US3823264A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Cascode video output feedback amplifier
Assignee: RCA Licensing Corp
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Filing: 1972-02-16
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Granted: 1974-07-09
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Expires: 1992-02-16
Abstract
Abstract A video output amplifier utilizes two transistors arranged in cascode configuration for driving the cathode electrode of a color television kinescope. A negative feedback network couples the collector electrode of the output transistor of the cascode configuration to the base electrode of the input transistor of the pair, and includes an arc current limiting resistor which serially couples the output transistor to the kinescope cathode.
Inventors
- 👤 P Haferl
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 20:00
CPC Classifications
H; H04; H04N; H04N5/00; H04N5/14; H04N5/148; H03; H03F; H03F1/00; H03F1/08; H03F1/22; H03F3/00; H03F3/04; H03F3/72; H04N3/00; H04N3/10; H04N3/16; H04N3/20; H04N9/00; H04N9/64; H04N9/648
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
210 words
A video output stage for a television receiver adapted to drive the cathode electrode of a picture tube kinescope whereat voltage arcs may undesirably be produced, comprising: first and second transistors having emitter, base and collector electrodes arranged in cascode amplifier configuration, with the emitter electrode of said second transistor being coupled to a point of reference potential and with there being existent an inherent capacitance between the collector electrode of said first transistor and said point of reference potential; means coupling the collector electrode of said first transistor to said picture tube cathode electrode for applying video signals thereto, said means comprising only passive circuit elements and including a current limiting resistance; and a negative feedback network from the collector electrode of said first transistor to the base electrode of said second transistor; said current limiting resistance being included in the feedback network between said first and second transistors and cooperating with said inherent capacitance to form a filter circuit to delay the application of said voltage arcs from said picture tube cathode electrode to the collector electrode of said first transistor until after said voltage arcs are applied via the remainder of said feedback network from said picture tube cathode to the base electrode of said second transistor.
Claim 2
Dependent Claim
210 words
A video output stage for a television receiver adapted to drive the cathode electrode of a picture tube kinescope whereat voltage arcs may undesirably be produced, comprising: first and second transistors having emitter, base and collector electrodes arranged in cascode amplifier configuration, with the emitter electrode of said second transistor being coupled to a point of reference potential and with there being existent an inherent capacitance between the collector electrode of said first transistor and said point of reference potential; means coupling the collector electrode of said first transistor to said picture tube cathode electrode for applying video signals thereto, said means comprising only passive circuit elements and including a current limiting resistance; and a negative feedback network from the collector electrode of said first transistor to the base electrode of said second transistor; said current limiting resistance being included in the feedback network between said first and second transistors and cooperating with said inherent capacitance to form a filter circuit to delay the application of said voltage arcs from said picture tube cathode electrode to the collector electrode of said first transistor until after said voltage arcs are applied via the remainder of said feedback network from said picture tube cathode to the base electrode of said second transistor.
Claim 3
Dependent Claim
71 words
The video output stage of claim 1 wherein there is included a first source of operating potential, and wherein said feedback network includes first, second and third resistors serially between the collector electrode of said first transistor and said operating potential source, with the junction of said second and third resistors being coupled to the base electrode of said second transistor, and with said first resistor representing said current limiting resistance.
Claim 4
Dependent Claim
48 words
The video output stage of claim 2 wherein the cathode electrode of said picture tube is connected to the junction of said first and second resistors and wherein a spark gap means is additionally included, coupled between said picture tube cathode electrode and a point of reference potential.
Claim 5
Dependent Claim
44 words
The video output stage of claim 3 wherein a semiconductor rectifier is further included, coupled between the base and emitter electrodes of said second transistor of said cascode configuration, and, being poled in the opposite direction to the base-emitter junction of said second transistor.
Claim 6
Dependent Claim
93 words
The video output stage of claim 4 wherein the emitter electrode of said first transistor is connected to the collector electrode of said second transistor, wherein the collector electrode of said first transistor is coupled to a second source of operating potential, wherein the base electrode of said first transistor is coupled to a third source of operating potential, wherein the emitter electrode of said second transistor is connected to said point of reference potential, and wherein the base electrode of said second transistor is coupled to receive applied input signals for amplification.
Claim 7
Dependent Claim
52 words
The video output stage of claim 5 wherein a fourth resistor is included to coupled the collector electrode of said first transistor to said second source of operating potential and wherein a fifth resistor is included to coupled the base electrode of said first transistor to said third source of operating potential.
Claim 8
Dependent Claim
41 words
The video output stage of claim 6 wherein said first and second transistors are of N-P-N conductivity type and wherein a sixth resistor is included to couple the base electrode of said second transistor to receive positive-going input signals for amplification.
Claim 9
Dependent Claim
32 words
The video output stage of claim 7 wherein said first source of operating potential is of negative polarity and wherein said second and third sources of operating potential are of positive polarity.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-07-08 | 1978-01-07 | 1978-07-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-07-08 | 1982-01-07 | 1982-07-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-07-08 | 1986-01-07 | 1986-07-09 | $7700.00 | Window Closed / Lapsed |