A magnetic bearing is a bearing which supports a load using magnetic levitation. Magnetic bearings support moving machinery without physical contact, for example, they can levitate a rotating shaft and permit relative motion without friction or wear. It also known as ACTIVE MAGNETIC BEARING (AMB). In active magnetic bearings (AMB) a stable equilibrium is achieved by means of one or more control loops. The use of control loop for maintaining the gap between the shaft and bearing differentiate the active magnetic bearings (AMB) from passive ones. They are in service in such industrial applications as electric power generation, petroleum refining, machine tool operation and natural gas pipelines.