Patent US4234762A successfully refreshed from Google Patents.
US4234762A
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Ring trip detector circuit
Assignee: AT&T Inc
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Filing: 1978-12-29
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Granted: 1980-11-18
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Expires: 1998-12-29
Abstract
Abstract A ring trip detection circuit is disclosed for a remotely generated ringing signal in a subscriber loop carrier system. The ring trip detection circuit is enabled only during the high voltage half-cycle of the ringing signal to increase ring trip detection sensitivity and reduce the size and complexity of the ring trip detection circuit.
Inventors
- 👤 Barry S. Bosik
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 10:01
CPC Classifications
H; H04; H04M; H04M19/00; H04M19/02; H04M19/026
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
68 words
A ring trip detection circuit for subscriber loop carrier systems wherein the ringing signal source provides one half-cycle of the ringing signal which is of a substantially higher voltage than the other half-cycle, said detection circuit characterized by a voltage detector for detecting an off-hook condition in a telephone subscriber station set, and means for enabling said voltage detector only during said half-cycle having said substantially higher voltage.
Claim 2
Dependent Claim
68 words
A ring trip detection circuit for subscriber loop carrier systems wherein the ringing signal source provides one half-cycle of the ringing signal which is of a substantially higher voltage than the other half-cycle, said detection circuit characterized by a voltage detector for detecting an off-hook condition in a telephone subscriber station set, and means for enabling said voltage detector only during said half-cycle having said substantially higher voltage.
Claim 3
Dependent Claim
31 words
The ring trip detection circuit according to claim 1 further characterized in that said voltage detector comprises a voltage divider, a midpoint of which is connected to operate a transistor gate.
Claim 4
Dependent Claim
26 words
The ring trip detection circuit according to claim 2 further characterized by unilateral conducting means connected from said midpoint to one end of said voltage divider.
Claim 5
Dependent Claim
33 words
The ring trip detection circuit according to claim 1 further characterized in that said enabling means comprises a transistor switch having its collector-emitter path connected in series with the output of said detector.
Claim 6
Dependent Claim
39 words
A voltage detection circuit for intermittently applied voltages characterized by means for detecting said voltages, and means for enabling said voltage detection means only during those periods in which a nonzero portion of said intermittent voltage is being applied.
Claim 7
Dependent Claim
39 words
A voltage detection circuit for intermittently applied voltages characterized by means for detecting said voltages, and means for enabling said voltage detection means only during those periods in which a nonzero portion of said intermittent voltage is being applied.
Claim 8
Dependent Claim
47 words
The voltage detection circuit according to claim 5 characterized in that said intermittent voltage appears across a telephone set connected in the telephone loop when the telephone subscriber goes off-hook, and said intermittently applied voltage comprises a ringing signal for operating a telephone ringer in said set.
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) | 1983-11-18 | 1984-05-19 | 1984-11-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-11-18 | 1988-05-19 | 1988-11-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-11-18 | 1992-05-19 | 1992-11-18 | $7700.00 | Window Closed / Lapsed |