Abstract: A power module includes a semiconductor substrate and spaced power transistor circuits formed in the substrate, each having respective anode and cathode portions. A power module housing substantially encloses the substrate. Flexible cathode straps and flexible anode straps are connected to the respective anode and cathode portions and extend out of the power module housing spaced from each other. At least two anode straps and cathode straps fold over at least a portion of the power module housing to overlap each other and form phase straps. The remaining cathode and anode straps fold over at least a portion of the power module housing such that respective cathode and anode straps overlap each other, thereby lowering inductance and reducing voltage overshoots at turn off.

Abstract: A power module includes a semiconductor substrate and spaced power transistor circuits formed in the substrate, each having respective anode and cathode portions. A power module housing substantially encloses the substrate. Flexible cathode straps and flexible anode straps are connected to the respective anode and cathode portions and extend out of the power module housing spaced from each other. At least two anode straps and cathode straps fold over at least a portion of the power module housing to overlap each other and form phase straps. The remaining cathode and anode straps fold over at least a portion of the power module housing such that respective cathode and anode straps overlap each other, thereby lowering inductance and reducing voltage overshoots at turn off.

Abstract: An aircraft engine start system eliminates the need of a separate exciter field inverter by rearranging the exciter field windings and by utilizing external AC power. The aircraft engine is started by external AC power and once the engine has started, the engine can supply power back to a variable frequency AC bus as well as back to a constant frequency AC bus through the start/generator converter mode.

Abstract: A plurality of power semiconductor switching devices are included in a circuit module in a pattern whereby interconnecting lead lengths are minimized to provide improved circuit characteristics and to insure uniform current sharing when said devices are paralleled during switch-on, switch-off and steady state conditions.

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.

Abstract: A rotating rectifier assembly has a substrate which has a metal core and a ceramic coating. An exciter rotor which produces an ac signal and the rectifier assembly are disposed about a generator shaft. The substrate has rectifiers arranged in a rectifying circuit. An ac lead extends from the ac windings in the exciter rotor to the rectifying circuit where a dc signal is generated and fed to a main generator rotor.

Abstract: A shaft and a substrate having mating beveled sections for improved heat transfer therebetween. A shaft having a first section, a second section and a beveled section, between the first and second sections such that the second section has a smaller outer diameter than the first section, is provided for rotation within a generator. A substrate having power and heat generating components mounted thereon and a beveled inner radial surface is mounted on the shaft such that a beveled inner radial surface mates with the beveled section of the shaft to provide greater surface area where the substrate and shaft interface, so as to improve heat transfer therebetween as compared to a shaft having a diameter along its entire length equal to the second section and to permit an adjustably tighter fight. The second section of the shaft is threaded to receive a hold-down collar having a threaded inner radial surface for securing the substrate in position.