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Variable Resistors

Browse our wide range of variable resistors, including potentiometers, rheostats and thermistors from market-leading electronics brands, including Vishay, Bourns, EPCOS and RS Pro.

What are Variable Resistors and How Do They Work?

Variable resistors are electrical components that give you control over the current flow through an electric circuit. They can be used in a variety of different types of devices, like guitars and basses. By adjusting the resistance, these components can increase or decrease the current flow, providing precise control over the circuit's performance. Variable resistors have defined maximum and minimum values that can dictate the range of current they can regulate. Without variable resistors, managing and fine-tuning electrical circuits would be impossible, highlighting their critical role in various applications.

What Does a Variable Resistor Do in a Circuit?

A variable resistor’s role in a circuit is to allow the amount of resistance to be changed. When resistance decreases, the flow of the current increases. There are different types of variable resistors that can be used for different functions and environments.

Types of Resistors

The three most common types of variable resistors are:

1. Potentiometers

The most common type of variable load resistor is the potentiometer. The potentiometer can be used as a voltage regulator by introducing a variable amount of resistance into a circuit or as a means of adjusting the power in a circuit. Potentiometers can also be known as "pots" or, more specifically, slider pots, trimmer pots or thumbwheel pots.

2. Rheostat

A rheostat is a variable resistor which is used to control current within an electrical circuit. They can control the resistance without interrupting it. Unlike the potentiometer, the rheostat only uses two leads. A connection is made to one end of the resistive element, and the other connection is made to the wiper end of the electronic variable resistors. Rheostats are commonly used in motor control.

3. Trimmer Resistors

Unlike other resistors, a trimmer resistor is a smaller component that’s used to be placed within your circuit and not adjusted again. They are also known as “trimpots”.

Other Types of Variable Resistors

In addition to the common types, there are several other variable load resistors designed for specific applications:

Ceramic Transient Voltage Suppressors: Used to protect circuits from transient voltage spikes, ensuring stable operation and protecting sensitive components.
Metal Oxide Varistors: Designed to handle high voltage and energy, they protect circuits from voltage surges and spikes by clamping excessive voltage levels.
Potentiometer Accessories: Includes various components like knobs and mounting nuts that aid in the installation and operation of potentiometers.
Potentiometer Knob: Provides a user-friendly interface to adjust the potentiometer easily, enhancing the precision of manual adjustments.
Potentiometer Mounting Nuts: Secure the potentiometer in place, ensuring stable and reliable operation within the circuit.
Rheostat Dials: Allow precise control over the rheostat, facilitating accurate adjustments in current control applications.
Thermistors: Temperature-sensitive resistors that change resistance with temperature variations, used in temperature measurement and control applications.
Trimmer Resistor Adjustment Tools: Specialized tools designed to adjust trimmer resistors accurately, ensuring precise resistance settings.
Trimmer Resistor Mount Adapters: Facilitate the mounting and integration of trimmer resistors into various circuit designs.

What is the Difference Between a Fixed Resistor and a Variable Resistor?

Fixed resistors like the wire wound resistor have a set resistance value that doesn’t change, making them suitable for applications where a constant resistance is needed. These resistors are typically used in circuits that require a stable and unvarying resistance to maintain consistent performance. In contrast, variable resistors allow the resistance to be adjusted, providing flexibility in controlling the current and voltage within a circuit. This adjustability is crucial for applications that require fine-tuning and dynamic control of electrical parameters. Fixed resistors are ideal for simple, unchanging applications, while variable resistors are used in dynamic environments where adjustments are necessary to achieve the desired electrical performance.

Industry Applications

Variable resistors are used in a wide range of industries due to their versatility and precision:

Telecommunications: Used in adjusting signal levels and tuning circuits to ensure clear and reliable communication.
Consumer Electronics: Found in volume controls, tuning circuits, and calibration settings in devices such as radios, TVs, and audio equipment.
Automotive: Used in dashboard controls, lighting systems, and engine management systems to adjust and control various functions.
Industrial Control Systems: Employed in motor controls, process automation, and instrumentation to regulate and monitor system performance.
Medical Devices: Used in diagnostic equipment, therapeutic devices, and patient monitoring systems to adjust settings for accurate and safe operation.

Your Trusted Variable Resistors Supplier and Manufacturer

RS Australia is a leading supplier and manufacturer of high-quality variable resistors, recognised for our extensive selection and exceptional reliability. Choose RS for your variable resistor needs and experience unmatched service and quality in Australia. As a trusted provider, we offer customised solutions tailored to meet your specific needs. With our expert support and efficient delivery services, RS ensures that you receive the best components for your applications. Whether you need to buy variable resistors for a small project or a large-scale operation, we have you covered.

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