Introduction to Potentiometers

Potentiometers are variable resistors with three terminals, commonly used as voltage dividers. They can adjust levels of analog signals, and are key in circuits for controlling device functions like volume.

A potentiometer consists of a resistive element like carbon film or cermet, a sliding contact (wiper), and a control shaft. The wiper moves over the resistive element, changing the resistance.

There are mainly two types: rotary and linear. Rotary potentiometers are more common, used in knobs. Linear potentiometers, or sliders, are used in mixing consoles and equalizers.

Potentiometers come with different tapers which affect their response. Linear tapers provide a direct correlation between position and resistance, while logarithmic tapers are ideal for audio applications, mimicking human hearing perception.

Specifications include resistance value, tolerance, and power rating. Resistance values can range from 1 ohm to several megaohms. Power ratings determine the maximum wattage the potentiometer can handle without damage.

Beyond volume control, potentiometers are in joysticks for position sensing and are vital in custom circuits. They tune filters, adjust brightness, and can be part of sensor interfaces for physical computing.

Potentiometers can degrade due to wear and contamination. Conductive plastic materials offer longer life and better accuracy but at a higher cost. Sealed units resist environmental factors, prolonging their lifespan.