| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a controller capable of accurately detecting a stop position of a rotor even if a power source voltage supplied to a brushless motor fluctuates. <P>SOLUTION: When a brushless motor 1 is started, a controller 2 energizes the brushless motor 1 by PWM control at a duty ratio corresponding to the voltage value supplied from a battery source 15, in the stop position detecting section of a rotor. The position of rotor is detected by the induction current generated after energization is stopped. Based on the detected rotor position and the voltage value of the battery source 15, PWM control exerts energization for applying a constant power to the rotor. Then, the controller 2 stops energization, and detects an excitation switching timing signal that occurs according to the rotational position of the rotor which is free running. The detected excitation switching timing signal is used for a normal excitation pattern selecting means to make transition to sensorless driving. <P>COPYRIGHT: (C)2010,JPO&INPIT |
