Patent ID: 7211974
Filing Date: 2007-05-01
Classification: H02P

Abstract:
1. A motor drive system comprising: a movable body with a plurality of permanent magnets, alternately magnetized at opposite poles, continuously disposed thereon; a plurality of stators each consisting of an array of electromagnetic coils disposed so that they do not come into contact with said movable body, said electromagnetic coil arrays having a plurality of phases, there being phase difference between the electromagnetic coils of the respective phases; and a drive circuit that moves said movable body based on the attraction—repulsion between said movable body and electromagnetic coils generated by supplying an excitation current to each electromagnetic coil array to alternately magnetize the electromagnetic coils in each electromagnetic coil array at opposite poles, wherein said drive circuit includes: wherein said movable body is constructed to have a plurality of constitutions in which the same heteropolar arrangement of a plurality of different permanent magnets constitutes a pair, and, when the position between said heteropolar arrangement constituting a pair is 2π, said each sensor is able to linearly detect an arbitrary position between said 2π.