JAMES EDWIN RANDALL
Pilots at Fernando Cir, Orange, CA
License number
California A1550525
Issued Date
Feb 2017
Expiration Date
Feb 2019
Category
Airmen
Type
Authorized Aircraft Instructor
Address
Address
18131 Fernando Cir, Orange, CA 92861
Professional information
Infra-Sonic Detector And Alarm With Self Adjusting Reference
US Patent:
4991145, Feb 5, 1991
Filed:
Jun 2, 1989
Appl. No.:
7/361027
Inventors:
Steven G. Goldstein - Los Angeles CA
James E. Randall - Villa Park CA
Joseph A. Dattilo - Manhattan Beach CA
Gary E. Vanyek - Huntington Beach CA
James E. Randall - Villa Park CA
Joseph A. Dattilo - Manhattan Beach CA
Gary E. Vanyek - Huntington Beach CA
Assignee:
Rabbit Systems, Inc. - Santa Monica CA
International Classification:
G08B 1322
US Classification:
367 94
Abstract:
A detector and alarm is provided for monitoring air pressure variations in a monitored space, which variations correspond to an intrusion. An infra-sonic detector includes a microphone or the like and a low pass filter to retain only low frequency infra-sonic signals or a bandpass filter to retain a particular range of frequencies between approximately 5 Hz and 12 Hz. The instantaneous infra-sonic signals are compared against a variable reference signal, which is a voltage lagging or delayed variant of the instantaneous signals. In this manner the detector is self adjusting for slow variations in the instantaneous signals but responds immediately to rapid variations to trigger an alarm. In one embodiment the detector only senses negative going air pressure changes to trigger an alarm in order to minimize the incidence of false alarms.