Patent ID: 6604434
Filing Date: 2003-08-12
Classification: G01F

Abstract:
A method of determining the direction of rotation of a rotating magnetic field, comprising:sensing the change in polarity of magnetic flux encountered at a first point located within the rotating magnetic field with a first bistable ferromagnetic wire that comprises a core and a shell, wherein the core has a higher coercivity than the shell; sensing the change in polarity of magnetic flux encountered at a second point located within the rotating magnetic field with a second bistable ferromagnetic wire that comprises a core and a shell, wherein the core has a higher coercivity than the shell, wherein said second point is located at a position that is subsequent in the direction of rotation from said first point; creating a first stream of signals corresponding to said change in polarity of magnetic flux at said first point; creating a second stream of signals corresponding to said change in polarity of magnetic flux at said second point; and determining the direction of rotation of the magnetic field by comparing the change in polarity detected at said first point with the change in polarity detected at said second point.