| 摘要 |
PURPOSE:To eliminate noise by interrupting an input signal when the noise is detected and amplifying an output signal of a gate circuit with an amplification factor in response to the interrupting time. CONSTITUTION:A signal where noise is superimposed continuously is inputted to an input terminal 11. A level of an output signal of a detection circuit 13 goes to logical ''1'' at the noise generating timing and gate circuits 14, 20 are turned off. A voltage across a resistor R1 is fed to a differential amplifier 23 via a voltage controlled amplifier 21 whose amplification factor is controlled by an output voltage of a differential amplifier 23 and an LPF22. A voltage controlled amplifier 15 amplifies an output signal of the circuit 14 and since the duty ratio of signals (g), (f) are corresponded together, an output signal (h) of the amplifier 15 is equal to a signal on which no noise is superimposed. |
