Patent attributes
A control apparatus for a three-phase brushless motor, in which a control circuit includes time interval calculation means (133 in FIG. 4). The time interval calculation means (133) is endowed with at least one time interval calculation mode. In the time interval calculation mode, pluralities of time intervals which correspond to an addition section obtained by adding up two or more Q continuous sections are calculated on the basis of two position detection signals which lie at both the ends of the addition section, among position detection signals successively generated. The control circuit determines pluralities of energization switching timings on the basis of the pluralities of time intervals. The control apparatus for the three-phase brushless motor can decrease the deviations of the energization switching timings attributed to the errors of the mounting positions of position sensors or to the errors of the magnetized positions of a rotor, without requiring any complicated adjustment.