8.1.1 Components of an R/C Servo

Interface: three wires. As mentioned, one for power, one for ground and one for control.

Motor: R/C servos use tiny DC motors internally to convert electrical energy to motion. There is a wide variety of these DC motors used in R/C servos. The inexpensive ones are quite crude, while expensive ones use coreless high efficiency DC motors.

Control circuit: a small circuit board holds all the electronic components necessary to control the DC motor of an R/C servo.

Gears: R/C servos have very fine and precise gearing. Inexpensive ones have plastic gears, while expensive ones have metallic ones.

Potentiometer: a potentiometer is used to encode the angular position of the output shaft of an R/C servo.