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A guide to LED power supply: Dimmable

Time to read 4 min

Advice Centre > Accessories > Power Supply > A guide to LED power supply: Dimmable

LED lighting is increasingly popular in a range of applications, from domestic settings to office buildings and hospitality settings. Besides their energy-saving properties, excellent aesthetics and superior lifespan, LED lights are beneficial for their ability to be controlled using manual or pre-programed effects.

By having control over your LED lights, you can control their brightness to achieve different effects at specific times throughout the day. So how does this work, and what do you need to consider when choosing dimmable LED lighting?

In this piece, we explain what a dimmable LED power supply is and how to choose the right dimmable LED power supply for your individual needs, and explore some of the best dimmable LED power supplies stocked here at WeLoveLEDs. Click on one of the links below to jump to that section:

What is a dimmable LED power supply?

Dimmable LED power supplies are a particular type of power supply that allows you to adjust the brightness of LED lights. The three main functions of dimmable power supplies are:

  • Resistive dimming doesn’t need an external voltage, instead using a potentiometer to offer variable resistance from a driver across the internal control voltage
  • 0-10V or 1-10VDC dimming refers to a 0-10V or 1-10V source being applied to an LED driver. A control voltage of 1V equates to an output voltage of 10%
  • Pulse-width-modulation (PWM) signal dimming is an external circuit that controls the average voltage to the dimming input

Many of our dimmable power supplies have a built-in three-in-one capability which features all three of these functions.

There are also different types of dimmable power supply, each with its own benefits.

Triode for Alternating Current, or TRIAC, is one of the most popular types of dimmable power supply. When used to control LED lighting, TRIAC power supplies are also often referred to as TRIAC dimming. TRIAC modules are three-terminal devices that are wired to mains supplies and function as a dimmer switch by controlling the amount of electrical energy passing through a bulb.

TRIAC dimming is beneficial for its ability to control the intensity of LED lighting, which helps when attempting to create a particular atmosphere. This makes TRIAC power supplies a popular choice for commercial planners that envision a mood for their event.

Digital Addressable Lighting Interface (DALI) power supplies are another type of dimmable power supply used for LED lighting. DALI power supplies utilise a two-way digital protocol to send a dimming control signal to a network of LED drivers and dimmable LED bulbs. Each bulb and driver is given its own address, which the DALI unit sends signals to with instructions, such as decrease the brightness or turn off completely.

DALI lighting control systems are beneficial for their ability to control lighting networks across multiple areas. This makes DALI power supplies most useful when you need to light larger areas such as entire buildings, but still want a single central control unit that offers stability, precision and instant operation.

How to choose the right dimmable power supply for your LEDs

Choosing the right dimmable power supply for your LEDs can be tricky if you don't know what factors to consider in a product. Some of the things you should bear in mind when looking for a dimmable power supply include:

Size of power supply

The size of the power supply is important when choosing an LED power supply. You want to make sure that the unit fits into the location you’re intending to install it.


The voltage of the power supply is also an essential factor that needs to be considered when buying an LED power supply. LED products require a minimum voltage in order to work at a sufficient level; if not enough voltage is supplied to an LED product, it won't work as intended. A 24v LED strip light display, for example, should be paired with a 24v power supply.

Maximum wattage

The wattage of an LED product is the measure of power of a product. It is calculated by voltage multiplied by current and is important because, just as LED products require a minimum amount of power, there is also a maximum amount of power. If this maximum wattage is exceeded, then the product is likely to overheat. This could cause total failure to the product and be a safety risk by becoming a fire hazard.

Application environment

The surrounding environment of the product is crucial when it comes to choosing the most suitable power supply. All elements of the environment should be considered, most critically the temperature and moisture levels. If your application involves exposure to moisture such as rain, look for a power supply with a high IP rating to ensure it is resistant to at least light splashes.

Dimmable LED power supplies from WeLoveLEDs

200w 24v PSU Dimmable LED Power Supply200w 24v PSU Dimmable

This product has a 100-265VAC input only, cooling by free air convection and 85% full load burn-in test. It allows control over LED products to dim to a suitable level of lighting, with an 8.33A rated current to provide energy continually and consistently to LED products. It is suitable for LED lighting and moving sign applications.

200w 12v PSU TRIAC Dimmable LED Power Supply200w 12v PSU TRIAC Dimmable

This constant voltage TRIAC unit has a built-in three-in-one dimming function, 180-240VAC input, 86% full load burn-in test, cooling by free air convection and IP66 rating. It works with leading edge TRIAC dimmers and is suitable for LED lighting and moving sign applications.

180w 12v PSU Dimmable LED Power Supply180w 12v PSU Dimmable

Fully encapsulated with IP66, 85% full load burn-in test, cooling by free air convection and 100-265VAC input only, this unit uses a 15A current to provide energy continually and consistently to LED products.

100w 24v PSU DALI Dimmable LED Power Supply100w 24v PSU DALI Dimmable

This unit has a built-in DALI interface and dimming range from 0.1% to 100%. It has a constant voltage output, IP66 rating and 100-265VAC range. It offers protections from short circuits, overloading, overcurrent and overtemperature.

Frequently asked questions

How does an LED driver differ from a typical power supply?

They don’t differ—they are the same thing!

Does an LED dimmer on a DC circuit save electricity?

Yes. Dimming on the mains side of the circuit will save on the amount of energy used. In real terms it doesn’t amount to a lot, but it is a saving. Dimming on the low voltage side again will have a saving, but this is even less than the mains dimmer.