A motor drive controller for driving a brushless direct current motor includes a motor drive unit; a magnetic sensor for detecting a magnetic field generated by rotation of the motor and outputting the magnetic field as each of magnetic signals; and a bias adjuster for adjusting and outputting a bias voltage used in magnetic field detection by the magnetic sensor. The bias adjuster adjusts the bias voltage to a second voltage value lower than a first voltage value that allows the magnetic sensor to detect the magnetic field in a first period after a phase change of the magnetic signals. The bias adjuster also adjusts the bias voltage to a first voltage value in a second period from an end of the first period until a subsequent phase change of the magnetic signals.