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Brushed D.C. Motors vs Brushless D.C. Motors

BRUSHED D.C. MOTORS vs BRUSHLESS D.C. MOTORS

What is a brush?
A brush is a silver, copper, or graphite compound that transfers electric current from the power source to the commutator(electromagnet polarity changing element of an electric DC motor).
How do brushed DC motors work?
Brushed DC motors function as a result of the interaction between a rotating electromagnet and a mechanical rotary switch that maintains the current’s direction. The electromagnet, part of a system called an armature(the thing that spins the motor), is created by electric current passing through a rotating set of 2 or more wire coils. The mechanical rotary switch, called a commutator, changes the polarity of the armature every cycle so that the armature can push or pull on the permanent magnets that are on the outside part of the motor to continue spinning.
How do brushless DC motors work?
Brushless DC motors work as a result of the interaction between an external rotor that is a permanent magnet and three pairs of driving coils (electromagnets). The brushless motor also has a set of drive electronics that control which pair of driving coils is activated at a given time. A brushless motor works by activating the three sets of driving coils in series so that they push the external permanent magnet around the center shaft. The stages of driving coil activation can be adjusted to various speeds by the electronic speed controller.
Brushed vs Brushless
Brushed - A brushed motor is controlled by two wires: it is simple to control due to the lack of electronics as well as the analog nature of the control(voltage based). This lack of electronics allows brushed motors to function in extreme environments. Brushed motors are difficult in the necessity for frequent maintenance to replace brushes as well as less reliability and longevity. Generally, brushed motors are more simple to manufacture, build, and control but lack the refinement of brushless motors.
Brushless - Brushless motors are controlled by electronic speed controllers and a system of sensors which allows for more precise control than the mechanical switch for brushed motors. The lack of brushes (which wear down over time and need to be replaced) allows for less frequent maintenance. Brushless motors have more consistent speed and torque as well as a generally greater efficiency. They have a greater ratio of power to size than their bulkier brushed relatives as a result of their better thermal characteristics. The speed is limited only by voltage and therefore has a wider range than brush/commutator reliant motors. While being more expensive and complex to produce and construct(especially the expensive electronic elements), brushless motors are a more refined and longer lasting solution that are more likely to fit a variety of use cases.
Anatomy of brushed DC motor vs brushless DC motor
brushed-brushless.jpgGeneral comparison and explanation
Scientific publication discussing the benefits of brushless DC motors

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