HIGH RESOLUTION CAPACITIVE SENSOR FOR ACTIVE MAGNETIC BEARINGS

Abstract

To obtain high precision rotation with active magnetic bearings, high resolution sensor are needed. From a literature study, finite element modeling and mathematical derivations, the electrostatic principle of fringe capacitance is investigated. It is used for the design of an optimized sensor pattern. For a fixed sensing area of 75 [(mm)^2], different fringe capacitances have been realized on flexible and rigid PCBs varying the distance between two conductors (from 0.1 to 0.3 [mm]) and the width of the conductors (also from 0.1 to 0.3 [mm]).