Abstract: A voltage control system has a pair of clockwise and counterclockwise interleaved coils on a portion of a transformer core, the coils having multiple spaced turns providing sets of co-planar alternate electrical contact pairs extending linearly to form a tapping system for varying the output voltage of the transformer. A conductive electrical bridging member is movable in the linear direction of extension of the contacts and bridges a selected pair of contacts, one contact from each coil, to alter the effective number of electrical turns of the two coils between a minimum and maximum output voltage. An adjunctive feature is to provide both a contact lead to the bridging member and appropriate rectification at output ends of the pair of coils in order to produce a direct current output.