How to adjust the speed of a brushless DC motor? How to control the speed? Many customers who are just starting to use brushless DC motors will consult about this issue.
With the widespread application of
DC brushless motors in fields such as healthcare, automation equipment, robots, and automobiles, there are many questions about controlling the speed, forward and reverse rotation of DC brushless motors to meet different transmission control requirements. Today, we will share three methods for controlling the speed of DC brushless motors.
Method 1: Use voltage to control speed, torque is mainly controlled by current, usually with a matching motor driver. Changing the output voltage of the driver can also control the speed of the brushless motor. If you don't have a driver and want to control the motor yourself, you need to check the power and working current of the motor.
Method 2: PWM speed control. The PWM speed control principle of DC motors is different from the speed control principle of AC motors. It does not adjust the motor speed through frequency modulation, but adjusts the pulse width of the driving voltage and cooperates with some corresponding energy storage components in the circuit to change the amplitude of the voltage delivered to the armature, thereby achieving the goal of changing the speed of DC brushless motors. Its modulation method is amplitude modulation.
There are two ways to control PWM:
1. Using PWM signals to control the conduction time of the transistor, the longer the conduction time, the longer the work time, and the higher the motor speed.
2. Using PWM control signal to control the conduction time of the transistor and changing the control voltage to achieve it.
Method 3: If it is a low-power DC brushless motor, resistance speed control can also be used (not recommended, the method is very simple, just connect a potentiometer in series, only this method will reduce efficiency, so it is not recommended). High power DC brushless motors cannot use resistance speed control because it requires a small resistance and high-power resistor (the motor working resistance is very small), which is difficult to find and the efficiency of this solution is too low. It is best to find a matching motor driver.
The above are three commonly used methods for controlling speed of brushless DC motors. If you still don't know how to operate them, you can ask us.
