12V Lighting transformers (for 50W MR16 bulbs)

[Boac]

Just had my second of four go - do these things have an expected 'life'?

[llondel]

About a month past the warranty period.

[CharlieOneSix]

About 3 years ago I changed all my 50W 12V Halogen MR16 bulbs with transformers to 5W 240V LED GU10 bulbs - there were about 30 of them. Well worth doing for the saving in electricty consumption and they don't use transformers. A complication with mine was that the existing huge and ugly golf ball fittings left unusually large 95mm holes in the ceilings so I fitted Eterna CR80WH converter plates which will cover holes from 70-140mm - as below:

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The converter plates came with everything necessary to change from MR16 to GU10 fittings but bulb purchase is separate. Looking online I see that the price of 5W GU10 LED spotlight bulbs has tumbled since I bought them. I have had only one fail since they were installed and that was within the 3 year warranty so it was replaced.

This video might be useful if you go ahead - it's South African but just as applicable in the UK although the fittings are slightly different. We found that a warm white colour temperature bulb was best - 3000K. Cool white was too unfriendly.

[Boac]

C16 - excellent stuff, thanks. I have been toying with that change for a year or so but putting it off because... well, you know........... I'll do some Amazoning.

[Pontius Navigator]

BOAC, interesting, I had fitted two transformers into a range of kitchen cupboards. One set along the top, one along the bottom. The cable for the bottom was not long enough. I got around that by mounting it in the double bottom of the plate rack I made. When we sold the house I never told them where it was. They could have fun. They will have been in place a good few years now.

But more useful, I have display cabinet and its lights failed. I had assumed a fuse. I will need to change the lights instead.

[Boac]

C16 - convinced! I have ordered 1 to see how it goes. I have an 80mm cut-out so it should be fine. Thanks again.

[CharlieOneSix]

I did just one in an unused bedroom first. It is a different output from halogen and the difference will soon annoy you! I bet you end up doing the other three....

[Boac]

I'm sure I will. The 'output' is not that important - I'll probably go for the around 4500k 'cold'. It's a 'working area'. Bulbs now to source.

[CremeEgg]

Spend alot of my life dealing with such issues. Historically I've always paid more for a decent transformer say 7GBP rather than the usual ones at half that price and used ones rated at say 70W for a 50W lamp; better longer life rather than running at 100%. Never had a failure in 20 years. The cheaper contractor style transformers beloved of kitchen fitters I'd give a good life of 5 years.

First fitted LEDGU10 lamps about 15 years ago when the best you could get were around 45GBP a lamp and were so dim that you had to put them about 18"/450mm apart to get any decent light from their 1.5W rating. Now down to around 5GBP - beware anything cheaper - always use a recognised brand - I use Megaman in the UK. Their 6W gives out 650 lumens - better than a 50W halogen. A few years ago you were struggling to get anywhere over 300 lumens off a 7W lamp.

MR16 halogen lamps tend to be yellower around 2700K colour temperature or what the manufacturers marketing people call "warm white". GU10 lamps come in a variety of colours from 2500K warm white through to a "cool white" around 4000K to a bluey daylight at 6000K - although true sunlight is around 10,000K when overhead in Ex-Ascot land. Beware what the true colour is as some brands warm white are really a shade of yellow - or as one customer said to me when I put in warm white "they are not warm white they are tumeric!".

GU10 downside is that the beam angle is fixed at around 40 degrees whereas MR16 lamps could be obtained with beam angles varying from 8 degrees up to about 90 degrees. Used 8 degree ones in the local dentist so that patients wouldn't be blinded by glare when "relaxing" in the dentists' chair.

Prefer to use individual GU10 lamps in a variety of holders rather than all in one integral LED fittings - when they go will the manufacturers still be around and producing identical models? Doubt it. No such issues with individual lamps - all built to an industry size standard. As others have stated all manner of hole coverings available to cover up old fittings. LED certainly huge energy savers using around 10% - some shops complain of needing more heating after swopping out the halogens.

