Patent US3832703A successfully refreshed from Google Patents.
US3832703A
Expired / Lapsed
US
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Apparatus for detecting signal transmission
Assignee: Ltv Electrosystems Inc
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Filing: 1973-06-04
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Granted: 1974-08-27
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Expires: 1993-06-04
Abstract
Abstract A broadband coupler tied to a transmission line directs a portion of signal energy on the line to a diode signal detector. The signal detector responds to the energy directed from the transmission line through the coupler to produce a transmission signal current during the presence of a signal on the line. This transmission signal current activates a high input impedance transistorized switch having an indicator lamp energized by the closing of the switch. Only during the transmission of a signal and the energization of the indicator lamp does the circuit require energy from a supply source.
Inventors
- 👤 R Lenert
- 👤 E Rose
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 12:43
CPC Classifications
G; G01; G01R; G01R19/00; G01R19/145
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
175 words
Apparatus for detecting the transmission of video signals over a transmission line comprising: detector means resistively coupled to said transmission line and responsive to the transmission of a signal on said line to pass a transmission signal current, voltage dropping means connected in a series circuit with said detector means to generate a base drive voltage at the junction with said detector means that varies with the transmission signal current, a first transistor having a base electrode connected to the junction of said detector means and said voltage dropping means and operated into a conducting state in response to the base drive voltage, a second transistor connected to said first transistor in a Darlington configuration and having a collector electrode connected to the collector electrode of said first transistor, and alarm means having one terminal connected to the collector electrodes of said transistors and a second terminal connected to a supply source to be actuated from the supply source when said first transistor operates into a conducting state in response to the base drive voltage.
Claim 2
Dependent Claim
175 words
Apparatus for detecting the transmission of video signals over a transmission line comprising: detector means resistively coupled to said transmission line and responsive to the transmission of a signal on said line to pass a transmission signal current, voltage dropping means connected in a series circuit with said detector means to generate a base drive voltage at the junction with said detector means that varies with the transmission signal current, a first transistor having a base electrode connected to the junction of said detector means and said voltage dropping means and operated into a conducting state in response to the base drive voltage, a second transistor connected to said first transistor in a Darlington configuration and having a collector electrode connected to the collector electrode of said first transistor, and alarm means having one terminal connected to the collector electrodes of said transistors and a second terminal connected to a supply source to be actuated from the supply source when said first transistor operates into a conducting state in response to the base drive voltage.
Claim 3
Dependent Claim
32 words
Apparatus for detecting transmission of a signal over a transmission line as set forth in claim 1 wherein said detector means is a hot carrier diode having a fast switching response characteristic.
Claim 4
Dependent Claim
48 words
Apparatus for detecting the transmission of a signal over a transmission line as set forth in claim 2 wherein said voltage dropping means includes a resistor connected in series with said diode and to the base electrode of said first transistor to generate a base drive voltage therefor.
Claim 5
Dependent Claim
44 words
Apparatus for detecting the transmission of a signal over a transmission line as set forth in claim 1 including inductor means tied to the transmission line and to ground to provide a D.C. return path to ground for static charges on the transmission line.
References Cited (Backward Citations)
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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) | 1977-08-26 | 1978-02-25 | 1978-08-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-08-26 | 1982-02-25 | 1982-08-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-08-26 | 1986-02-25 | 1986-08-27 | $7700.00 | Window Closed / Lapsed |