Ground fault interruptor circuit with electronic latch
US5177657A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 16, 1991 |
| Grant date | Jan 5, 1993 |
| Priority date | — |
| Expiry date | May 16, 2011 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02H3/331
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A ground fault interruptor circuit interrupts the flow of current to a pair of lines extending between a source of power and a load. The ground fault interruptor circuit includes a circuit breaker comprising a normally open switch located in one or both of the lines, a relay circuit for selectively closing the normally open switch, an electronic latch circuit operable in first and second bi-stable states and a fault sensing circuit for sensing the presence of a fault condition in at least one of the lines. The electronic latch circuit causes the relay circuit to close the normally open switch and maintain the normally open switch in its closed position when the electronic latch circuit is in the first bi-stable state. The electronic latch circuit also causes the relay circuit to permit the normally open switch to return to its normally open condition when the latch circuit is in its second bi-stable state. A fault sensing circuit senses the presence of a fault condition in at least one of the lines and causes the electronic latch circuit to latch in its second state upon detection of the fault condition.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.