Patent US4059807A successfully refreshed from Google Patents.
US4059807A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Pulse width modulated amplifier
Assignee: Sony Corp
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Filing: 1975-10-29
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Granted: 1977-11-22
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Expires: 1995-10-29
Abstract
Abstract A pulse width modulation circuit which comprises a mixer for combining an input audio signal with a feedback signal and for developing a difference signal to feed to an integration circuit. The integration circuit is coupled to a pulse width modulator which has a sawtooth carrier input for modulating the input audio signal. The resulting pulse modulated signal is then fed to a pulse amplifier and a low-pass filter and finally to a load. The output of the low-pass filter is coupled back to the mixer.
Inventors
- 👤 Osamu Hamada
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 10:39
CPC Classifications
H; H03; H03F; H03F3/00; H03F3/20; H03F3/21; H03F3/217; H03F1/00; H03F1/34
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
90 words
A pulse width modulated amplifier circuit comprising: a mixer having audio and feedback inputs and an output, means for integrating a signal derived from said output, means for pulse width modulating a signal derived from an output of said integrating means, means for filtering said pulse width modulated signal and for applying said filtered signal to a load, and means for feeding back a portion of said filtered signal to said mixer, said integrating means eliminating any modulating signal from the feedback from passing to said pulse width modulating means.
Claim 2
Dependent Claim
90 words
A pulse width modulated amplifier circuit comprising: a mixer having audio and feedback inputs and an output, means for integrating a signal derived from said output, means for pulse width modulating a signal derived from an output of said integrating means, means for filtering said pulse width modulated signal and for applying said filtered signal to a load, and means for feeding back a portion of said filtered signal to said mixer, said integrating means eliminating any modulating signal from the feedback from passing to said pulse width modulating means.
Claim 3
Dependent Claim
41 words
A pulse width modulated amplifier circuit in accordance with claim 1 wherein said pulse width modulating means comprises means for developing a sawtooth wave and for using said sawtooth wave to modulate said signal derived from the output of said mixer.
Claim 4
Dependent Claim
40 words
A pulse width modulated amplifier circuit in accordance with claim 2 wherein said filtering means comprises a low-pass filter and wherein means are provided to amplify said pulse width modulated signal between said pulse width modulator and said filtering means.
Claim 5
Dependent Claim
121 words
A pulse width modulated amplifier circuit comprising: an input circuit, an integration circuit for integrating a signal derived from the output of said input circuit, a pulse width modulator and means for feeding thereto a carrier signal and said output signal from said integration circuit, said pulse width modulator producing a signal having a pulse width which corresponds to the level of the output signal from said integration circuit, a low-pass filter connected to the output of said modulator, and a feedback circuit connected to the output of said low-pass filter to feedback the output of said low-pass filter to said input circuit, said integrating means eliminating any modulating signal from the feedback from passing to said pulse width modulating means.
Claim 6
Dependent Claim
121 words
A pulse width modulated amplifier circuit comprising: an input circuit, an integration circuit for integrating a signal derived from the output of said input circuit, a pulse width modulator and means for feeding thereto a carrier signal and said output signal from said integration circuit, said pulse width modulator producing a signal having a pulse width which corresponds to the level of the output signal from said integration circuit, a low-pass filter connected to the output of said modulator, and a feedback circuit connected to the output of said low-pass filter to feedback the output of said low-pass filter to said input circuit, said integrating means eliminating any modulating signal from the feedback from passing to said pulse width modulating means.
Claim 7
Dependent Claim
39 words
A pulse width modulated amplifier circuit in accordance with claim 4, wherein an amplifier is provided between said pulse width modulator and said low-pass filter, and the carrier signal supplied to said pulse width modulator is a sawtooth signal.
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) | 1980-11-21 | 1981-05-23 | 1981-11-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-11-21 | 1985-05-23 | 1985-11-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-11-21 | 1989-05-23 | 1989-11-22 | $7700.00 | Window Closed / Lapsed |