| 摘要 |
PROBLEM TO BE SOLVED: To drive a stepping motor driven by a low-voltage power supply at sufficiently high speed. SOLUTION: When the stepping motor 6 is driven at high speed, a control circuit 5 generates a voltage command of a command value corresponding to a frequency of a command pulse input signal 7, and a step-up converter 2 boosts power supply voltages 1 on the basis of the command value. The stepping motor 6 is driven at high speed by applying the voltages boosted by the step-up converter 2 to a step-down converter 3 and a PWM inverter 4. When the stepping motor 6 is stopped or driven at low speed, the switching of a switching element of the step-up converter 2 is stopped on the basis of a command of the control circuit 5, the power supply voltages are applied to the step-down converter 3 and the PWM inverter 4 without being boosted, and the switching loss of the switching element is reduced. COPYRIGHT: (C)2007,JPO&INPIT |
