| 摘要 |
An electronically commutated, direct-current motor of a fan has, in a two-piece housing, a stator formed on one piece of the housing and a blade-equipped rotor attached to a shaft mounted in the housing. The rotor supports an odd number of diametrically opposed pairs of magnets which consist of permanent magnets with opposite poles. On the stator are mounted two coils positioned diametrically, a Hall element, and a diametrically positioned flux-conduction plate that faces the pole surfaces of the magnets of the rotor and is angularly offset from the coils. The Hall element senses the poles of the magnets passing by and generates an output voltage. In response to the Hall element output voltage, an electronic control circuit in the stator sends an excitation current to the coils for alternately attracting or repelling the magnets. The rotor's rotational direction is determined by the resting position of the magnets, as imposed by the flux-conduction plate associated with the coils. This fan has only a few components, is very flat, and runs very smoothly.
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