Eddy current testing excitation signal source based on DDS (Direct Digital Synthesis) technology

Abstract

The invention discloses an eddy current testing excitation signal source based on a DDS (Direct Digital Synthesis) technology, and the eddy current testing excitation signal source comprises a singlechip, a CPLD (Complex Programmable Logic Device) module, a waveform memory, a D / A (Digital-to-Analogue) converter, a low-pass filter, a power amplification circuit, a liquid crystal touch screen and an upper PC (Personal Computer) machine, wherein the liquid crystal touch screen is connected with the singlechip; the upper PC machine is connected and in series communicated with the singlechip; the CPLD module is connected with the singlechip; the waveform memory is connected with the singlechip and the CPLD module; the D / A converter is connected with the singlechip and the CPLD module, and the D / A converter is connected with the low-pass filter; and the low-pass filter is connected with a power amplifier. The eddy current testing excitation signal source disclosed by the invention can generate standard excitation signals, namely sine waves, pulse waves, and the like with parameters easily adjusted, and excitation signals with any waveforms for eddy current testing.

Description

technical field [0001] The invention relates to an excitation signal source, in particular to an eddy current detection excitation signal source based on DDS technology capable of generating arbitrary waveforms, and belongs to the technical field of non-destructive detection equipment. Background technique [0002] Eddy current testing is one of the conventional methods of non-destructive testing, and has been widely used in many industrial fields such as machinery, petrochemical, aviation, and metallurgy. Eddy current detection has the following characteristics: 1) It is effective for non-magnetic materials, has no pollution to the environment, and is easy to operate; 2) Non-contact measurement does not require couplant, which is convenient for high-speed and efficient detection; 3) It can detect the surface of conductive materials and near For defects such as surface cracks, the response signal contains rich feature information such as crack depth, width, and shape; 4) It ...

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Problems solved by technology

However, the dedicated DDS chips used in the above documents can only generate standard excitation signals such as sine waves and square waves in the form of hardware circuits, and cannot realize the output of arbitrary waveform excitation signals, and the cost is high, which limits the application of eddy current excitation signal sources.

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