I am in the process of restoring a 1954 470 series train set. I have the original AC Power variable voltage transformer (#4B), but wanted to get into the modern era and have a way to at least control the voltage on the track with a digital communication interface (RS-232 or USB). I've read about DCC, but these all seem to be DC based. I was looking at the Lionel TMCC TPC 300/400 and their Powermaster, but can't quite figure out how I could hook a computer to the Comm terminal (if at all) and the protocol. Is there any known AC 100w+ power units that have a serial interface or (bluetooth) that can change the power output (vary the voltage)? Basically, a variac with digital control if one is made. Ultimately, I would like to create a control panel on a PC to control the speed of the train, and have sensors on sections of the track to provide position information of the train to control it. Any help in this area would be appreciated.