Design of High Frequency Magnetic Field Detection Device

Abstract

为了研究高频激励源对经颅磁刺激线圈产生的磁场特性的影响，同时为解决目前通用特斯拉计只能检测恒定中强磁场、少数特斯拉计也仅能检测200 Hz以下的交变磁场的问题。因此，基于法拉第电磁感应定律，研究设计了用于检测70 kHz以上的交变高频磁场的检测装置。该磁场检测装置由AD8130模块电路与两个NE5532模块电路级联而成，可几乎无失真地检测到频率10 KHz~60 MHz、幅度0~25 V的交变信号；AD8130模块是差分放大模块，NE5532模块是运算放大器，这两个模块联合使用将检测线圈接收到的感应电动势大小放大6615倍输出。 In order to study the influence of high-frequency excitation source on the characteristics of mag-netic field produced by transcranial magnetic stimulation coil, and to solve the problem that the current general Tesla meter can only detect the constant medium strong magnetic field, and a few Tesla meters can only detect the alternating magnetic field below 200 Hz. Therefore, based on Faraday’s law of electromagnetic induction, a detection device for detecting alternating high frequency magnetic field above 70 kHz is designed. The magnetic field detection device is composed of ad8130 module circuit and two ne5532 module circuits, which can detect the alternating signal with the frequency of 10 khz - 60 mhz and the amplitude of 0 - 25 v almost without distortion; ad8130 module is the differential amplifier module, ne5532 module is the operational amplifier, and the two modules jointly use to amplify the induced electromotive force received by the detection coil by 6615 times.