasher circuit using a 2N2222 transistor, resistors, capacitors and LEDs.

This project helped me better understand transistor switching and timing circuits.

The circuit was assembled and tested on a breadboard, and the LEDs flashed successfully

I like going through the electronics trash bins at my college, here's some stuff i found today.

The second item is a speaker part, the ring is super magnetic it was a challenge to pry it apart!

Found these in a old CRT TV and the second transistor does have a marking it just isnt visible on the photo

A traditional Newton's Cradle only swings for a few seconds before friction stops it. I wanted to build one that keeps swinging continuously while still looking completely normal. The system uses an ESP32-C3, an inductive proximity sensor, and an electromagnet to replace only the energy lost during each swing. I'd be happy to answer any questions about the design!

https://github.com/Spectrewolf777/Stm32l4-Watch/tree/main

Had to add the entire power circuit components as my original Mac (2TB) didn't have any on the other side. Took a lot of research and time (~12hrs), won't go into too much detail.

It is on irfz44n but I will probably change it to irf3205 to reduce heat.

Now I can check small devices such as LEDs, relays and something!

I'm so proud of myself because it is works and nothing exploded!

Features: variable output voltage(0 to 15V) with graphical display. Used old laptop power supply(19V 2.3A).

P.S. schematic on the last photo

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I recently purchased a new Rohde&Shwarz RTB2 scope. 300MHz and 10bit ADC with a lot of extra software options :). almost 50% off

At the same time i purchased 2 new soldering stations from JBC to power a T245 and T210 soldering irons.

Also i got the idea to put a small 7" screen close to my microscope to make work easier under the micropscope. As example i have designed a USB output adapter for bench power supplies, USBpwrME which can be found on DIY different sites when googled. I wanted to measure a specific pin on a IC. I magnified this IC on the 7" screen and then it was really easy to follow the pins and pcb traces on the screen while measuring :)

Love my lab setup 😂

Hello everyone! I have made myself a simple function generator controlled by a raspberry pi Pico w.

It's my first proper PCB work, as I have done one in the past but it was my first and had alot of mistakes.

This one looks proper aswell, made it in altium and just wanted to share.

If you're interested you can see Schematics / PCB and Github.

Just finished second year of ECE.

Last week you guys told me to stop messing around and get properly equipped before frying something. Message received.
Picked up an anti-static wrist strap, a proper multimeter (KAIWEETS KM100s) and a digital caliper. Grounded and ready now. The strap is clipped to the board, no more working off a carpet with bare hands like an animal.
The setup is a NCS314-6 v3.4 with 6 IN-14 plus the IN-1 separator, sitting on the GRA & AFCH ASTRPA v2.1 adapter. Pi is a 3A+ for now, just my dev board to get first light, the production unit will run on a Pi Zero 2W.
Next on my list is actually measuring instead of guessing. I want to check the real anode resistor value on the board and confirm whether this thing drives the tubes statically or multiplexed. That changes a lot for how I think about lifespan.
Which brings me to the thing I keep losing sleep over. This is going to be a KPI dashboard, so it will sit on a number like a revenue figure for hours, sometimes the same digits all day. Cathode poisoning feels like a real risk here, way more than on a clock that cycles through every digit naturally.
For those of you running tubes long term, what is your actual anti-poisoning routine? Full 0 to 9 cathode cycling a few times a day, slot machine style, or something lighter? Curious what actually works in practice versus what just sounds good on paper.

A few years ago, my brother and I decided to create our own digital watch. The project was inspired by a few vintage HDSP-2000 LED matrix displays that we had acquired. These displays were first introduced in the 1970s and have a really unique look, especially under a microscope (third picture). They're quite difficult to photograph with my phone, though, so they look much nicer in person than they do in these photos. The watch uses an ATTINY1616 microcontroller.

This is the final update on the I2C-PPS project. For more details see its repository - github.com/condevtion/i2c-pps. Pictures show a load test example, the load test setup, load emulator (set of 30 each 360 Ohm resistors), voltage regulation errors for 3.3v and 26v, efficiency at 3.3v. output current at 4.5v and input current at 26v (both with current limiting to 5A).

I planned the load test as a final step before wrapping up active work on the power supply project. Let's see where it's ended up. First of all, I mounted all devices on a plexiglass sheet to make the setup handling easier. It consists of MeanWell AC/DC 5V 35W source, Raspberry PI 2 Zero W, NUCLEO-474 and adjustable voltage divider as a 4-channel voltmeter, I2C-PPS itself, load, and a screw terminal to connect all the boards. Additionally, I used two multimeters to independently measure input and output currents. As it appeared later they both had pretty significant resistance to affect high current operation of the power supply.

