| 摘要 |
PURPOSE:To eliminate the variation of the drive voltage of an induction motor even when the power supply voltage fluctuates or a DC bus voltage fluctuates due to the power mode and regenerative mode of the motor, to suppress the torque fluctuation of the motor, to prevent the over exciting of the motor, to surely prevent the motor from generating heat, and to share an input power supply voltage. CONSTITUTION:In a motor drive device for a sewing machine in which a drive voltage is applied across an induction motor 2 for driving the sewing machine from an inverter 11, the inverter 11 is constituted so that it can variably control the frequency and value of the drive voltage, and a voltage detector 13 which detects a DC bus voltage to the inverter 11 as the information required for appropriately holding the drive voltage is provide. |
