A magnetic power controller of amorphous cores for a 200 kHz switching regulator

A half wave pulsewidth modulation (PWM) control device based on the principle of the half wave magnetic amplifier has interesting characteristics for controlling a high frequency switching regulator. We call it the magnetic power controller. By using the magnetic power controller of an amorphous core having a highly rectangular dynamic hysteresis loop and using a self-oscillating inverter, a highly reliable 200kHz switching regulator is realized, in which the current surge caused by the reverse recovery of the diode is well suppressed by the surge suppression characteristic of the magnetic power controller. The efficiency of this switching regulator is higher than 80% for an input voltage 110 ± 20V and for an out-put power 98W (5V, 10A and 24V, 2A). Peak to peak voltage of the switching noise observed in the output voltage is as small as 10mV under the above condition. The amorphous core used in this paper is of a Corich system with approximately zero magnetostriction.