×

Hall effect apparatus for determining the angular position of a rotating part

  • US 4,086,533 A
  • Filed: 11/08/1976
  • Issued: 04/25/1978
  • Est. Priority Date: 11/12/1975
  • Status: Expired due to Term
First Claim
Patent Images

1. A device for detecting the specific angular positions of a rotating part comprising, a Hall-effect crystal, a fixed magnetic circuit for exciting the Hall-effect crystal which circuit includes two identical permanent magnets which are disposed at a small distance from and substantially parallel to each other and having adjacent poles of like magnetic polarity situated in proximity to the Hall-effect crystal to apply a magnetic excitation field thereto, said fixed magnetic circuit having an axis of symmetry along which the crystal is disposed, said rotating part including first and second soft-magnetic elements respectively located on opposite sides of said axis of symmetry and each having a leading end and a trailing end defined by the direction of travel of the rotating part, said first and second soft magnetic elements being relatively displaced so that the trailing end of one soft magnetic element coincides with the leading end of the other soft magnetic element and movement of the rotating part causes said first and second soft magnetic elements to successively and alternately pass in the proximity of said adjacent poles, a first soft-magnetic element which passes one of the magnets near its said adjacent pole being immediately followed by a second soft-magnetic element which passes the other magnet near its said adjacent pole to cause a reversal in the direction of the active component of the magnetic excitation field whereby the Hall-effect cyrstal responds by reversing the polarity of an output signal generated therein.

View all claims
  • 0 Assignments
Timeline View
Assignment View
    ×
    ×