中文摘要：

对金属结构进行电磁加载，会在裂纹处产生应力波信号，利用该现象可以实现对金属缺陷的无损检测，即电磁声发射技术。脉冲激励源作为电磁加载的核心，其输出电流的频率、幅值等参数对加载效果有显著影响。针对电磁加载实验中对激励源的要求，设计基于半桥型开关电路原理的可调稳压电源、以电容器作为储能元件的充放电回路，并利用单片机实现对电容充放电过程的调控，以产生频率和幅值可调的脉冲电流。将激励源应用于电磁加载实验，输出结果达到了设计要求。

英文摘要：

Electromagnetic loads of metal structures will produce stress wave signal at the crack,this phenomenon can be used to non-destructive testing of metal defects,which is electromagneticacoustic emission.Pulse excitation as the core of electromagnetic loading,the frequency and amplitudeof its output current have significant effects on loading effect.In order to meet the requirements ofimpulse excitation for electromagnetic loading experiment,an adjustable regulated power supply basedon half bridge switching circuit principle and a charge and discharge circuit with capacitor as energystorage were designed.Pulse current with adjustable frequency and amplitude was produced bycontrolling charge and discharge process of capacitor through MCU system.The result of theelectromagnetic loading experiment shows that the excitation source meets design requirements.