Abstract: In a forward converter power supply comprising a transformer having a primary winding connected to a primary circuit and a secondary winding connected to a secondary circuit, and a switching transistor in the primary circuit, an active network snubber in the primary circuit for receiving and storing continuing current from the transformer primary winding upon switching of the transistor and for returning current through the transformer primary winding so as to resent the transformer and thereby returning parasitic energy in the transformer caused by leakage inductance and magnetizing current to the energy source.

Abstract: A system for simultaneously and independently controlling a plurality of electric motors from a number of dispersed stations. The system operates by transmission of duty cycle modulated selected frequencies superimposed on a DC track voltage on a common power line servicing the motors. The modulation is variable and determines the speed of the motors. Transmitters are portable and designed removably to plug into a common signal transmission cable anywhere along its length without interaction. Receivers, each tuned to a specific frequency and associated with and controlling a motor, are coupled to the common power line.