Abstract: A turn-on control system for series variable transformer type voltage drop compensators comprising a voltage corrective variable compensating winding in combination with a voltage sensing main control to sense the voltage deviations of the utility's incoming service line with respect to a given reference voltage and a regulating control which operates the variable compensating winding. Upon occurrence of a power brownout the voltage corrective assumes its highest corrective position. Upon blackout the control system actuates the disconnection of the voltage corrective variable compensating winding and regulating control. Upon return of power the voltage corrective variable compensative winding is first placed at its lowest corrective position and the subsequent reconnecting of the voltage corrective control operation is effected.