| 摘要 |
PURPOSE:To reduce magnetic noise of a load motor by reducing the ON/OFF frequency of a power switch at the positioning stopping time. CONSTITUTION:When a positioning stop is performed, a voltage correcting circuit 27 confirms that a motor is decelerated and stopped by a speed detection signal Nf when inputting a positioning signal. It corrects to subtract the output signal of the circuit 17 at this time from the voltage command from a converter voltage instructing circuit 15 such as a normal converter voltage command to reduce the converter voltage command lower than the value of the normal operating state, and reduced the converter voltage. As a result, the ON/OFF frequency of the power switch becomes low, the magnetic noise frequency of a motor decreases, thereby reducing unpleasant feeling. |
