Accession Number : ADD007907

Title :   D. C. - A. C. Inverter Protection.

Descriptive Note : Patent Application,

Corporate Author : DEPARTMENT OF THE ARMY WASHINGTON DC

Personal Author(s) : Ashley,Albert H

Report Date : 01 Oct 1980

Pagination or Media Count : 11

Abstract : The A.C. synthesizer is a unit developing several hundred watts at 60 Hz by pulse-width modulation techniques, with an 8 KHz sawtooth oscillator modulating a 60 Hz reference. Several failure modes common to electronic equipment caused the output stages designed for a pulse rate of 8 KHz to experience inputs from 60 Hz to as low as D.C., which inputs destroy expensive transistors. The addition of a retriggerable 'one-shot' (monostable multivibrator) to inhibit the pulse width modulator output if not retriggered each 8 KHz cycle eliminates the catastrophic effect of most failure modes, allowing the output stage to reject low frequency pulses. (Author)

Descriptors :   *Patent applications, *Inverters, *Switching circuits, Catastrophic conditions, Electronic equipment, Low frequency, Pulse modulation, Pulse rate, Transistors, Modulators, Protection, Failure, Pulses, Output

Subject Categories : Electrical and Electronic Equipment
      Electric Power Production and Distribution

Distribution Statement : APPROVED FOR PUBLIC RELEASE