DCmotor

DCmotor, commonly written as DC motor, is an electrical machine that converts direct current electrical energy into mechanical energy. It operates on the principle that a current-carrying conductor placed in a magnetic field experiences a force, and that the interaction of stator and rotor windings creates torque.

Construction of a DCmotor centers on the stator, which provides a magnetic field, and the rotor (armature) with windings. In brushed designs, a commutator and brushes provide mechanical commutation, along with bearings and a shaft. In brushless designs, permanent magnets provide the stator field and electronic controllers switch current in the windings, eliminating brushes.

Operation involves supplying DC to the motor to induce current in the rotor windings, generating torque. The speed is roughly proportional to the applied voltage minus losses, while the load torque reduces speed. In brushed motors, the commutator reverses current each half turn to maintain torque in one direction. In brushless motors, electronic commutation uses sensors to switch current in the stator windings, providing smoother operation and longer life.

Control and performance: Speed can be controlled by varying the supply voltage or using pulse-width modulation (PWM) with a motor driver. Torque is roughly proportional to current, and efficiency varies with design. Brushless DC motors (BLDC) are often more efficient and longer lasting, while brushed motors are simpler and cheaper but require more maintenance due to brush wear.

Applications of DCmotors are widespread, including general machinery, robotics, actuators, automotive starters, printers, and small to large industrial drives. They are favored for straightforward control and good low-speed torque, with trade-offs in heat generation, efficiency, and the need for control electronics.