Brushless DC motor system with optically scannable member for commutation

摘要

A brushless DC motor system includes a multi-pole DC motor having coils and permanent magnets. Optically scannable markers are applied on the circumference of a rotating member of the motor in fixed association with the magnets. By means of a scanner, these markers are converted to signals. These signals are evaluated with respect to their phase position and moment of commutation, and as a result commutation current is supplied to the coils.