MR16s & GU10s

flyingscotno1

elstimpo wrote: »

All i can say is that 320 lumens is not going to replace a 50w Halogen. Won't get anywhere near.

Having bought them I'd totally disagree, they match excellently for brightness and I'd struggle to tell the difference. Most definitely brighter than 35W and right up there with 50W ones. Been excellent replacement for the Halogens we use for a long time.

Only struggle would be to find a dimmer to cope with the LEDs but they aren't on a dimmer.

elstimpo

flyingscotno1 wrote: »

Having bought them I'd totally disagree, they match excellently for brightness and I'd struggle to tell the difference. Most definitely brighter than 35W and right up there with 50W ones. Been excellent replacement for the Halogens we use for a long time.

Only struggle would be to find a dimmer to cope with the LEDs but they aren't on a dimmer.

Ok, well i've never seen anything less than 7w properly replace a 50w Halogen and that had 550 lumens. In fact in 12 years, i've only ever seen one LED product properly replace a 50w Halogen. Halogens have around 800 lumens, well under half that won't properly replace it.

However, every human eye see's light differently, which is the key here. Whilst the facts and the figures would prove the lamp in question doesn't replace a 50w Halogen, but that doesn't matter if the product you have found works for you and suits the purpose you want it to. A lot of people who want a 50w halogen replacement, don't realise that you might not need an actual (in terms of performance) 50w replacement in order to light your area properly. If you have all 60w incandescent bulbs in your home and you switched them all to 40w, initially you'd think they are too dull, but give it a week and quite often your eyes will adapt and you won't need anything brighter.

So, i'm happy you have found an LED product you like and enjoy and suits your application :T

elstimpo

flyingscotno1 wrote: »

Only struggle would be to find a dimmer to cope with the LEDs but they aren't on a dimmer.

You would need a specialist LED dimmer driver for each individual spot.

flyingscotno1

elstimpo wrote: »

Ok, well i've never seen anything less than 7w properly replace a 50w Halogen and that had 550 lumens. In fact in 12 years, i've only ever seen one LED product properly replace a 50w Halogen. Halogens have around 800 lumens, well under half that won't properly replace it.

Is it maybe to do with lumens not being quite the right way to measure LEDs as many manufacturers including Phillips are quoting more representative Candela figures rather than lumens? Doesn't matter anyway really these were bulbs are very good, far better than other LED efforts so far.

Having tried different bulbs at the same time, I've seen a difference with others and these are perhaps a tad lighter than the 50w but difficult as it is a more yellow colour and not as pure a light. Definitely as bright as the 35w, IMV but I could never see a big gap between 35w halogens and 50W ones- indeed the store I worked in scrapped 50w a few years back.

Are we not getting to the stage where dimmers are working without drivers- certainly some are on sale? Not something I'm worried about anyway.

elstimpo

flyingscotno1 wrote: »

Is it maybe to do with lumens not being quite the right way to measure LEDs as many manufacturers including Phillips are quoting more representative Candela figures rather than lumens? Doesn't matter anyway really these were bulbs are very good, far better than other LED efforts so far.

Having tried different bulbs at the same time, I've seen a difference with others and these are perhaps a tad lighter than the 50w but difficult as it is a more yellow colour and not as pure a light. Definitely as bright as the 35w, IMV but I could never see a big gap between 35w halogens and 50W ones- indeed the store I worked in scrapped 50w a few years back.

Are we not getting to the stage where dimmers are working without drivers- certainly some are on sale? Not something I'm worried about anyway.

I've just come back from the 2011 Hong Kong Lighting Fair. One of the aspects i was most interested in this year was to see how the dimmable LED Spot had developed (those that don't need a driver). There really wasn't much there as it's incredible difficult to do.

There was one 6w version i saw, that i am getting samples on but in general of the LED Spot products i have seen that are dimmable without a driver, i wouldn't sell any of them for my business. Usually they don't dim in a smooth manner, they can flicker at certain points of the dimming process and i would worry about the lifespan of a product like this. I have a 5 year warranty on all products that i sell so i can't take a risk on something like this and my head engineer has constantly warned me away from them. If you want LED Spot that can be dimmed, the best thing you can do is buy the LED Spot that suits you and then get the drivers fitted to your circuit. It's the only way i would ever suggest anyone dimm's an LED spot (at present).

I am putting together a package at the moment for our top of the range LED Spot, the dimmer driver and then a system which means you can have 5 different pre programmed settings for up to 8 different rooms and control the lighting for the entire house, flat, restaurant etc from your phone, laptop or ipad. It's very cool stuff.

One thing to consider is that dimming a lamp of any kind is only for effect. You won't see any energy or cost savings by running a lamp at 50% of it's performance. The usage costs will be exactly the same no matter how bright you run them.

In terms of Lumens, i think they are actually a very good way for people to understand how bright a bulb is, but beam angle is a critical aspect for an LED Spot.

The main thing is that a huge % of people use lights that are far too bright than they need to be, but their eyes have become accustomed to that brightness. I had a customer buy some 5w LED Spots from me and he put them in to replace his 50w Halogens and was hugely dissapointed. He got straight on the phone and i told him that he should live with them for a week, if he still wasn't happy, he could send them back and i'd upgrade them to the 7w version free of charge. 4 days later he phoned to say that they were absolutely fine and did the job well. This proved he didn't actually need 50w halogens in the first place and had he done the same thing with 35w Halogens, then his eyes would have adapted to them as well.

koru

Thank you to all contributors for a very interesting thread.

