"Tiny Cooling Fan" is to provide the use of a DC power source: DC motor stator and rotor two major components, there is a stator pole (winding or permanent magnet), rotor windings, the power, the rotor is also formed on the magnetic field ( pole), there is an angle between the stator and the rotor poles attract each other in the rotor magnetic field (N and S poles between) under the motor rotation. "Tiny Cooling Fan" to change the brush seat, you can change the angle between the rotor and stator poles (assuming that is the angle between the stator pole starting side to the other side of the rotor poles, the magnetic poles of the rotor stator pole is pointing direction of rotation) direction, thus changing the direction of rotation "Tiny Cooling Fan" motor.