Patent US3891865A successfully refreshed from Google Patents.
US3891865A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Intrusion detector
Assignee: United States Department of the Navy
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Filing: 1973-11-14
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Granted: 1975-06-24
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Expires: 1993-11-14
Abstract
Abstract A low-current detection device responsive to both audio and seismic input signals received over predetermined periods of time at preselected amplitude levels. At the end of the predetermined time periods a tone code generator combines the audio input signal with identifying tone codes. The combined audio signal and identifying tones are passed to a transmitter whose output is enabled for a predetermined period of time. A switch is provided to selectively power the transmitter for night operation only.
Inventors
- 👤 Salvatore R Picard
- 👤 Robert F Starry
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 06:29
CPC Classifications
G; G08; G08B; G08B13/00; G08B13/16; G08B13/1654; G08B13/1663
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
234 words
A low current counting device for indicating the receipt of at least two pulses within a predetermined period of time, comprising, in combination: first switching means including a first transistor having a base operatively connected to receive individual ones of said pulses, an emitter connected to ground, and a collector, and timing means having one terminal of a resistor, the cathode of a zener diode and one terminal of a first capactitor commonly connected to said collector, one terminal of a second capacitor operatively connected to the anode of said zener diode for providing an output signal for said predetermined period of time whereby said output signal is indicative of the end of the first one of said pulses, the other resistor terminal being connected to a voltage supply and the other first and second capacitor terminals being connected to ground; second switching means having an input commonly connected to receive said first switching means output signal and said pulses for switching to a nonconductive state in response to the second one of said pulses within said first switching means predetermined period of time, and an output for providing a signal indicative thereof; and third switching means having an input connected to receive said second switching means output signal for switching to a conductive state in response to said second switching means output signal, and an output for providing said counting device output signal.
Claim 2
Dependent Claim
234 words
A low current counting device for indicating the receipt of at least two pulses within a predetermined period of time, comprising, in combination: first switching means including a first transistor having a base operatively connected to receive individual ones of said pulses, an emitter connected to ground, and a collector, and timing means having one terminal of a resistor, the cathode of a zener diode and one terminal of a first capactitor commonly connected to said collector, one terminal of a second capacitor operatively connected to the anode of said zener diode for providing an output signal for said predetermined period of time whereby said output signal is indicative of the end of the first one of said pulses, the other resistor terminal being connected to a voltage supply and the other first and second capacitor terminals being connected to ground; second switching means having an input commonly connected to receive said first switching means output signal and said pulses for switching to a nonconductive state in response to the second one of said pulses within said first switching means predetermined period of time, and an output for providing a signal indicative thereof; and third switching means having an input connected to receive said second switching means output signal for switching to a conductive state in response to said second switching means output signal, and an output for providing said counting device output signal.
Claim 3
Dependent Claim
51 words
A low current counting device according to claim 1 wherein said second switching means further comprises: a second transistor having a base operatively connected to receive said pulses and said first switching means output signal, an emitter connected to ground, and a collector for providing said second switching means output signal.
Claim 4
Dependent Claim
47 words
A low current counting device according to claim 2 wherein said third switching means further comprises: a third transistor having a base operatively connected to receive said second switching means output signal, an emitter connected to ground, and a collector for providing said counting device output signal.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-06-23 | 1978-12-23 | 1979-06-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-06-23 | 1982-12-23 | 1983-06-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-06-23 | 1986-12-23 | 1987-06-24 | $7700.00 | Window Closed / Lapsed |