A SYSTEM FOR REGULATING THE VOLTAGE TO A LOAD AS A LINEAR FUNCTION OF AN INPUT SIGNAL COMPRISES A CONTROLLED RECTIFIER IN SERIES WITH THE LOAD AND A SOURCE OF FULL WAVE RECTIFIED AC VOLTAGE. A CONTROL CIRCUIT IS CONNECTED TO THE RECTIFIER GATE ELECTRODE TO CONTROL THE FIRING ANGLE AS A FUNCTION OF SAID INPUT SIGNAL. THE CONTROL CIRCUIT INCLUDES A COMPARATOR TO WHICH IS APPLIED THE INPUT SIGNAL AND A CONSINUSOIDAL SAWTOOTH SIGNAL IN SYNCHRONISM WITH THE RECTIFIED AC PULSES, THE AMPLITUDE THEREOF BEING DIRECTLY PROPORTIONAL TO THE AMPLITUDE OF THE RECTIFIED AC PULSES AND STARTING FROM THE ZERO LEVEL OF THE INPUT SIGNAL. UPON EQUALITY OF THE TWO SIGNALS, THE COMPARATOR SUPPLYS A CONTROL SIGNAL TO THE RECTIFIER GATE ELECTRODE.