US4039965A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Audio frequency transistor amplifier
Assignee: Toshiba Corp
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Filing: 1976-04-20
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Granted: 1977-08-02
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Expires: 1996-04-20
Abstract
Abstract In an audio frequency transistor amplifier comprising an output amplifier circuit to be coupled to a load, a preceding stage amplifier circuit coupled to the input of the output amplifier circuit, and a negative feedback circuit including a DC blocking electrolytic capacitor or polarized capacitor coupled between the output amplifier circuit and the preceding stage amplifier circuit to feed the output signal of the output amplifier circuit back to the preceding stage amplifier circuit, the electrolytic capacitor, when an audio signal to be amplified is fed back to pass therethrough, generates harmonics of the audio signal due to its nonlinear property, thereby to cause a decrease in the articulation and resolution of reproduced sound. The invention resides in coupling in parallel, in order to eliminate or reduce the harmonic noises generated by the electrolytic capacitor, a nonpolarized capacitor having a much smaller loss than the electrolytic capacitor to the same. For the purpose of raising the harmonic noise eliminating or reducing effect, a plurality of nonpolarized capacitors may be coupled in parallel to the electrolytic capacitor.
Inventors
- 👤 Kazuo Ishii
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 22:25
CPC Classifications
H; H03; H03F; H03F3/00; H03F3/30; H03F3/3083; H03F3/3086; H03F3/3091
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
114 words
A transistor amplifier for amplifying audio frequency signals comprising: an output amplifier circuit to be coupled to a load, a preceding stage amplifier circuit coupled to the input of said output amplifier circuit, a negative feedback circuit including a DC blocking electrolytic capacitor having input and output terminals coupled between said output amplifier circuit and said preceding stage amplifier circuit, said electrolytic capacitor generating undesirable harmonics of said audio frequency signals whereby the audio fidelity of said transistor amplifier is reduced; and, a first nonpolarized capacitor connected directly between said input and output terminals in parallel with said electrolytic capacitor for short circuiting said undesirable harmonics and enhancing the fidelity of said transistor amplifier.
Claim 2
Dependent Claim
114 words
A transistor amplifier for amplifying audio frequency signals comprising: an output amplifier circuit to be coupled to a load, a preceding stage amplifier circuit coupled to the input of said output amplifier circuit, a negative feedback circuit including a DC blocking electrolytic capacitor having input and output terminals coupled between said output amplifier circuit and said preceding stage amplifier circuit, said electrolytic capacitor generating undesirable harmonics of said audio frequency signals whereby the audio fidelity of said transistor amplifier is reduced; and, a first nonpolarized capacitor connected directly between said input and output terminals in parallel with said electrolytic capacitor for short circuiting said undesirable harmonics and enhancing the fidelity of said transistor amplifier.
Claim 3
Dependent Claim
22 words
An audio frequency transistor amplifier according to claim 1, wherein said first nonpolarized capacitor has a smaller capacitance than said electrolytic capacitor.
Claim 4
Dependent Claim
18 words
An audio frequency transistor amplifier according to claim 1, wherein said first nonpolarized capacitor is a paper capacitor.
Claim 5
Dependent Claim
19 words
An audio frequency transistor amplifier according to claim 1, wherein said first nonpolarized capacitor is a metalized paper capacitor.
Claim 6
Dependent Claim
19 words
An audio frequency transistor amplifier according to claim 1, wherein said first nonpolarized capacitor is a plastic film capacitor.
Claim 7
Dependent Claim
32 words
An audio frequency transistor amplifier according to claim 1, werein a second nonpolarized capacitor having a smaller loss than said first nonpolarized capacitor is coupled in parallel to said first nonpolarized capacitor.
Claim 8
Dependent Claim
23 words
An audio frequency transistor amplifier according to claim 6, wherein said second nonpolarized capacitor has a smaller capacitance than said first nonpolarized capacitor.
Claim 9
Dependent Claim
32 words
An audio frequency transistor amplifier according to claim 6, wherein a third nonpolarized capacitor having a smaller loss than said second nonpolarized capacitor is coupled in parallel with said second nonpolarized capacitor.
Claim 10
Dependent Claim
23 words
An audio frequency transistor amplifier according to claim 8, wherein said third nonpolarized capacitor has a smaller capacitance than said second nonpolarized capacitor.
Claim 11
Dependent Claim
131 words
A transistor amplifier for amplifying audio frequency signals comprising: a predriver amplifier circuit coupled to receive an audio input signal; a driver amplifier circuit coupled to the output of said predriver amplifier circuit; a complementary push-pull output amplifier circuit coupled to the output of said driver amplifier circuit; a negative feedback circuit including a DC blocking electrolytic capacitor having input and output terminals coupled between said complementary push-pull output amplifier circuit and said predriver amplifier circuit, said electrolytic capacitor generating undesirable harmonics of said audio frequency signals whereby the audio fidelity of said transistor amplifier is reduced; and, at least one nonpolarized capacitor connected directly between said input and output terminals in parallel with said electrolytic capacitor for short circuiting said undesirable harmonics and enhancing the fidelity of said transistor amplifier.
Claim 12
Dependent Claim
131 words
A transistor amplifier for amplifying audio frequency signals comprising: a predriver amplifier circuit coupled to receive an audio input signal; a driver amplifier circuit coupled to the output of said predriver amplifier circuit; a complementary push-pull output amplifier circuit coupled to the output of said driver amplifier circuit; a negative feedback circuit including a DC blocking electrolytic capacitor having input and output terminals coupled between said complementary push-pull output amplifier circuit and said predriver amplifier circuit, said electrolytic capacitor generating undesirable harmonics of said audio frequency signals whereby the audio fidelity of said transistor amplifier is reduced; and, at least one nonpolarized capacitor connected directly between said input and output terminals in parallel with said electrolytic capacitor for short circuiting said undesirable harmonics and enhancing the fidelity of said transistor amplifier.
References Cited (Backward Citations)
DE1143234B
Cited
DE1901433A1
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1980-08-01 | 1981-01-31 | 1981-08-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-08-01 | 1985-01-31 | 1985-08-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-08-01 | 1989-01-31 | 1989-08-02 | $7700.00 | Window Closed / Lapsed |