Patent ID: 6486663
Filing Date: 2002-11-26
Classification: G01R

Abstract:
A method for determining the direction of an exterior magnetic field B, using a magnetroresistive sensor, having the following steps:superimposing a fluctuating magnetic field on the exterior magnetic field B; generating a first and second signal, dependent on the sine and cosine of the angle of the exterior magnetic field relative to a reference direction; eliminating or ignoring any signal component dependent on the fluctuating magnetic field; ascertaining a third signal, which can be associated with an angle of the exterior magnetic field relative to the reference direction, on the basis of the first and second signal, this third signal having a periodicity of 180Â°; ascertaining a correction logic signal K5, taking into account the signal component, eliminated from the first and second signal and dependent on the fluctuating magnetic field, which signal component assumes a first level for an angle of the exterior magnetic field B in a first angle range, in particular between 0 and 180Â°, and a second level in a second angle range, in particular between 180Â° and 360Â°; and ascertaining the actual angle of the magnetic field B on the basis of the logic correction signal K5 and of the third signal.