Application of ASCR in 40-KHz Sine-Wave Converter

Efficient bulk power conversion from a 140-volt battery source to 48 volts dc can be accomplished by using ASCR's (Asymmetrical Silicon Controlled Rectifiers) in a 70-kHz series resonant circuit that operates at a repetition rate of 40 kHz. This paper describes a dc-to-dc converter that can deliver 2.5 kilowatts output power with an efficiency greater than 80 percent using a pair of S7310M's connected in the push-push configuration. The magnetic portion of the circuit consists of an input charging choke and an output transformer whose windings are connected such that the induced voltages are additive to provide a high charging voltage to the capacitors in the LC resonant circuits. In addition, this new circuit will prevent the ASCR's from latching on when the extreme output condition of either open or short circuit is present.