AVR or switching regulators rapidly switch a series of relays that send power to energized coils that increase watts to 10,000 Watts in 120,208 or 220,360VAC all with built in surge suppression using MOV components. or reduce voltage to connected load. The device does this automatically and maintains voltage to load based on the percentage of the transformer coils.

CHICAGO DIGITAL POWER offers models from 250 Watts to 4000 Watts