Variable Voltage Transformers

A variable transformer is an efficient and trouble free method of varying AC voltages.  The output coltage is varied by rotating a carbon tipped brush arm along a sliver plated commutator, either manually or by means of a motor drive.  The voltage output can be varied from zero up to line voltage.

The variable transformers are available in single and three phase construction.  Both open type or housed in a metal enclosure.  The single phase variables are also available in a popular encapsulated style.