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US 4,059,807 AGranted
Pulse width modulated amplifier
AssigneeSony Corporation
InventorOsamu Hamada
Life of this patent
Estimating the term…
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.
Claims5
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.
3 more elements
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.
4 more elements
Dependencies are inferred from the claim text.