Patent ID: 6118283
Filing Date: 2000-09-12
Classification: G01B,G01D

Abstract:
A rotary position sensor comprising:a single stator;a single rotor;a first surface formed on one of either the single rotor and the single stator, the first surface including a plurality of conductive plates formed in a circular arrangement thereon;a second surface formed on the other of the single rotor and the single stator, the second surface including a single conductive plate formed thereon;a signal generator providing a polyphase signal driving each conductive plate of the plurality of conductive plates with a separate component thereof;the single stator and single rotor being immediately juxtaposed such that the first surface is oriented substantially parallel to the second surface and the single rotor is able to rotate independently from the single stator, and wherein the plurality of conductive plates face the single conductive plate;an input shaft attached to the single rotor such that rotary motion of the input shaft alters the position of the single conductive plate relative to each of the plurality of conductive plates, thereby forming a variable capacitance between each conductive plate of the plurality of conductive plates and the single conductive plate; anda phase detector having a first input electrically coupled to the single conductive plate and a second input electrically coupled to an intermediate signal output of the signal generator, the phase detector determining phase relationship between the separate components of the polyphase signal driving the plurality of conductive plates and an intermediate signal, the polyphase signal and the intermediate signal capacitively coupled between the plurality of conductive plates and the single conductive plate.