Patent US3562416A successfully refreshed from Google Patents.
US3562416A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Television receiver a.g.c. and a.f.c. circuits including cascaded amplifiers with distinct outputs
Assignee: US Philips Corp
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Filing: 1967-07-13
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Granted: 1971-02-09
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Expires: 1987-07-13
Abstract
Abstract An amplifier circuit for producing a first substantially constant output and a second variable output includes a loop circuit of a first amplifier to which input signals are applied, a second amplifier having an adjustable amplification factor, and a gain control circuit dependent upon the amplitude of the output of the second amplifier for controlling the gain of the first amplifier. The constant output of the second amplifier may be employed in a phase or frequency control circuit in a television receiver, while the variable output of the first amplifier may be the video signal to be applied to a display device.
Inventors
- 👤 Jan Abraham Cornelis Korver
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 19:08
CPC Classifications
H; H04; H04N; H04N5/00; H04N5/44; H04N5/57; H04N5/59; H04N9/00; H04N9/44; H04N9/455; H04N9/64; H04N9/68
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
183 words
An amplifier circuit comprising a source of signals, a first gain controllable amplifier stage, means applying said signals to said first stage, a second gain controllable amplifier stage, means applying the output of said first stage to said second stage, means connected to the output of said seconD stage for producing a control voltage dependent upon the amplitude of output signals from said second stage, means for keeping the product of the amplification factors of said first and second stages substantially constant for all of the signals applied to said first stage comprising means applying said control voltage to said first stage for controlling the amplification of all of the signals in said first stage, first and second output circuits connected to the outputs of said first and second stages respectively, and means for adjusting the amplification of said second stage independently of time, whereby all of the signals derived from said second output circuit have a substantially constant amplitude and all of the signals derived from said first output circuit have an amplitude inversely dependent upon the amplification of said second stage.
Claim 2
Dependent Claim
183 words
An amplifier circuit comprising a source of signals, a first gain controllable amplifier stage, means applying said signals to said first stage, a second gain controllable amplifier stage, means applying the output of said first stage to said second stage, means connected to the output of said seconD stage for producing a control voltage dependent upon the amplitude of output signals from said second stage, means for keeping the product of the amplification factors of said first and second stages substantially constant for all of the signals applied to said first stage comprising means applying said control voltage to said first stage for controlling the amplification of all of the signals in said first stage, first and second output circuits connected to the outputs of said first and second stages respectively, and means for adjusting the amplification of said second stage independently of time, whereby all of the signals derived from said second output circuit have a substantially constant amplitude and all of the signals derived from said first output circuit have an amplitude inversely dependent upon the amplification of said second stage.
Claim 3
Dependent Claim
32 words
A circuit as claimed in claim 1 wherein said control voltage applying means comprises a gate circuit, and further comprising a source of periodic gating pulses coupled to control said gate circuit.
Claim 4
Dependent Claim
74 words
A circuit as claimed in claim 1 wherein said signals comprise a video signal and a frequency-modulated audio signal, and said first stage applying means applies said video signal to said first stage; and further comprising means for detecting said audio signals coupled to said source of signals, and means for generating an automatic frequency control voltage including a phase detector coupled to output of both said detector and said audio signal second stage.
Claim 5
Dependent Claim
77 words
A circuit as claimed in claim 1 wherein said signals comprise video luminance and chrominance signals, and said first stage applying means applies said chrominance signal to said first stage; and further comprising means for amplifying said luminance signal, a third amplifier stage having an input coupled to the output of said first stage, and means for varying the gain of both said luminance amplifying means and said third amplifying stage whereby the saturation remains a constant.
Claim 6
Dependent Claim
45 words
A circuit as claimed in claim 4 wherein said means for varying both said luminance amplifying means and said third stage comprises a source of direct current and a potentiometer circuit coupled to said direct current source and luminance amplifying means and said third stage.
Claim 7
Dependent Claim
46 words
A circuit as claimed in claim 4 further comprising two synchronous detectors coupled to the output of said third stage to detect said luminance signal, and a subcarrier oscillator coupled to the output of said second stage to provide a reference carrier for said synchronous detectors.
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) | 1974-02-08 | 1974-08-10 | 1975-02-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-02-08 | 1978-08-10 | 1979-02-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-02-08 | 1982-08-10 | 1983-02-09 | $7700.00 | Window Closed / Lapsed |