Patent ID: 7764030

Claim:
A control device for a three-phase brushless motor, comprising: the three-phase brushless motor in which a plurality of stator coils are arranged around a rotor; a switch circuit which changes-over energizations for the respective stator coils; a position detection signal generation device which comprises at least three position sensors and which successively generates position detection signals in correspondence with rotational positions of the rotor; and a control circuit which receives the position detection signals and which calculates a plurality of energization switching timings for the respective stator coils, so as to control said switch circuit, wherein: the position detection signals are successively generated from the at least three sensors, where the position detection signals have sections in between, where each of the sections is an angular interval between two adjacent position detection signals; said control circuit comprises a time interval calculation module which calculates, in a one time interval calculation mode, a plurality of time intervals based on at least two of the position detection signals separated by an addition section obtained by adding at least two contiguous sections; and said control circuit determines the plurality of energization switching timings based on the calculated plurality of time intervals.