When the motor of the brushless motor driver rotates, the control unit must first determine the order of opening (or closing) the power transistors in the converter according to the position of the motor rotor sensed by the hall-sensor, and then according to the stator winding, AH, BH, CH (these are called upper arm power transistors) and AL, BL, CL (these are called lower arm power transistors) in the converter, Make the current flow through the motor coil in order to generate a clockwise (or reverse) rotating magnetic field and interact with the magnet of the rotor, so that the motor can rotate clockwise/counterclockwise.