| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a motor drive capable of continuously controlling the rotational speed of a motor, while suppressing heat generation in a switching element. <P>SOLUTION: A signal processing section 26 of the motor drive 21 divides the switching current supply period of each phase into a first current supply period for setting duty to an upper-limit value D0 and a second current supply period for setting the duty to 100%, when a PWM duty command D1, decided by a duty calculation circuit 5, exceeds the upper-limit value D0, and sets the length of the second current supply period according to the duty command D1. <P>COPYRIGHT: (C)2008,JPO&INPIT |
