"Tiny Cooling Fan" in practical applications, the nominal value of maximum wind, the air supply is not the actual heatsink get, air volume, it does not mean strong ventilation capacity. Due to air flow, air flow path will encounter in their fins obstruction, the impedance will restrict the free flow of air. That "Tiny Cooling Fan" when the wind increases, pressure decreases. Therefore, there must be an optimum operating point operations, namely the intersection of fan performance curve and drag curve. In the operating point, the slope of the "Tiny Cooling Fan" characteristic curve for the minimum, change the system characteristic curve was minimum. The larger the amount of wind, cold air heat absorption is bigger, can take more heat transfer of air flow, cooling effect is more obvious.