Patent attributes
An object of the present invention to accurately and reliably detect rotational positions of a rotor irrespective of noise overlapping inductor voltage. Employed for accomplishing the aforementioned object in the present invention is a motor-driving device for rotating and driving a rotor by supplying predetermined drive signals to stator coils each corresponding to each phase of a DC brushless motor, the device comprising: a drive-signal-generating unit for generating the drive signals by switching direct current power based on a pulse-control signal; and a control-signal-generator unit for generating the pulse-control signal that controls the drive-signal-generating unit by intermittently generating the pulse-control signal; and for detecting the rotational position and the rotational velocity of the rotor based on inductor voltage obtained from the stator coils in a period in which generation of the pulse-control signal is suspended in each phase.
