US Patent 9538686 Fan comprising a printed circuit board cooling circuit

A fan includes a sealed electronics housing, in which a printed circuit board having electronic components is arranged. The electronics housing is divided into an upper region and a lower region. A cooling wheel which is arranged in the lower region is axially adjacent to the printed circuit board. The printed circuit board has at least one central opening and a plurality of peripheral-edge openings or gaps in order to bring the upper region into fluid communication with the lower region. Air is drawn out of the upper region into the lower region by the cooling wheel via the at least one central opening and, via the plurality of peripheral-edge openings or gaps. The air is fed back into the upper region. An air circuit having at least one air flow develops along a surface of the printed circuit board on which the electronic components are arranged.