The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Feb. 17, 2004
Filed:
Oct. 11, 2002
Gilbert Wache, Avilly St-Leonard, FR;
Cegelec, Rueil-Malmaison, FR;
Abstract
A sensor for detecting defects in a component includes an electric coil fed with a varying electrical current to create a varying magnetic field penetrating at least partly into the component under test, and a defect detector including a magnetoresistor. The above components are accommodated in a protective housing having a detection face disposed near and parallel to a surface of the component under test. The coil has its axis &Dgr; perpendicular to the detection face and the magnetoresistor is in the vicinity of the detection face. The magnetoresistor is a giant magnetoresistor and is disposed so that its sensitivity axis &Dgr; sensitive to variations in a magnetic field is parallel to the detection face of the housing. The sensor further includes a first permanent magnet disposed so that it magnetically biases the magnetoresistor in the direction of its sensitive axis &Dgr; to a value such that the operating point is a point on a curve, representing the output signal of the magnetoresistor as a function of the value of the component of the magnetic field in the direction of the sensitive axis, which is situated in the vicinity of the middle of a substantially rectilinear portion of the curve.