Ive never seen one of these, but i guess if you needed a ultra stable oscilator circut, more than a quartz crystal could offer alone, this is the way you would do it.

Its most likely from some kind of millitary radio my grandpa took apart.

Its really neet, the thing comes appart so you can swap out the crystal inside.

Idk what i want to do with it, but maybe ill make a really accurate and power hungry quartz clock with it. Or some kind of QRP transmitter.

Realisticaly none of my projects would need something more accurate than a unheated crystal tho.

Instead of LDO regulators, I used 1N4007 diodes to step down the voltage; this prevents the battery from draining while the device is idle. Since the charging module did not fit into the battery compartment, I placed it inside the device; with a fully charged battery, the device can theoretically operate continuously for 140 hours.DEVELOPMENT FOLLOWİNG THE CONVERSATİONS :I don’t understand why people are making fun of this. The device no longer looks like it did in the photos, and there’s no risk of electric shock; I simply wanted to convert my multimeter to run on a rechargeable battery.😭😭😭😭. OKAY OKAY, THAT'S ENOUGH, YOU'VE CRITICIZED ME SO MUCH THAT I AM CHANGING IT BACK, WHY COULD IT REALLY BE BAD?

hello everyone! I've been building my own pick-and-place machine for a while now (it finally has a name: Vectra), and I just made a wrote up about the toolhead electronics.

I couldn't find a toolhead board I could just buy, so I made one: three 70 x 47 mm PCBs stacked on top of each other, i think you may like it !

I made it using a 27 MHz crystal oscillator and tuning the LC tank to the third harmonic multiple of the crystal (81 MHz), and i got a very very stable transmission and got a *somewhat* decent range with a crude dipole antenna i made (i got about 15 meters of transmission range in a crowded city.)

The HP 6642A (0-20 V / 0-10 A) is a great bench supply, but it can only be remote-controlled over GPIB, and real USB-GPIB adapters are expensive. So I built my own adapter from a cheap Arduino Uno and wrote a web-based control panel for it.
🔧 How I built the adapter:
• Desoldered a 24-pin GPIB (IEEE-488) plug from the board with a soldering iron and desoldering pump, then cleaned the pins
• Tinned the plug pins and 17 wires, then soldered one wire directly to each signal pin: 8 data lines (DIO1-8), 3 handshake lines (DAV, NRFD, NDAC), 5 control lines (EOI, IFC, SRQ, ATN, REN) and ground (pins 18-24 joined together)
• Plugged the other wire ends straight into the Arduino headers: DIO1-6 → A0-A5, DIO7-8 → D4-D5, EOI → D12, DAV → D11, NRFD → D10, NDAC → D9, IFC → D8, SRQ → D3, ATN → D2, REN → D6, GND → GND
• Secured everything in place with hot glue, no heat-shrink needed
• No resistors or other parts needed, just wires
• Flashed the open-source AR488 firmware with a custom pin layout matching my wiring. The Arduino now acts as a USB-GPIB adapter
💻 The control app is web-based, so the control panel runs in any browser on Windows, macOS or Linux:
✅ Live voltage, current and power readout with CV/CC mode
✅ Set voltage and current limit, with step buttons and saved presets
✅ Live chart with min/max/average, energy (Wh) and charge (Ah)
✅ Record data to CSV files, with a built-in viewer
✅ Automatic sequences: voltage steps, ramps, sweeps and loops
✅ Software protection: auto-off on over-current, over-power or over-voltage, a timer, and end-of-charge detection for batteries
✅ Event log, and it keeps recording even with the browser closed

This cobbled together driver is one of the most resilient circuits I've ever built on a bare copper board, it has survived multiple inverse connections (electrolytic cap dies anyway), and the transistors barely heat up during operation above 9V. All for LESS than $10.

Heya everyone I'm Berry!! ^^

Some of you may remember my post , my electrolysis machine I posted about , and well it was the 6th iteration and it had room for improvements so I'm here again with a new improved design that I'm satisfied with and ready to share with the world!!

This is the 8th iteration! I've named it , E.L.E.C.T.R.A. Mark VIII , or "Electrolytic Low-Current Epilation & Current Threshold Regulation Apparatus" Yep! Anthony Edward Stark like abbreviation heheh

The biggest thing I did was better documentation , I created a more thorough documentation and made it into both a website and a doc file!! Both of them have almost the same information!! ^^

Though yeah , I'll be updating website more than the docx file , because I dread doing anything that involves a docx file :3

And yes! I've treated my facial hair with it successfully without any damage to my skin . With no visible scars marks or literally anythingg!! I've treated eight hair on my face in total!! four with mark VIIand other four with mark VIII of the machine!!

