What is Brushless DC electric motor?

A brushless DC electric motor , also known as an electronically commutated motor or synchronous DC motor, is a synchronous motor using a direct current electric power supply. It uses an electronic controller to switch DC currents to the motor windings producing magnetic fields which effectively rotate in space and which the permanent magnet rotor follows. The controller adjusts the phase and amplitude of the DC current pulses to control the speed and torque of the motor. This control system is an alternative to the mechanical commutator used in many conventional electric motors.

The construction of a brushless motor system is typically similar to a permanent magnet synchronous motor , but can also be a switched reluctance motor, or an induction motor. They may also use neodymium magnets and be outrunners , inrunners , or axial.

The advantages of a brushless motor over brushed motors are high power-to-weight ratio, high speed, nearly instantaneous control of speed and torque, high efficiency, and low maintenance. Brushless motors find applications in such places as computer peripherals , hand-held power tools, and vehicles ranging from model aircraft to automobiles. In modern washing machines, brushless DC motors have allowed replacement of rubber belts and gearboxes by a direct-drive design.