Patent US3908170A successfully refreshed from Google Patents.
US3908170A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Hybrid video amplifier
Assignee: Lanteris Space LLC
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Filing: 1974-12-09
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Granted: 1975-09-23
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Expires: 1994-12-09
Abstract
Abstract A high performance video amplifier employs a vacuum tube output stage and a transistor driver. A complementary pair of transistors is series connected into the tube cathode circuit and the pair is driven by a differential driver amplifier. The video input is applied to one input of the differential amplifier and the other input is connected to a cathode current sensing resistor to stabilize the amplifier.
Inventors
- 👤 Frederick T Buhler
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 14:20
CPC Classifications
H; H03; H03F; H03F5/00; H04; H04N; H04N5/00; H04N5/14; H04N5/148
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
85 words
A transistor vacuum tube hybrid video amplifier comprising a vacuum tube having an output load resistor from which an output signal is taken and a driver circuit connected to vary the current flowing in said tube, said driver circuit comprising: a pair of complementary transistors connected in series with the cathode of said tube a differential transistor amplifier connected to said pair to drive said pair differentially, and means for applying an input signal to at least one of the transistors in said differential amplifier.
Claim 2
Dependent Claim
85 words
A transistor vacuum tube hybrid video amplifier comprising a vacuum tube having an output load resistor from which an output signal is taken and a driver circuit connected to vary the current flowing in said tube, said driver circuit comprising: a pair of complementary transistors connected in series with the cathode of said tube a differential transistor amplifier connected to said pair to drive said pair differentially, and means for applying an input signal to at least one of the transistors in said differential amplifier.
Claim 3
Dependent Claim
56 words
The amplifier of claim 1 wheren the other transistor in said differential amplifier is connected to a current sensing resistor connected in series with the cathode of said tube whereby the current flowing in said tube is stabilized and the gain of said amplifier appRoximates the ratio of said load resistor to said current sensing resistor.
Claim 4
Dependent Claim
22 words
The amplifier of claim 2 wherein said pair of complementary transistors is connected to a biasing network that include offset biasing means.
Claim 5
Dependent Claim
117 words
A video signal amplifier comprising: a power tetrode vacuum tube output stage having a plate load output resistor and fixed d-c potentials applied between a designated common connection and the screen grid and control grid electrodes, a series combination of a pair of complementary transistors and a current sensing resistor connected between the cathode electrode of said tube and said common connection, a differential transistor amplifier having an output circuit connected to directly drive said pair of complementary transistors in push-push operation and a pair of input terminals, one of said input terminals being connected to said current sensing resistor, and the other of said input terminals being connected to a signal input terminal for said amplifier.
Claim 6
Dependent Claim
117 words
A video signal amplifier comprising: a power tetrode vacuum tube output stage having a plate load output resistor and fixed d-c potentials applied between a designated common connection and the screen grid and control grid electrodes, a series combination of a pair of complementary transistors and a current sensing resistor connected between the cathode electrode of said tube and said common connection, a differential transistor amplifier having an output circuit connected to directly drive said pair of complementary transistors in push-push operation and a pair of input terminals, one of said input terminals being connected to said current sensing resistor, and the other of said input terminals being connected to a signal input terminal for said amplifier.
Claim 7
Dependent Claim
32 words
The amplifier of claim 4 wherein said differential transistor amplifier has a directly connected emitter configuration with said emitters being connected to a transistor connected to operate as a constant current source.
Claim 8
Dependent Claim
26 words
The amplifier of claim 5 wherein said differential amplifier output circuit includes a constant voltage differential device connected to provide offset bias for said complementary transistors.
References Cited (Backward Citations)
US3253225A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-09-22 | 1979-03-24 | 1979-09-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-09-22 | 1983-03-24 | 1983-09-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-09-22 | 1987-03-24 | 1987-09-23 | $7700.00 | Window Closed / Lapsed |