Servos

Servos are electromechanical devices that convert a control signal into precise angular or linear motion. A servo typically combines a motor, a feedback sensor, and control circuitry within a compact housing, enabling closed-loop control of position, speed or torque.

Operation: A servo receives a command signal representing a desired output, such as a target angle. The feedback sensor measures the actual position, and the controller drives the motor to minimize the error. The result is a closed-loop system that regulates position, velocity, and torque.

Types: Electric servos include brushed DC and brushless DC (BLDC) servo motors. Linear servos provide straight-line motion, while rotary servos produce rotation. Many systems use gearing to increase torque and reduce speed. Feedback devices include potentiometers, encoders, and resolvers.

Control and interfaces: In hobby and RC contexts, hobby servos are typically controlled by standardized pulse-width modulation signals that specify a target position. Industrial and CNC servos use higher-precision closed-loop drives with programmable motion profiles and external controllers.

Applications and considerations: Servos are widely used in robotics, automation, CNC machines, aircraft control surfaces, and hobby electronics. They offer precise motion and repeatability but can be more complex and costly than open-loop motors, requiring calibration and tuning.