Apparatus for detecting abnormal conditions of transmitted signals
US4071873A · kind A · utility
5Cited by
5References
18Claims
0Family size
Assignees
Inventors
Key dates
| Filing date | Jun 21, 1976 |
| Grant date | Jan 31, 1978 |
| Priority date | — |
| Expiry date | Jun 21, 1996 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02H3/30
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
In a protective relaying system wherein a carrier wave frequency modulated by an electric quantity is transmitted to a receiving station for operating a relay and an abnormal condition of the transmitted signal is detected by detecting the frequency variation of the carrier wave, there is provided an abnormal condition detector which compares the lengths of contiguous or closely adjacent periods, or functions thereof, of the received carrier wave.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.