摘要
本文提出了一种用于差动电容传感器的电路 ,采用弱信号检测技术 ,将被测微小电容变化量转换成直流电压信号 .输出电压与差动电容变化量成线性关系 ,经过单片机处理后能自动补偿偏差电容和电路的漂移 .实验表明 ,最小被测电容变化量可达 8f F,灵敏度可达 3.82× 10 1 1 V/ F.
A circuit for differential capacitance transducers is proposed in this paper. By using a method for measuring weak signal, it can be used for detect the low capacitance changes. The output dc. voltage is a linear function of the capacitance change. The signal that is processed by single chip microcomputer can be used for compensate to offset capacitances and drifts automatically. The experiment results show a good correspondence with the theoretical analysis. The resolution of the measurement of capacitance change is showed to be 8 fF. A sensitivity of 3.82×10\+\{11\}V/F was given according to these measurement values.
出处
《传感技术学报》
CAS
CSCD
2002年第1期51-54,共4页
Chinese Journal of Sensors and Actuators
关键词
电容传感器
电容/电压转换
差动测量
偏移补偿
capacitive transducer
capacitance to voltage conversion
differential measurement, offset compensation
