Abstract: The invention teaches a brushless DC motor, comprising a brushless DC motor unit and a controller unit, wherein the brushless DC motor unit comprises a stator assembly, a permanent magnet rotor assembly magnetically coupled with the stator assembly, an enclosure supporting the installation of stator assembly and the permanent magnet rotator assembly, an end shield installed at the end of the enclosure, the rotating shaft of the permanent magnet rotor assembly projecting out of the end shield; the controller unit comprises an integrated power module, a microprocessor unit, a rotor position sensing circuit, a power source circuit, an I/O interface circuit, a current-sensing circuit, and a controller box; and the controller unit is electrically connected to the brushless DC motor unit.

Abstract: Taught herein is a controller for a direct current brushless motor connected to a high voltage control system, comprising a microprocessor and an input/output interface circuit connected between the high voltage control system and the microprocessor; wherein the input/output interface circuit is a step-down circuit for transforming a high voltage control signal into a low-voltage control signal. The controller enables the high voltage control system to cooperate with motor, therefore a user is not necessary to design a new high voltage control system when replacing the conventional AC motor with the DC brushless motor, which saves time, and reduces cost.

Abstract: The invention teaches a speed control system for a brushless DC motor for a ceiling fan, comprising a power circuit 1, a microprocessor circuit 2, a power drive circuit 3, a speed regulation circuit, and a brushless DC permanent magnetic motor 5, wherein the input terminal of the power circuit 1 is connected to the output terminal 101 of an AC power source, the output terminal of the power circuit 1 serves to power the various circuits, the output terminal of the microprocessor circuit 2 is connected to the input terminal of the power drive circuit 3, the output terminal of the power drive circuit 3 is connected to the coil windings 501 of the brushless DC permanent magnetic motor, and the output terminal of the speed regulation circuit is connected to the input terminal of the microprocessor circuit 2. The speed control system of the invention provides the advantages of low energy consumption, low noise during the operation of the motor, and a stable operation at low speeds.