| 摘要 |
PURPOSE: To provide a method which can drive a brushless DC motor by detecting the information about the induced voltage without using a filter, and estimating the position of a rotor from the variation to time of voltage. CONSTITUTION: A brushless DC motor is so controlled as to output a PWM signal to control an inverter circuit at least two or more times at least within 60 deg. in electric angle of itself, and time terminal voltage of the current free voltage of the brushless DC motor is detected synchronously with the ON period of the PWM signal, and based on the change rate to time of the detected terminal voltage, commutation timing is decided. |
