Advice on dimmable LED drivers

Do you need LED Drivers?

If you are changing your MR16 12volt halogen lamps to MR16 LEDs then you will undoubtedly wonder whether you need to buy specialist drivers. The LED driver suppliers will most probably say you do but clearly they have a vested interest in making a sale, but the answer lies in the technology inside your LEDs. If the LED MR16 has an internal driver that can accept both AC and DC input of 12 volts then you do not need the LED driver however conversely if it does not have the internal driver it will normally work with a standard halogen transformer but you will see inefficiencies and a reduction in lifespan. To add more the reduction in life is normally quite drastic, of the order of 50% so do check the specification of the LED MR16s ideally before you purchase them. LED drivers are not cheap so it is always worth purchasing LEDs with internal drivers as the overall cost of service will be lower. However this is just the case for non-dimmable MR16 LEDs and the dimmable variety are more complex so please read on.

Dimmable LED Drivers

If you are investing in the dimmable LED MR16 then these are far more sensitive to the choice of driver and indeed the dimming switch. LED lamps use very low currents and accordingly the drivers need to operate at very low wattage which generally requires a specialist driver. If you run a dimmable LED of a standard halogen dimmable driver then the chances are it will flicker which you turn it down and it will not operate smooth whilst you dim the lamp. This is primarily because the halogen dimmer is designed to operate at higher wattage so one way to overcome this issue is to put a dummy lamp or resistance in parallel to the LED so increase the load. This can often work but then you are burning energy to run the dummy lamp which is then negating the benefit that you would have  accrued by moving to LEDs in the first place!

So the best solution is to use a specialist dimmable LED driver and compatible dimmer switch.  The best way to go about this is to actually purchase drivers and dimmers that are compatible and tested with the lamps as this way you can be assured that the operation will be satisfactory. However if this is not possible then there are some steps worth taking. Firstly, check the VA rating of the dimmer and try to make sure that the total loading from your LEDs is just less than this rating. For instance if you have a 20VA LED driver and 6W LED MR16s then it would be best to use 3 lamps. The second step is to ensure that you use a dimmer switch which can operate in the range of the total loading of the sum of the LED wattage that it is controlling. So these are 2 good guidelines but I would still recommend that you do a test before investing or check there is a return policy.

For these reasons we have elected to offer a dimmable LED driver which is compatible with our MR16 LEDs as this can save a lot of pain.


2 thoughts on “Advice on dimmable LED drivers”

  1. Hi!

    I am looking out for some information. i want to know that PL lamps can run on dimmer system???
    It can be run through ballast but it starts flickering when its low/dim.
    Is there any other option that we can run pl lamps without flickering ????

    1. Hi There

      At present standard PL lamps use the CFL technology which is inherently not dimmable. There are some lamps which are dimmable for example the 25w spiral dimmable we have on the website but these need special dimmable drivers built in to make them work. Also this makes them more expensive. I have not seen these as PL lamps as yet.
      The other option is the LED PL lamp but the surface mount SMD LED’s are also not dimmable. Hopefully in time the manufacturers will bring out a dimmable version!!

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