DESIGN AND IMPLEMENTATION OF PCB-TYPE CAPACITANCE DISPLACEMENT SENSORCOLLOCATED WITH MAGNETIC BEARINGS

This paper presents the design of a printed circuit board (PCB) -type capacitance displacement sensor with the capability of being collocate d with a magnetic bearing. The capacitance sensor is less influenced b y a magnetic field environment than other sensors, and the desired cap acitor pattern that can be fitted to the magnetic bearing is easily ma nufactured using PCB technology, so that the developed sensor can be c ollocated with a magnetic bearing. The sensor signal-processing unit d rives the sensor by means of a switching method. Performance evaluatio n of the sensor has been carried out for both static and dynamic chara cteristics. Finally, the experimental behaviors on the output of the s ensor are described for application to the control of the magnetic bea ring system. (C) 1998 Elsevier Science S.A. All rights reserved.