| 摘要 |
PURPOSE:To make a release rapidly at an output side in case of a steep decrease in input signal level, by increasing the gain of volume by decreasing the output of a DC voltage buffer when the output of a set level circuit is lower than the output level of the DC voltage buffer for a certain time. CONSTITUTION:By an electric signal, AGC volume 1 controls the gain, and set level circuit 2 outputs variation power more than a constant level among the output of volume 1. Here, when the output level of circuit 2 is lower than the output level of DC voltage buffer 4 for a certain time, the output level of circuit 3 is decreased steeply to lower the output level of buffer 4, thereby increasing the gain of volume 1. Consequently, the output level can be released in case of a sudden level drop of an input signal without causing the AGC circuit to get unstalbe. |
