DafyddElvy
1:22.5 & 15mm Scale Trams, , NG Steam Railways

A while back I asked about a simple electrical circuit for my tram trailers and this coupling is why.Tell me more about the electrical contacts
With two wires I power the trailer tail light and the internal LED lights.
With the very simple (it had to be for me) circuit I can power the trailer from either end, the only thing I can't do without a manual switch is power a second trailer, that would require a third wire.
I have no doubt someone much cleverer than I could prove me wrong, with a bit of electronic trickery.
Should say, I mount these coupling in a square tube, effectively acting as an extension bar, the coupling fork goes in the square tube, which has a ring at the opposite end to fit directly to the normal coupling fixing point, and with a bit of tweaking of the screw it swings quite freely and holds its height.
David