Commutating brushless d.c. motor without position sensor using current signal involves commutating when current signal indicates loop current threshold value; commutation time is adjusted so loop current reaches maximum after commutation

摘要

The d.c. motor commutation method involves commutating when a current signal indicates a threshold value of the loop current. The commutation time point is adjusted so that the loop current reaches a maximum after commutation. The maximum of the loop current is determined by analyzing the gradient of the current curve. An independent claim is also included for a device for commutation of a brushless d.c. motor without a position sensor.