Abstract: An electronic power supply utilizes a full wave bridge rectifier circuit whose alternating current voltage source is derived from a multi-primary and multi-secondary winding transformer whose windings are selectively disposed in series or parallel circuits, thereby enabling the apparatus to be effectively employed on a wide variety of A.C. voltage sources. Two adjacent legs of the bridge rectifier employ S.C.R.'s gated simultaneously symetrically by pulses obtained from a unijunction transistor driven by the output of an operational amplifier whose input terminals are coupled to voltage and current sensing networks located at the output terminals of a filter coupled to the D.C. side of the full wave bridge.