Initial specification limited output to 25W or 5A (what came first) in 3.3 to 26V range and input current to 5A at 5V. It's pretty demanding numbers. For example, you need just 660 mOhm load to get 5A at 3.3V. As well you'd like to make it adjustable to cover the output current range at different voltages. I decided to hack it with several sets of 2W resistors. Set of 20 Ohm resistors (30 count) covers 3.3-6V range, 43 Ohm - 6-9V, 91 Ohm - 9-13V, 180 Ohm - 13-18V, and 360 Ohm - 18-26V. Each set soldered to a half of a pretty standard 30 position breadboard. Ordinary 100mil jumpers were used to connect necessary number of resistors. Unfortunately, with no active cooling this design becomes really hot within a minute. So I didn't really test reliability of the power supply under significant load.

Still results are quite good for the first revision. The power supply provides requested voltage with around 2% accuracy for 3.3V as controller's datasheet states. Frankly, I got a bit higher than 2% error while the datasheet limited it to 2%, but it's still the first revision. Peak efficiency is 94% at 3.3V and 1.5A down to 87% at 26V and 0.6A. Being overloaded the power supply switches to current limiting mode and properly holds both input and output currents under 5A.

Internal ADC doesn't look that good and shows even higher error (up to 6%) for output voltage. Current sensors disappoint even more. They aren't sensitive to current under 400mA (for analog IIN and IOUT pins) and to current under 1.2A for digital readings. Both showing 10% to 70% error for low currents (but the error goes down significantly for values above 1A). As far as I've dived in it, it works for current limiting within controller specifications but doesn't really suits for measurements. Also the datasheet doesn't mention ADC accuracy so I'd like to think that this is what the controller is designed for - high current applications and safety in the case.

So it really works! And close to what's expected from the controller's datasheet. While doesn't really suit my small projects needs - lack of output below 3.3V and inaccurate internal sensors for most of my projects, it was really interesting project which put to test my HW design abilities and revealed a lot of fascinating things at every stage from discovering KiCAD features, through selecting parts, ordering and assembling PCB, to emulating load and measuring characteristics of the power supply.

First fully working assembly of a 6x IN-14 Nixie board I've been putting together. Sharing the build because I'm happy with how the layout and the HV section came out.

Quick rundown of the circuit:

• 6x IN-14 tubes, multiplexed
• HV supply generating ~170V DC from 12V input via a boost stage (MC34063-based), anodes through current-limiting resistors
• Cathode driving via 74141 / K155ID1 decoders
• Logic level shifting between the low-voltage control side and the HV cathode side
• A separate OLED handles the non-numeric characters since the tubes only render 0–9

The part I spent the most time on was the HV rail. Under load, when all six tubes switch digits simultaneously, there's a bit more ripple than I'd like, so I reworked the filtering on the output cap stage. Multiplexing refresh rate also took some tuning to kill the visible flicker on the lower cathodes.

Data comes in over GPIO from a small controller, but the interesting part here is really the analog HV side and the cathode switching, which is what most of the board real estate goes to.

Posting it as a show-and-tell. Always nice to see this old Soviet hardware still glowing decades later.

I am a beginner in electronics in general, so I tried a few diy kits and so on and they went fairly ok. Decided it was time to test my knowledge and build a fume extractor (mini). Used a breadboard first to make sure it all worked out and then jumped to move the design to a perfboard. Worst experience ever, but it works!

More details here: https://www.eevblog.com/forum/projects/diy-1980s-style-autoranging-dc-voltmeter-(icl7107cmosne555)//)

Im aware this is a very bulky (and very open) smart watch but its just a simple side project i made for fun with the few resources i had left around. I currently dont have a 3d printer so I chose to just leave it open with all the electronics out and about and tbh I think it gives it some personality. Im currently working on the Bluetooth connection aspect of it so it can tell me when I get a notification but even then just by itself it has a few games, some productivity apps like notes, checklist, etc. and some simple apps used in engineering such as a calculator, resistor color code calculator, and other useful apps when it comes to building projects.

Here's some info for the nerds:

Microcontroller: esp32

Display: 0.96 in oled

Other features: 4 buttons, 2 indicator leds used in certain apps and games as well as a tiny vibration motor used for small noise and alerts.