DC brushless motor and general DC motor has the same working principle and application characteristics, and its composition is not the same. In addition to the motor itself, the former also more than a commutation circuit, the motor itself and the commutation circuit closely together. Many low-power motor motor itself is integrated with the commutation circuit, from the appearance of DC brushless motor and DC motor exactly the same.
DC brushless motor itself is the electromechanical energy conversion part of the DC brushless motor in addition to motor armature, permanent magnet excitation two parts, but also with a sensor. The motor itself is the core of the brushless DC motor, brushless DC motor is not only related to performance indicators, noise vibration, reliability and service life, etc., brushless DC motor also involves manufacturing costs and product costs. As a result of the use of permanent magnetic field, so that the brushless DC motor out of the general design and structure of the DC motor to meet the requirements of a variety of applications, DC brushless motor and the province of copper materials, manufacturing easy direction. The development of permanent magnet magnetic field is closely related to the application of permanent magnet material. The application of the third generation permanent magnet material makes the brushless DC motor move towards high efficiency, miniaturization and energy saving.
DC brushless motor in order to achieve the electronic commutation must have a position signal to control the circuit. Early use of electromechanical position sensor to obtain the position signal, has been gradually using electronic position sensor or brushless DC motor method to get the position signal, the easiest way is to use the armature winding potential signal as the position signal. DC brushless motor to achieve the motor speed control must have a speed signal. The speed signal is obtained by obtaining the position signal similar method. The simplest speed sensor is the combination of the frequency measuring generator and the electronic circuit. DC brushless motor commutation circuit by the drive and control of two parts, these two parts are not easy to separate, especially low-power circuit is often integrated into a single dedicated ASIC.
DC brushless motor in the power of the larger motor, the drive circuit and control circuit can be integrated into one. The driving circuit outputs the electric power, drives the armature winding of the motor and is controlled by the control circuit. At present, the DC brushless motor drive circuit from the linear amplification state into the pulse width modulation of the switch state, the corresponding circuit components from the transistor discrete circuit into a modular integrated circuit. Modular integrated circuit with power bipolar transistor, power field effect transistor and isolation gate field effect bipolar transistor and other components. Although the isolation gate field effect bipolar transistor is more expensive, but from a reliable safety and performance point of view, the choice of DC brushless motor is more appropriate.