Device for monitoring the state of an electric switch or an electric relay
US4710645A · kind A · utility
18Cited by
2References
7Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | May 28, 1986 |
| Grant date | Dec 1, 1987 |
| Priority date | — |
| Expiry date | May 28, 2006 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01H47/002
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A device for monitoring the state of a relay comprises an electrical insulation transformer whose secondary winding is connected, through a rectifier, to the output terminals of the relay. The primary winding of the transformer is in series with an oscillator having an impedance greater than that of the primary winding when the relay is closed. A transistor receives a signal from the primary winding and delivers an on-off output signal representing the impedance across the terminals of the relay.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.