| 摘要 |
PURPOSE:To control the gain with an optimum time constant automatically independently of types of signals, by changing the time constant of control through the detection of time change of signals, in a circuit controlling the gain according to the envelope information of the signals. CONSTITUTION:One of an input signal is inputted to a variable gain circuit 3 and another is inputted to a circuit 5 controlling the gain of a variable gain circuit according to the envelope information. A part of the envelope information is inputted to an inverting input terminal of a differential amplifier 13 via a delay circuit 12 and inputted to a noninverting input terminal as it is. As a result, the change in the time input signal is picked up as an output of the differential amplifier 13. This change amount is given to a gain control signal generating circuit 8 to change in the time constant of attack and recovery time. |
