Signal processing device for piezoelectric sensor

摘要

A signal processing device is provided which is designed to process an output of a piezoelectric sensor to produce a signal which indicates a load applied to the piezoelectric sensor accurately without being affected adversely by leakage current occurring in the piezoelectric sensor and electrical disturbances. The signal processing device includes a differentiating circuit which differentiates the output of the piezoelectric sensor and an integrating circuit which integrates an output of the differentiating circuit to produce an output signal as a function of the output of the piezoelectric sensor. The frequency range of the output signal is selected based on a frequency range of the load applied to the piezoelectric sensor.