| 摘要 |
PURPOSE:To reduce an influence due to step-out by changing the values of an energizing time length and an energizing period to exciting coils, to be greater than values at the time of a normal state, when the exciting coils and wirings are out of order. CONSTITUTION:When the faults of the exciting coils and wirings of a stepping motor 15a are detected by a fault detecting means 16, then by drive signal from a drive signal generating circuit 17, the stepping motor 15a is driven in a period longer than that at the time of a normal state without the faults. Accordingly, even if the attenuation oscillation of the rotor of the stepping motor 15a is started, drive signal is fed to the stepping motor 15a after oscillation is sufficiently attenuated, and so an influence due to step-out can be reduced. |
