L.E.D Bulbs in Downlights with Transformers

[Westovski]

Hi guys,

Looking for a bit of info if possible.

I picked up some cheap downlights from Wickes the other day that don't need transformers, I was planning on doing some research about why some have and some don't have transformers but they were on often so i picked them up anyway.

I've since been informed by a friend that bulbs go more regularly and they use more electric - first of all, is this true? What are the good and bad points of downlights with no transformers as oppose to those with.

Secondly, is it possible to use the newer LED bulbs in these downlights without transformers or would this simply not work?

Many thanks in advance for any responses.

 

[Westovski]

Forgot to add - they're GU10 fittings if that makes any difference.

 

[ban-all-sheds]

I've since been informed by a friend that bulbs go more regularly and they use more electric - first of all, is this true?

The last part isn't - a 50W LV lamp uses just as much electricity as a 50W ELV one.

ELV lamps tend to have longer lives than LV ones because the filaments are thicker, as they carry more current, and with good quality transformers there's better control over the voltage they receive. But longer is relative - the life of incandescent MR16 lamps is never going to be particularly long.

What are the good and bad points of downlights with no transformers as oppose to those with.

ELV - better lamp life, more expensive to buy, more to go wrong, harder to swap to low-energy lamps.

LV - shorter lamp life, cheaper to buy, less to go wrong, easier choice of low energy lamps.

All of them - dreadful basic design if what you want is general room illumination, because that type of lamp was deliberately designed to actually be no good at that task.

Secondly, is it possible to use the newer LED bulbs in these downlights without transformers or would this simply not work?

If they are LV GU10s they'll work.

 

[TicklyT]

Two of the different 'flavours' of downlighters are GU10 and MR16.

GU10s run directly from the mains, so don't require a transformer. That makes them susceptible to variations in the mains supply voltage shortening the lamp life.

MR16s are usually 12 volt lamps, run from a transformer, or, more usually a switch mode power supply that is often mistaken for a transformer.
The power supply gives a stable optput voltage, that may prolong the lamp life, or allow the lamp to run nearer it's limits, giving a slightly whiter light.

Both are inefficient ways of lighting a room. It often takes several 50 Watt spotlights to give the same ambient light level as a single 60 Watt pendant.

Most mean peppering the ceiling with holes, compromising it's fireproofing and sound insulation properties.

There's also the problem of heat dissipation. The lamps give out a lot of heat, and nees an area clear of any insulation or combustible materials around the fittings.

GU10 and MR16 LEDs are available. GU10s are usually a direct replacement for the TH lamps, but MR16s probably won't dissipate enough power to keep the SMPSs ('transformers') happy, requiring replacement with a specific LED driver.

 

[Westovski]

That's a superb response. Everything I wanted to know summed up perfectly.

Thank you very much

 

[Westovski]

Just to be clear, we're just doing it for aesthetic purposes, we're the kind of couple who have lamps on all the time - barely using the main light, we just wanted to not have a pendant as we've got a projector in the lounge.

Thanks for the responses though

 

[ban-all-sheds]

Two of the different 'flavours' of downlighters are GU10 and MR16.

FYI - they aren't "different" as those two characteristics of lamps are not related in any mutually exclusive way.

GU10 is the type of base, MR16 is the type of envelope. Nearly all GU10 base lamps have MR16 envelopes (you can get MR11 ones, but they are uncommon). Most lamps with MR16 envelopes have either GU10 or GU5.3 bases.


This should be borne in mind if considering a new installation of luminaires using MR16 lamps: http://www.luxmagazine.co.uk/2012/02/low-voltage-halogen-lamps-set-to-be-banned-from-next-year/ (be aware that they incorrectly use the term "low voltage" to refer to 12V lights).

 

[RF Lighting]

ELV lamps tend to have longer lives than LV ones because the filaments are thicker, as they carry more current, and with good quality transformers there's better control over the voltage they receive. But longer is relative - the life of incandescent MR16 lamps is never going to be particularly long.

Of the 5no. MR16 lamps in my bathroom, I have replaced ONE in the last ten years. I would hardly class that as not particularly long.

All of them - dreadful basic design if what you want is general room illumination, because that type of lamp was deliberately designed to actually be no good at that task.

A single light is not good at lighting a room. Several lights do a fantastic job of lighting a room

 

[ban-all-sheds]

If they weren't deliberately designed to be no good at providing general room illumination you wouldn't need several of them.

That you do need several is proof that they are not fit for purpose.

 

[Bill Stickers]

I've got TWO headlights on the front of my car. I guess these mustn't be fit for purpose either.

 

[Diyisfun]

I've got TWO headlights on the front of my car. I guess these mustn't be fit for purpose either.

builtin redundancy
Lots of lighting make for mood & atmosphere, I have some of my table lamps remote controled, its amazing how you change a room by lighting design

 

[ban-all-sheds]

I've got TWO headlights on the front of my car. I guess these mustn't be fit for purpose either.

You should probably cut down the amount of guessing you do - you're clearly useless at it.

You could perhaps use the time saved to consider what are the ideal characteristics of car headlamps, and how they differ in those respects from lights for general room illumination.

 

[Diyisfun]

I think you comment just for the sake of it.

 

[ban-all-sheds]

I think that what goes on inside your head doesn't resemble "thought", and that I really couldn't care less what it makes you write.

 

[RF Lighting]