| 摘要 |
<P>PROBLEM TO BE SOLVED: To detect the rotation speed of a motor at a low cost and control the rotation speed independent from an ambient temperature and a sewing machine torque. <P>SOLUTION: This motor control circuit calculates a correction target actual speed W added with a speed correction value Δδ found by subtracting a sewing machine speed M converted from a target speed (n) as a motor side speed, adds it to the target speed (n) executing the rotation command of a motor 3 to calculate the motor speed deviation value ΔV, and sets a pulse width of a driving circuit 4 by the motor speed deviation value ΔV, so as to execute a control independent from the ambient temperature and the sewing machine torque. A mechanical pulse generator such as a position sensor 8 constantly monitors the rotating speed and corrects the output of a back electromotive force detecting circuit 2 so as to dispense with a plurality of expensive and mechanical pulse generators, and the output of the low-cost back electromotive force detecting circuit 2 is corrected and used, so that the rotating speed of the motor 3 is detected at a low cost and the rotation speed is controlled independent from the ambient temperature and the sewing machine torque. <P>COPYRIGHT: (C)2007,JPO&INPIT |
