Reddit:Electronics

Behold: My first major project that isn't just big electric components or basic relay logic.

This is a WiFi servo controller that I'm building to control a homemade automatic power transfer switch for our home's backup generator.

Two large main servos are powered by the large buck converter module, and a third auxiliary servo is run off of a 3.3V regulator. A second regulator powers the ESP-01S WiFi control module to avoid voltage fluctuations when the small servo is powered.

The ESP-01S handles the signals for controlling the servos, and is connected to my Home Assistant home automation system via Tasmota.

It's DEFINITELY not pretty, and I still have a lot to learn about soldering, but it DOES work.

...For about 3 seconds until it sent the full 12V supply voltage into one of the servos and destroyed it...

I'm guessing the 3.3v regulator I used to power the small auxiliary servo just isn't up to the job. That means this whole thing has to go back to the drawing board. :(

So I made those PCBs at home. Those are adapters from SOP to DIP so prototyping is easier. Took me like a day

I think you already know, but since July 1st a tax of €3 per ARTICLES is now mandatory. (they say it’s by categories but in reality, no)

For €30 of electronic components, I have +€50 of taxes. For a person who has started to be interested in electronics recently, it hurts.

So I come to try to find alternatives to aliexpress, with similar prices if possible… If the delivery lasts 6 months but there are no taxes I DONT CARE, I need the components at an affordable price.

Thanks, and I hope that the aliexpress sellers will quickly find a solution for us

Purchased AD SSM2019 amplifier from DigiKey, only 1 unit. Got 26… :)

Don't ask me, ts is on another whole level of abstract

Ignore the rock drawer I didn't have a better place for my cool rocks

I have a couple of these receivers I got in a pile of old stuff and by defuse they're USB but I wanted to use them with my microcontrollers, so I ripped one apart with a simple pry tool then removed the pressed on RF shield to expose the goodies.

Looking at the USB to serial transceiver, I see it's a PL-2303HX and looking at the datasheet, pin 1 is serial TX and pin 5 is serial RX, so I traced them to two open solder bridges.

Closing those to solder bridges with questionable soldering using an oversized tip resulted in the two unused pins now making connection

I decided to use the existing cabling so I used a small pry tool to lift up the plastic tab holding the green and white USB data wires and pulled them out and inserting them into their new homes

After snipping off the USB connector, red to +5v, black to negative, and the two serial lines to my ESP32 pins,

I started streaming NMEA datagrams over uart ❤️

NOTE: the default speed for this receiver is 4800bps

"This model was specifically designed for microelectronics, eliminating the image lag common in cheap USB microscopes connected to a PC."

Here's some animations I made of transistors turning on and off. In order, we have an NPN BJT, n-channel MOSFET, and finally an n-channel JFET. The red and blue dots represent electrons and holes, and white flashes are recombination events. The density of dots is proportional to the actual density of charge carriers.

In the first set of animations, the velocity of the dots is equal to the velocity obtained by summing the diffusion and drift currents and dividing by the charge density, but diffusion is not explicitly shown. In the second set of animations, the dots undergo diffusion and drift, and this makes it a more correct depiction of carrier motion. The drawback is of course that the jiggling makes it more visually confusing.

I made these with my semiconductor simulator (https://brandonli.net/semisim/). I also have higher quality versions of the animations here.

Very simple circuit - i had a bunch of these charger/booster modules laying around and decided to learn about the dangers of bare 18650 batteries. Excited to do more.

I wanted to modify my PS3 controller to USB-C, but it used a through hole connector. Not a problem!