Abstract: Digital servo control technology has become more and more important in motor control because of its high precision, reliability and flexibility. This paper offers a three dimension solid model of the brushless DC motor with CAD and CAA which can calculate the physical parameters of the motor quickly and accurately. The model of digital servo control system for brushless DC motors is provided; the related speed and phase control loop are designed; and the system is programmed and realized in the single-chip microprocessor μPD78148.

Key words: digital control, servo control system, single-chip processor, brushless DC motor