"Tiny Cooling Fan" in more than two sets of rotor coils, the wire around the system, called winding Generating a magnetic field when current flows through the winding, the role of the magnetic field and the stator magnetic field generating force. Since the stator is stationary, so "Tiny Cooling Fan" rotor is rotated by the force. It is a special apparatus commutator DC motor by changing the composition of a number of segments, each two adjacent commutator intermediate insulating film. In the spring pressing surface of the commutator brushes fixed, the rotation of the armature winding can be coupled with an external circuit. When "Tiny Cooling Fan" rotor turned a certain angle, the commutator to access another supply voltage winding, and continue to produce a magnetic field in the winding. Visible, due to the presence of the commutator, the armature coil by the electromagnetic torque remains unchanged at this electromagnetic torque is applied to the rotation of the armature.