TRIAC Dimmable LED Drivers

TRIAC Dimmable LD Drivers
Installation Advice

The term “TRIAC dimmable LED driver” tends to be used to refer to a LED driver that is compatible with leading edge, or trailing edge dimming switches.  

What you actually need is a “Phase Cut Dimmable LED driver”. 

ADM stocks a wide range of phase cut dimmable LED drivers, which are compatible with most of the leading edge and trailing edge dimmers used in Australia. You can browse our product range by clicking on the following link: 

Phase Cut Dimmable LED Drivers 

Mean Well PCD-16-700B TRIAC dimmable LED driver
Indoor Constant Voltage TRIAC dimmable LED driver
Outdoor Constant Voltage TRIAC dimmable LED driver


Leading edge dimmers use a TRIAC (triode for alternating current) switch to control the power. Which, of course is where the term “TRIAC dimmable LED driver” comes from.  

However, trailing edge dimmers use a completely different technology, typically using MOSFETs or IBGTs to control the power. Hence, why the term “TRIAC dimmable LED driver” is not always an accurate description. 

When buying a phase cut dimmable LED driver it is advisable to ascertain that it is compatible with the dimmer switch you intend to use before buying.  

Reputable brands, such as MEAN WELL and Power Source publish details of dimmer switches that their LED drivers are compatible with.  

However, it is advisable to test the compatibility for yourself. Especially, if you are designing or installing a lighting system that is going to use multiple dimmers and drivers. 

Why use a Phase Cut (TRIAC Dimmable) LED Driver?

Phase cut LED drivers that can be used with leading edge (TRIAC) dimmers and leading edge dimmers that you find in most homes. This means that they are ideal if you are retrofitting LED lighting and want to be able to use the existing wiring and dimmer switches.

They are also used in commercial retrofit projects. 

Most modern lighting control systems use either an analogue control signal, such as 1-10V, 0-10V or PWM to control the LED drivers, or the DALI lghting communications protocol. Typically, when installing LED lighting in a commercial project you will find that 0-10V, 1-10V, or DALI LED drivers are used. This sort of installation requires dedicated wiring to be run from the control systm to the LED driver, which means internal walls and ceilings need to be removed and replaced.

With heritage sites it is not always possible to tear down walls and ceilings to run new wires. So, a solution that can work with existing wiring is required. 

Phase cut dimmable LED drivers are ideal because they don't require any dedicated wiring to be run to the LED driver. They can just be hooked up to the existiing wiring. If a DALI system is being used, then a simple DALI to trailing edge dimming converter can be installed, such as the Hytronik HDD2200.

phase cut dimmable led driver and DALI to trailing edge dimmer wiring diagram

This will take the commands from the DALI lighting system and then 'chop' the AC phase to effect the required dimming.

Questions About TRIAC and Phase Cut Dimmable LED Drivers

If after reading this article, still have questions regarding AC phase cut dimmable LED drivers or the term TRIAC dimmable LED driver, then please do not hesitate to contact ADM on 1300 236 467.

Our expert team is on hand to help you select the most appropriate LED driver for your application, and to answer any questions that you may have.  

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Power Source


30 April 2019