Based on impedance principle

a resonance frequency measuring system for magnetoelastic sensor is designed. The system consists of MCU controller

AC excitation circuit

DC biasing circuit

and detection circuit

and communication with upper computer is performed through serial RS——232. AC excitation circuit employes voltage controlled current source mode to avoid influence of coil impedance change on AC enciting current.Experimental results show that the resonance frequency of magnetoelastic sensor can be detected rapidly. The system is easy to operate

has high precision

good stability

and high integration

which can satisfy detecting requirements for magnetoelastic sensor study.