LecturePg. 121-126The concept of magnetic levitation is not a new one and can be easily traced back to the 1800s [1). It is only recently, however, that the congruous technologies of electronic control systems, power electronics, and magnetic materials have begun to merge to make the magnetic suspension device a viable product. A brief overview is presented of an active magnetic bearing technology [2]. The required systems engineering interface with the machine designer is discussed. Finally, case histories of various turbomachinery in North America presently operating on magnetic bearings are reviewed