Automatic level control circuit for restricting sound level

摘要

The invention provides an automatic level control circuit which restricts and outputs a large input voice level received from microphone without causing the large input voice level to saturate when a microphone is used in a sound generating device such as a ka-ra-o-ke set. An automatic level control circuit includes a first potential divider comprising an automatic level control circuit for restricting sound level. The first potential divider includes a first resistor and a first transistor, where one end terminal of the first resistor is connected to an input terminal. An amplifier is connected to a connection point of the first resistor and the first transistor of said first potential divider and a second potential divider is provided. The second potential divider includes a second resistor and a second transistor connected to an output terminal of said amplifier. A voltage comparator includes a plus terminal which is connected to a connection point of the second resistor and the second transistor of the second potential divider, and a minus terminal that is connected to a reference voltage. A charging/discharging circuit includes an input that is connected to an output of the voltage comparator, and an output that is connected to a gate terminal of the first and second transistors.