US3876828A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Sync separator
Assignee: Admiral Corp
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Filing: 1973-01-08
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Granted: 1975-04-08
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Expires: 1993-01-08
Abstract
Abstract A noninverting, hum tolerant sync separator having a video signal coupled to an emitter of a transistor and an RC time constant in the base circuit. The separated sync pulse is taken from the collector and coupled to the television deflection system.
Inventors
- 👤 Ralph H Cook
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 01:41
CPC Classifications
H; H04; H04N; H04N5/00; H04N5/04; H04N5/08
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
144 words
In a television receiver having means for developing a video signal having a hum modulation frequency and a positive going sync pulse and a deflection circuit utilizing said sync pulse to synchronize deflection of the beam of a cathode ray tube, a sync separator circuit comprising: a transistor having the video signal applied to its emitter and having a time constant circuit coupled to the base to assure that the base to emitter voltage is substantially constant at hum modulation frequencies of the video signal, said time constant being large enough to faithfully separate the sync interval and also being chosen to be small enough to permit the base voltage to follow the hum frequency on the input video signal, and means for deriving the separated sync pulses at the collector of said transistor and for coupling the same to said television deflection circuit.
Claim 2
Dependent Claim
144 words
In a television receiver having means for developing a video signal having a hum modulation frequency and a positive going sync pulse and a deflection circuit utilizing said sync pulse to synchronize deflection of the beam of a cathode ray tube, a sync separator circuit comprising: a transistor having the video signal applied to its emitter and having a time constant circuit coupled to the base to assure that the base to emitter voltage is substantially constant at hum modulation frequencies of the video signal, said time constant being large enough to faithfully separate the sync interval and also being chosen to be small enough to permit the base voltage to follow the hum frequency on the input video signal, and means for deriving the separated sync pulses at the collector of said transistor and for coupling the same to said television deflection circuit.
Claim 3
Dependent Claim
24 words
A sync separator in accordance with claim 1, wherein said base of said transistor is referenced to circuit ground through said time constant circuit.
Claim 4
Dependent Claim
23 words
A sync separator in accordance with claim 2, wherein said time constant circuit comprises a parallel combination of a resistor and a capacitor.
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) | 1978-04-07 | 1978-10-07 | 1979-04-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-04-07 | 1982-10-07 | 1983-04-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-04-07 | 1986-10-07 | 1987-04-08 | $7700.00 | Window Closed / Lapsed |