| 摘要 |
PURPOSE: To detect the rotor position of a brushless motor reliably. CONSTITUTION: The controller for a brushless motor comprises an inverter section 4 for driving a brushless motor 3, and a circuit 5 for detecting the position detection timing of the rotor 3a of the brushless motor 3 for each phase thereof, and a microcomputer 10a for receiving the detection and signal and calculating the drive timing of switching elements at the inverter section 4 based on the position detection timing. A drive signal is delivered to a drive circuit 6b at the timing thus calculated and a signal for chopping the driving interval of the switching element to control the r.p.m. of the rotor is delivered to the drive circuit 6b. The chopping frequency is varied such that the duration of drive pulse does not become shorter than that required for turning the switching element ON. |
