| 摘要 |
PROBLEM TO BE SOLVED: To provide a magnetic pole position detecting circuit which can cope with a wide range of rotations, stable low-speed rotations, and the maximum efficiency control under an arbitrary load, in a brushless motor is driven in a sensorless state. SOLUTION: A drive controller for brushless motor is provided with a means 2, which compares the level of the terminal voltage of a motor 1 with a threshold level 5a, means 3 and 9 which insulate and transmit the compared result 2a of the means 2 to a control means 6 side, and the control means 6 which reads the transmitted results only during a conduction turned-on period through pulse width modulation. Since the threshold level 5a is obtained by insulating and smoothing the outputted result of a pulse width modulating means PWM which outputs an arbitrary value on the control means 6 side, a magnetic pole position detecting circuit which can perform magnetic pole position detection having no frequency characteristic can be realized without requiring a band pass filter. |
