Abstract: Circuitry for providing high voltage DC power from commercially available 60 hertz AC utility power. The incoming 60 hertz AC voltage is rectified to a DC voltage. This DC voltage is then converted to a high frequency AC voltage by means of a sine wave inverter. This high frequency sine wave voltage is then converted to a different voltage and rectified by a voltage doubler. The inversion and rectification are under the control of logic circuitry which includes means for sensing line faults to provide circuit protection.

Abstract: A battery charging system includes a circuit for sequentially connecting each of a plurality of banks of batteries to a constant current generator for a first predetermined period of time, for example, one hour, and then disconnecting all banks for a second predetermined period of time, for example, fifteen days. A plurality of controlled switching devices are sequentially gated to connect sequentially the banks of batteries, each for the first predetermined period of time, between the output terminals of a constant current generator. For n battery loads, the controlled rectifiers are gated by n outputs of a counter/decoder circuit having n + 1 outputs. The counter/decoder circuit is operated by clock pulse signals supplied thereto by a counter/time base circuit.

Abstract: A semiconductor switching device is connected in shunt with an A.C. voltage source to be regulated. A modified full-wave bridge rectifier is connected across the voltage source by a first pair of diagonally opposite nodes. A control circuit including a capacitor is connected across the output between a second pair of diagonally opposite nodes of the bridge rectifier to control a gate electrode of the switching device to control the triggering of the switching device in response to the voltage across the bridge rectifier output. The triggering of the switching device regulates the voltage supplied by the voltage source. The bridge rectifier includes an impedance network comprising first and second resistors branching from one of the nodes of the second diagonal pair, each resistor being connected via a diode to a different node of the first diagonal pair.