shop talk from my electrical engineering days:

I think my favorite power-related mishap involved the board layout engineer using the wrong DC barrel plug in the layout (center-negative instead of center-positive)

none of us caught it during layout review because we were focusing on the complicated things like the FPGA and the main component

the board is normally powered by USB so everything was testing fine on the first prototypes

until like Friday afternoon when we were like "okay let's make sure the DC power failover works" and we go to plug it in and the fuckin power-source-selection IC pops and leaves a crater

that was fun

@rey

My second internship we had a power supply known as the Trace Breaker. It was a 15V, 50A linear supply that weighed a fucking ton. You'd use it on boards with a short somewhere and ramp the voltage slowly while using a thermal camera. I actually had a board I designed fail and we couldn't break a trace even at max amps, because the PCB shop failed to etch a corner of the board under some connectors! It was a huge power/ground short that was like 20% of a layer. XD

@zetasyanthis @rey for stuff like that, i think an H-field probe is a lot easier to use

if a lot less impressive

remind us to tell you about liquid crystal hotspotting sometime
-F

@Felthry @rey

It might be, but blowing shit up (the usual result of this sort of nonsense) is kinda fun. :P

@zetasyanthis @rey We once put a piece of #30 gauge wire wrap wire across the terminals of an "ultra high current" (capable of up to 1500 A) SMU and programmed it to just do pulses of current increasing until it breaks

it made it to several amps before it just melted
-F

@zetasyanthis @rey this actually had a purpose, believe it or not: we wanted to determine a rough measurement of the fusing current of a similar type of wire

figured this was a good enough approximation so put it in there and let it do its thing

it actually fried the socket we poked it into in the process, which indicates there was a lot of contact resistance
-F

@Felthry @rey

Hopefully the socket wasn't that expensive? XD

@Felthry @rey

And that must have been one hell of an SMU to hit 1500A!

@zetasyanthis @rey you should hear the clunking of the contactor when we turn it on

it can only do very short pulses of 1500 A, of course

It came with banana plug cables with a little mechanism inside the plugs that makes them expand when you twist a collet, to increase contact pressure. they're also on some #6 AWG welding cable instead of the more conventional for banana plugs #14 AWG
-F

@zetasyanthis @rey it's an Agilent N1265A ultra high current unit by the way, hooked up to a B1505A semiconductor parameter analyzer
-F

@Felthry @rey

I miss my lab days now. Maybe one day I'll get back into stuff with them. :(

@zetasyanthis @rey i wish you could get stuff like this without being a big company

but this thing was bought used, at like a 50% discount, and it still cost more than a house
-F