| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a stepping motor drive unit which can be started quickly with a relatively small driving force.SOLUTION: A stepping motor drive unit for driving a stepping motor where a plurality of stators 24 are arranged to face a magnetized rotor 22 includes a start preparation circuit for rotating a rotor to a predetermined start preparation position R1 by feeding a current to the exciting coil 28 of each stator, and a drive current control circuit for starting the rotor by generating a revolving magnetic field while controlling a current to be fed to each exciting coil after the rotor is moved to the start preparation position. The start preparation position is set so that a cogging torque, generated when the rotor is attracted to the stator by magnetic force in the non-conduction state of each excitation coil, acts in the starting direction of the rotor.</p> |
