| 摘要 |
A method and apparatus for controlling the speed of a multi-phase, brushless DC electrically commutated motor (ECM). Voltage is commutated to the windings of the ECM based on rotor position information derived from back EMF or Hall effect sensors. The application of the commutating voltages is arranged such that the voltage applied to the windings always leads the back EMF generated in the windings by a selected constant lead angle. The speed of the motor is then controlled by pulse width modulating (PWM) the voltage applied to the windings of the ECM. |
