This is a video of a 7mm scale GWR Tubular Home Signal, it has :
Working light - smd warm white led (warm white leds show a green light through a blue lens as per prototype.
Powered by an Tower Pro 9g servo motor controlled via a MERG Servo4 board running a modified Chris White sema4f firmware. The original sema4f has bounce as an option in both directions. I did not feel this to be prototypical and preferred the action of either the Megapoints or GF Controls board.
However by a simple alteration of the firmware, I was able to have the arm bounce on return to Danger and hesitate slightly on moving to Clear in a similar way to the commercial offerings. In fact I prefer it .
Setup was implemented by using Chris Whites utility program which again, is MERG members only.