And over a hundred body hair with mark VI , VII and VIII together!! ^^

The perfboard build is by u/biosphereprime , it's still a work in progress , though I wanted to share!! ^^

So here's the link to both the website and docx file!!

[Docx file](https://github.com/ELECTRA-VII/ELECTRA/raw/4eecc7593b665329133732333d119d9a3f01b801/ELECTRA_Mark_VIII_Guide-1.docx)

[Website](https://electra-vii.github.io/ELECTRA/)

And well do feel free to post your question down here , dm me regarding it , and reach me out if you end up making it i'd be happy to help :))

I would love to add the pictures of other's builds and thier experience to the website and doc!! ( ˶ˆᗜˆ˵ )

Done my first diy soldering kit, loved every second of it 🤙

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I recently took this apart to create a functional schematic of it as of to my knowledge none currently exist. I also plan to eventually use a separate Z80 that way I can make the Z8 on it can easily communicate. My goal is to try to make a CP/M computer using the shell and hardware of this + some stuff of my own
Here are some pictures of the 4 main boards

If this project goes well I might release the schematics I make online, though I’m trying to be as nondestructive as possible to its going to be hard in some areas

Digilent have discontinued the AD2 ... its still a good box so I looked into using a custom HDL for the FPGA and a web based GUI ...It alows you to use the AD2 without installing anything ... just open the HTML file in a browser ( chrome ) and select your AD2 box.

open source AD2 web interface

Pic2: First I scraped back the insulation on the cable and soldered on some 0.1mm enameled wire. I sealed it with the green UV resin.

Pic3: Then I had to map the ripped connector, because of course they wouldn't run the wires in order. That would have been too easy.

Pic 4: Finally I sealed the whole thing with the resin. Yes, I tested it before this stage and yes the thing works fine now!

I've built a timeline of geolocated advancements in the History of Electronics, from basic transistors and capacitors to high-na euv lithography.
No paywall or ads:
https://whatitwas.org/s/post?id=user-post-1789415081958-ysqpm&collection=collection-history-of-electronics

During another trip to HQ in San Jose. Lots of computers and lots of electronics too.

A great history park. I visited during a trip to company HQ in San Jose

So, I had a perfectly functional height-adjustable desk. The only problem? It had a manual crank. Naturally, instead of spending 10 seconds turning a handle, I decided to spend countless hours engineering a solution. As one does.

The result is my DIY Arduino-powered sit-stand desk controller!

I repurposed a 12V windshield wiper motor, connected it to the original desk mechanism, and built a custom controller around an Arduino Uno and an IBT-2 motor driver.

A few features I've managed to squeeze into it:

• Proportional joystick control – push a little for slow movement, push further for full speed.

• Soft start and stop – because launching my monitors into orbit wasn't part of the plan.

• Current monitoring using an ACS712 sensor, with configurable overcurrent shutdown.

• Upper and lower limit switches to prevent the desk from travelling too far.

• OLED display showing motor current, movement direction, PWM output (with a little progress bar, obviously), and limit-switch status.

• Physical emergency power cutoff, just in case the electrons decide to misbehave.

• Custom 3D-printed enclosure housing the electronics.

The motor typically draws around 10–11 A under load, and I've configured a 20 A software overcurrent threshold.

Everything is running on a 12V power supply, and I'm genuinely surprised at how smoothly the proportional joystick control works.

Is it cheaper or easier than buying an electric standing desk? Probably not.

Was it necessary? Absolutely not.

Did I learn a ridiculous amount about Arduino programming, PWM, motor drivers, current sensing, wiring, and 3D printing? Absolutely.

And now I get to adjust my desk height with a joystick, which, let's be honest, is objectively cooler than a button.

I've attached a couple of renders of the controller, including a look at the electronics inside.

Went through a few designs on this. Eventually, simplified the final one. Plant buddies need more air flow. A 12 dollar bucks Target fan would work but that’s SO BORING. Wanted something fun to look at and practical. Played off free form style. Improvised a lot. Made it work. Originally had an arduino powering a driver with a servo moving the fan. Worked but was foo complicated. Plus powering a driver and a microcontroller was unnecessarily complicated. Stripped it down to a mosfet driver with pot to control speed. Put it on a 9v. Done. Easy. Aesthetically fun and practical. Love it. Will definitely do another one.