Replacement of MR11 Halogen bulbs with MR11 LED

[jimbobfruitbat]

Hi!
We have 7x MR11 20W Halogen bulbs in our landing ceiling.



I have bought 7x MR11 3W LED bulbs. Each pack is titled "6 Pack MR11 GU4 12-24V 3W LED Bulb, Cool White 6000K, Equivalent to 30W 20W Halogen Spotlight Bulb, 300LM, GU4 Bi-Pin Base, 120°Beam Angle, Non-Dimmable, for Hallway, Living Room" (link to item: https://amzn.eu/d/94faLsX).

I have replaced the Halogen bulbs with these MR11 LED bulbs. They work, however there is a slight flicker. I suspect it has something to do with the transformer. The only transformer I was able to locate, is this "PrimeLine Dimmable Electronic Transformer", which was behind one of the bulbs hidden above the ceiling. None of the other bulbs appear to be attached to a transformer, so I'm assuming this one is doing a job for the chain of 7 bulbs. I don't particularly want to pull up all the floorboards in the loft to find out, especially as the one transformer I did find, came down from the hole very easily, so I'd expect that to be the case for the other six, were they to have a transformer. In fact, there is one other bulb which I can see from inside the loft, and I know for sure that it has no transformer of its own.



The transformer has "20-60W" printed on it, which I understood meant that it would do for 7x 3W LED bulbs (21W in total) without flickering. I'm now thinking, I need an LED driver instead. So, my question is this:

What kind of LED driver should I be looking for, given that I have 7x MR11 LED bulbs?

...assuming it is in fact an LED driver that I need!

 

[quasar9]

You have answered it yourself ! Drivers for halogen can put out quite a rough waveform, ok for halogens but sensitive LED can flicker. The other issue is you are right on the low end of its output which can be causing its own issues. IMHO it’s better to change the whole assembly and use mains voltage gu10 bulbs. These 12volt systems are not as popular as they were years ago.

Look for drivers specified for LED and dimmer if you use one. The bulbs should be dimmable too.

 

[MGW]

One MR11 as LED is rare, as most LED's do not have multifaceted reflectors, this is what MR stands for, straight pins will not have a GU designation the U indicates bayonet fitting, LED's can be AC, seen them marked 50 Hz, but the type with 10–30 volts are normally designed for battery power, and want a smooth supply.

The errors point to the seller not knowing what they are selling, you have clearly just written down what they have said, but no idea as a result if designed for AC or DC and even if a DC power supply will be smooth enough, but have found that using one quartz bulb does seem to often stop the flicker.

I would also say look at using GU10 instead.

 

[FlyByNight]

Muy guess would be that there are possibly 3 transformers tucked away - two each doing 2 lamps - 40w and one doing 3 - 60w. If you can locate them obviously not easy and then try having one tranformer for all seven - 7x3 w = 21w.

 

[jimbobfruitbat]

Thank you for all the replies. The recommendation to swap them all for GU10 is one I've seen before, and I can understand why. For the moment however, I'm going to need to persevere with MR11 in some form or other.

I tried, as an experiment, mixing the LEDs with Halogens, but it made no difference, the LEDs still flicker. For the time being, it looks like we will keep buying old MR11 Halogen bulbs where they are still available and delay making the switch at a later date.