CN101881753A - A high-efficiency eddy current lift-off effect suppression device - Google Patents

Abstract

The invention relates to an efficient vortex lift-off effect suppression device, which is characterized in that an excitation signal amplifier is connected with a power amplifier, and the power amplifier is respectively connected with an X-R vector multiplier and a detection coil; the detection coil is connected with a phase sensitive detector, and the phase sensitive detector is connected with an A/D converter; and the A/D converter is connected with a DSP digital signal processor, and the X-R vector multiplier is connected with the phase sensitive detector. The technical effect of the invention is as follows: the impact of the lift-off effect on the impedance of the coil is approximately linear, and the phase transformation can be simply utilized to realize the suppression of the lift-off effect; and compared with the traditional resonant circuit method, the traditional unbalanced bridge method and the like, the method is simple and convenient and easy to implement, and has low cost and good reliability.

Description

A kind of vortex lift-off effect suppression device efficiently

Technical field

The present invention relates to a kind of lift-off effect suppression device, relate in particular to a kind of vortex lift-off effect suppression device efficiently.

Background technology

Disturb the principal element of coil impedance variation that Lift-off effect is arranged according to analyzing in the EDDY CURRENT principle, when test specimen is detected a flaw, adopt the putting type magnetic test coil to carry out the surface of material for test and subsurface when detecting a flaw, the interference of Lift-off effect is maximum, also is ubiquitous.As a rule, Lift-off effect cause coil impedance variation often greater than the influence of crackle or other damage.Therefore, must be suppressed, otherwise EDDY CURRENT will be difficult to carry out Lift-off effect.The general method of lifting from has both at home and abroad at present: resonant circuit method, unbalanced electric bridge etc., in the resonant circuit, need to adjust the capacitor C of connecting with coil, make LC that resonance ability operate as normal take place, measure for different test specimens, all need to adjust resonant tank, the bridge balance method need be adjusted the electric capacity with coils from parallel connection of coils, and output voltage is not changed with lifting from.Though these two kinds of methods can play the effect that inhibition is lifted from, and need adjust the working point repeatedly, bring great inconvenience to flaw detection.

Summary of the invention

The object of the present invention is to provide a kind of vortex lift-off effect suppression device efficiently, Lift-off effect is approximately straight line to the influence of coil impedance, can simply utilize phase tranformation to realize the method that Lift-off effect suppresses.

The present invention is achieved like this, it comprises pumping signal amplifier, power amplifier, X-R quadrature resolver, magnetic test coil, phase-sensitive detector (PSD), A/D converter, DSP digital signal processor, it is characterized in that the pumping signal amplifier connects power amplifier, power amplifier connects X-R quadrature resolver and magnetic test coil respectively, magnetic test coil connects phase-sensitive detector (PSD), phase-sensitive detector (PSD) connects A/D converter, A/D converter connects the DSP digital signal processor, and X-R quadrature resolver connects phase-sensitive detector (PSD).

Technique effect of the present invention is: Lift-off effect is approximately straight line to the influence of coil impedance, can simply utilize phase tranformation to realize the method that Lift-off effect suppresses, the method is than simple and convenient, easy realization, with low cost, good reliabilitys such as traditional resonant circuit method, unbalanced electric bridges.

Description of drawings

Fig. 1 is a functional-block diagram of the present invention.

Pumping signal amplifier 2,power amplifier 3,X-R quadrature resolver 4,magnetic test coil 5, phase-sensitive detector (PSD) 6, A/D converter 7, DSP digital signal processor in the drawings, 1,

Embodiment

As shown in Figure 1, the present invention is achieved like this, pumping signal amplifier 1 connects power amplifier 2, power amplifier 2 connectsX-R quadrature resolver 3 andmagnetic test coil 4 respectively,magnetic test coil 4 connects phase-sensitive detector (PSD) 5, phase-sensitive detector (PSD) 5 connects A/D converter 6, and A/D converter 6 connects DSPdigital signal processor 7, andX-R quadrature resolver 3 connects phase-sensitive detector (PSD) 5.By in hardware circuit, having designedX-R quadrature resolver 3 and phase-sensitive detector (PSD) 4 carries out waveform transformation and detection; Then output signal is carried out A/D converter 6, in DSPdigital signal processor 7, utilize software to implement the inhibition of Lift-off effect.

Claims (1)

1. vortex lift-off effect suppression device efficiently, it comprises pumping signal amplifier, power amplifier, X-R quadrature resolver, magnetic test coil, phase-sensitive detector (PSD), A/D converter, DSP digital signal processor, it is characterized in that the pumping signal amplifier connects power amplifier, power amplifier connects X-R quadrature resolver and magnetic test coil respectively, magnetic test coil connects phase-sensitive detector (PSD), phase-sensitive detector (PSD) connects A/D converter, A/D converter connects the DSP digital signal processor, and X-R quadrature resolver connects phase-sensitive detector (PSD).

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