Volume control for an audio apparatus

Abstract

This invention relates to a volume control for an audio apparatus and more particularly to a fader for fading in or out a level of an audio signal. The volume control of the invention comprises a charge and discharge circuit having a capacitor charged and discharged by a constant current in response to a fade-in or fade out operation, and a function generator to generate a signal having a logarithmic waveform periodically repeated. A control signal generator compares the voltage across the capacitor of the charge and discharge circuit with the logarithmic waveform signal from the function generator to generate a control signal logarithmically varying in accordance with variation in the voltage across the capacitor of the charge and discharge circuit. An impedance controller logarithmically changes an impedance of an audio signal line in accordance with the control signal to logarithmically change the level of the audio signal in substance.

Dependencies are inferred from the claim text.