With the rapid development of microprocessor technology in recent years, as well as high switching frequency, low power electronics applications. Brushless dc motor controller to keep the good performance of speed adjustment, and with no sliding contact and commutation spark, high reliability, long service life and low noise advantages. Therefore widely used in aerospace, nc machine tools, robots, electric cars and other industries. According to the different methods of its power, it can be divided into chord square-wave brushless dc motor (BLDCM) wave brushless dc motor. Its Chinese wave voltage waveform of brushless dc motor and power supply current waveform is using the rectangular wave, and string wave voltage waveform of brushless dc motor and power supply current waveform is sine wave. Above is about the knowledge of the brushless dc motor controller, hope for your help.