| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a larger output torque while a rotational frequency of a motor is obtained with a back electromotive force. <P>SOLUTION: A motor control apparatus is provided with a means 18 of setting a rotational speed, a conduction output circuit 29 supplying power to a sewing machine motor 11 by on/off-control, a first speed detecting part 16 calculating a current speed from a back electromotive force by self-induction of the sewing machine motor, a second speed detecting part 17 calculating the current speed from the back electromotive force by electromagnetic induction, a selection processing part deciding whether the current speed is calculated by the first speed detecting part or the second speed detecting part, and a control means 40 calculating the on/off time of the conduction output circuit based on a deviation between the rotational speed designated by the speed setting means, and the detected detection speed and controlling the output of the sewing machine motor. <P>COPYRIGHT: (C)2009,JPO&INPIT |
