"Micro Cooling Fan" convert electrical energy into mechanical energy of the rotating machinery. It consists of three parts of the star, the rotor and the commutator, a rotor with more than two coils, the magnet wires wound, the winding is known. When the forces current through the magnetic field, the magnetic field generated by the star field winding produced. Since the "Micro Cooling Fan" The star is fixed, the rotation force of the rotor. Commutator DC motor is a special apparatus, a plurality of commutator segments, each two adjacent commutator segments are insulated middle ware. Brush the surface of the commutator fixed to a spring loaded, rotable armature winding is connected to an external circuit. When the "Micro Cooling Fan" a certain angle of rotation of the rotor, the commutator, the power supply voltage is connected to the other winding, the winding generates a magnetic field. As seen, due to the presence of the commutator, the armature coil by electromagnetic torque remains constant, the rotational torque in the armature of the electromagnetic