Electronic overcurrent detection and tripping circuit
US4250532A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Feb 12, 1979 |
| Grant date | Feb 10, 1981 |
| Priority date | — |
| Expiry date | Feb 12, 1999 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02H3/105
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
An electronic overcurrent detection and tripping circuit for circuit breakers is disclosed. The circuit includes an instantaneous trip circuit, a short time delay trip circuit, a long time delay trip circuit and a ground trip circuit. Each of the circuits is provided with adjustable ranges which can be set by suitable tap blocks or the like. A novel power supply is provided for the circuit which incorporates a unique series-connected zener diode and sensing resistor. The power supply circuit also provides sufficient power for tripping a magnetic latch of the circuit breaker whose current is being monitored. Each of the circuit functions can be disabled for purposes of tests by simply placing the function tap block pin in an appropriate test position.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.