Potentiometers

Regulate the current flowing through a circuit with a high-quality potentiometer. These variable resistors are designed to control electrical resistance in a range of settings, from industrial to domestic.

If you are searching for a potentiometer, whether you need a linear digital potentiometer or you're searching for a robust and revolutionary panel-mounted potentiometer knob, you will find it here at RS. We have over 500 products in stock that work with different currents and are made by trusted manufacturers.

Read on to find out more about potentiometers and the settings they work in.

What are potentiometers?

Potentiometers - often referred to as a pot or potmeter - are three-terminal variable resistors that control the flow of electric current. Here, resistance levels are manually varied using switches or other controls.

The electrical resistance levels are measured in Ohms (Ω). There are different types of potentiometers available, including 10KΩ potentiometers and slide potentiometers that are designed for applications where regular adjustments are needed, such as in medical or commercial electronics settings.

The one you choose will depend on the application, but it's important to note that all potentiometers operate similarly.

How do potentiometers work?

To operate a potentiometer, a sliding contact is moved across a uniform resistance. This means the input voltage is applied to the full length of the resistor and the output voltage is the difference between the fixed and sliding contacts.

Three parts make up a potentiometer. These are the resistive element, the sliding contact - also referred to as the wiper - and three terminals.

Two of the three terminals are for the resistive strip. Here, the two terminals are wired to the resistive element, which is usually made from a material such as carbon. When the slider is moved along the track, the current flow changes. Different potentiometers have different systems in place for this procedure to occur. For instance, a mechanical trimmer uses a rotary switch while digital potentiometers use transistors to control the flow.

Another component of the potentiometer wiring setup is the third terminal. This is where the divided voltage is generated. If the potentiometer is pointing to the positive contact, the full voltage will be applied from the third terminal. If it's moved to the negative contact, there will be no output. If it's placed in the middle, the third terminal will put out half the voltage. However, this applies to potentiometers with a linear taper and other types may differ.

Guitar potentiometers: linear vs audio pots

One main example of how potentiometers can differ is in music - specifically in guitar potentiometers. These typically have one of two taper types: audio or linear.

We've already looked at linear taper versions, but in music especially, audio taper potentiometers are common. These pots are logarithmic - or log - tapers, and these are potentiometers that change resistance logarithmically as you turn the wiper. This is because we detect sound logarithmically, and the logarithmic scale is used to measure decibel levels.

A linear potentiometer allows too much current in at once, meaning that sound levels shoot up from zero to maximum output too quickly. An audio version sees a 'bend' where the straight linear resistive strip typically sits. This allows the wiper to gradually move around, slowly releasing the output and, in turn, gradually increasing the sound volume.

In some cases, a linear potentiometer is ideal, for example, if you want to shift the volume quickly. But in most situations, a smoother shift in volume is experienced when using an audio pot.

Digital potentiometers

While digital potentiometers operate in a similar way to their manual counterparts, there is one crucial difference. Digital pots use digital inputs to adjust the settings, whereas a dial or slider is used to control the output on a manual version.

To do this, transistors control the current flow. These transistors are in place of the mechanical resistor on a manual pot. The output depends on the position of the transistors.

Digital potentiometers are used in situations where environmental factors come into play, such as dust, moisture, or grease. As these pots are protected by the case they come in, they are less vulnerable to outside elements. Therefore, they are suited to applications such as sensor calibration and programming power supplies.

Where can potentiometers be used?

As well as musical applications, potentiometers are used in a wide range of settings. They're found in radio and TV receivers for volume control, medical equipment, wood processing machines and to regulate speed in motors. They're also found in lighting and control systems, such as heat controls on a radiator, or as an indicator of gasoline left in a vehicle.

Buy potentiometers from RS

Whether you need a new linear slide potentiometer or want a digital version, choose RS. We are a North America-based authorized distributor of pots, and we work with leading names in the industry to bring you the latest Nidec Copal Electronics, NTE Electronics, Ohmite, and Bourns potentiometers. We're proud to bring you a range of high-quality products that meet the highest standards.

If you have any questions, we are here to help. Get in touch with the team today. You can also find advice and tips in our expert content hub.