电容式传感器测量用二极管双T型交流电桥的分析

Analysis on Diode-double-T-type Alternating Current Bridge Used for the Detection of Capacitor Sensor

从电路基本原理和分析方法出发,详细推导了电容式传感器测量用二极管双T型交流电桥的输出电压,并分析了相关电路参数对测量结果的影响。这些工作是对"传感器原理及实验"课程教学内容的补充和完善,同时也给后续的工程应用设计提供了技术参考。为保证调理电路获得尽可能大的输出电压,设计时应根据被测电容的大小,选择合适的电阻R_1,保证激励信号的周期远大于时间常数τ_1、τ_2的条件下,尽可能的提高信号频率。

The output voltage of diode-double-T-type alternating current bridge used for the detection of capacitor sensor is derived from the basic principle and analysis method of circuit, and the influence of relative parameters on the output voltage is analyzed. This work is supplementary and improvement for the teaching contents in the course of ‘the principle and experiment of sensors’, and provides technical advise for application design in relative project. For acquiring as large output voltage as possible , appropriate value of resistance R1 is needed to be chosen according to the value of the detected capacitor, and a source signal with as high frequency as possible may be adopted providing that its period is much larger than the time constant τ1 and τ2.