Patents Assigned to G.D.I. Electronics
  • Ultrasonic intrusion alarm system
    Patent number: 4263665
    Abstract: An intrusion alarm system for use such as in homes including an ultrasonic motion detector having means for selectively actuating switch means for a light and a sound alarm. The circuit includes a transducer for emitting a beam of ultrasonic energy and a sensor for detecting the modulation of the ultrasonic energy by movement occurring in the beam. The sensor provides a signal in response to said modulation to turn-on an electric light, and to turn-on a sound alarm.
    Type: Grant
    Filed: June 11, 1979
    Date of Patent: April 21, 1981
    Assignee: G.D.I. Electronics
    Inventor: Gary P. Watts