| 摘要 |
PURPOSE:To response even to an over loaded input generated instantaneously by beforehand storing a limiting characteristic in a ROM, reading the characteristic and converting it to analog signals by means of a voltage potentiometer type D/A converter. CONSTITUTION:After input audio signal is amplified by a preamplifier 1 and branched into three signals. The signal of branch A is rectified in full wave by a rectifier circuit 2 and inputted through an A/D converter 3 to the address input terminal of a ROM 4. The output of the ROM 4 is inputted to a voltage potentiometer type D/A converter 5, and the output value of the converter 5 is multiplied to a voltage in proportion to the input audio signal of branch B inputted to the reference signal input of the converter 5. Therefore, an attenuating operation is enabled corresponding to the instantaneous value of a waveform based on the set limiting characteristic is conducted. |
