the magnetic bearing thus providing a low cost and efficient means for dynamically suspending the rotor of the rotary device application_number US 40688809 A description following is a description of various aspects and embodiments of the present invention presented in conjunction with the figures identified above first a description of some principles underlying the present invention will be given the discussion will then proceed with a description of specific embodiments of the present invention the present invention is directed to the operation of magnetic bearings and bearingless drives for use in rotary devices an important aspect of the present invention is the departure from the use of a conventional position sensing system based on cartesian x y coordinates to the use of a polar u03c1 u03c6 coordinate system where the conventional position sensing system produces an x position signal and a y position signal that represents the displacement of the rotor of the rotary device in an x y coordinate system a polar coordinate position sensing system in accordance with the present invention produces a time varying signal whose magnitude is proportional to the absolute value of displacement of the rotor from a neutral desired position and a phase shift that represents the direction of the displacement where the phase shift is relative to the time varying signal when the rotor is at its neutral position thus using a system of polar coordinates permits the use of the time varying output signal u of the position sensor and is a most straightforward and natural way to represent the radial position of the rotor the presentation of information in the form of a single.