Abstract: A synchronous generator start converter offers power conversion for performing multiple functions such as starting AC generators as a motor, charging batteries and also providing regulated DC output without degradation of input power quality. The converter utilizes common magnetic components and common semiconductor rectifiers within its three subcircuits. The three subcircuits include flyback converters, a square wave inverter and a field excitation controller.

Abstract: This invention provides for an enabling circuit that ensures a positive turn-on of semiconductor switches configured for the generation of a synthesized waveform, thereby eliminating misfiring of the switches due to electronic noise or logic malfunction. The circuit is configured to separately compare a sample waveform with a positive reference voltage and a negative reference voltage. The two results are directed to separate logic AND gates which have respective control signal inputs that regulate the formation of the positive and negative portion of a synthesized waveform. The output signals from the two AND gates connect to logic means to control the firing of the semiconductor switches.

Abstract: A power converter that can be used either as a start converter or as a variabe speed constant frequency converter is utilized within a stepped waveform VSCF system having engine start capability. Interfacing with the converter are a load bus, a contactor, a field excitation controller and a starter/generator having a main generator, an exciter generator and a permanent magnet generator. Magnetic components and semiconductor components perform multi-functions and minimal degradation of input power quality occurs.

Abstract: A multi-step, alternating current power supply that provides for a failed-operation redundancy safety system that compensates for a short-circuited power switch and maintains an AC regulated output voltage without introducing undesirable harmonic components. The firing and logic controller 33 senses a short-circuited power switch 46 within an inverter bridge 32 and disables all complementary power switches 48 within the faulted bridge and enables the remaining power switches 50 in the faulted bridge. The firing sequence is adjusted for the remaining healthy power switches 52 by increasing the phase shift of the individual waveforms 54. The generator voltage is increased as required to maintain the desired AC voltage output level 56.

Abstract: A two-sided hermetically sealed package of a metal matrix composite material includes a heat sink and integral cooling fins on each of the two sides which are totally enclosed to retain cooling fluid. Power semiconductors are mounted on ceramic substrates having metallic conductors mounted on both sides thereof. The substrates are mounted to the heat sinks. Cooling is provided by the passage of cooling fluid into one end of the enclosed fins, over the fins and out the other end. The metal matrix composite material and the ceramic are thermally matched and the package is provided with a minimum number of thermal interfaces.