Patents Assigned to S.A. Promocab
  • Dual sensitivity intrusion detection system
    Patent number: 4437089
    Abstract: At least two circuits of sensors for detection of human presence are arranged in a protected zone and are capable of producing electric signals when they detect a human presence. In a preferred embodiment, when a human presence is detected by a first sensor circuit, the sensitivity of the sensors of the second sensor circuit is increased.
    Type: Grant
    Filed: June 23, 1981
    Date of Patent: March 13, 1984
    Assignee: S.A. Promocab
    Inventor: Serge Achard