| 摘要 |
<P>PROBLEM TO BE SOLVED: To prevent erroneous position signal detection due to ringing of a terminal voltage generated when energization to a stator winding is changed from OFF to ON with a simpler configuration than a conventional one. <P>SOLUTION: During an off-period of a PWM signal and during a period until the ringing following the turn-on of the PWM is extinguished, on-driving of a transistor 18 is performed, and a reference voltage Vr is generated which has a high voltage level exceeding an allowable voltage range of terminal voltages Vu, Vv, Vw. In other than these periods, off-driving of the transistor 18 is performed, and the reference voltage Vr is used as a virtual neutral point voltage. When the logic of comparison signals Cu, Cv, Cw does not coincide with the next scheduled normal logic accompanying rotation of a motor 2, a control part 20 does not adopt the logic change. <P>COPYRIGHT: (C)2010,JPO&INPIT |
