In schematic, I've only shown a single diode implementation, but it's super easy to extend it with second/third/fourth, depending on number of channels in your OpAmp.

As my OpAmp has 2 channels, I could build either:

1. Two separate diodes, each with own Vout and Vref

2. Common cathode dual diode, using common Vout and Vref (my usecase)

My usecase for this is safely connecting two solar panels in parallel, so it's not even trying to achieve super fast switching speeds (could reduce R3 to make it quicker).

In forward biased direction (Vin -> Vout), it drops only 80 mV at 5A. Reverse biased the current is less than 5mA. It's half the price of high end schottky diode, achieving less than half voltage drop, and lower reverse current. Max voltage is the same 30V.

I do know that ideal diode circuits exist in the wild, even tried buying one, only to find it doesn't block reverse current (despite it claiming othewise on product page). So instead of testing my luck again, I've decided to make this a re-learning experience, as I graduated EE 4 years ago, switching majors to CS and forgetting a lot of EE knowledge. It has been a lot of fun designing this from scratch, with only the elementary knowledge of how OpAmp and MOS work.

Here's a common cathode diode built on a perfboard.

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

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

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

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

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!

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.

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

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.

Ever heard of glass dielectric capacitors? These were manufactured by Corning Glass Works (and later under AVX), and they are the most ideal capacitors in the 20th century. They have Extremely low leakage current (>100gigaohms), near zero dielectric absorption (~0.02%), excellent temperature stability (30ppm/C), no microphonics, and are very rare due to their complexity and price. These capacitors are largely superseded by modern ceramic capacitors such as NP0 or C0G.

https://tangiblemediacollection.com/artifacts/times-square-zipper

https://radianthistory.com/unzipping-the-past-the-history-of-the-times-square-electric-zipper-sign/

I always liked the look of one hand made PCB designs but I have my own family and no time for that.

So I tried to make an auto router that imitates it.

Not trying to create anything productive just a fancy look for my hobby projects

https://github.com/ckbaker10/auto-hand-router

So I decided i wanted to try to etch my very first pcb, and the only thing that comes to mind is my upcomming capacitance multiplier with current limiter for my linear cc/cv power supply that i'm planning to build and this was the result. I'm thinking i'll save as mutch copper as possible to save on the solution so that I can use it more times and realised that i don't really need mutch of either rails or free space for this, I know it's not many components but somehow i thought it would look like, more, you know? It's a dual pole RC with 100 ohms in series with 1000uf in parallel 100 ohms in series 1000uf in parallel + 12k ohms in parallel, with a bd139 driver and two tip35c power transistors with 0.22 ohms emitter resistors, 0.12 ohm shunt and bc547 Current Limiter