Patent ID: 6342770
Filing Date: 2002-01-29
Classification: H02P

Abstract:
A method of starting an electronically commutated DC motor including a stator having at least one winding and a rotor, said method comprising the steps of:(a) exciting the winding with at least one initial start pulse having a voltage and a repetition frequency which are sufficient to ensure rotation of the rotor under a maximum load in normal operation; (b) detecting back EMF generated in the winding by the rotation of the rotor; and (c1) if the back EMF is detected, controlling the rotation of the rotor based on the detected back EMF; (c2) if the back EMF is not detected, increasing the voltage of said at least one initial start pulse until any of (i) the back EMF is detected, (ii) a current generated in the winding by said at least one initial start pulse reaches a maximum acceptable current level, and (iii) the voltage of said at least one initial start pulse reaches a maximum acceptable voltage level, wherein, in the latest instance, supply of said at least one initial start pulse to the winding is discontinued.