What is a Potentiometer?

What is a  Potentiometer?

Potentiometer Definition

A potentiometer (also known as a pot or potmeter) is defined as a 3-terminal variable resistor used to control the flow of electric current by adjusting resistance.

Working Principle

Potentiometers work by moving a sliding contact across a uniform resistance, adjusting the voltage output based on the contact’s position.

Types of Potentiometers

• Rotary potentiometer

• Linear potentiometer

Digital Potentiometers

Digital potentiometers offer higher accuracy and reliability than mechanical ones, using electronic controls to vary resistance.

Advantages of Digital Potentiometers

• Higher reliability

• Increased accuracy

• Small size, multiple potentiometers can be packed on a single chip

• Negligible resistance drift

• No moving part

• Tolerance up to ±1%

• Very low power dissipation, up to tens of milliwatts

Disadvantages of Digital Potentiometers

• Not suitable for high temperature environment and high power application.

• The nonlinearity in the wiper resistance adds a harmonic distortion to the output signal. The total harmonic distortion, or THD, quantifies the degree to which the signal is degraded after crossing through the resistance.

Applications

• Comparing the emf of a battery cell with a standard cell

• Measuring the internal resistance of a battery cell

• Measuring the voltage across a branch of a circuit