Abstract: A drive circuit for a voltage-controlled switch. The drive circuit includes a normally-on switch including first and second terminals and a control terminal, wherein the first and second terminals have a conduction path therebetween, the second terminal is connected to a conduction control terminal of the voltage-controlled switch, and the control terminal of the normally-on switch is biased by a drive voltage relative to the first terminal of the normally-on switch.

Abstract: A regulated power supply system is disclosed including a source of unidirectional electric current, and at least one switch device including a saturable reactor controlled between a saturated condition and an unsaturated condition in a duty cycle such that the load voltage tends to remain constant with varying load current. In one embodiment, a pair of switch devices are coupled, respectively, between the ends of a center-tapped secondary winding of a transformer having a primary winding fed from an inverter, and a pair of rectifier devices coupled to provide the unidirectional current to the load. Control of the switch devices is effected by applying an appropriately varying control voltage to like electrodes of respective inverted control diodes each coupled to the junction between a respective switch device and its associated rectifier device. The control diodes are driven from the output of a comparator amplifier responsive to the difference between the load voltage and a reference voltage.