All About Potentiometers and Variable Resistors

For electronics to carry out the various procedures that they are intended to be capable of, they often rely on a number of electromechanical components to govern voltages and resistance. With components known as resistors, a circuit may have its current flow reduced, signal levels adjusted, voltages divided, transmission lines terminated, and more. When there is a need for varying voltage values and resistances, components known as variable resistors and potentiometers are used.

While variable resistors and potentiometers can feature the same exact construction and assembly, their difference may be found in the methods in which each is connected to a circuit or assembly. Generally speaking, variable resistors will feature three connections. With one connection attached to a sliding contact and the others to the ends of a fixed resistor, the resistivity of the component can be adjusted by moving the wiper. As the wiper is moved alongside a linear or rotary track, the contact’s position is adjusted as well.

Potentiometers serve as the most common type of variable resistor, and they are often used as a potential divider. The naming of the component comes from its function in a circuit, allowing for a variable potential to be formed at the tapping point terminal. Due to their capabilities during operation, potentiometers are often found in amplifier gain controls, allowing for the governing of audio volume. Additionally, they can also be used for applications such as distance or angle measurement, as well as can tune circuits. If the potentiometers are used for the calibration of a circuit board, trimports and trimmer types are most common.

When the wiper component is connected to a side of the track, it is simply considered a variable resistor. In such assemblies, the resistor acts as a two terminal device and can adjust the resistance across its two terminals. To adjust resistance, the wiper will short circuit the resistance of the track.

Rheostats are another common type of variable resistor, and they are similar in construction to potentiometers. Their difference, however, lies in the fact that they are implemented in systems to provide variable resistance. As such, they utilize only two of their terminals, as one connection is placed at the end of the resistant element and another on the wiper. While rheostats once excelled in power control applications, they have since been superseded by more powerful switching components. Nowadays, rheostats often serve as variable resistors that can be used for tuning or calibration.

Depending on the application in question, a number of variable resistors may be used, each providing their unique advantages and disadvantages. While a number of systems have since moved on from variable resistors, such components are often found in radios, joysticks, audio equipment, and much more. To measure the value of a particular resistor, a ohmmeter may be used. By connecting probes to the resistor component, a voltage can be induced and measured with meter movement.

With the proper variable resistor and potentiometer components, a number of electronics and circuits can benefit from voltage adjustment. At ASAP Parts Online, we serve as your sourcing solution for resistor components, offering competitive pricing and rapid lead-times on all that we carry. As the only independent distributor with a no China sourcing pledge, all parts have been stocked from leading global manufacturers and have been thoroughly tested for quality assurance. If you find particular items from our inventory that you wish to procure, you may begin the purchasing process at any time through the submission of an Instant RFQ form. Get started today and experience how ASAP Parts Online is revolutionizing the part procurement process for our customers.

1. mary wilson
2. Posted on February 12, 2021
3. electronics

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