| 摘要 |
PURPOSE:To easily regulate detection sensitivity without using high-impedance component in a device for detecting vehicle movement using a piezoelectric element. CONSTITUTION:The output from piezoelectric elements for detection 24, 25 having piezoelectric effect is connected to input capacitors Ca, Cb of a switched capacitor circuit, putting-on and off of capacitors for regulation C1-C5, C11-C15 connected between the output sides and inverse input terminals of operation amplifiers 41, 42 are set with analog switches 51-55, 61-65 and a capacity ratio of both the capacitors is regulated. As a result, by means of piezoelectric elements for detection 24, 25 electric charge caused by Coriolis force is converted into voltage and it is possible to precisely detect angular velocity without receiving leakage of the electric charge and influence of outside noise. In addition, since the capacity ratio can be regulated with the analog switches, detection sensitivity of the angular velocity can be regulated easily. |
