A potentiometer is a manually adjustable variable resistor with 3 terminals. Two terminals are connected to both ends of a resistive element, and the third terminal connects to a sliding contact, called a wiper, moving over the resistive element. The position of the wiper determines the output voltage of the potentiometer. The potentiometer essentially functions as a variable voltage divider. The resistive element can be seen as two resistors in series(potentiometer resistance), where the wiper position determines the resistance ratio of the first resistor to the second resistor.

 

A potentiometer is also commonly known as a potmeter or pot. The most common form of potmeter is the single turn rotary potmeter. This type of pot is often used in audio volume control (logarithmic taper) as well as many other applications. Different materials are used to construct potentiometers, including carbon composition, cermet, wirewound, conductive plastic or metal film.

 

A wide variety of potmeters exist. Manually adjustable potmeters can be divided in rotary or linear movement types. Besides manually adjustable pots, also electronically controlled potentiometers exist, often called digital potmeters.

 

The following symbol is used for a potentiometer. The potentiometer symbol on the left is according to the IEC standard. The potmeter symbol on the right is according to the old American standard.