Brushless dc motor control device

The present invention variations in rotor rotational speed of the brushless DC motor becomes small, to provide a control device for a brushless DC motor which can be as close to the maximum value or the average value. The first control state when A rotor is in the position where the first pole thereof is detected by the sensing coil, the rotor is a second case in a position where the second pole thereof is detected by the sensing coil It is arranged to be switched to the control state. In the first control state, the control unit actuates the switching transistor current flows persistently to the drive coil in the energized state, the second control state, the control unit is in the energized state and the deenergized state of the switching transistor It is replaced, intermittently flowing a current to the drive coil. .FIELD 1