涡流无损检测中变频激励新方法

DDFS（直接数字频率合成器）技术是一种重要的频率合成方法，具有频率精度高、频率变换快、相位可连续线性变化等优点，在涡流无损检测中有着广泛的应用前景。在阐述DDFS原理的基础上，分别论述了直接利用凌阳公司生产的片上型微处理器SPCE061A及利用Micro Linear公司生产的单片电路ML2035实现变频激励的两种方法，详细阐述了两种变频激励方法的实现过程，通过实验测试分析了两种方法的优缺点。通过涡流无损检测仪等实际应用表明所阐述方法合理可行、效果良好。

A New Methods of Variable Frequency Excision for Eddy Current Nondestructive Testing

Direct Digital Frequency Synthesizer（DDFS） technology is one of the important method of frequency synthesis, it has many important characteristics, such as high accuracy, frequency transformed quickly, phase changed continuously and so on, it has applied widely in eddy current testing field. The principle of the DDFS was described, and realization methods of variable frequency excision on the SPCE061A SOC MCU made by Sunplus and ML2035 using DDFS made by Micro Linear were given respectively. This paper expatiates the realization processes of the two methods of variable frequency, and analyzes the merits and demerits by experiments. The applied results show that the methods satisfied and effects favorable according to eddy current nondestructive testing requirement.