Train Wheel Slip Controller
This micro-controller pretty much does what it says. It simply requires that you have a "clutch" installed between the motor of your train and drive wheels of your train. The micro-controller will take the input from your throttle, and the "slip" input from your drive wheel, and do it's best to control the clutch to make sure your drive wheels don't slip.
This controller can, technically, also be used for steam trains by replacing the "clutch" with a variable valve on the steam drive line.
