Radiotone Special Roller Carbon Brush Variable Autotransformer (colloquially known as Variac) uses Roller brushes and these roller brushes are manufactured from special graphite slabs & have a metal insert. The movement of the carbon brush on the Variable Autotransformer track is with minimum friction. Thus it is very very smooth & effortless. It also ensures longer life.
Models : 2A, 4A, 8A, 10A
Higher rated models of Radiotone Special Roller Carbon Brush Variable Autotransformer available for Oil Cooled applications.
Models for Oil cooled : 15A, 20A, 28A