Method and device for operating a brushless motor

摘要

In the case of a brushless motor, the frequency of an output signal from a synchronisation signal producing device, a duty ratio in a synchronised operating mode and a duty ratio in a rotor position detection operating mode are set such that the rotation speed in the rotor position detection operating mode is equal to or less than the rotation speed in the synchronised operating mode, as a result of which a smooth transition is made possible from the synchronised operating mode to the rotor position detection operating mode.