LED lighting transformer information

Updated February 21, 2017

A light emitting diode (LED) is a lighting system that has been around since the 1960s. LEDs are small in size, but can be grouped together to create large amounts of light. All LEDs require a transformer, which regulates the flow of electricity into the lighting system from the power source.

What is a transformer?

A transformer is made from two coils of wound wire that are connected so that one of the coils will send electricity to the other. One of these coils, the primary coil, is connected to the electrical power source, and it sends electricity to the other, called the primary voltage. The way in which the two coils are connected decides the level of voltage in the second coil. The transformer can either increase or decrease the level of voltage running into it. The turns ratio is the measure of this change.

There are several different types of transformers. However, almost all LED lights work with magnetic transformers, due to their reliability. It is not recommended to use any other type.


LED lights are made out of small, 6.35 mm (1/4 inch) wide diodes. For larger lights, many small ones are grouped together. Conventional light works by heating up a metal filament inside the light until it glows with heat. LEDs do not heat up a filament, and therefore light up without giving off very much heat, making them an excellent option for lighting systems in which heat is a concern. They are also much more energy-efficient that standard lighting systems.

LED lighting comes in two different types: mains voltage LED and low voltage LED. Mains voltage LEDs are quite simple and can be connected to conventional lights. However, low voltage LEDS require a transformer.

Basic low voltage LED transformers

LED transformers are usually built into the LED fixture or they come inserted into the plugs for portable LED devices. Low wattage LED transformers usually take in about 120 volts of alternating current (AC) from the outlet at a time and convert it to 12 or 24 volts of direct current (DC). The transformer will usually have a total amount of wattage that it can handle, and the number of lights it can be used for must have a lower total wattage than this level.

Other types of transformers

Larger LED transformers for products such as garden lights come in two forms. They are either box-shaped or toroidal (doughnut-shaped). They can be placed anywhere that is convenient. They come in black weatherproof boxes and can be placed on buildings, fences, or walls and under decks or even man-holes.

If you cannot find a place to hide your transformer above ground, you can buy a ground burial transformer, especially designed to be buried but still protected. These are specially built so that no moisture can get into the transformer. This process is called resin sealing, and it protects the transformer from dangers such as seepage or condensation.

Uses of LEDs

Once you have the proper transformer for your LED, you can use it for a wide variety of both indoor and outdoor lighting tasks.

Indoors, LEDs can be used anywhere in any way you might desire, including staircases, hallways, living rooms, kitchens, nurseries and bathrooms.

Outdoors, LED lights are widely used for gardens, decks, patios and driveways.

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About the Author

Justin Mitchell has been a writer since 2009. In 2002, he received a B.A. in theater and writing from the University of Northern Colorado. Mitchell worked as an ESL teacher in Europe and Asia before earning a master's degree in journalism from the City University of New York. He has written for the "New York Daily News" and, among other outlets.