用于电容传感器的脉宽调制电路

摘要

A PWM circuit was presented,and it can measure small displacement.The circuit was based on a newly developed differential capacitive transducer,and composed of 7555 timer,filter,and so on. It can transform small displacement into DC. voltage, which is a linear function of the displacement change. The measurement precision is ±0. 1 mm. The circuit is simple,convenient and low cost,and has good stability and anti-jamming. Experimental results show that the least-squares linearity of displacement measurement is 0. 33% ,and sensitivity is 0. 065 V/mm.%设计了一种脉宽调制电路,用于小位移测量.电路以自制的差动电容传感器为基础,由7555定时器、滤波器等电路组成,将微小的位移变化量转化为直流电压,且与位移量基本成线性关系,能实现精度为±0.1 mm的位移测量.电路结构简单、调试方便、成本低,具有很好的稳定性和抗干扰性.实践表明:位移测量的最小二乘线性度为0.33％,灵敏度为0.065 V/mm.