锁定放大技术在ACFM检测电路设计中的应用

摘要

扰动磁场检测信号是微弱信号且总是不可避免地含有噪声和干扰信号.利用锁定放大技术设计一扰动磁场检测电路,包括去2.5 V直流电路、放大滤波电路、移相电路、电压型开关式乘法器.该设计电路实现了对扰动磁场微弱信号的测量与消噪处理.试验表明,利用锁定放大技术设计优化ACFM检测电路是一种有效的方法.%ln ACFM , the detection signal is the weak signal and alwaya inevitably includes the noise and the unwanted signal.This paper used the lock-in amplifier technology, designed a magnetic disturbance detection circuit including eliminate 2. 5 V DC circuit, amplifying and filtering circuit,phase-shifting circuit and the switching voltage multiplier. This design circuit enables performed the measurement and do-nosing for weak magnetic signal of ACFM. The experiment indicated that the use of lock-in amplifier technology to design and optimize ACFM detection circuit is an effective method.