Over the past year or so I've built a number of HO scale motorized Amusement Park rides manufactured by a German model company called Faller. Recently, I've been dusting them off and been using Picaxe chips to automate them and control LEDs that I've added.
The most recent one I've modified is a Flipper model. I ended up building two circuit boards. One contains a Picaxe 18A chip to control a 7 character LED sign. The other board also contains an 18A chip and controls various LEDs, the model's AC motor via a Relay switch and detects pulses from a Reed Switch to determine when to stop/start the motor. This board takes a 16vAC source (for the motor), converts the AC to DC (for the LEDs) and further down-converts this to 5vDC for the chip.