DC POWER

VARIABLE TRANSFORMER - Carl E. Holmes Company (CEHCO)

Variable DC power supplies are AC to DC power supplies with a variable DC output. The output can be varied with a Variable Transformer (also known as variac). The Variable Transformer can be adjusted manually or with a motorized control. The AC input power can be single phase or three phases. With single phase AC input, the DC output ripple is very high (50%). With three phase AC input, the DC output ripple is low (5%). This would be a key benefit for selecting three phase AC input instead of single phase.