| 摘要 |
PROBLEM TO BE SOLVED: To avoid any damage to a stepping motor when the motor is overloaded by comparing the expected current value of the motor with the conducting current value detected by means of current detecting means by means of a motor drive instructing means when the voltage instructed by a voltage instructing signal is impressed upon the stepping motor or generating step-out information when the compared results do not fall with a set range. SOLUTION: The value of an expected current which flows to a stepping motor 171 when the voltage instructed by voltage instructing signals PA1 and PB1 from a motor drive instructing means is impressed upon a stepping motor 171 in response to the signals PA1 and PB1 is compared with the value of the conducting current of the motor 171 which is made to flow to the motor 171 when a motor driver 199a impresses a voltage upon the motor 171 in response to the signals PA1 and PB1 and detected by means of current detecting means 101AI, 101A2, 101BI, and 101B2. When the compared results do not fall within a set range, step-out information is generated. Therefore, any damage to the stepping motor can be avoided when the motor is overloaded. |
