Variable Resistors

Bring flexibility and durability to your electrical applications with the RS reliable range of quality variable resistors. We have been supplying industrial customers and hobbyists for nearly a century, so whatever the circuit you wish to create and control, you can trust our adjustable resistors to perform.

We offer several types, including potentiometer variable resistors, digital variable resistors, trimmer potentiometers, and rheostats. A range of resistances are available too, including 10k and 100k variable resistors, and all come from trusted manufacturers including Bourns, ETI Systems, Nidec Copal Electronics, and Ohmite.

Use the search options to the left of the page to narrow your search or scroll down to find out more about variable resistors, including what they are, the different types of variable resistors, how they function, and real-world applications.

Get in touch with our helpful advisors for more information or visit our information-packed expert hub.

What are variable resistors?

Variable resistors, also known as variable load resistors or potentiometers, allow the user to increase or decrease the component's resistance to current as required, between a minimum and maximum value. This decreases or increases the current flowing through the adjustable resistor, respectively.

They are typically used in applications where user input is crucial, such as when the equipment requires calibration from an engineer, or the end-user must be able to control functionality.

Variable resistors typically feature a wiper which is moved along a resistant track by the user input (such as a knob or slider). When placed close to the source of the current, this wiper allows more current to flow through the component and vice versa. That's because electrical resistance is proportional to the length of the resistant material within the circuit.

How do different types of variable resistors function?

There are several types of adjustable resistors available, each designed for different applications and settings:

Potentiometer variable resistor

One of the most common types of variable resistors, potentiometers feature three terminals - two outer terminals attached to the voltage source and connected by a track of resistant material, and an inner terminal connected to a wiper.

The position of this wiper can be adjusted, in turn reducing or increasing the current flowing through the outbound terminal. If only the outside two terminals of the potentiometer variable resistor are used, then the component will function as a fixed resistor.

Trimmer potentiometers

Also known as trim pots, trimmer potentiometers operate in the same manner as potentiometers, except are only designed to be calibrated and set a very limited number of times by the user - typically only being adjusted a few times during the lifespan of the component. They are typically used in large pieces of equipment, such as audiovisual products, that are adjusted by engineers.

Rheostats

Similar to potentiometers, rheostats nevertheless only feature two terminals - one fixed terminal connected to the voltage source, and a moving terminal connected to the washer. Given the amount of current flowing through this sort of variable resistor, they typically feature heavy-duty, wire-wound resistive parts.

Digital variable resistor

Performing the same role as a potentiometer or rheostat, digital variable resistors change electrical resistance digitally as opposed to mechanically. They do this using an integrated control unit that takes a signal input from a computer-based microcontroller, interprets the data, then uses it to guide the movements of a wiper akin to those used in mechanical potentiometers.

H2: What are variable resistors used for?

With the use of a variable resistor, electrical circuits of all types can have the voltage flowing through them accurately controlled and changed.

That means that practically any electrical device or application that requires or can be adapted by the user will use a variable load resistor of some sort. Cars, audio equipment, appliances, machinery - adjustable resistors are truly ubiquitous components.

H2: Why choose RS for your variable resistors?

Our range of variable resistors for sale combines useful features, great value, and extensive choice.

We have long-standing partnerships with some of the best-established manufacturers of adjustable resistor components, such as Panasonic, Piher Amphenol, Spectrol, Vishay, and TE Connectivity.

Our focus on quality parts means all our variable resistors can be thoroughly relied on to do the job well without the need for troublesome maintenance, and with parts spanning several wattages, ohms, and form factors, you're sure to find one to suit the job.

Explore the range using the search filters to the left, then either place your order or contact our experts if you have any questions about our variable load resistor range.

Visit our expert hub and find out more about our range of components and how to get the most out of their use.