LED Lighting & Controls

LED Lighting while being beneficial in a lot of ways, primarily output and efficiency output versus the energy consumed brings with it, a whole new set of issues that we at ATPL, in the business of lighting controls have to deal with regularly. Since the LED juggernaut is rolling on with no signs of stopping, it is best that we understand that everything (Lighting) in a project is going to be LED and prepare ourselves accordingly.

Just because we have dimmers does not mean that LED fixture will dim!

One of the most common misconceptions among end users is that if they have opted for Lighting controls, the LED lights purchased will dim. It is necessary to inform them that not every LED light is dimmable. In fact, the majority of the LED lights that are available in the market today are not fitted with dimmable drivers. One question that everyone needs to ask when purchasing an LED lighting fixture is “Is it dimmable”?

This brings us to the basic question - What makes the LED light dimmable? or

'What comprises of an LED fixture'?

In short, an LED Lighting fixture comprises of:

a) The Light Engine – which is the LED chip that emits light when current passé through it

b) Power supply or Driver that supplies the right amount of current through the LED chip

c) Heat Sink and casing, that ensures the right temperature for a longer life of the LED chip. It is the 

LED driver that receives the dimming signal from the dimmer and varies current or voltage accordingly to allow dimming of the light output. The LED driver either maintains a constant current or a constant voltage while varying the other, to vary the light output from the LED engine.
The type of dimming signal varies and is again dependent upon what the driver will accept. The common types prevalent in the market are 1-10 volts, phase controlled dimming (line voltage dimming), DALI dimming and DMX dimming. Please be clear that the dimming signal types does not have a bearing on the quality of dimming. The capability of the dimmable driver to a large extent determines the dimming quality and that its capability comprises of parameters that have to do with consistent performance and light output (Flicker free dimming) over the stated range of dimming signal.