Patent ID: 6198276
Filing Date: 2001-03-06
Classification: G01D

Abstract:
A ferromagnetic-ball sensor, comprising:a base having a pathway for a ferromagnetic-ball;a magnet mounted on the base for forming a magnetic field between the magnet and ferromagnetic-ball passing through the pathway; anda magnetic field detection element for detecting a part of the magnetic field formed by the magnet, wherein the magnetic field detection element has a magneto-resistive face responsive to a magnetic field parallel to the magneto-resistive face;whereby the base, the magnet, and the magnetic field detection element are arranged such that the magnetic field detection element detects a modification of a part of the magnetic field when the ferromagnetic ball travels through the pathway;an angle between the center of the magnet and the center of the magnetic field detection element with respect to the center of the ferromagnetic ball passing through the pathway is in a range of one of 42-80 degrees, 132-170 degrees, 222-260 degrees, and 312-350 degrees; andan angle between the magneto-resistive face and a plane passing through the centers of the ferromagnetic ball and of the magnetic field detection element is in a range of one of 42-80 degrees, 132-170 degrees, 222-260 degrees, and 312-350 degrees.