Digital audio amplifier
First Claim
1. In a digital amplifier having an audio signal source for producing an audio frequency analog signal to be amplified, voltage controlled attenuation means, modulation means for converting said analog signal to a pulse width modulated pulse train, means for detecting an onset of a clipping condition in said audio signal and means for converting said onset of clipping condition into a missed pulse in said pulse train, improved means for producing a control voltage proportional to an extent of the clipping condition, said improved means comprising:
- (a) means for counting a predetermined number of missed pulses in said pulse train;
(b) means for generating a voltage output proportional to the extent of clipping in response to an occurrence of said predetermined number of missed pulses; and
(c) means for applying said voltage output to said attenuation means for attenuating said audio frequency analog signal.
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Accused Products
Abstract
A digital amplifier contains a circuit for converting the onset of a clipping condition into a missed pulse in a pulse width modulated pulse train generated from an analog signal and an improved circuit for producing a control voltage proportional to the extent of the clipping condition, which circuit includes a pulse counter for counting a predetermined number of missed pulses in the pulse train and a voltage generator for producing a voltage proportional to the extent of clipping when said predetermined number of missed pulses occurs. The generated voltage is applied to an attenuator for attenuating the analog input signal.
55 Citations
7 Claims
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1. In a digital amplifier having an audio signal source for producing an audio frequency analog signal to be amplified, voltage controlled attenuation means, modulation means for converting said analog signal to a pulse width modulated pulse train, means for detecting an onset of a clipping condition in said audio signal and means for converting said onset of clipping condition into a missed pulse in said pulse train, improved means for producing a control voltage proportional to an extent of the clipping condition, said improved means comprising:
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(a) means for counting a predetermined number of missed pulses in said pulse train; (b) means for generating a voltage output proportional to the extent of clipping in response to an occurrence of said predetermined number of missed pulses; and (c) means for applying said voltage output to said attenuation means for attenuating said audio frequency analog signal. - View Dependent Claims (2, 3, 4, 5, 6, 7)
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Specification