Switching Regulator Controlled by High-Frequency Magnetic Amplifier

The operation of a push-pull converter constructed using a self-excited inverter (a multivibrator) is described. While the switching losses of FETs in the inverter were small, turn-on and turn-off slopes changed depending on the load conditions, so that the oscillating frequency varied slightly. Two types of magnetic cores were used in experiments; power conversion efficiencies reached 76 percent or more for load currents from 5 to 10 A, and the oscillating frequency changed by about 10 percent in the 0 to 10 A range. Use of a core with good frequency characteristics should enable operation at up to 1 MHz.