US3693093A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Agc impedance converter and voltage level shifter for high impedance source
Assignee: Electrohome Ltd
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Filing: 1970-10-02
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Granted: 1972-09-19
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Expires: 1990-10-02
Abstract
Abstract A signal receiver of a type including an AGC network providing an AGC signal and also of a type employing a varactor tuner is provided with an AGC converter network to convert the AGC output signal to a level and source impedance suitable for use with the tuner.
Inventors
- 👤 William G Russell
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 12:37
CPC Classifications
H; H03; H03G; H03G3/00; H03G3/20; H03G3/30; H03G3/3052; H03J; H03J3/00; H03J3/02; H03J3/16; H03J3/18; H03J3/185; H03J5/00; H03J5/02; H03J5/0218; H03J7/00; H03J7/02; H03J7/04; H03J7/08; H03J7/12
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
153 words
In combination with a signal receiver of a type including AGC network means providing an AGC signal and a tuner of a type employing the voltage variable capacitance characteristic of a voltage variable capacitance diode for varying the tuning of said receiver and having an AGC signal input terminal; an AGC converter network for converting the AGC output signal of said AGC network means to a level and source impedance suitable for use with said tuner, said AGC converter network including at least a first transistor having base, collector and emitter electrodes, means supplying said AGC output signal to said base electrode of said transistor, a level shift device providing a substantially constant voltage drop independent of the magnitude of current flow therethrough connected in series circuit between said emitter electrode of transistor and said AGC signal input terminal of said tuner, and means biasing said level shift device to a conductive condition.
Claim 2
Dependent Claim
153 words
In combination with a signal receiver of a type including AGC network means providing an AGC signal and a tuner of a type employing the voltage variable capacitance characteristic of a voltage variable capacitance diode for varying the tuning of said receiver and having an AGC signal input terminal; an AGC converter network for converting the AGC output signal of said AGC network means to a level and source impedance suitable for use with said tuner, said AGC converter network including at least a first transistor having base, collector and emitter electrodes, means supplying said AGC output signal to said base electrode of said transistor, a level shift device providing a substantially constant voltage drop independent of the magnitude of current flow therethrough connected in series circuit between said emitter electrode of transistor and said AGC signal input terminal of said tuner, and means biasing said level shift device to a conductive condition.
Claim 3
Dependent Claim
15 words
The invention according to claim 1 wherein said level shift device is a Zener diode.
Claim 4
Dependent Claim
86 words
The invention according tO claim 1 wherein there is a second transistor having base, collector and emitter electrodes, said transistors being connected in Darlington configuration with said collector electrodes connected together and said emitter electrode of said first transistor connected to said base electrode of said second transistor, said AGC output signal being supplied to said base electrode of said first transistor and said level shift device being connected between said emitter electrode of said second transistor and said AGC signal input terminal of said tuner.
Claim 5
Dependent Claim
15 words
The invention according to claim 3 wherein said level shift device is a Zener diode.
Claim 6
Dependent Claim
26 words
The invention according to claim 4 wherein said means supplying said AGC output signal to said base electrode of said first transistor includes voltage divider means.
Claim 7
Dependent Claim
107 words
The invention according to claim 1 wherein there is a second transistor having base, collector and emitter electrodes, means connecting said first and second transistors to decrease the conductivity of said second transistor in response to conduction of said first transistor, said AGC output signal being supplied to said base electrode of said first transistor and said level shift device being connected between said emitter electrode of said second transistor and said AGC signal input terminal of said tuner, and means for applying a reverse bias between said base and emitter electrodes of said first transistor to provide a delayed AGC signal from said AGC converter network.
Claim 8
Dependent Claim
15 words
The invention according to claim 6 wherein said level shift device is a Zener diode.
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) | 1975-09-19 | 1976-03-20 | 1976-09-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-09-19 | 1980-03-20 | 1980-09-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-09-19 | 1984-03-20 | 1984-09-19 | $7700.00 | Window Closed / Lapsed |