12 Volt motion detector - Classic Toy Trains Magazine

Looks like a neat neat device. I've been working on a similar one for making my streetlights come on if I shut the room lights off. It may be cheaper and a lot less aggravating to just buy that gizmo.

I wouldn't think a gateman and a semaphore would exceed 8 amps, but I've been wrong before.

If you are looking at ones with an adjustable time, make sure you know what you are buying. Some relays use the timer on energizing (such as when the train blocks the light, it starts the timer; when the timer times out, the signal get juice) while others use it on deenergizing (such as the train blocks the light, the signal gets juice; when the train no longer blocks the light, the timer starts, and the device turns off when the timer times out)

J White