dc brushless motor uses inverter or switching power supply to drive each stage of the stepper motor. Generally speaking, dc brushless motor has three windings, just like an AC synchronous motor. The winding of dc brushless motor adopts current pulse. The number of coil windings determines the pole of the motor. dc brushless motor usually has four poles. Compared with DC motor based on commutator, motor speed and torque control can be effectively carried out. Compared with the conventional commutator, the dc brushless motor has a longer life.
A digital controller is needed to maximize the efficiency of dc brushless motor. Maxon has developed a digital controller based on electronic control (EC) amplifier to operate dc brushless motor. DEC 24/2 (Digital EC Controller) is a small shape factor unit (20.38 mm x 24.2 mm), which can drive a dc brushless motor with 48W power consumption. Module 24/2 is a 1-quadrant controller, which can accelerate the speed and torque of dc brushless motor in the same direction. It can drive motor up to 80000 rpm. The three speed can choose to use two digital input pins. The binary combination of 1 and 0 can choose the three speed of the digital controller. The module 24/2 can also change the rotation direction of dc brushless motor using similar binary signal speed selection scheme.