Patent US4241313A successfully refreshed from Google Patents.
US4241313A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Audio power amplifier
Assignee: Nippon Gakki Co Ltd
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Filing: 1975-08-21
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Granted: 1980-12-23
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Expires: 1995-08-21
Abstract
Abstract An audio power amplifier comprising a first stage voltage amplifier circuit, a second stage voltage amplifier circuit and a last stage power amplifier circuit. The first stage voltage amplifier circuit is of differential amplifier type including a pair of field effect transistors for voltage amplifying an audio frequency signal. The second stage voltage amplifier circuit includes a field effect transistor for voltage amplifying the output signal from the first stage voltage amplifier circuit. The second stage voltage amplifier circuit also serves as a drive stage. The last-stage power amplifier circuit includes a pair of field effect transistors having drain voltage versus drain current characteristics similar to static plate voltage versus plate current characteristics of a triode vacuum tube for power amplifying the output signals of the second stage voltage amplifier circuit.
Inventors
- 👤 Takao Takehara
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 12:52
CPC Classifications
H; H03; H03F; H03F3/00; H03F3/45; H03F3/45071; H03F3/45076; H03F3/4508; H03F3/181; H03F3/183; H03F3/185; H03F3/30; H03F3/3001; H03F3/3008; H03F3/3022; H03F3/3023; H03F3/3044; H03F3/3045; H03F3/305; H03F3/3054; H03F3/45085; H03F3/45179; H03F3/45183; H03F3/45376; H03F3/45381; H03F2200/00; H03F2200/516; H03F2203/00; H03F2203/45; H03F2203/45498; H03F2203/45591; H03F2203/45686; H03F2203/45701; H03F2203/45702
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
105 words
An audio power amplifier comprising a first-stage voltage amplifier circuit of differential amplifier type including a pair of field-effect transistors for voltage amplifying an audio frequency signal, a second-stage voltage amplifier circuit including a field effect transistor for voltage amplifying the output signal from said first-stage voltage amplifier circuit, said second-stage voltage amplifier circuit also serving as a drive stage, and a last-stage power amplifier circuit including a pair of field-effect transistors having drain voltage versus drain current characteristics similar to static plate voltage versus plate current characteristics of a triode vacuum tube for power amplifying the output signals of said second-stage voltage amplifier circuit.
Claim 2
Dependent Claim
105 words
An audio power amplifier comprising a first-stage voltage amplifier circuit of differential amplifier type including a pair of field-effect transistors for voltage amplifying an audio frequency signal, a second-stage voltage amplifier circuit including a field effect transistor for voltage amplifying the output signal from said first-stage voltage amplifier circuit, said second-stage voltage amplifier circuit also serving as a drive stage, and a last-stage power amplifier circuit including a pair of field-effect transistors having drain voltage versus drain current characteristics similar to static plate voltage versus plate current characteristics of a triode vacuum tube for power amplifying the output signals of said second-stage voltage amplifier circuit.
Claim 3
Dependent Claim
148 words
An audio power amplifier comprising: a first-stage amplifier circuit for amplifying an audio frequency signal, a second-stage amplifier circuit including an n-p-n transistor and a p-n-p transistor, said transistors being connected in complementary symmetry form for phase inverting the output signal of said first-stage amplifier circuit, said second-stage amplifier circuit also serving as a drive stage, and a last-stage power amplifier circuit including a pair of p-channel and n-channel power field-effect transistors having drain voltage versus drain current characteristics similar to static plate voltage versus plate current characteristics of a triode vacuum tube and connected in complementary symmetry form for power amplifying output signals from said second-stage amplifier circuit, the output signal from said second-stage n-p-n transistor being connected to drive said p-channel power field-effect transistor having triode characteristics, the output signal from said p-n-p transistor being connected to drive said n-channel power field-effect transistor having triode characteristics.
Claim 4
Dependent Claim
148 words
An audio power amplifier comprising: a first-stage amplifier circuit for amplifying an audio frequency signal, a second-stage amplifier circuit including an n-p-n transistor and a p-n-p transistor, said transistors being connected in complementary symmetry form for phase inverting the output signal of said first-stage amplifier circuit, said second-stage amplifier circuit also serving as a drive stage, and a last-stage power amplifier circuit including a pair of p-channel and n-channel power field-effect transistors having drain voltage versus drain current characteristics similar to static plate voltage versus plate current characteristics of a triode vacuum tube and connected in complementary symmetry form for power amplifying output signals from said second-stage amplifier circuit, the output signal from said second-stage n-p-n transistor being connected to drive said p-channel power field-effect transistor having triode characteristics, the output signal from said p-n-p transistor being connected to drive said n-channel power field-effect transistor having triode characteristics.
