| 摘要 |
PURPOSE:To generate sufficient torque at the time of high speed and to prevent overcurrent at the time of low speed by setting low the voltage to be applied to a stepping motor at low voltage and setting it high at high voltage. CONSTITUTION:When a step pulse signal is given, it is converted into an exciting signal of windings for a stepping motor 5 with a decoder driver 4, by which the stepping motor 5 rotates. On the other hand, the pulse rate of the step pulse signal is decided by using a step rate detection circuit 1, where when the rotating speed command is of a value not larger than the specified value, a switching circuit 2 is turned OFF and when the rotating speed command is of a value not smaller than the specified value, the switching circuit 2 is turned ON. The voltage supplied to the stepping motor 5 thereby is low when the rotating speed command is of a value not larger than the specified value, while it is high when it is not smaller than the specified value. |
