Abstract: Apparatus for opening and closing electrical circuits including one or more normally-open switches and normally-closed switches. A normally-open switch includes at least one MOSFET assembly consisting of a plurality of MOSFETs of different current-carrying capacities connected in parallel and circuitry for turning on the MOSFETs in time sequence. The normally-closed switch includes a pnp bipolar transistor, an npn bipolar transistor, and a circuit for short-circuiting the emitter-base junctions of the two transistors. The base and the collector of the npn transistor are connected respectively to the collector and the base of the pnp transistor. The normally-open and normally-closed switches both include a means for accommodating a current flow in either direction through the switch terminals.

Abstract: The capacitor coupled converter (CCC) is a DC-DC converter which produce a DC source as the output. It has two input terminals for connection to a DC voltage source, two output terminals for connection to a load, and a plurality of circuit control terminals for receiving a plurality of control waveforms. The basic elements of the CCC are two switches connected in series across the input terminals. An inductor in series with a transformer is connected to the junction of the two switches. Two capacitors with parallel diodes are connected across the input DC voltage source. The junction between the two capacitors is connected to one of the primary terminal of the transformer. The secondary terminals of the transformer is connected to an AC-DC converter, typically two diodes which rectify the AC to DC. The DC is then filtered by an inductor-capacitor filter. During operation, the two switches periodically and alternately open and close.

Abstract: The double modulation converter (DMC) is a DC-AC converter for driving an AC-DC converter. It has two input terminals for connection to a DC voltage source, two output terminals for connection to an AC-DC converter, and a plurality of circuit control terminals for receiving a plurality of control waveforms which cause a bipolar stream of width- and amplitude-modulated pulses to appear at the output terminals when a load is connected across the output terminals. The basic elements of the DMC are two switches connected in series across the input terminals. One output line connects an output terminal to the junction of the two switches. The other output line connects the other output terminal to one of the input terminals. During operation, the two switches periodically and alternately open and close, the closure of one switch causing a pulse of one polarity to appear across the output terminals, and the closure of the other switch causing a pulse of opposite polarity to appear across the output terminals.