Title:
Vibration detection vault alarm system
United States Patent 3147467
US Patent References:
Electrical measurement
- - 2400571
Capacity alarm system
- - 2455376
Circuit for detection of frequency differences and apparatus employing same
- - 2623931
Approach alarm system with unwanted signal elimination
- - 2767393
Sensitivity control of apparatus for detecting disturbances in an enclosure
- - 2903683
Electrical measurement
- - 2400571
Capacity alarm system
- - 2455376
Circuit for detection of frequency differences and apparatus employing same
- - 2623931
Approach alarm system with unwanted signal elimination
- - 2767393
Sensitivity control of apparatus for detecting disturbances in an enclosure
- - 2903683
Inventors:
Peter, Laakmann
Publication Date:
09/01/1964
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Export Citation:
Assignee:
AMERICAN DISTRICT TELEGRAPH CO
Primary Class:
International Classes:
G08B13/16
US Patent References:
| 2942247 | Alarm warning system for swimming pools |