"220V Cooling Fan" in the works above AC DC fans and fan is not the same. Conductor by the current, generates a magnetic field, when the conductor is placed in another field, will produce suction or repulsion, causing objects to move. In the "220V Cooling Fan" fan inside, surrounded by silicon rubber magnets, two coils wound around the axis part and a Hall sensor component as two synchronous detection device controls a group of circuit which makes the winding axis set of coils work in rotation. Steel have different magnetic poles, the magnetic pole and the repulsive force absorbing rubber magnet. When the suction repulsion is greater than the "220V Cooling Fan" of static friction, the blades rotate naturally. Since the Hall sensor component provides a synchronization signal, the fan was able to continue to operate. Many people have been very concerned about this, do not know the real difference between the DC fan and flow fan somewhere. We first analyze it very important from the fan bearings.