| 摘要 |
PURPOSE:To control the extent of phase shifting to a constant value even if a resistance and a capacitor in use have variance by connecting the resistance to the input side of a gain-controllable amplifier and connecting the capacitor between its input and output. CONSTITUTION:A signal input terminal 21 is connected to the input terminal of the gain-controllable amplifier 22 through the input resistance R in series, and the output terminal of the amplifier 23 is a signal output terminal 23. Then, the capacitor C for coupling is connected between the input and output terminals of the amplifier 22, and a variable DC voltage VCT for gain control is applied to the control input terminal of the amplifier 22. The values of the resistance R and capacitor C have variance, and even if the extent of phase shifting varies, that is corrected with the voltage VCT. |
