关键词: PVDF压电薄膜, 低频, 电荷放大电路, 滤波电路

Abstract:

A detecting circuit consisted of differential charge amplifier circuit with two capacitances feedback and two order low pass filter circuit is designed to solve the problem of high impedance of PVDF piezoelectric film sensor, weak output signal in low frequency load and being easily interrupted by external noise. An experiment of PVDF piezoelectric film sensor in low frequency load of 0.2~20 Hz is done in this thesis. The results of the above circuit and traditional circuit are compared. Results show that output voltage amplitude increases 90% and there is strong anti-interference ability using above circuit. Subsequent circuit is easier to process signal.

Key words: PVDF piezoelectric film, low frequency, charge amplifier circuit, filter circuit