State grasp device, and switching control device of power switching apparatus employing the state grasp device
US7936549B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Mar 22, 2005 |
| Grant date | May 3, 2011 |
| Priority date | — |
| Expiry date | Jul 29, 2028 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01H2011/0068
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A state grasp device that needs no optical adjustment, and can be downsized. An exciting current waveform of an opening electromagnetic coil of an electromagnetic operating set functioning to drive a moving contact of a switching device includes an inflection point appearing subsequently to a maximum value, the inflection point taking place at the time of the contact being parted. Accordingly, a wear amount of contact from the change over time can be obtained. A position of the inflection point is obtained, for example, by focusing the rate of change in current; and a wear amount of a switching contact is obtained from the change over time of a time when the inflection point takes place. With the device, the use of a mechanical detection device, such as an optical detector, can be eliminated.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.