05159246 is referenced by 24 patents and cites 21 patents.

A sensorless type, brushless direct-current motor which is equipped with a rotor having a plurality of magnetic poles and multi-phase coils which are wound around a magnetic core to form magnetic paths and whose first terminals are connected in common to each other, the rotor being rotationally driven by selectively supplying bidirectional currents to the other terminals of said multi-phase coils. The motor is provided with an energization circuit which successively performs energizations of the multi-phase coils with predetermined patterns for all combinations of two of the multi-phase coils when the rotor is in a stopping state. A voltage-measuring circuit measures a voltage developed at the commonly connected first terminals of the multi-phase coils at every energization pattern in correspondence with a variation of an inductance generated in the coils due to the magnetic flux passing through the magnetic core. A position detecting unit detects a relative position of the rotor with respect to the multi-phase coils on the basis of the voltage measured by the voltage-measuring circuit so that the rotation of the motor is started on the basis of the detected relative position.

Detection of relative position between magnetic pole and drive coil in brushless DC motor
Application Number
Publication Number
Application Date
August 16, 1991
Publication Date
October 27, 1992
Yasuhiro Ueki
Pollock VandeSande & Priddy
Victor Company of Japan
H02K 29/00
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