Overcurrent protection device
US4697218A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jul 24, 1984 |
| Grant date | Sep 29, 1987 |
| Priority date | — |
| Expiry date | Jul 24, 2004 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02H3/08
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
The device, for AC operation, is applicable more especially to the protection of very high tension installations. It comprises a rectifier (12), a comparator for comparing the rectified current and a threshold value (s) and for making, in the case of overshoot, a new comparison after a time equal to and 1/2T+.DELTA.T, T being the nominal period of the AC current and .DELTA.T a fraction of T of the order of a tenth, after overshoot. The new comparison is made with a circuit comprising a memory (22), a timer (24) and a circuit (34) including two inverters and an AND gate. Tripping is produced if overshoot occurs during the new comparison.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.