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United States Patent | 3,978,477 |
Schmitz | August 31, 1976 |
In a solid state security system having a plurality of alarm sensors for generating output signals in response to alarm conditions and a corresponding plurality of resettable latching circuits for developing digital output signals indicative of alarm conditions for processing by logic circuits to develop alarm output signals, an automatic test circuit responds to a single activating signal by sequentially supplying simulated alarm condition signals to the respective latching circuits to determine the operational integrity of the latching and logic circuits. At the conclusion of the test sequence the automatic test circuit transmits reset signals to the resettable latching circuits.
Inventors: | Schmitz; Lawrence S. (Pittsburgh, PA) |
Assignee: |
Westinghouse Electric Corporation
(Pittsburgh,
PA)
|
Appl. No.: | 05/582,011 |
Filed: | May 29, 1975 |
Current U.S. Class: | 340/515 ; 340/516; 340/521; 340/523 |
Current International Class: | G08B 29/08 (20060101); G08B 29/14 (20060101); G08B 29/06 (20060101); G08B 29/00 (20060101); G08B 029/00 () |
Field of Search: | 340/420,416,410,414,226,213R,253C,384E,409,312,279,276 |
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3678509 | July 1972 | Carlo et al. |
3699569 | October 1972 | Lee |
3750131 | July 1973 | Fletcher et al. |
3803568 | April 1974 | Higashide |
3818433 | June 1974 | Okamoto et al. |