Amplifier with automatic gain control.

摘要

An amplifier in which the gain (Ai) is automatically controlled to a maximal value comprises means (Di) for detecting ringing tones and means (Vi) for reducing the gain upon the detection of ringing tones. Also proposed is a circuit (Di) for detecting ringing tones. A dynamic equilibrium can be obtained by alternately raising in the event of ringing tones and reducing the gain in the absence of ringing tones.