Patent ID: 6240191
Filing Date: 2001-05-29
Classification: H03F,H03G

Abstract:
An audio level control circuit using pulse width modulation, comprising:audio signal input means for receiving an audio signal;operator input means responsive to operator actuation for providing an operator control output;pulse width modulation signal generator means connected to said operator input means and responsive to the operator control output thereof for producing pulse width modulated signals having a variable duty ratio in accordance with the operator control output;rectifier means connected to said pulse width modulation signal generator means for transforming the pulse width modulated signals generated by said pulse width modulation signal generator means into a DC level, and producing an output;audio signal level regulating integrated circuit means connected to said rectifier means and to said audio signal input means for regulating a level of the audio signal according to the output of said rectifier means and producing an audio output;audio signal processor means connected to said audio signal level regulating integrated circuit means for processing the audio output thereof to produce an audio signal output; andaudio output means connected to said audio signal processor means for amplifying the audio signal output of said audio signal processor means;wherein said audio signal processor means comprises an audio signal level detector for detecting an audio signal level of the audio output of said audio signal level regulating integrated circuit means, for regulating the detected audio signal level, and for feeding the regulated audio signal level back into said audio signal regulating integrated circuit means.