| 摘要 |
PURPOSE:To materialize the reduction of power consumption in the drive of a stepping motor a low cost. CONSTITUTION:In the condition that one end of the drive coil of a stepping motors 16 is connected to, for example, the side of high potential, the other end is connected to the side of low potential by the time when minimum power for rotating a rotor is gotten, and a drive coil is supplied with a current, and then the other end of the drive coil is opened, and in this condition the detection of the induced electromotive force is performed at the other end. Only in the condition that the induced electromotive force can not be detected, the drive current is supplied with a current larger in effective value than usual. Hereby, efficient drive can be performed without consuming wasteful power. Moreover, since the judgment on whether the rotor has rotated or not is performed by detecting the voltage at the other end of the drive coil, the detection circuit can be simplified. |
