"Sam Goldwasser" wrote in message
...

Probably is and would matter for a high power Variac. I wonder what
the limiting factor is on current between adjacent turns. What other
factors will be important besides resistance of the winding and brush/
contact?

Clearly these have a high volts per turn ratio. One shorted turn is limited
some by the impedance of the other windings, but really the resistivity of
the brush is critical.

N