Patent US3683289A successfully refreshed from Google Patents.
US3683289A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Transistor amplifiers
Assignee: Thales Communications Ltd
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Filing: 1970-05-19
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Granted: 1972-08-08
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Expires: 1990-05-19
Abstract
Abstract A transistor push-pull amplifier having a Class A transistor pair driving a Class B transistor pair by way of an interstage inductive coupling comprising a pair of mutually coupled tapped windings, the said windings being connected in the Class A circuits and those portions between the taps and corresponding ends of the winding being also connected in the Class B circuits.
Inventors
- 👤 Ernest W Rogers
- 👤 Lewis P Learney
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 21:46
CPC Classifications
H; H03; H03F; H03F3/00; H03F3/26; H03F3/189; H03F3/19; H03F3/191
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
282 words
A multi-stage transistor amplifier for electric wave signals having first and second branches for providing push-pull operation of the amplifier, comprising in cascade a first stage for operation under class A conditions, an inductive device having a pair of tapped windings, and a second stage for operation under class B conditions, an output electrode of a transistor in the first branch of the first stage being connected to one end of one of said tapped windings, an output electrode of a transistor of the second branch of the first stage being connected to one end of the other one of said tapped windings, an input electrode of a transistor in the first branch of the second stage being connected to the tapping of said one tapped winding and an input electrode of a transistor in the second branch of the second stage being connected to the tapping of said other one of said tapped windings, the two said windings of said inductive device being coupled in a sense such that power for driving a transistor of the second stage is provided by the transistor of the first stage to which it is directly connected and in part by the other transistor of the first stage, by way of the said inductive device, said amplifier including means for connecting the other end of said one tapped winding through a first resistor to a common point and means for connecting said other one of said tapped windings through a second resistor to said common point, said first and second resistors providing conductive paths for the output electrode currents of the first stage transistors and bias for the control electrodes of the second stage transistors.
Claim 2
Dependent Claim
282 words
A multi-stage transistor amplifier for electric wave signals having first and second branches for providing push-pull operation of the amplifier, comprising in cascade a first stage for operation under class A conditions, an inductive device having a pair of tapped windings, and a second stage for operation under class B conditions, an output electrode of a transistor in the first branch of the first stage being connected to one end of one of said tapped windings, an output electrode of a transistor of the second branch of the first stage being connected to one end of the other one of said tapped windings, an input electrode of a transistor in the first branch of the second stage being connected to the tapping of said one tapped winding and an input electrode of a transistor in the second branch of the second stage being connected to the tapping of said other one of said tapped windings, the two said windings of said inductive device being coupled in a sense such that power for driving a transistor of the second stage is provided by the transistor of the first stage to which it is directly connected and in part by the other transistor of the first stage, by way of the said inductive device, said amplifier including means for connecting the other end of said one tapped winding through a first resistor to a common point and means for connecting said other one of said tapped windings through a second resistor to said common point, said first and second resistors providing conductive paths for the output electrode currents of the first stage transistors and bias for the control electrodes of the second stage transistors.
Claim 3
Dependent Claim
23 words
A multi-stage amplifier as claimed in claim 1, in which the inductive device comprises a pair of coils having a high mutual inductance.
Claim 4
Dependent Claim
30 words
A multi-stage amplifier as claimed in claim 2, in which the inductive device comprises two coils with corresponding turns wound in the same sense and located side by side. transistors
Claim 5
Dependent Claim
132 words
A multi-stage amplifier as claimed in claim 1, in which the transistors of the first and second stages are of the same conductivity type, that is, all are of n-p-n type or all are of p-n-p type, the emitter of each first stage transistor is connected to one end of one tapped winding, the other end of each tapped winding is connected by way of a resistor to a common point and the base electrodes of each second stage transistors are connected to the tapping of that winding to which the first stage transistor of the same branch is connected, the two said resistors connected to the common point providing conductive paths for the emitter currents of the corresponding first stage transistors and base electrode bias for the corresponding second stage transistors.
References Cited (Backward Citations)
US3488603A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-08-08 | 1976-02-07 | 1976-08-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-08-08 | 1980-02-07 | 1980-08-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-08-08 | 1984-02-07 | 1984-08-08 | $7700.00 | Window Closed / Lapsed |