variac

[m l williams]

Tom, a variac with a rectifier will control a dc motor, but does not do a very good job of it. Things like filters for smooth operation, speed contol under varying loads, etc. are not handled simply. A simple dc controller will usually cost less than a variac, and will be motor ready when you get it. E-mail me at alliedel@pine-net.com if you need specifics. mw