"220V AC Cooling Fan" is not a surprising thing, is not uncommon in everyday life, has a variety of uses diversion, ventilation, cooling and so on. This chapter 尌 fan type air-cooled heat sink used for brush less DC fan -DC Brush less Fan slightly introduction. Typically used in air-cooled heat sink "220V AC Cooling Fan" shape is a flat bottom surface of a square column, leaving the four corners of the mounting holes required for installation, the DC motor through the bracket on the frame, connected to the rotor blades together, through bearings mounted on the motor body. Some "atypical" of "220V AC Cooling Fan" with a more specific shape and design, but the overall structure and this is not much difference. Seemingly simple structure in which there are a lot of knowledge; knowledge of the various fan-related knowledge is an important step in understanding of air-cooled heat sink.