| 摘要 |
<P>PROBLEM TO BE SOLVED: To solve the problem in detecting the position of a rotor by an induction voltage detecting means by using a relatively inexpensive microcomputer whose speed is low, (1) that a minimum number of revolutions is high and (2) that the motor steps out easily because of a high number of starting revolutions. <P>SOLUTION: At the time of starting or driving at a low speed in which the on-time of a PWM signal is short and stable position detection cannot be achieved by an induction voltage detecting system, an operation is switched to a zero cross system to perform the operation. <P>COPYRIGHT: (C)2003,JPO |
