Brushed DC motors are one of the earliest motors designed. DC motors are easy to understand and it is easy to control the speed. DC motors generally provide better performance at low speeds than a comparable AC motor; most DC motors can operate over a speed range reliably down to 5-7% of the rated speed as listed on the motor’s name plate.
In general for a DC motor, the torque of the motor is proportional to the amount of current applied to it, and rotational speed is proportional to the voltage. Applications include camera lenses or shutter controls, robotic actuators and pumps, stepper motors, and low noise test or instrumentation systems.
