Electronic trip circuit breaker with CMR current sensor
US5923514A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 5, 1997 |
| Grant date | Jul 13, 1999 |
| Priority date | — |
| Expiry date | Nov 5, 2017 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02H1/0007
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A current sensor has a closed loop magnetic hoop with a gap and a central aperture for receiving a conductor. An IC chip incorporating a Giant MagnetiResistive (GMR) sensor is positioned in the gap to provide a measure of the current in the conductor. A relatively small current transformer provides the necessary information about the direction of the current to an electronic trip unit for a circuit breaker as well as power supply for the IC chip and the trip unit. The trip unit operates in the presence of AC and DC faults. In a three phase power system, a single GMR chip in the proximity of three closely spaced phase conductors, together with a current measurement from the neutral line, enables trip units to operate on the occurrence of AC and DC faults.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.