Claim 5
Dependent Claim
24 words
The audio power amplifier according to claim 2, wherein said first-stage amplifier circuit for amplifying an audio frequency signal consists of an operational amplifier.
Claim 6
Dependent Claim
28 words
The audio power amplifier according to claim 2, wherein said first-stage amplifier circuit for amplifying an audio frequency signal is a differential amplifier including a pair of transistors.
Claim 7
Dependent Claim
165 words
An audio power amplifier comprising a first-stage amplifier circuit including an n-p-n transistor and p-n-p transistor, said transistors being connected in complementary symmetry form for amplifying an audio frequency signal, a second-stage amplifier circuit connected to the output side of said first-stage amplifier circuit including a second n-p-n transistor and a second p-n-p transistor, said second transistors being connected in complementary symmetry form, said second-stage amplifier circuit also serving as a drive stage, and a last-stage power amplifier circuit including a p-channel power field-effect transistor and a n-channel power field-effect transistor, said field-effect transistors having drain voltage versus drain current characteristics similar to static plate voltage versus plate current characteristics of a triode vacuum tube and being connected in complementary symmetry form for amplifying output signals of said second-stage amplifier circuit, the output signal from said second n-p-n transistor being connected to drive said p-channel power field-effect transistor, the output signal from said second p-n-p transistor being connected to drive said n-channel power field-effect transistor.
Claim 8
Dependent Claim
165 words
An audio power amplifier comprising a first-stage amplifier circuit including an n-p-n transistor and p-n-p transistor, said transistors being connected in complementary symmetry form for amplifying an audio frequency signal, a second-stage amplifier circuit connected to the output side of said first-stage amplifier circuit including a second n-p-n transistor and a second p-n-p transistor, said second transistors being connected in complementary symmetry form, said second-stage amplifier circuit also serving as a drive stage, and a last-stage power amplifier circuit including a p-channel power field-effect transistor and a n-channel power field-effect transistor, said field-effect transistors having drain voltage versus drain current characteristics similar to static plate voltage versus plate current characteristics of a triode vacuum tube and being connected in complementary symmetry form for amplifying output signals of said second-stage amplifier circuit, the output signal from said second n-p-n transistor being connected to drive said p-channel power field-effect transistor, the output signal from said second p-n-p transistor being connected to drive said n-channel power field-effect transistor.
Claim 9
Dependent Claim
166 words
An audio power amplifier comprising: a first-stage amplifier circuit for amplifying an audio frequency signal, a second-stage amplifier circuit including a p-channel field-effect transistor and an n-channel field-effect transistor, said field-effect transistors having drain voltage versus drain current characteristics similar to static plate voltage versus plate current characteristics of a triode vacuum tube and being connected in complementary symmetry form for amplifying the output signal from said first-stage amplifier circuit, and a last-stage power amplifier circuit including a p-channel power field-effect transistor and an n-channel power field-effect transistor both having drain voltage versus drain current characteristics similar to static plate voltage versus plate current characteristics of a triode vacuum tube and being connected in complementary symmetry form for power amplifying output signals from said second-stage amplifier circuit, the output signal from said second-stage p-channel field-effect transistor being connected to drive only said p-channel power field-effect transistor, and the output signal from said second-stage n-channel field-effect transistor being connected to drive only said n-channel power field-effect transistor.
Claim 10
Dependent Claim
166 words
An audio power amplifier comprising: a first-stage amplifier circuit for amplifying an audio frequency signal, a second-stage amplifier circuit including a p-channel field-effect transistor and an n-channel field-effect transistor, said field-effect transistors having drain voltage versus drain current characteristics similar to static plate voltage versus plate current characteristics of a triode vacuum tube and being connected in complementary symmetry form for amplifying the output signal from said first-stage amplifier circuit, and a last-stage power amplifier circuit including a p-channel power field-effect transistor and an n-channel power field-effect transistor both having drain voltage versus drain current characteristics similar to static plate voltage versus plate current characteristics of a triode vacuum tube and being connected in complementary symmetry form for power amplifying output signals from said second-stage amplifier circuit, the output signal from said second-stage p-channel field-effect transistor being connected to drive only said p-channel power field-effect transistor, and the output signal from said second-stage n-channel field-effect transistor being connected to drive only said n-channel power field-effect transistor.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1983-12-23 | 1984-06-23 | 1984-12-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-12-23 | 1988-06-23 | 1988-12-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-12-23 | 1992-06-23 | 1992-12-23 | $7700.00 | Window Closed / Lapsed |