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www.ultimatehandyman.co.uk Forum Index -> Electric Forum UK
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MeanMrMustard
Junior Member
Joined: 22 Jul 2008
Posts: 3
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 Posted: Tue Jul 22, 2008 2:35 am Post subject: Problem with 12v LED downlight replacement globes |
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HI, I've recently purchased a number of LED 12v globes to replace the standard 50w downlights I have in my home.
I was under the impression that these LED globes would work as a direct replacement..... not the case.
After swapping them over and turning the lights back on with the new LED globes in place I get a split second burst of light (the amount i expect they are supposed to put out) but then they just 'glow' giving practically no 'light'.
Is this a transformer issue? is there any way to modify the exisiting transformers to suit the LED globes?
Any help would be greatly appreciated.
Cheers. |
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Rich-Ando
Approved Electrician
Joined: 24 Mar 2007
Posts: 2483
Location: Derby, Derbyshire
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| Posted: Tue Jul 22, 2008 8:59 am Post subject: |
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hi MeanMrMustard  to the forum.
if you could post a link to what they actually are with all of the tech info it would help us a little more.
the only thing to be aware of is that LED lights are no where near the same brightness as halogens. they are more of a decorative light. |
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MeanMrMustard
Junior Member
Joined: 22 Jul 2008
Posts: 3
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| Posted: Tue Jul 22, 2008 9:55 am Post subject: |
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HI Rich,
Thanks for such a speedy reply!
I've found this information on the LED MR16 12v 20LEDS white globes I've purchased..............
Run on 12Vac using standard MR16 ( GU5.3 ) connector. Will fit standard downlight or ceiling light.
Start saving money by turning off those mini Halogen heaters and replace them with these low current LED lights.
· Save Energy, Save Environment, Save Money
· Low Power, Low Heat ( approx. 1.2 Watts ).
· Lifespan greater than 20,000 Hours.
· Current consumption : 80mA.
· Color : cool white ( 6000K )
· Brightness : 43 Lumens.
· Number of LED : 20
*****************************************It is recommended to use these 12Vac LEDs with wire wound magnetic transformer ( normally much heavier unit ).
NOTE : These 12Vac LED lights might not work with more modern 12Vac electronic switching transformers. It is because these electronic transformers will not start up with very low load. Experiment has shown that it has worked if you connect more than two of these LED lights in parallel to one electronic transformer. Or alternatively is to connect one or two LED lights in parallel with another low wattage Halogen globe.
Please also note that these LED lights also work with DC voltage but will only attain full brightness when the supply voltage is between 15Vdc to 20Vdc. Using a 12 V car battery on these LED lights will only give half brightness*******************************************
I guess it answers part of my query! pretty sure the transformers I have are the 'light weight' el cheapo's. It meantions I may be able to have success if I run multiple globes from a single transformer? any thoughts on this?
And if so... whats the correct proceedure to do this?
Cheers |
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Rich-Ando
Approved Electrician
Joined: 24 Mar 2007
Posts: 2483
Location: Derby, Derbyshire
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| Posted: Tue Jul 22, 2008 12:41 pm Post subject: |
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what area are you intending to light with these? if it is a main area you are going to be seriously disappointed from how dark it is.
i would say that whoever sold you these as a replacement has mislead you.
a few articles recently have said they are managing to massively improve the Lumens output of LED's but when you look at this above: -
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| Brightness : 43 Lumens. |
that is a comparison of 43 Lumens to anything like 1000 Lumens per 50Watt halogen lamp. you can probably already see a physical brightness difference without even turning them on now.
if you require a light equivalent comparison and also taking saving money on the running costs, try looking for CFL fittings. they look exactly the same as you already have with halogen spots but are like little fluorescents. they need to be about 11Watt ones to match the 50Watt halogen and the light output is more even. the halogens tend to spot the light, CFL lamps bounce the light off each surface giving a more even light. |
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MeanMrMustard
Junior Member
Joined: 22 Jul 2008
Posts: 3
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| Posted: Tue Jul 22, 2008 12:58 pm Post subject: |
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I was hoping to use them as replacement globes in my bedroom, living area's, kitchen etc....
wow.... 43 Lumens compared to 1000? Geeeeezz...
I have them now I guess, I might try and wire a few into a single transformer and see how it goes... |
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Stoday
Electricity economics consultant
Joined: 20 Jan 2006
Posts: 3080
Location: Sitting on the Bog
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| Posted: Tue Jul 22, 2008 4:55 pm Post subject: |
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43 lumens? That's a high output for a LED lamp.
At least you were quoted a value for the light output; most LED lamps don't. Maybe because the lamp power is so small and the lamp so dim that the Lamp Regulations don't apply.
Doubtless BAS would like to know that the Energy Information (lamps) Regulation 1999, SI 1517, requires lamps of over 4W to state their lumen output. |
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Rich-Ando
Approved Electrician
Joined: 24 Mar 2007
Posts: 2483
Location: Derby, Derbyshire
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| Posted: Tue Jul 22, 2008 5:03 pm Post subject: |
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| Stoday wrote: |
Doubtless BAS would like to know that the Energy Information (lamps) Regulation 1999, SI 1517, requires lamps of over 4W to state their lumen output. |
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