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Potentiometers

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Potentiometers are used for ...

Volume controls
- Use a logarithmic or log pot for this. When the pot is set to 50%, it sounds like half volume.
Tone controls
Power Supply Voltage adjustment
- Use a linear pot for this. When the pot is set to 50%, the output voltage is half.
Angular Position Measurement. For a linear potentiometer, the output voltage is directly proportional to the angle of rotation of the shaft.

For the Falstad Circuit Simulation, CTRL+Click Potentiometer Simulation
In options, check European Resistors and uncheck Conventional Current.
Adjust the pot and watch the voltages change.

Alternatively view Resistors_Variable.txt.
Save or copy the text on the web page. Import the saved or copied text into the Falstad simulator.

Here is the new HTML5 Simulator Site.

A potentiometer (pot) is a variable resistor with an adjustable slider. You can think of it as two resistors (one on each side of the slider). The diagram above shows the commonest arrangement. There is another straight version often called a fader. Both types are used as volume and tone controls. They are notorious for being unreliable. Dirt gets into the moving parts and corrosion causes problems. Digital pots are available. These don't suffer from these mechanical problems.

When used for position sensing, potentiometers are classed as input transducers.