Self-diagnostic ultrasonic intrusion detection system
US4647913A · kind A · utility
11Cited by
7References
12Claims
0Family size
Assignee
Inventor
Key dates
| Filing date | Jan 15, 1985 |
| Grant date | Mar 3, 1987 |
| Priority date | — |
| Expiry date | Jan 15, 2005 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG08B29/04
- WIPO fieldControl
- WIPO sectorInstruments
Abstract
A self-diagnostic ultrasonic motion detection system includes an ultrasonic transceiver operative in a transmit mode and in a receive mode. In normal operation, the ultrasonic transceiver in its transmit mode has a characteristic electrical impedance. Potential electro-mechanical, electrical, acoustical, and other sources of false and failure of alarm situations manifest as changes in the electrical impedance of the transceiver in its transmit mode. The electrical impedance is monitored, changes from the nominal are detected, and a suitable self-diagnostic alarm signal is produced in response thereto.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.