Variable Transformers

Variable transformers are small components that allow precise control over electrical current, voltage, and power. They put out voltages of differing amounts from the same input voltage, which makes them useful in applications requiring manual adjustment, including devices for heating and lighting.

We stock a selection of quality variable transformers from leading manufacturers including Superior Electric, RS PRO, and Staco Energy Products Co. We have carefully selected these suppliers to ensure that you only receive high-quality components that are built to last.

Many of our variable transformers are in stock and ready to be shipped with same-day delivery. You can browse our selection below, check their corresponding specifications, and then simply place your order online.

Read more about the use, benefits, and applications of variable auto transformers below. If you have any questions in the meantime, please feel free to get in touch with the team.

What are variable transformers?

Variable transformers are a type of autotransformer, and their main purpose is to regulate and increase voltage. Thanks to their dial-control compatibility, these adjustable transformers can be used as lighting dimmers in household and commercial settings.

Each variable transformer normally contains a wiper or brush that rotates underneath an external dial with a knob. As the person using the transformer turns the knob, the surface area changes on the point of contact between the brush and the coil.

In turn, variable transformers allow a smooth transition from low voltages to outputs that can, in many cases, be higher than the input voltage. However, the single-coil design of adjustable transformers means that there is no separation between the load and the source voltage. They are therefore not suitable for certain applications, especially those that must protect an operator or a device from high voltages.

What are the benefits of adjustable transformers?

Variable transformers play a key role in maintaining the correct voltages for the operation of motors and electrical equipment. They're lightweight, easy to maintain, and offer a higher efficiency than other transformers.

The main advantage of variable output transformers is the cost: they can perform a similar function to much more expensive equipment. They make a cost-effective method for the delivery and distribution of enormous amounts of electricity.

Which variable transformers are available?

Single-phase variable transformers

Single-phase variable transformers contain only one pair of transformer windings. These are insulated coils, usually made from copper or aluminum. Each single-phase variable transformer relies on these two windings - one primary, and one secondary - to transform the input voltage.

These types of variable transformers are best suited to residential and domestic settings. Frequent applications include air conditioning, heating, and lighting systems, along with other devices in the home.

3-phase variable transformers

In a three-phase variable transformer, power is generated as three pairs of windings rotate through a magnetic field. Three-phase power is commonplace in most types of electrical power systems, including distribution: it can provide electricity to the grid.

Our three-phase variable transformers are much more efficient, so they make an excellent choice for industrial applications. When it comes to large-scale systems and high-power machinery, three-phase variable transformers are preferred.

What are the applications of variable transformers?

Voltage correction

Variable transformers are often supplied with manual control knobs. This feature allows users to guarantee a smooth and continuous variation of voltage. Since they can be manually controlled, they vary distinctly in function when compared to digitally controlled devices, which operate in voltage increase or decrease only.

Dimmable lights

Variable auto transformers ensure that the voltage within lamp circuits remains at safe and recommended levels. When variable transformers are used to control dimmable incandescent lighting circuits, the lamps last longer.

Electrical testing

Variable transformers' ability to adjust the voltage on a circuit with such precision makes them invaluable for industrial testing purposes. Personnel can test two extremes as a result: the minimum and maximum threshold voltages at which the component or device being tested can operate.

Heating control

Used in conjunction with inbuilt thermostatic control on each device, control from an adjustable voltage transformer enables consistent, predictable heating. These devices therefore make a convenient addition to internal heating systems in ovens and other appliances.

Why buy variable autotransformers with RS Americas?

With a range of over 3.5 million parts available from more than 650 international suppliers, we can offer more brands than any other electrical distributor in North America. Our variable voltage transformers are provided by known and trusted suppliers, which helps us to deliver only the best components.

Once you have found the variable transformer that meets your requirements, our fast shipping means you won't be waiting too long. Our distribution center in Fort Worth, Texas, enables smooth and seamless picking, packing, and shipping.

Feel free to contact us if you have any questions. And if you want to learn more technical tips, head over to our expert hub for industry updates and helpful guides.