Editing Servomechanism (section)

==Servomotor==
{{main|Servomotor|servo (radio control)}}
[[File:Servomotor.jpg|thumb|right|200px|Industrial [[servomotor]]<br/>
The grey/green cylinder is the [[Brush (electric)|brush-type]] [[DC motor]].  The black section at the bottom contains the [[Epicyclic gearing|planetary]] [[Reduction drive|reduction gear]], and the black object on top of the motor is the optical [[rotary encoder]] for position feedback.]]
[[image:servo.jpg|thumb|right|200px|Small R/C servo mechanism.<br>
1. [[electric motor]]<br>
2. position feedback [[potentiometer]]<br>
3. reduction [[gear]]<br>
4. [[actuator arm]] ]]
A ''servomotor'' is a specific type of motor that is combined with a [[rotary encoder]] or a [[potentiometer]] to form a servomechanism. This assembly may in turn form part of another servomechanism. A potentiometer provides a simple analog signal to indicate position, while an encoder provides position and usually speed feedback, which by the use of a [[PID controller]] allow more precise control of position and thus faster achievement of a stable position (for a given motor power). Potentiometers are subject to [[Temperature coefficient of resistance|drift]] when the temperature changes whereas encoders are more stable and accurate.

Servomotors are used for both high-end and low-end applications. On the high end are precision industrial components that use a rotary encoder. On the low end are inexpensive [[servo (radio control)|radio control servos]] (RC servos) used in [[radio-controlled model]]s which use a free-running motor and a simple potentiometer position sensor with an embedded controller. The term ''servomotor'' generally refers to a high-end industrial component while the term ''servo'' is most often used to describe the inexpensive devices that employ a potentiometer. [[Stepper motor]]s are not considered to be servomotors, although they too are used to construct larger servomechanisms. Stepper motors have inherent angular positioning, owing to their construction, and this is generally used in an open-loop manner without feedback. They are generally used for medium-precision applications.<ref>{{cite web |title=How to drive a servo motor & its industrial applications |url=https://electronicscomponents.co.uk/how-to-drive-a-servo-motor-its-industrial-application/ |website=Components CSE |access-date=31 January 2023 |ref=Toggle}}</ref>

RC servos are used to provide actuation for various mechanical systems such as the steering of a car, the control surfaces on a plane, or the rudder of a boat. Due to their affordability, reliability, and simplicity of control by microprocessors, they are often used in small-scale [[robotics]] applications. A standard RC receiver (or a microcontroller) sends [[pulse-width modulation]] (PWM) signals to the servo. The electronics inside the servo translate the width of the pulse into a position. When the servo is commanded to rotate, the motor is powered until the potentiometer reaches the value corresponding to the commanded position.