Made a replacement for one of a pair of single phase half controlled bridge rectifiers that were originally made by my predecessor. Managed to fit it into a very much smaller case, and added in some more protective features... necessary features, after someone further up the chain of command blew up the (over £100) controller part in the previous one.

Basically what it does is converts mains alternating current (AC) electricity to high voltage direct current (DC) electricity, with some control of the "effective" DC value output. We use it for controlling the speed of a large DC motor.

Took a couple of record shots to remind me of how I'd laid the bits out inside the case. Thyristor module visible at the back, in the extra.