It would.be as easy as a few dollars for a bridge rectfier and maybe an extra diode or two to knock voltage to 12vdc max.. The "hard part" (if you can call it that) is the resistor, which they include. That dials them in for up to 12v. Adding another resistor would increase the source voltage you can use, or you could lower a higher voltage to 12v another way if you chose.
I think it was mentioned in another thread the Miller lights, etc are ac/dc ready.
