An intruder detection system is provided with circuitry for reducing the risk of false alarms from spurious sources. Such circuitry comprises a pulse generator for producing current pulses of predetermined pulsewidth and amplitude each time the output of an intrusion detecting element exceeds or falls...http://www.google.fr/patents/US4764755?utm_source=gb-gplus-shareBrevet US4764755 - Intruder detection system with false-alarm-minimizing circuitry
Intruder detection system with false-alarm-minimizing circuitry
