Intrusion alarm cable supervision system
US4032916A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 27, 1975 |
| Grant date | Jun 28, 1977 |
| Priority date | — |
| Expiry date | May 27, 1995 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG08B29/06
- WIPO fieldControl
- WIPO sectorInstruments
Abstract
A cable supervision system especially adapted for use in an intrusion alarm installation and which is capable of monitoring at a central control unit all lines of an interconnection cable for proper signal levels and balance. Under intended cable signal conditions a predetermined sensible impedance is provided which is monitored at the control unit. A monitoring circuit is coupled to the end of a system cable remote from the control unit, this circuit being operative to monitor the signal conditions of all lines of the cable. In response to proper signal conditions on the cable as determined by this monitoring circuit a predetermined impedance is provided which is sensed at the control unit to detect a change in impedance which would signal a tamper or cable failure alarm.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.