I have some MR16 (GU5.3) halogen spotlights (non-dimmable) at home and they are pretty power hungry. I want to replace them with non-dimmable MR16 LED lamps. I would have thought that it would be as simple as a straight swap for the lower-power LED replacements. However, in some articles I have read that the transformers for the halogen lights might not drive the lower-wattage LED lamps. I am sceptical. The halogen and LED varieties both run on 12V. Doesn’t the lower power demand of the LED lights mean that they will work fine with the existing transformers? I did not know that drawing too little current from a transformer for it to work properly was a thing.
Another difficulty I have just read about is that the 12V supply for the halogen bulbs is probably unrectified, although I do not really have a way to check easily. Apparently there are some MR16 LED lamps that can be swapped into an unrectified supply, but are at least four times more expensive than the simple type.
If the supply is unrectified, I either have to buy the more expensive lamps or replace the transformer(s), making this a lot less economical than I had hoped, and more of a pain to do.
Old or cheep electronic transformers don’t regulat below a rated wattage, and just flicker so have to be upgraded when you go led , pull one out and look at its power rating, or just use one of the old ones for all the lamps , if you can get a wire in .
As for a dc only mr16 I have not had that problem , but iron lighting transformers and old electronic ones have a prity grim output and probably best to replace
Halogens are use so much electric that replacement will pay for itself quickly.
Fittings with built-in transformers are only £12 a throw from tlc I will get them for you on my trade account if you want
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I did exactly this in my flat. Some of the transformers coped, some did not. Most were the same make/model and it was pretty random. There were a few of another make that did not work at all.
The easiest thing IMO is to remove the transformer and replace it with a 230V housing and LED bulb (GU10 rather than MR16). The GU10 are much the same price if I recall correctly.
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Thanks for the replies.
The trouble with re-doing the wiring is that it is accessible in the ceiling only through the narrow apertures of the light fittings themselves, or from above by moving furniture and ripping up carpets to get under the floorboards. Both methods seem problematic to me. I think the wiring was done from above at a time when there was no carpet or furniture up there.
You should be able to just yank the transformer out through the hole (have a hoover on standby) and replace it from there. The whole fitting comes out (it’s held in place with a spring) and then you’ve enough room for manoeuvre to get stuff through the hole.
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It should be possible thrue th holes, if it’s installed right.failing that a shunt on the back of the bulbs will do it