What Is a Brushless DC Motor Driver?
A brushless DC motor driver is a semiconductor device that drives and controls a motor based on instructions from a microcontroller or another control unit.
Creating a drive circuit with semiconductor discrete components is possible. However, controlling brushless DC motors is complex, requiring many components and sophisticated software control.
Thus, motor drivers are often utilized to decrease software development efforts and component counts.
Applications of Brushless DC Motor Drivers
Brushless DC motor drivers are crucial for devices using brushless DC motors, enabling precise speed control. They find applications in hard disk drives, NC-controlled machines, automobiles, and hybrid vehicles.
Specifically, in automobiles, they are used for door lock motors, electric power steering motors, and headlight axis adjustment motors, among other applications.
Principle of Brushless DC Motor Drivers
In a motor, the electromagnet is stationary. By altering the current flow direction through the coil, it’s possible to change the electromagnets’ polarity, enabling attraction and repulsion.
Electronic control is necessary to drive a brushless DC motor. To rotate the motor, a rotating magnetic field is created by changing the current direction in the motor windings.
While induction motors, which operate on AC power, use AC voltage to generate a rotating magnetic field, brushless DC motors, operating on DC power, cannot employ the same method.
Unlike brushed DC motors, where commutators and brushes change the current direction, brushless DC motors use semiconductor switches, such as transistors, for this purpose.
Features of Brushless DC Motor Drivers
The benefits of using brushless DC motor drivers include comprehensive on-chip protection functions and reduced effort in developing microcontroller control software. Additional advantages are fewer components, minimized board mounting area, and simplified motor drive realization.
Moreover, while brushed DC motors rely on brushes for current direction control, necessitating periodic replacement due to wear, brushless DC motor drivers achieve brushless current control, offering a longer lifespan and lower maintenance.
Other Information on Brushless DC Motor Drivers
1. Coil Configuration of Brushless DC Motors
Brushless DC motors feature three coils, with one coil interconnected to the others, allowing current to flow through two coils by connecting one to the positive side and the other to the negative side.
Each coil connects to two semiconductor switches, with motor rotation achieved by sequentially controlling these switches. A brushless DC motor driver is essential for generating a rotating magnetic field and rotating the motor by sequentially controlling the semiconductor switches.
2. Relationship with Microcontrollers
A microcontroller is essential for controlling the timing and speed of motor rotation. However, most microcontrollers cannot directly control motors through their input/output ports.
In such cases, a motor driver facilitates motor control by mediating control signals between the microcontroller and the motor. Upon receiving a signal from the motor driver, the motor alters the polarity of each electromagnet to move the motor.