电容式雨量传感器信号处理电路的设计

摘要

The capacitance signal processing is one of key technologies of capacitive precipitation gauge.A capacitance meas-uring circuit based on dual 555 timers was designed.The measured capacitance was put in the oscillation circuit produced by the dual 555 timers, and the oscillation frequency could change when the capacitance changed.The oscillation frequency could subse-quently be transformed into voltage signal by phase distinguish, integral and amplified circuit.The components and parameters of circuit were chosen by calculation so that the relationship between input capacitance and output voltage could be linear.The linear relationship and the feasibility of the circuit are confirmed by experiments.%电容信号处理是电容式雨量传感器的关键技术之一。设计了一种基于双555定时器的电容信号处理电路，该电路将被测电容接入由双555定时器产生的振荡回路中，振荡频率随电容的变化而变化，再经过鉴相、积分、放大电路，输出适宜测量的直流电压信号。通过计算确定出电路参数，并选择适当的元器件，以保证输入电容量与输出电压之间存在线性对应关系。试验结果证实了这一线性关系，说明该电路设计是合理可行的。