What is the difference between a linear and rotary potentiometer
A potentiometer consists of a three-terminal resistor and a moving contact, all of which form an adjustable voltage divider. Their name comes from the fact that they serve as a voltage divider that varies electrical potential.
They can be classified as rotary or linear potentiometers:
Rotational potentiometers
A rotational potentiometer offers control using a spinning knob that adjusts the point of contact between the wiper and a nearly-circular resistor. The rotation is typically – but not always - limited to one revolution, and the resistor is an almost-complete circle with a small notch removed.
Pros and Cons of Rotational Potentiometers
Pro: Space-saving. These pots rotate in place, which may make them better suited to small applications or devices.
Pro: Easy to seal. These pots seal well for two reasons: the knob naturally forms a sort of cap and the only point of entry for contamination is the small space between the knob and the housing in which it turns
Con: Hard to read. These devices offer little visual indication as to their positioning, making it difficult to read or compare them. Rotational pots may have a small indicator mark, but that may not be very intuitive for comparing or reading absolute levels.
Linear or Slide potentiometers
You can find slide potentiometers commonly on lighting and soundboards. These devices feature a small handle that can slide either horizontally or vertically – depending on installation – to control the point of contact between the wiper and the resistor.
Pros and Cons of Linear Potentiometers
Pro: Intuitive visual feedback. By putting an array of slide pots next to each other, it’s easy to compare the levels visually. This quality is why you’ll typically see linear pots in soundboards and graphic equalizers. The visual appearance of the array of sliders translates easily into a working idea of the tonal effect created.
Con: Vulnerability. These pots feature an open slot that runs the entire length of the slider, making them relatively easy to contaminate, harder to keep clean, and often shorter-lived as a result.
Where are linear potentiometers used?
The variety of applications for linear potentiometers is very large. They are used for length measurement in many laboratories as well as in industrial applications. The sensors are easy to install and offer precise measurement values even under difficult conditions. Linear potentiometers are well suited for use in precision engineering as well as more everyday products.
Application examples include:- Test/ lab applications
- Mobile vehicle
- Medical
- Agricultural machinery
- Industrial processing
- Robotics
- Industrial machinery
- Motorsport
- Audio and graphics
