Intruder detection system with passive self-supervision
US5057817A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Aug 31, 1990 |
| Grant date | Oct 15, 1991 |
| Priority date | — |
| Expiry date | Aug 31, 2010 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG08B29/16
- WIPO fieldControl
- WIPO sectorInstruments
Abstract
A multizone intruder detection system comprises a supervisory circuit for verifying, from normal traffic or activity in each of the zones of protection while the system is disarmed, that each of the intrusion sensors is, indeed, functional. In the event one or more sensors does not trip (i.e., sense activity) during the disarm period, the supervisory circuitry inhibits re-arming of the system until the non-tripped senso(s) is "walk-tested" to verify that it is still functional. According to the invention, a programmable timer enables re=arming of the system for a predetermined (preferably brief) time interval immediately following disarmig of the system. This feature offers the edvantage of allowing the user to re-enter the protected premises "after hours" for a brief period of time without having to walk-test all zones of protection before re-arming the system.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.