"Small Cooling Fan" is an important component of the stator of the motor, the motor of the silicon steel coil, PCB boards, namely the motor housing and the rotor magnetic stripe, here are generally soft magnetic stripe, external electromagnetic field to the magnetic Chong magnetic strip and close its magnetic, poles and "Small Cooling Fan" of the speed of the motor what to do with it, the conventional fan is usually 4-pole motor, which means that there are four coils, use IC to switch four coils magnetic field, the motor work without brushes, multiple poles, the magnetic field change on behalf of fast, high-frequency IC switching coil, high frequency would increase the energy conversion efficiency of silicon steel, so that "Small Cooling Fan" the same current value can achieve higher dynamic power, so the speed will increase, so the speed is proportional to the number of poles lean relationship