Abstract: A regenerative variable frequency drive includes an active converter connected to an inverter. The converter has a filter capacitor, an inductor, two half bridges, bus bars that connect to the inverter and bus capacitors. The converter converts single phase AC power to DC power and DC power to single phase AC power, boosts the AC power, reduces input line harmonics, maintains input current in phase with utility voltage in order to achieve near unity power factor, and maintains constant DC voltage between the bus bars.

Abstract: A phase converter that converts single phase AC electric power to balanced three phase AC power. Two input terminal connected to the output of a single phase AC power source connect directly to two output terminals of the converter. The phase converter has two serially connected storage capacitors with a common connection, a charging circuit for controlled charging the storage capacitors and an output circuit for controlled discharge of the storage capacitors to provide single phase AC power to a third output terminal. The charging circuit controls input to the storage capacitor to provide a sinusoidal input current and to step up the voltage to the storage capacitors. The output circuit provides output power to the third output terminal of a predetermined phase and amplitude, relative to the other two output terminals, to result in balanced three phase AC power at the three output terminals.

Abstract: An improved normally off insulated gate field-effect transistor capable of peration at frequencies in excess of 1 GHz wherein the substrate is a semi-insulating semiconductor. The substrate may be Fe or Cr doped InP or Fe or Cr-doped GaAs. Contacts for the source and drain electrodes are realized by forming n.sup.+ contacts for the n-channel device and p.sup.+ contacts for the p-channel device. Au-Sn will form n.sup.+ contacts while Au-Zn will form p.sup.+ contacts.