1. AN ELECTRIC CONTROL SYSTEM COMPRISING A LOAD CIRCUIT, A SOURCE OF ALTERNATING VOLTAGE, A FULL-WAVE RECTIFIER CONNECTING SAID SOURCE TO SAID LOAD CIRCUIT AND ENERGIZING SAID CIRCUIT WITH FULL-WAVE RECTIFIED ALTERNATING VOLTAGE, MEANS IN SAID LOAD CIRCUIT ESTABLISHING A UNIDIRECTIONAL VOLTAGE IN OPPOSITION TO SAID SOURCE AND OF A VALUE SMALLER THAN THE PEAK VALUE OF SAID SOURCE, A SATURABLE REACTOR HAVING A GATE WINDING CONNECTED IN SERIES WITH SAID LOAD CIRCUIT AND SAID RECTIFIER, A CONTROL WINDING ON SAID REACTOR, AND A SOURCE OF CONTROL VOLTAGE CONNECTED TO ENERGIZE SAID CONTROL WINDING IN A DIRECTION OPPOSING THE FLUX CHANGE ESTABLISHED IN SAID REACTOR BY THE VOLTAGE APPLIED TO SAID GATE WINDING.