Reddit:Electronics

Created this pcb to learn how to drive SRM.

Firmware is open source though. A small (52x30) PCB to forward USB HID reports over BLE. Plus additional buttons and a rotary encoder.

Fully TTL driven Nixie clock I have been buildng recently. It have 6x IN-14 and 2x IN-19V Nixie tubes. Clock pulse is taken from mains frequency by optocoupler and devided by 7490 cunters. It can be set for 50Hz o 60Hz. There will be an option to choose beside Mains CLK, Crystal CLK and External CLK. There is also output to drive other clocks as "slave". Later on I will add "Day of the week" display.

Hey!

I repaired the LCD ribbon cable in a Nintendo DS Lite. I know it’s completely not worth it since a new screen is super cheap, but I wanted to practice soldering and test my skills. And it actually worked!

I intentionally placed a human hair on one of the pictures—for scale. I used an ultra-thin wire from a phone speaker coil to reconnect the traces. This was more of an experiment than a necessity, but the screen works like new, so mission accomplished.

The photos are a bit blurry since I took them with my phone through a microscope eyepiece—I don’t have a proper adapter.

All this effort for something that costs just a few bucks—but the satisfaction is priceless!

The first photo is a cross section from a 12pF 3kV capacitor along it's width. The second photo is that same capacitor along it's length.

The third photo is of a 47uF capacitor along it width, but with the layers in the wrong direction giving this damascus like texture. The fourth and fifth photo is this same capacitor along the width (the same orientation as the first photo). Unfortunately, not much can be seen here. I assume that the capacitor plates are too thin and densely packed for my microscope.

The sixt photo is of a (pretty bad) crimp terminal. It's just a random terminal I had laying around and I didn't know which cable size and crimping die I had to use for it.

The last photo is a cross section of a piece of solder wire, clearly showing its flux core within. I used it to hold the crimped terminal in place while the epoxy was hardening. That's why the crimp terminal can be seen behind it.

I still need to get vacuum pump to get rid of the air bubbles, and I also used very cheap epoxy so the clarity of it is not great. But for some first experiments, I think I can call it a success. Next up, I would like to capture some PCB details such as burried and capped via's.

I ran across this today for $5. I believe it is a PNP Germanium power transistor.

Along with mica insulators it has a note that looks original. It reads “2N278 transistors are not recommended for replacement in Delco built car radios.”

Max Voltage: 45VCEO, 50VCBO. Max Current: 15 Amp. Dissipation: 170 watt. Package: TO-36.

That is a lot higher dissipation spec than I expected.

My buddy dead bugged a QFN, he is so much more patient than I am. Apparently the engineer connected the belly pad to the wrong voltage

But ıt burned because ı forgot to add rezistors a and b

I'm in the process of stripping this old scoring machine down to replace the insides with an Arduino. I think this machine dates back to the 1960s. Interestingly, it only has modes for Épée and foil (no saber), but yeah it is a fairly interesting piece of history.

Just

Took this out of a unit cause it wasn’t turning on, flipped it over and multiple resisters and caps were gone. Most likely a power surge. Thought would be interesting to post cause don’t see this every day