Patent ID: 7911174
Filing Date: 2011-03-22
Classification: G01D,H02K,H02P

Abstract:
1. A system for sensing the position of a rotor in a hybrid stepper motor wherein the rotor has first and second spaced-apart armatures with the first armature defining a plurality of north poles at a radial perimeter thereof and the second armature defining a plurality of south poles at a radial perimeter thereof, said system comprising: first and second Hall sensors adapted to be mounted in a spaced-apart relationship and in direct opposition to the radial perimeter of at least one of the first and second armatures of the rotor, said first and second Hall sensors positioned to generate electrical outputs that are 90° out of phase with one another as the rotor rotates; and means coupled to said first and second Hall sensors for adjusting said electrical outputs relative to a reference and for adjusting amplitude of said electrical outputs to account for spacing differences between the rotor and each of said first and second Hall sensors.