Answer

Definition

Servo motor: Closed-loop actuator with motor + feedback sensor (encoder/pot) + driver that controls position/velocity precisely via error correction $e=\theta_{ref}-\theta_{actual}$.

Types (explain one: DC Servo)

DC Servo: DC motor + encoder + PID controller. Input PWM/analog, encoder feedback, driver H-bridge controls direction/speed. Types: DC, AC, brushless.

Working: Controller compares desired vs actual via encoder → PID → H-bridge → motor rotates → encoder updates until error zero.

Applications

• Robot joints, CNC, robotic arm, gimbal.
• Conveyor, 3D printer.

Advantages

• High precision, fast response, high torque with gear.
• Closed-loop, no step loss (vs stepper).

Disadvantages

• Costly, needs tuning (PID), complexity, requires feedback, hunting.

Final Answer

Servo = motor+feedback closed-loop; DC servo via encoder PID; advantages precision, disadvantages cost and tuning, used in robot joints/CNC.