Patent ID: 6549003
Filing Date: 2003-04-15
Classification: G01D

Abstract:
A position transducer comprising:magnetic field developing means for developing a magnetic field whose strength and direction change in response to a position of the magnetic field developing means; magnetic field detecting means moved relatively to the magnetic field developing means for detecting a magnetic field developed by the magnetic field developing means and for providing an electrical signal corresponding to the detected magnetic field; and relative position detecting means for detecting a relative position of the magnetic field detecting means relative to the magnetic field developing means in response to the electrical signal provided from the magnetic field detecting means, wherein the magnetic field detecting means consists of two sensor units each formed from a sensor coil wound on a high permeability core and driven in phase with each other with a high frequency, the two sensor units being disposed in different positions in a direction perpendicular to a moving direction of the magnetic field detecting means relative to the magnetic field developing means, and the relative position detecting means detects the relative position of the magnetic field detecting means relative to the magnetic field developing means by determining a difference between outputs of the two sensor units.