What Makes An “LED Compatible” Dimmer Switch?
What Makes An “LED Compatible” Dimmer Switch?
Firstly, you need to make sure your led dimmer switch" href="led-dimmer-switch.html">led dimmer switch operates on either leading edge (MLV) or trailing edge (ELV) dimming technology. Selecting the correct dimmer type and dimming technology is crucial for compatibility with dimmable LED bulbs, ensuring smooth operation and preventing issues like flickering or reduced lifespan.
If you’ve got an old inductive dimmer switch it’s never going to work with LED lights. These two slightly different styles of dimming are known as TRIAC or mains dimming.
They dim the lighting by adjusting the voltage or current supplied to the lights, which is essential for achieving smooth dimming with dimmable LED bulbs. Compatible LED drivers play a key role in this process, helping to regulate power and prevent flicker or damage. When the lights are being dimmed, the voltage gets cut off so fast that the lights are flickering, but too fast for the human eye to see. For best results, always use dimmable LED bulbs and ensure the dimmer type and dimming technology match your LED setup.
How ‘Leading Edge’ Dimmers Control LED Lights
Leading edge dimmers cut off the voltage at the beginning of the sin wave and trailing edge cut off the voltage at the end. This diagram shows the difference between leading edge and trailing edge.
Leading edge dimmers are traditionally used with incandescent bulbs and halogen lamps, especially on mains voltage circuits, due to their compatibility with the electrical characteristics of these light bulbs. Leading edge dimmers contain a coil and can buzz slightly. This can be annoying, particularly in a living room or bedroom. Leading edge dimmers such as the Varilight V-Com are able to take much larger loads, even up to 600 watts on one switch, making them suitable for various light bulbs, including incandescent and halogen types.
What About ‘Trailing Edge’ Dimmers?
Trailing edge dimmers contain solid state components and are virtually silent, offering smoother dimming thanks to advanced trailing edge technology designed for silent running. These dimmers are compatible with capacitive loads, such as electronic transformers commonly used in LED lighting, making them ideal for modern lighting setups. They tend to operate better for lower lighting loads of up to 100 watts of LED and some can dim just 1 LED. Many trailing edge dimmers also feature soft start functionality, which provides a gentle transition when lights are turned on or dimmed, enhancing lamp longevity and ensuring smooth operation. Advanced features like multi way dimming and the option to use a dimmer module for integrated lighting control setups are also available. The latest dimmer switch has zero minimum load.
But just because a dimmer switch is leading edge or trailing edge it doesn’t mean it’s an LED dimmer switch. Modern LED dimmer switches such as the Zano ZGRIDLED, Varilight V-Pro, V-Com or V-Pro Multi-Point and Hamilton Litestat are programmable. This means that you can tweak the settings of the dimmer to match the type of LEDs and the load (wattage) on the circuit. They’ve all been extensively tested to offer a broad range of dimming compatibility with the most popular LED lighting brands.
The Dimmer Switches We Sell Are Incredibly Advanced
Although the Varilght V-Pro looks like an ordinary dimmer switch with a rotary knob, it’s far from basic. The settings can be easily adjusted by turning the knob in a sequence (click here to view the operating instructions).
This allows you to change the drive mode settings from leading edge to trailing edge. But the leading edge mode isn’t true leading edge, it’s a modified leading edge with no TRIAC, that’s why they also have the V-COM model which is true leading edge, born and bred. Other functions include the ability to trim off any nuisance flickering that might be happening. Users can fine-tune the light output and achieve flicker-free dimming even at low light levels, ensuring smooth operation and comfort in various lighting environments. Flickering can sometimes still happen when the load is very low and when you attempt to dim the lights to a very low setting. Additionally, reducing light output through dimming can help lower energy consumption, making your lighting setup more efficient.
Why LED Lights Flicker & How To Solve This Problem
Dimmer switches struggle to detect that there is any load on the circuit which causes flickering, strobing or flashing to happen. With a programmable dimmer switch, you can trim off this and delete it from existence. This won’t allow you to dim the lights to a certain level of say 1–20% but it will solve your problem. This video below shows how easy it is to program the Varilight V-Pro:
Some minimum load or flickering issues can be solved by putting a resistive load on the circuit. One way of testing this before ordering one is to replace one of the LEDs on the circuit with a halogen. If the halogen stabilises the load, then the resistive load should work and resolve your problem. Addressing these issues ensures you achieve the right lighting atmosphere and comfort in your space.
Remember – Not All LED Lights Are Dimmable
Not all LED lights are dimmable, some manufacturers still offer versions that are non-dimmable which cost slightly less. I once incorrectly predicted that all LED lights would become dimmable as standard, just like incandescent and halogens are, but this didn’t happen as non dimmable are cheaper. In a price conscious world the slight saving on offer has proven me wrong. Although this is happening more-so with integrated LED downlights. Some dimmable LED bulbs operate on low voltage and require compatible dimmers and drivers for proper and safe operation. We state clearly on our website, which LEDs are dimmable and which ones are not.
Loading Advice & “De-Rating” Dimmers
An LED load is different to a halogen or incandescent due to its high inrush currents and current spikes. An LED load needs to be treated as if it’s much higher even though it consumes less energy. For optimal performance with LED lamps, it is important to use LED compatible dimmer switches, as these are specifically designed to handle the unique requirements of LED lighting. You either need to de-rate the dimmer switch or overrate the LED.
Some manufacturers recommend to de-rate the dimmer switch to 10% of its load, so a 400 watt dimmer would be rated at 40 watts when dimming LEDs. I’ve found this rule to be useless as it still doesn’t mean an LED will dim smoothly and 40 watts of LED doesn’t equate to many lights, it’s not even 7× 6 watt LED downlights.
Varilight also had their own de-rating system but they’ve now rated all of their dimmer switches for LED loads to begin with. The V-Pro can dim up to 120 watts of LED and they have a high output V-Pro that can handle 300 watts. Something else to watch out for is that the V-Pro will only dim between 1 and 10 dimmable LEDs. This is just a guide as I’ve known instances where up to 14 of the Aurora Ice 5W GU10 LED have been dimmed successfully but it does depend on the brand of LED that is used. Generally Aurora lights work well with home automation systems like Lutron and Lightwave.
Although the Varilight V-Pro no longer has a minimum load, it did used to be 10 watts for halogen and 2.5 watts for LED. Other brands have their own set of rules to follow as they play catch-up to Varilight.
Further Reading On LED Compatibility With Dimmer Switches
Even if you completely understand all of the science behind dimming and sine waves it still doesn't mean you can successfully match an LED light to a dimmer switch. Some combinations are simply not compatible and don't work. We stick with only trusted lighting brands that we're familiar with and are happy to offer technical support about compatibility.
You can't go too far wrong with the Varilight V-Pro for loads of up to 120 watts and the Varilight V-Com for loads of up to 600 watts. They're the bullet-proof universal dimmer switches and remain the benchmark for LED dimming compatibility.