Abstract: An alternating power supply system is provided with a circuit which employs a transformer having three windings. The primary and secondary windings are wound in the direction upon a magnetically permeable core. A third winding is connected to a load and produces flux in the core in the opposite direction. The magnetic field produced by the third winding proportionally decreases the power input of the primary winding while maintaining the power output of the secondary winding. The circuit thereby reduces the power drain necessary to operate a given load.