公开(公告)号：US3619723A

公开(公告)日：1971-11-09

申请号：US3619723D

申请日：1970-09-30

Applicant: GEN ELECTRIC

Inventor： WALDEN JOHN P

IPC: H02H1/04 ,  H02H3/33 ,  H01H47/18

CPC classification number: H02H1/04 ,  H02H3/33

Abstract: A full- or half-wave peak current detector of a few milliamperes of power circuit fault current includes, for each polarity, a normally conducting first transistor continuously supplied with base current. In response to sensing an instantaneous abovethreshold fault current, the base current is diverted through a mirror-image connected second transistor, turning off the first transistor for so long as the above-threshold current exists. For full-wave detection the role of the transistors is reversed on the other polarity. This actuates one or more series RC filter networks to delay the output indication and reduce the detector sensitivity to high-frequency transients or noise. The valid power frequency output signal opens a circuit interrupter.

公开(公告)号：US3569819A

公开(公告)日：1971-03-09

申请号：US3569819D

申请日：1969-01-16

Applicant: GEN ELECTRIC

Inventor： MARTZLOFF FRANCOIS D ,  MCMURRAY WILLIAM ,  WALDEN JOHN P

IPC: H02M7/521 ,  H02M1/00 ,  H02M1/38 ,  H02M3/315 ,  H02M1/18 ,  H02H7/14

CPC classification number: H02M1/38

Abstract: When a short circuit or shoot-through occurs in a power circuit having two thyristors in series with commutating circuit inductors, a shunt capacitor isolated from the DC power supply by an impedance automatically resonates with the inductors to turn off both thyristors. A second automatic recovery system for repeated short circuits that occur before the capacitor has recharged operates to temporarily disable the power supply. In a high-voltage inverter the impedance is a resistor functioning to dampen voltage overshoots and to implement a relay or solid state second recovery system.