A control system providing a universal input for receiving a control signal for actuating tap-changing equipment. The system accommodates virtually any signal voltage level commonly used for control of the tap-changing equipment, modifies the received signal to a desired format, and inputs the modified signal to a controller for decoding and actuation of the tap-changing motor. The system is fully electronic, eliminating the use of electromechanical contacts for control of the tap-changer and providing a flexible approach to monitoring and diagnostics even from a location remote from the tap-changing equipment.