| 摘要 |
PURPOSE:To simplify the total system as compared with a conventional system where power supply voltage is varied by including a PWM control means in a driving circuit thereby providing a variable speed function in a brushless motor incorporating the driving circuit. CONSTITUTION:Driving circuit 6 for a brushless motor comprises a switching power element group 2, means 8 for producing a commutation signal for the switching power element group 2 from the output of a position sensor 5, a switching power element driving means 7, a speed error signal generating means 9 for comparing an externally provided rotational speed command signal with the output from the position sensor 5, and a PWM control means 10 for controlling the ON duty of the switching power element group 2. |
