| 摘要 |
PROBLEM TO BE SOLVED: To suppress the occurrence of wasteful power consumption by properly executing pulse-down operation. SOLUTION: A detection period T of a stepping motor is divided into a first segment T1 for detecting an induced signal VRs occurring at least in a second quadrant II, a second segment T2 provided later than the first segment T1 so as to detect the induced signal VRs in a third quadrant III, and a third segment T3 provided later than the second segment T2, by rotation of a rotor immediately after the drive by a main driving pulse P1. When the rotational drive is executed by a main driving pulse P1MAX of the maximum energy and if a rotation detecting circuit does not detect the induced signal VRs exceeding a reference threshold voltage Vcomp in the second segment T2, a control circuit rotationally drives the stepping motor by fixing the main driving pulse to a prescribed main driving pulse P1A with the maximum energy or more. COPYRIGHT: (C)2010,JPO&INPIT |
