Dual technology intruder detection system
First Claim
1. A dual-technology intruder detection system comprising first and second intruder-detecting subsystems, each being adapted to detect intrusion by a different technology and to produce an output signal in response to intrusion detection, means for normally activating an alarm in response to the production of output signals from said first and second subsystems within a predetermined time interval, a supervisory circuit, operatively connected to one of said subsystems for producing a supervisory signal in response to a malfunction of said one subsystem, and default means, responsive to said supervisory signal, for causing said alarm-activating means to activate an alarm in response to receipt of an output signal from only the other of said subsystems.
1 Assignment
0 Petitions
Accused Products
Abstract
A dual-tech intruder detection system includes a pair of intruder-detecting subsystems, each functioning to detect intrusion by a technology different from the other, and apparatus for activating an alarm in response to both subsystems detecting intrusion within a predetermined time interval. A supervisory circuit serves to detect a malfunction in one of the subsystems. Default apparatus, responsive to the output of the supervisory circuit, causes the alarm activating apparatus to activate an alarm in response to the still functioning subsystem'"'"'s detection of intrusion.
-
Citations
7 Claims
- 1. A dual-technology intruder detection system comprising first and second intruder-detecting subsystems, each being adapted to detect intrusion by a different technology and to produce an output signal in response to intrusion detection, means for normally activating an alarm in response to the production of output signals from said first and second subsystems within a predetermined time interval, a supervisory circuit, operatively connected to one of said subsystems for producing a supervisory signal in response to a malfunction of said one subsystem, and default means, responsive to said supervisory signal, for causing said alarm-activating means to activate an alarm in response to receipt of an output signal from only the other of said subsystems.
Specification