基于开关电容的电容传感器接口电路设计与测试  

Design and test of a capacitance sensor interface circuit based on switched capacitor

作　　者：邢文奇[1] 胡红利[1] 罗政元[1] 

机构地区：[1]西安交通大学电力设备电气绝缘国家重点实验室,西安710049

出　　处：《工业仪表与自动化装置》2012年第6期18-21,共4页Industrial Instrumentation & Automation

基　　金：国家自然科学基金项目(51177120);863计划资助项目(2009AA04Z130)

摘　　要：电容传感器已广泛应用于压力、压差、位移、加速度、振动等非电量的精密测量,参比电容传感器有望用于气固两相流测量等领域,而接口电路是电容传感器应用中的核心和关键技术。基于开关电容原理开发的电容传感器接口电路,从原理上消除了电路中寄生电容的影响和直流偏移,使得电容传感器的应用更加广泛。在活塞式压力校验台上,对开关电容接口电路进行了性能测试。结果表明,开关电容接口电路迟滞误差为0.84%,非线性误差为1.33%,重复性误差为1.20%,可应用于参比电容传感器测量系统。Capacitance sensors have been widely used in the precision measurement of pressure, differential pressure, displacement, acceleration, vibration, etc, reference capacitance sensors are expected for gas-solid two-phase flow measurement, and interface circuit is the core and the key of the capacitance sensor applications. A developed capacitance sensor interface circuit based on the principle of switched capacitor can overcome the effects of stray capacitance and baseline drift in the circuit, which makes the applications of the capacitance sensor more extensive. Moreover, the performance testing of the switchedcapacitor interface circuit is fulfilled on the piston pressure calibration stage. The results show that the switched-capacitor interface circuit hysteresis error is 0.84%, nonlinearity error is 1.33% , and repeatability error is 1.20%. It can be applied in the measurement of pulverized coal concentration.

关 键 词：电容传感器 开关电容 接口电路 压力传感器 标定 

分 类 号：TM934.23[电气工程—电力电子与电力传动]