慢变弱电信号实时处理系统及其应用

A Real-Time Processing System of Slowly-Varying Weak Electric Signals and Its Applications

本文介绍一种可对毫秒级变化的弱电信号进行采集及处理的实用系统。该系统采用一个输入电阻≥10^(13)Ω、输入端漏电流≤10^(-15)A的运算放大器组件来构成脉冲补偿式电流积分及,I/F或V/F转换器,用以实现被测信号的数字化;其I/F或V/F转换器结构简单,转换线性达5×10^(-15)A,大大提高了A/D转换的准确度,而且不需放大和量程换档就可对弱电信号进行大范围采集和转换,采集范围可达10^(-7)～10(-15)A,从而使该系统可用于工业控制、弱电测量以及环境参数监测等方面。

This Paper introduces a practical system which can be used to measure or process any weak signals the frequency of which is less than 10~3HZ. In order to construct a pulse-compensating current integrator and current/frequency or voltage/frequency convertor which is used to make weak-signals digitized in the system, an operational amplifier package is adopted whose input-resistance is higher than 10^(13)Ω and input leakage current is lower than 10^(-14)A. While collecting and converting signals, the I/F or V/F convertor, which has simple circuit construction and good converting linearity within 5×10^(-15)A, can highly raise the accuracy of A/D conversion and does not need amplifiers and switches for the weak signals ranging from 10^(-7) to 10^(-16) A, so that the system may be used in industrial control, measurement of weak signals, or other environmental monitoring, etc.