Pressure change intrusion detector
USRE34788E · kind E · reissue
Assignee
Inventors
Key dates
| Filing date | May 19, 1992 |
| Grant date | Nov 15, 1994 |
| Priority date | — |
| Expiry date | May 19, 2012 |
Classification
- Technology area (CPC —)General
Abstract
Apparatus utilizing change in pressure condition in an area to be protected to indicate intrusion or change in conditions of the area by using a pressure detection device to detect pressure waves at low and infrasonic frequencies which includes a pressure transducer sensitive to change in pressure to provide an output signal. In some instances an amplifier is provided to amplify the output signal, a signal conditioning circuit is provided to delay a portion of the signal, and a detector device is provided to detect the signal with a comparator provided to compare the signal with the delayed signal and actuate an alarm. .Iadd.Additionally, a device producing signals responsive to pressure waves and selected sonic frequencies is taught. If the signals are coincidently received at a coincidence detector, an alarm is activated. Further, the signals can be stretched and/or delayed before receipt at the coincidence detector. .Iaddend.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.