This is a relay board I’m building for a friend of a friend; I’m going to control it with an Arduino eventually. It’s for controlling a model train.
I’m happy because I got all 12 relays in and working. Next step is wiring up the sockets for the custom data cables I’m building to go to the ‘duino, and a rebuilt power supply.
Update: I added a closeup of a single relay channel, with the schematic hand drawn over the photo: