US3683112A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Temperature compensated amplifier employing complementary pairs of transistors
Assignee: Pye Electronic Products Ltd
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Filing: 1970-04-16
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Granted: 1972-08-08
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Expires: 1990-04-16
Abstract
Abstract An amplifier including a first transistor and second and third transistors forming a complementary pair. The first and second transistors are of the same type. An input signal is applied to the emitter of the first transistor and a constant current to its collector, which is also connected to the base of the second transistor. The bases of the first and third transistors are connected while the emitters of the second and third transistors are commoned and connected to a load. A power supply is connected to the collectors of the second and third transistors.
Inventors
- 👤 Robert Nettleship
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 00:43
CPC Classifications
H; H03; H03F; H03F1/00; H03F1/30; H03F1/307; H03F3/00; H03F3/30; H03F3/3069; H03F3/3071
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
157 words
A transistor circuit comprising first and second transistors of the same conductivity type and a third transistor of opposite conductivity type, each of said transistors having first and second main electrodes and a base electrode, a power supply, means connecting said second and third transistors with each of their main electrodes in series across the terminals of the power supply to form a complementary pair with a common junction, means connecting a first main electrode of the first transistor to the base of said second transistor and the base of said first transistor directly to the base of said third transistor, means connecting said common junction to a load, means for applying a constant current to said first main electrode of the first transistor, and means for applying an input signal only to the second main electrode of said first transistor whereby said signal is only transmitted to said second or third transistors through said first transistor.
Claim 2
Dependent Claim
157 words
A transistor circuit comprising first and second transistors of the same conductivity type and a third transistor of opposite conductivity type, each of said transistors having first and second main electrodes and a base electrode, a power supply, means connecting said second and third transistors with each of their main electrodes in series across the terminals of the power supply to form a complementary pair with a common junction, means connecting a first main electrode of the first transistor to the base of said second transistor and the base of said first transistor directly to the base of said third transistor, means connecting said common junction to a load, means for applying a constant current to said first main electrode of the first transistor, and means for applying an input signal only to the second main electrode of said first transistor whereby said signal is only transmitted to said second or third transistors through said first transistor.
Claim 3
Dependent Claim
43 words
A circuit as claimed in claim 1 wherein said signal applying means comprises a fourth transistor having first and second main electrodes connected in series with the main electrodes of said first transistor and of the same conductivity type as said first transistor.
Claim 4
Dependent Claim
68 words
A circuit as claimed in claim 1 further comprising a capacitor, said load connecting means including means connecting one terminal of the load to one terminal of the power supply and the other load terminal to said common junction via said capacitor, and wherein said constant current applying means includes a resistor connected to said other load terminal and to said first main electrode of the first transistor.
Claim 5
Dependent Claim
55 words
A circuit as claimed in claim 1 wherein said first and second transistors are of the NPN type and said third transistor is of the PNP type, said first transistor first main electrode comprising the collector electrode, and the emitter electrodes of said second and third transistors being connected together to form said common junction.
Claim 6
Dependent Claim
115 words
A circuit as claimed in claim 1 wherein said signal applying means comprises a fourth transistor having first and second main electrodes connected in series with the main electrodes of said first transistor, a fifth transistor having a first main electrode connected to the base of the fourth transistor and a base electrode coupled to the signal source, first negative feedback means including a first resistor connected between a second main electrode of the fifth transistor and a common junction between said first and fourth transistors, and second negative feedback means comprising a second resistor connected bEtween the second main electrode of the fifth transistor and the common junction between the second and third transistors.
Claim 7
Dependent Claim
64 words
A circuit as claimed in claim 1 wherein the second main electrode of the first transistor comprises the emitter electrode and the first main electrode thereof comprises the collector electrode, and further comprising means connecting the emitters of said second and third transistors together in common to form said common junction and their collectors to the positive and negative terminals of said power supply.
Claim 8
Dependent Claim
99 words
A circuit as claimed in claim 6 further comprising means connecting one terminal of said load to that terminal of said power supply to which the collector of said second transistor is also connected, and wherein said means connecting the common junction to the load comprises a capacitor coupling the other terminal of the load to the common junction of the emitters of said second and third transistors, and wherein said constant current means comprises a resistor connected to the collector of the first transistor and to a junction between the capacitor and said other terminal of the load.
Claim 9
Dependent Claim
32 words
A circuit as claimed in claim 1 in which the second and third transistors form the output transistors of an audio amplifier and the load comprises a loudspeaker or combination of loudspeakers.
References Cited (Backward Citations)
US3551832A
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 |