Original poster: "Andy Cobaugh by way of Terry Fritz <twftesla-at-qwest-dot-net>" <kb3ewy-at-rcn-dot-com> Unless of course you have a micro switch to turn the variac off when it is at "zero" :-) That's the way mine is (the controller is a modified control box for dielectric testing: www.hipotronics-dot-com ) Andy, KB3EWY http://users.rcn-dot-com/tcobaugh/andy/tesla.htm