| 摘要 |
PURPOSE:To start a motor with less dissipated current surely and to make it possible to raise its rotational speed up to a target speed, even when a low- voltage power source is used. CONSTITUTION:When starting action is started, a 3-phase mode control part 11 sets a mode changing signal 16 to a bipolar drive mode in the first place, outputs it to a drive circuit 12 along with 3-phase control signals 15, and performs bipolar drive of a motor 13. When the motor 13 begins to rotate, the 3-phase mode control part 11 confirms its condition with a speed signal 19 detected by a speed detecting part 14, and outputs 3-phase control signals 15 for acceleration to the drive circuit 12. When the 3-phase mode control part 11 detects by using the speed signal 19 afterwards that the motor 13 has reached a specified changing rotational speed, changes the mode changing signal 16 over to a unipolar drive mode and accelerates it further, and waits until the motor 13 reaches steady rotational speed and the starting control is finished. |
