Dimmable LED Lighting

Last modified: 15th Nov 2018

Dimmable lighting not only alters the mood and ambience of a room, but it also brings additional benefits in the form of reduced energy consumption and improved light bulb longevity. Advances in LED technology means that the intensity of overhead lighting can be easily adjusted to suit any lighting design scheme.

Why LED dimming?

How dimming works

Types of LED dimming

Considerations when choosing a dimmer

Why LED dimming?

LED dimming allows the end user more control to select their preferred level of light for a particular activity or time of day. Dimming enables you to easily transform a brightly-lit workspace into an ambient or relaxing setting – not to mention save some energy at the same time!

How dimming works

How does LED dimming actually work? There are several types of dimming options and each operates differently, but the most popular example is mains dimming. This works by reducing the amount of power to the LED light source, effectively by blocking a fraction of the voltage. Within mains dimming, you have ‘trailing edge’ and ‘leading edge’. These again have their differences, making them compatible with different types of light form:

Leading-edge dimmers:

A dimming control is used to lower the light output of a source by reducing its operational wattage. A leading-edge dimmer uses a TRIAC (Triode for Alternating Current) switch to control power. Leading-edge dimmers are a common option, providing a cost-effective and simple solution compared to many alternatives.

Trailing-edge dimmers:

Alternatively, a trailing-edge dimmer uses a transistor and offers a more sophisticated solution that provides smoother, more silent dimming control. Mains Trailing Edge dimming can be used to dim most dedicated LED fittings when coupled with a mains-dimmable driver. We offer trailing-edge dimmable drivers for a number of our fittings.

What other types of dimming are there?


While mains dimming works well, low voltage dimming offers an alternative. 1-10v dimming operates effectively with dedicated LED fittings. This can be smoother than the leading-edge and trailing-edge mains dimming options, although on the downside requires a separate control cable to be run from the controller to the fitting’s driver.


DMX is most commonly used for colour-changing light installations and professional lighting control systems. The DMX dimming method relies on a signal being generated by a lighting control system and dedicated wiring between the controller and the driver.


The final and our favourite non-mains dimming method is the DALI (Digital Addressable Lighting Interface). We love it because it brings two-way communication into lighting, making it much more user-friendly and ideal for commercial or more complex lighting systems. With DALI, LED drivers can be linked to a central computer, allowing each of them to be controlled independently. Each lighting fixture is given an address in the system, allowing the user to dim the lights individually or by room. Sera Technologies offer several varieties of DALI dimmers and can advise on which would work best for your lighting project. DALI 2 develops on this concept even further; adopting a DALI 2 dimming method allows for more colour changing control and the ability to individually control twice as many light fittings (128 as opposed to 64), giving specifiers and designers many more possibilities.

Considerations when choosing a dimmer

The innovations we’ve seen in lighting and dimming mean that there’s now a workable solution for everybody, and you’ve never had more control over the brightness, colour and ambience of your lighting design. However, the drawback is now that there are so many options that it can take quite a bit of research to ensure you’ve chosen the right dimming solution. The main issue to be aware of is one of compatibility. Even the most experienced electrician or specifier may have trouble remembering which dimmer switch is best suited to their chosen light fittings. In many cases, existing dimmer switches don’t work well with newer LED bulbs. Unlike incandescent bulbs, which dim indiscriminately, LEDs either dim or they don’t. If a LED bulb is used with an incandescent dimmer switch, the bulb may only work at full brightness, may hum or flicker at certain levels or may even not turn on at all. This is due to the complex circuitry of the LED’s built-in driver. Although it is the driver which dictates whether an LED product will dim, the driver’s performance largely depends on its compatibility with the dimming device. The driver must be designed to understand and interpret the signalling by the dimming device for dimming to occur.

Another decision you will have to make will involve finding the balance between cost and control. For example, a DALI network arguably provides the best user experience, but the advanced technology that facilitates this can come at a higher price than other more established solutions. Once purchased, they’re extremely efficient to run, which should offset the initial higher cost. Ease of installation is another factor if your lighting project is constrained to a tighter timeframe and budget. Certain fittings require dedicated control cabling alongside power cables between fixtures, such as the DMX and DALI options. Furthermore, to gain maximum benefits from a DALI system, all your light fittings should be independently wired, meaning that retrofits, while possible, are certainly more complex. It’s also important to remember that smart bulbs are not designed to work with dimmer switches. They have a built-in mechanism that will conflict with a wall-mounted dimmer, causing the bulb to flicker, hum or simply not turn on. Using the app or included remote will avoid these common concerns.

At SERA Technologies, our team of experts can advise which dimmers are compatible with your chosen fittings, and vice versa. Send us a message on our contact page or via the Live Chat at the bottom of your screen, and we’ll ensure you don’t purchase incompatible products.

If you have any further questions or would like help from our experts, Contact Us.

We have a wide range of LED Lighting to suit your needs. Browse through our online shop.

Shop Now