能使输入信号衰减或者放大一定倍数的电压表输入线路必须在很宽的频带范围内保持传递系数不变。通常电压表输入线路可以采用反相输入的运算放大器,或者采用同相输入运算放大器与无源分压器的组合。这时输入装置中大都带有由电阻和电容组成的频率补偿。这样,在低频段输入线路的传递系数将取决于电阻器,而在高频段输入线路的传递系数将由电容器来决定。在高频段用调节微调电容器来使传递系数达到额定值。由于小体积电容器的制造精度低,而且可调范围窄,所以调节传递系数就成为长时间困难的工序。本文所叙述的电路无上述缺陷,该电压表 Voltmeter input lines, which attenuate or amplify input signals by a factor of several, must maintain their transfer coefficients over a wide frequency band. The voltmeter input line can usually use an inverting input op amp or a combination of a noninverting input op amp and a passive voltage divider. At this time, most of the input devices are provided with frequency compensation consisting of resistors and capacitors. Thus, the transmission coefficient of the input line in the low frequency band will depend on the resistor, and the transmission coefficient of the input line in the high frequency band will be determined by the capacitor. Adjust the trimmer capacitors at high frequencies to achieve the desired transfer coefficient. Due to the low manufacturing precision of the small-volume capacitor and the narrow adjustable range, adjusting the transfer coefficient becomes a long-term and difficult process. This article describes the circuit without the above drawbacks, the voltmeter