Patent ID: 6946808

Claim:
A motor drive control circuit that controls, with drive signals, a drive portion that feeds drive currents to stator coils of a motor, comprising: a drive signal output circuit; and a detection circuit, wherein the drive signal output circuit outputs rotor position detection drive signals to the drive portion before starting of the motor, wherein the detection circuit receives a common-terminal voltage of the stator coils when the drive signal output circuit is outputting the rotor position detection drive signals, and detects, according to the common-terminal voltage of the stator coils, a position of a rotor before starting of the motor, and wherein the rotor position detection drive signals are signals that control the drive portion so that, before starting of the motor, the drive portion feeds the stator coils with rotor position detection drive currents that cause the common-terminal voltage of the stator coils to vary with the position of the rotor but that do not cause the motor to rotate.