Motor control apparatus and motor control method for reducing influence of magnetic fluxes from yokes

摘要

A motor control apparatus for reducing the influence of magnetic fluxes from yokes on the switching of an energization direction. A rotor is rotatable and has a magnet. The magnet is circumferentially divided into a plurality of portions alternately multipolar magnetized to different poles. The coils are energized to excite the magnetic pole portions. Magnetic sensors output signals when detecting magnetic fluxes. Comparators output comparison result signals indicative of results of comparison between the output signals from the magnetic sensors and reference signals. A control circuit controls energization directions of the coils based on the comparison result signals. The control circuit changes the values of the reference signals according to a relationship between the polarities of the magnetic pole portions.