DC motors with permanent magnets are widely used in motion control applications. The efficiency of DC motors makes them the most popular choice for controlling torque, position or speed since they are easier to implement than AC motors. Brushless DC motors and brushed motors are the most frequently used types of DC motors. Before going in details about the efficiency of the DC motors and BLDC motors let’s learn what exactly it is. So keep reading.
Brushed DC motor
Brushed DC motors consist of an internal commutated motor that makes use of an electric brush for contact and is powered by direct current. The coil is rotated inside the magnets of a brushed DC motor. As the coil spins, the brush and commutator make contact with each other at different times, reversing the direction of the current. Thus, the DC brushed motor can be operated. The brushes on these motors need to be maintained periodically even though they are quite efficient.
Brushless DC motor
When compared to brushed motors, brushless DC motors makes less Acoustic Noise. DC motors with brushless technology (BLDC) are more efficient than those with brushes. Although brushless DC (BLDC) motors operate similarly to brush DC motors, their construction differs greatly. As opposed to brush DC motors, BLDC motors are powered by permanent magnets mounted on their rotors; the stator contains coil windings inside a laminated and slotted steel shell. Additionally, BLDCs do not have a mechanical commutator or carbon brushes.
A brushless motor has the advantage of being more efficient in comparison to a brushed DC motor because there is no brush involved that is constantly comes in contact with the in-built commutator. Since brushless motors do not make contact, heat and friction are not generated. It is more efficient to use a brushless motor since less energy is lost as heat. A BLDC motor can usually achieve 85-90% efficiency, while a brushed motor only achieves 75-80% efficiency. As a result, this enhanced efficiency lengthens the runtime of the batteries in devices such as power tools etc.
BLDC motors also have higher energy efficiency when compared to DC motors with brushed brushes. Due to the absence of friction of brushes, BLDC motors are capable of converting more mechanical power to electrical power when compared with brushed motors. Motor performance curves show the greatest gains in efficiency when no load or low load are applied. Motors with BLDC technology usually produce very less mechanical work than those with brushed DC motors. Due to its smaller body, BLDC motors dissipate less heat. In that regard, BLDC motors are more environmentally friendly, because they use less raw material in their construction.
Thus BLDC motor has greater efficiency than DC motor. The advantages of brushless DC motors (BLDC) over brushed DC motors have fueled their popularity for decades. Brushless motors are becoming more popular in many applications due to their lower costs and better performance. Unlike brushless DC motors which have a permanent magnet in the center, brushed DC motors have coils in their centers rotating around the permanent magnet. The brushless motor design has advantages over conventional motors in tasks that may make the most of its superior durability and efficiency. Brush DC motors have a user-friendly design that makes them ideal for applications with short cycle times. Brushless motors are becoming more and more accessible as their costs continue to decrease, allowing them to fill applications previously held only by brushed motors. The automotive industry has also adopted brushless motors for seat adjustment motors, as they are less noisy than other conventional motors.