The invention provides a valve controller of a motor utilizing type for
improving control accuracy and reducing cost. The valve controller
controls valve opening and closing of an engine by utilizing rotation
torque of the motor, and has a driving circuit receiving a control signal
generated by a control circuit, and applying an electric current to the
motor and driving the motor on the basis of a target rotation number of
the motor shown by this control signal using a frequency, and a target
rotating direction of the motor shown by this control signal using a duty
ratio.