If you want to dim LED's make sure you get dimmable versions and you may need new dimmers - depending on whether they are leading edge or trailing edge dimmers. A whole minefield awaits.

[Pontius Navigator]

I bought some unbranded GU10 and only one failure after we moved house. What is different with these it they have lots of small nodules that act like magnifiers.

As BOAC said, cool white for work areas.

[Boac]

LED bulbs have arrived (being Amazonian) but 1 x fitting due later this week being Flea-bayed. Will update on progress, but I'm sure C-16 is correct and I will change all 4.

[Boac]

C-16 - fitting arrive d today and is 'assembled' ready to fit when we come back on Friday. An excellent price on Ebay and a clever product. I expect to be ordering the other 3 on Friday

[Pontius Navigator]

My son in law made an interesting observation this weekend (probably not original) but with so many things now being 12 volts for which we use built in or plug in transformers why aren't houses built with a 12 volt circuit as well as a 240v circuit for the kitchen and bedroom (hair dryers etc)?

[ian16th]

My son in law made an interesting observation this weekend (probably not original) but with so many things now being 12 volts for which we use built in or plug in transformers why aren't houses built with a 12 volt circuit as well as a 240v circuit for the kitchen and bedroom (hair dryers etc)?

Things are getting that way, but towards USB charging connections.

I bought a cheap small bendy LED desk lamp, when I got it home I discovered that it has a USB charging point.

[Pontius Navigator]

At least with USB we now have a standard female socket on our 240v wall sockets and the industry is starting to move towards the USB C male for devices. These are all 5v so 12v devices such as my BT landline phones, Amazon Echo Dot 3rd Gen, BOSE speakers etc are all 12v and need transformers still.

[PHXPhlyer]

A friend of mine went semi-off grid almost thirty years ago, high up in the Wasatch Mountains of Utah. He built an cabin based on Forest Service lookouts. He wired it dual voltage, 120V for electrical service until winter storms cut it, and 12V for early solar installation. In winter they had to x-c ski or snowmobile out to the highway. Water from a creek until he was able to build a cistern. Pre cellphones, they used 2 meter ham radios to keep in touch when he went into SLC to work.
A wonderful builder and craftsman.

PP

[llondel]

My son in law made an interesting observation this weekend (probably not original) but with so many things now being 12 volts for which we use built in or plug in transformers why aren't houses built with a 12 volt circuit as well as a 240v circuit for the kitchen and bedroom (hair dryers etc)?

I am working on that concept here. A 12V bus with a float-charged battery on it (so actually 13.8V) capable of powering lighting in various parts of the house, plus some of the computer infrastructure. Your main problem is volts drop in the wires if you're pulling a lot of power. I even considered buying another solar panel - 250W peak output would run a fair bit while charging the battery to be used for the rest of the time. I'd have to figure out where to install the panel though, no room on the roof for more.

[Pontius Navigator]

Inspired by the topic I bought some new LED for my cabinet. 12vDC, each 3w, with multiple LEDs.

[Boac]

C-16 - all fitted and the other 3 on order. My mistake was to go for 5000k which is too 'white'. 3000k on their way. Thanks for the 'nudge'.

[CharlieOneSix]

Glad it worked out Boac. When we moved here 24 years ago we immediately converted the loft into additional bedrooms and an ensuite. There were three 'borrowed light' rectangular panels in the downstairs hallway ceiling which had opaque plastic in them and they took light from three Velux windows in the roof. The panels couldn't be left like that after the conversion so I had fake stain glass panels and new surrounds made and they were backlit with two fluorescent tubes behind each panel. I changed those a couple of years ago for two 900mm LED tubes in each panel - well worth doing and Mrs C16 no longer grumbles about her susceptibility to fluorescent tube flicker - which I never noticed!

In the photo below you can see two of three remaining small halogen fittings over the bar area. I can't change those to LED as I hadn't realised that when upstairs was the loft the previous owner had nailed the transformers to the joists. Unless I take up the carpet and floor upstairs I can't remove the transformers or get hold of the supply wiring. Bummer!

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