| 摘要 |
PURPOSE: To enhance the operational efficiency by detecting the rotor position accurately at all times regardless of the load in the control.method for brushiess motor. CONSTITUTION: A voltage induced in the armature winding of a brushless motor 3 is compared with a reference voltage at a position detecting section 4 and a rotor position detection signal is delivered to a control circuit 10. A switching element at an inverter section 4 is then turned ON/OFF to switch the armature winding current thus subjecting the switching element at an inverter section 3 to chopping control and performing rotation control and speed control. The control circuit 10 detects the ending timing of spike voltage occurring at the time of switching the armature winding current and calculates the Lime up to time cross point of the induced voltage and the reference voltage. Finally, the current switching timing of armature winding is determined at least based on the time thus calculated and the armature winding current of the brushless motor 3 is switched. |
