Title: Electromagnetic-piezo-resistance type micro mechanical resonant beam sensor
Application Number: 200610114276 Application Date: 2006.11.03
Publication Number: 1945215 Publication Date: 2007.04.11
Approval Pub. Date: Granted Pub. Date:
International Classifi-cation: G01D5/12;G01H11/00
Applicant(s) Name: Beijing Univ. of Aeronautics and Astronautics Address:
Inventor(s) Name: Fan Shangchun;Xing Weiwei;Cai Chenguang
Attorney & Agent: jiayu zhong luji
Abstract:
    The electromagnetic-piezoresistance type micro mechanical resonant beam sensor has single beam harmonic oscillator with ends fixed and set inside magnetic field in the width direction, and resonance frequency controlled by the measured physical quantity. The control circuit outputs exciting AC current to the piezoresistance film on the surface of the harmonic oscillator and detects the voltage across it, and the exciting current produces electromagnetic force to make the harmonic oscillator to vibrate. The piezoresistance film senses the first modal shape to generate corresponding AC resistance component. The exciting current and the AC resistance component are multiplied to obtain modulated vibration pick up signal, which is low pass filtered to obtain DC signal reflecting the resonance frequency changing tendency of the harmonic oscillator. The present invention can realize the continuous measurement of physical quantity and detect weak vibration signal in strong interference background.
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