Westinghouse Electric Corporation

Leland Electrosystems Inc.

Robert G Wagoner

John A Overman

Gary M Kuzkin

Victor B Bonneau

An aerospace power control system switches an aerospace load from a faulty ac power bus to a good ac power bus of two or more ac power buses if the currently connected ac power bus is about to fail. The voltage level and frequency of the power provided on the buses are monitored to determine which of the power buses are within required limits to provide power to the aerospace load. If monitoring of the currently connected ac power bus indicates that the bus is not within the required limits and may be shut down in the immediate future, the connection of the aerospace load is switched to another ac power bus which is within the required limits. The current provided to the load is monitored to determine zero-crossing points of the current with the switch from the currently connected faulty bus to a good bus being performed at a zero-crossing point of the load current. The level of the current being provided to the aerospace load is also monitored to detect a faulty load condition. If the load current exceeds defined limits, the load will be disconnected from all ac power buses to shut down the faulty load. The aerospace power control system is generally applicable to single phase and three phase ac power, with switch over at zero-crossing points being performed on a phase-by-phase basis for three phase ac power.

Aerospace power control system for monitoring and reliably transferring

A current variation reduction circuit for metal oxide semiconductor field effect transistors, which are controlled by the application of a drive voltage between the gate and drain terminals, includes a circuit for applying a compensation current to the gate terminal. The compensation current is of substantially equivalent magnitude and opposite polarity to current in the source to gate capacitance of the MOSFET in response to a change in the source to drain voltage of the MOSFET.

Current variation reduction for mosfet current sources

Remote power controllers for controlling power between an external power supply and a load include output stages including MOSFETs and a drive circuit connected to supply gate voltage of a preselected magnitude to each of the MOSFETs in response to a control signal. The magnitude of the gate voltage corresponds to a predetermined maximum drain current for each of the MOSFETs, with the maximum drain current being substantially constant over the expected operating temperature range of the power controller. An overload signal representative of excessive power dissipation in the MOSFETs is sensed and a trip signal is produced when that overload signal exceeds a threshold limit. The drive circuit responds to the trip signal to remove the gate voltage signal from the MOSFETs.

Current limited remote power controller

An AC solid state switch includes an inverse parallel connection of a pair of silicon controlled rectifiers. A circuit branch which includes the series connection of the main conducting paths of a pair of field effect transistors is electrically connected in parallel with the inverse parallel arrangement of silicon controlled rectifiers. Gate power sources provide continuous gate drive signals to the silicon controlled rectifiers and field effect transistors. By including the field effect transistors, voltage transients across the switch are reduced in high frequency AC power systems.

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Troy, OH, United States of America

Robert G Wagoner