From: whit3rd@gmail.com   
      
   On Wednesday, May 9, 2018 at 10:37:19 AM UTC-7, Robert Roland wrote:   
   > I have been thinking about the way a variac works. One thing that   
   > puzzles me, is the wiper design:   
   >   
   > If the wiper is too narrow, the output voltage will cut out when the   
   > wiper is between two turns of the coil.   
      
   Yep, the wiper gets hot, too.   Sometimes that kills the   
   variac...   usually not, though.  It's just not energy   
   efficient because of the shorted turn,   it might be amusing   
   to look at a FLIR image of a variac in operation.   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)