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US3928849A
Expired / Lapsed
US
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Intrusion detector self-test system
Assignee: United States Department of Energy
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Filing: 1974-12-17
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Granted: 1975-12-23
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Expires: 1994-12-17
Abstract
Abstract An intrusion detection system which automatically makes periodic tests of the operability of the system and provides an alarm in the event of a malfunction during the supervisory self-check regimen which alarm is distinguishable from the normal intrusion alarm.
Inventors
- 👤 Frank Schwarz
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 13:29
CPC Classifications
G; G08; G08B; G08B13/00; G08B13/18; G08B13/181; G08B13/183; G08B29/00; G08B29/12; G08B29/123; G08B29/14; Y; Y10; Y10S; Y10S250/00; Y10S250/01
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
215 words
In an intrusion alarm system the combination comprising: A. Detector operated means for providing an output signal of the first of two switching states under normal circuit operation nonintrusion conditions and an output signal of the second of said states in response to activation of the detector, B. Clock operated means for periodically providing (1) a first signal for simulating an intrusion, (2) a second signal for overriding said signal of said second state from said detector operated means, and (3) a third signal, C. First gate means operatively connected for receiving the output signal of said detector operated means and said third signal from said clock means for providing an output of a first of two states in response to either a normal condition, an intrusion, or a simulated intrusion and an output of the second of two states in response to a malfunction, and D. A second gate means operatively connected for receiving the outputs of said first gate, said detector operated means and said override signal for providing an output of a first of two states in response to either a normal condition or a simulated intrusion condition with normal circuit response thereto and of the second state in response to an actual intrusion or a simulated intrusion coupled with a malfunction.
Claim 2
Dependent Claim
215 words
In an intrusion alarm system the combination comprising: A. Detector operated means for providing an output signal of the first of two switching states under normal circuit operation nonintrusion conditions and an output signal of the second of said states in response to activation of the detector, B. Clock operated means for periodically providing (1) a first signal for simulating an intrusion, (2) a second signal for overriding said signal of said second state from said detector operated means, and (3) a third signal, C. First gate means operatively connected for receiving the output signal of said detector operated means and said third signal from said clock means for providing an output of a first of two states in response to either a normal condition, an intrusion, or a simulated intrusion and an output of the second of two states in response to a malfunction, and D. A second gate means operatively connected for receiving the outputs of said first gate, said detector operated means and said override signal for providing an output of a first of two states in response to either a normal condition or a simulated intrusion condition with normal circuit response thereto and of the second state in response to an actual intrusion or a simulated intrusion coupled with a malfunction.
Claim 3
Dependent Claim
22 words
The intrusion alarm system of claim 1 including means for providing a redundant path for the output of said detector operated means.
Claim 4
Dependent Claim
57 words
The system of claim 2 wherein said means for providing a redundant path includes a third gate means operatively connected for receiving the output signal of said detector operated means and a signal in response to said second signal of said clock means for producing an output of a first state in response to an actual intrusion.
Claim 5
Dependent Claim
22 words
The system of claim 3 wherein said first and second gates are NAND gates and said third gate is a NOR gate.
Claim 6
Dependent Claim
39 words
The intrusion alarm system of claim 1 wherein the detector of said detector operated means is of a passive type responsive to infrared radiation and said first signal of said clock operated means activates a source of infrared radiation.
Claim 7
Dependent Claim
15 words
The system of claim 5 wherein said source of radiation is a light emitting diode.
Claim 8
Dependent Claim
16 words
The intrusion alarm system of claim 1 wherein said first and second gates are NAND gates.
Claim 9
Dependent Claim
62 words
The intrusion alarm system of claim 7 wherein said first state of said detector operated means is a logical 1, said first, second and third signals of said clock means are logical 1''s, said first state of the output of said first gate is a logical 1 and said first state of the output of said second gate is a logical 0.
Claim 10
Dependent Claim
74 words
The system of claim 4 wheRein said first state of said detector operated means is a logical 1, said first second and third signals of said clock means are logical 1''s, said first state of the output of said first gate is a logical 1, said first state of the output of said second gate is a logical 0, and the first state of the output of said third gate is a logical 1.
Claim 11
Dependent Claim
26 words
The system of claim 9 including an OR gate as a fourth gate operatively connected to receive the outputs of said second and said third gate.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-12-22 | 1979-06-23 | 1979-12-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-12-22 | 1983-06-23 | 1983-12-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-12-22 | 1987-06-23 | 1987-12-23 | $7700.00 | Window Closed / Lapsed |