AUTOMATIC LEVEL CONTROL CIRCUIT

An automatic level control circuit is constituted by a variable gain amplifier means supplied with an input signal, for outputting a level controlled signal; detector means for detecting the output signal of the variable gain amplifier means; integration circuit means including an operational amplifier and a capacitor; means for applying an output voltage of the detector means to a first input terminal of the operational amplifier via a first resistor; means for applying a first reference voltage to the first input terminal via a second resistor; a first diode with one end connected to the output terminal of the operational amplifier and the other end connected to one end of the capacitor; a second diode connected between the other end of the capacitor and the first input terminal; a transistor with its first and second electrodes connected in parallel with the capacitor and its third electrode connected to the output terminal of the operational amplifier; and circuit means which decreases the gain of the variable gain amplifier means only when the output voltage of the integration circuit means appearing at the output terminal of the operational amplifier exceeds a second reference voltage.