| 摘要 |
PURPOSE:To reduce the distortion which is caused at the inside of an electric power amplifying circuit, by providing a voltage amplifying circuit having a reduced distortion in parallel to the electric power amplifying circuit to which a speaker or the like is connected and feeding back the difference of the output voltages of both circuits to the feedback point of the electric power amplifying circuit in an adverse phase. CONSTITUTION:A voltage amplifying circuit 2 having an extremely reduced distortion is provided in parallel to an electric power amplifying circuit 1. The output voltage V1 of the amplifier 1 and the output voltage V2 of the amplifier 2 are supplied to a differential amplifier 3 to deliver the difference voltage V1-V2 of both output voltages. This difference voltage is amplified to be fed back in an adverse phase to the feedback point of the circuit 1. The distortion of the circuit 2 is extremely reduced, and the distortion of the voltages V1-V2 is regarded equal to the distortion of the circuit 1. Thus the internal distortion of the circuit 1 can be extremely reduced by such feedback as mentioned above. Furthermore the distortion can be suppressed even to a fluctuation of the load impedance. |
