根据预多频涡流检测方法的要求，用AVR单片机+DAC组合方式开发了预多频激励信号源。可根据要求分时输出多个频率，各频率间实现无扰动过渡，也可以输出连续单一频率激励信号供阻抗分析用，并用单片机产生解调信号基准。采用计算机辅助编程方法自动生成供单片机使用的波形数据文件，减轻了单片机开发过程中的代码输入量。采用该激励信号源的自动化分选设备已成功地在生产中得到应用。

According to the requirement of pre-multi frequency eddy current testing method, pre-multi-frequency excitation source was developed by using AVR microcontroller plus DAC. According to the requirements of the time-sharing, multiple frequencies could be outputted with each frequency without interference between the transition. A continuous single frequency excitation signal for impedance analysis could be outputted as well. With the microcontroller, the demodulated signal benchmark could be produced. Using computer-aided programming method, the waveform data files for use by the microcontroller were automatically generated, with reducing the input of microcontroller development process of the code. Automatic sorting equipment has been successfully applied to production by using the excitation signal source.