| 摘要 |
<P>PROBLEM TO BE SOLVED: To extend a drive range by obtaining stable driving performance, even when a brushless DC motor is driven at a high speed/high load. <P>SOLUTION: Lead angle correction means 10 sets a terminal voltage lead angel value so as to maintain the current value constant detected by current detecting means A9. A second waveform generator 11 outputs a motor drive signal while keeping a duty constant with the set lead angle and a command frequency set based on the system status. Consequently, stable driving is enabled without position detection. In addition, stable driving is also enabled even when a brushless DC motor 4 is driven at a high speed or high load which is difficult to detect the position of the brushless DC motor 4, and a current detecting means B23 also protects against an overload current. <P>COPYRIGHT: (C)2012,JPO&INPIT |
