"220V AC Cooling Fan" nominal value of maximum wind blowing amount is not obtained actual fins, 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 limit the free flow of air. That is when the wind increases, air pressure decreases. Therefore, there must be an optimum operating point operations, namely the intersection of fan performance curve and drag the curve. At the operating point, the slope of the "220V AC Cooling Fan" characteristic curve to a minimum, change the system characteristic curve was the lowest. Whether any of it had to do with material laws and principles, and the principles of "220V AC Cooling Fan" operation is based on right-hand rule Ampere conductors through the current, generates a magnetic field around, if this conductor is placed on the other fixed magnetic field, will generate attraction or repulsion, causing objects to move.