Patent ID: 7348753

Claim:
A fan motor comprising: a single-phase stepping motor including a stator excited by applying an electric current to a coil to function as a single-phase magnetic pole, and a rotor which has a permanent magnet magnetized to a single phase and rotates as the magnetic pole of the stator changes; an impeller which is rotated by a rotating shaft of the rotor; a drive circuit for controlling an application of a current to the coil; and a coupling mechanism which couples the impeller to the rotating shaft relatively and rotatably, wherein the coupling mechanism couples the impeller slidably to the rotating shaft of the rotor, causes the rotating shaft to race with respect to the impeller at a time of starting the motor, and causes the impeller to rotate by following a rotation of the rotating shaft by friction during a steady operation, wherein the drive circuit applies pulse voltage to the coil and the coil constant is set so that a mean value of the current applied to the coil is 10 mA or smaller.