Trip device comprising at least one current transformer
US5726846A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Sep 19, 1995 |
| Grant date | Mar 10, 1998 |
| Priority date | — |
| Expiry date | Sep 19, 2015 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01H71/125
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A trip device comprises at least one current transformer for supplying power to electronic circuits. The current transformer comprises a magnetic circuit, surrounding a primary conductor, a secondary winding wound onto a part of the magnetic circuit forming a core, and a magnetic shunt branch connected on the magnetic core. The magnetic shunt comprises an air-gap. When the current flowing in the primary conductor is of low value, the magnetic flux stopped by the air-gap flows essentially via the core of the secondary winding. At high current levels the induction is greater and a large part of the magnetic flux passes through the shunt via the air-gap. The current transformer has a non-linear current response which limits excess power supplied to the electronic circuits and dissipated in the transformer. The trip device is useful, for example, in a circuit breaker.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.