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:
Apr. 01, 2003
Filed:
Jan. 28, 2002
Erland Max, Västra Frölunda, SE;
Volvo Lastvagnar AB, Gothenburg, SE;
Abstract
The invention relates to a method for substantially temperature-independent detection of the position of a moving element ( ) by way of an inductive position sensor ( ), comprising a coil ( ) and a core ( ) movable within the coil, the position of said core in relation to the coil ( ) being dependent on the position of said element ( ), whereby a measurement of the inductance of said coil ( ), corresponding to the core ( ) position, is detected by connecting a voltage to said coil ( ) and measuring the time period in which a current (i) through the coil ( ) is changed between two predetermined levels. The method follows the steps of feeding a regularly alternating voltage to the coil ( ), measuring the current (i) flowing through the coil ( ), measuring the period of time (t ) needed for the current (i) to change from a first predetermined level (i ) to a second predetermined level (i ), and determining a measurement of the core ( ) position through measuring the period of time (t ). Through the invention, an improved position detection is provided, primarily intended for automotive vehicle gearboxes, achieving a highly reduced temperature dependence.