AVC Internal Circuit
An Automatic Volume Control (AVC) circuit (also known as Automatic Gain Control or AGC) is a closed-loop feedback circuit that automatically stabilizes the output volume of an audio or radio signal. It compensates for fluctuations in signal strength to maintain a consistent listening experience without manual volume adjustments
How the AVC Circuit Works
The AVC circuit continuously monitors the audio signal and generates a feedback loop to dynamically adjust the gain of earlier amplifier stages.
The core functional process includes:Signal Sampling: The circuit continuously samples the amplitude of the output audio or radio signal.
Voltage Conversion: In radios, the detector stage rectifies the signal into a negative DC control voltage. The stronger the received signal, the more negative this control voltage becomes. In solid-state audio circuits, a buffering stage (e.g., using an operational amplifier) feeds the signal to a variable attenuator