| 摘要 |
PURPOSE:To set the amplitude of an output at a fixed level even the titled circuit is used for a reproduction system applying an integration detection system, by using a DC component reproduction circuit applying the quantization feedback method to a DC component reproduction circuit for reproduction of the low band frequency component, and using the output of an addition circuit of a DC component reproduction circuit applied with the quantization feedback method to the input of a peak wave detection circuit. CONSTITUTION:A feedback loop comprises a gain variable amplifier 21, an addition circuit 30, a peak detection circuit 23, a subtraction circuit 24 and an amplifier 26. The low band frequency component obtained by transmitting the output of an identification circuit 31 through an LPF33 and eliminating the output through a low band stop filter applied with an integration detection system is supplied to the circuit 30. The output of the circuit 30 goes to a reproduction signal having its low band frequency component reproduced. Then the input of the circuit 23 goes to a signal whose low band frequency component is reproduced. Thus the normal actuation is secured for an automatic gain control circuit even with the signal whose low band frequency component is deleted to use it as an input signal of the amplifier 21 with a fixed level secured for the output amplitude. |
