The halogen bulbs are 12 volts at 20 watts. Almost certainly the "High" setting is 12 VAC, and the "Low" setting is the same 12 VAC but through a half wave rectifier (just a diode). So, if you want to use the current switch and processor board, you'd need something that could be driven by 12VAC, both with and without a half wave rectifier. I'm guessing this would be tough to find; the best you could probably do would be a system that works when the switch is on "High", and doesn't work, but also doesn't burn up, when the switch is on "Low".