US3824412A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Circuit arrangement for the phase adjustment of a pal switch
Assignee: US Philips Corp
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Filing: 1972-08-30
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Granted: 1974-07-16
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Expires: 1992-08-30
Abstract
Abstract A PAL TV receiver has a multivibrator switching at one half of the line frequency and a circuit for stopping the switching operation if a PAL switch is out of phase with the chroma burst. A capacitor circuit is provided for releasing the stopping circuit so that the switch does not stop switching for too long a period.
Inventors
- 👤 K Kroner
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 19:34
CPC Classifications
H; H03; H03K; H03K3/00; H03K3/02; H03K3/26; H03K3/28; H03K3/281; H03K3/282; H03K3/2821; H04; H04N; H04N9/00; H04N9/44; H04N9/465
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
131 words
A circuit for a color television signal having a phase alternating color synchronizing signal and a given line frequency, said circuit comprising a PAL switch operating at one half of said line frequency, said switch operation defining a phase relationship with respect to said phase alterations of said synchronization signal, means for stopping said switch if it is out of phase with the color synchronizing signal, and means for causing said switch to resume switching after it has been stopped by said stopping means for a predetermined time regardless of the phase of said switch with respect to said synchronizing signal, said causing means comprising a delay circuit coupled to said switch and means for deriving a direct current from said delay circuit indicative of the stopped state of said switch.
Claim 2
Dependent Claim
131 words
A circuit for a color television signal having a phase alternating color synchronizing signal and a given line frequency, said circuit comprising a PAL switch operating at one half of said line frequency, said switch operation defining a phase relationship with respect to said phase alterations of said synchronization signal, means for stopping said switch if it is out of phase with the color synchronizing signal, and means for causing said switch to resume switching after it has been stopped by said stopping means for a predetermined time regardless of the phase of said switch with respect to said synchronizing signal, said causing means comprising a delay circuit coupled to said switch and means for deriving a direct current from said delay circuit indicative of the stopped state of said switch.
Claim 3
Dependent Claim
53 words
A circuit as claimed in claim 1 wherein said switch comprises a pair of transistors each having an emitter, said delay circuit comprises a capacitor coupled between said emitters, and said deriving means comprises means coupled to said capacitor for applying said direct current to one of said transistors to render it conductive.
Claim 4
Dependent Claim
24 words
A circuit as claimed in claim 2 wherein said applying means comprises a third transistor coupled to said capacitor and to said one transistor.
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) | 1977-07-15 | 1978-01-14 | 1978-07-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-07-15 | 1982-01-14 | 1982-07-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-07-15 | 1986-01-14 | 1986-07-16 | $7700.00 | Window Closed / Lapsed |