I am currently looking at converting the down lighters in our kitchen, having recently realised just how much they are costing me. Each 50 W bulb is on for 5 to 8 hours a day, so something like 2000 hours per year. That's 100 kwh per year. At 12 p per unit, that's £12 per bulb per year.

I have nine bulbs in the kitchen, so I am spending more than £100 per year in lighting just one room! Fortunately, this is the only room where I have large quantities of halogen lights.

I can therefore save £100 per year by switching my kitchen to LED. Not to mention the carbon dioxide emissions saved. LEDs are expensive, but if you are saving £12 per year for each bulb, it won't take long to recoup the cost of even some of the pricier (higher quality) LED bulbs. That's not even counting the further savings from the fact that halogens only last a year or two, so you have quite a lot of replacements to pay for.

My problem is that each of my light fittings has its own individual 12 V transformer which can only cope with supplying power of between 20 W and 60 W, so an LED of maybe 7 W is not going to work. I could replace the 9 transformers with 9 LED drivers, but these cost between £6 and £12 each. Or I could buy 9 new mains voltage downlight fittings, which would cost about the same.

Does anyone know if there is a particular advantage of 12 V versus mains voltage? Obviously, 12 V would be safer in a bathroom, but in a kitchen I would not have thought that this matters much. Mains voltage seems a bit simpler, because there is one less thing to go wrong (no LED driver) and I would guess that there must be some extra power drained in the driver, so mains voltage might have lower power consumption.

elstimpo

koru wrote: »

Thank you to all contributors for a very interesting thread.

I am currently looking at converting the down lighters in our kitchen, having recently realised just how much they are costing me. Each 50 W bulb is on for 5 to 8 hours a day, so something like 2000 hours per year. That's 100 kwh per year. At 12 p per unit, that's £12 per bulb per year.

I have nine bulbs in the kitchen, so I am spending more than £100 per year in lighting just one room! Fortunately, this is the only room where I have large quantities of halogen lights.

I can therefore save £100 per year by switching my kitchen to LED. Not to mention the carbon dioxide emissions saved. LEDs are expensive, but if you are saving £12 per year for each bulb, it won't take long to recoup the cost of even some of the pricier (higher quality) LED bulbs. That's not even counting the further savings from the fact that halogens only last a year or two, so you have quite a lot of replacements to pay for.

My problem is that each of my light fittings has its own individual 12 V transformer which can only cope with supplying power of between 20 W and 60 W, so an LED of maybe 7 W is not going to work. I could replace the 9 transformers with 9 LED drivers, but these cost between £6 and £12 each. Or I could buy 9 new mains voltage downlight fittings, which would cost about the same.

Does anyone know if there is a particular advantage of 12 V versus mains voltage? Obviously, 12 V would be safer in a bathroom, but in a kitchen I would not have thought that this matters much. Mains voltage seems a bit simpler, because there is one less thing to go wrong (no LED driver) and I would guess that there must be some extra power drained in the driver, so mains voltage might have lower power consumption.

My comments in bold, hope it helps.

My problem is that each of my light fittings has its own individual 12 V transformer which can only cope with supplying power of between 20 W and 60 W (ideal for 20, 35 and 50w halogen units but as stated probably not going to work with a single 7w LED; may and only may work, depending on the transformer design if 4-6 LED units are connected in parallel fashion) , so an LED of maybe 7 W is not going to work.


I could replace the 9 transformers with 9 LED drivers but I don't want the cost Or I could buy 9 new mains voltage downlight fittings, which would cost about the same. (Correct, the base fittings would have to be changed to suit GU10 units and the transformers removed, the actual fitting which hold the lamp itself accept both GU10 (240v) and GX5.3(12v) lamps

Do you know if there is a particular advantage of 12 V versus mains voltage? (Not really although 12 volt units can be connected with lower voltage cable and may be easier for the DIYer who is not happy with working with mains voltage. All LEDs are wired in parallel and fed back to one suitable transformer unit which has one mains connection. If necessary the lamps may be run off a back up battery supply directly and of course with the choice/change of one transformer would allow all connected LEDs to be dimmed via a dimmer unit providing you have the correct transformer.

Obviously, 12 V would be safer in a bathroom, (No, bathroom fittings have to adhere to a specific safety standard to protect the occupants, standard non approved fittings must NOT be used in bathrooms. Use of 240 or 12v LED units in bathrooms is perfectly acceptable and safe providing that the codes for the fittings are followed) but in a kitchen I would not have thought that this matters much. Mains voltage seems a bit simpler, (Yes it is, there is only a lamp and a fitting, no separate transformer for each unit) because there is one less thing to go wrong (no LED driver) and I would guess that there must be some extra power drained in the driver, so mains voltage might have lower power consumption. There is a LED driver, it is built into the base of the GU10 lamp; compare the length of a 240v GU10 and a 12v GX5.3. Essentially for most purposes there is little difference in the power consumption for comparable wattage lamps irrespective of whether they are 240v or 12v units.

koru

Thanks for the informative reply. So, if they have squeezed the driver electronics into the stem of a GU10 bulb, I wonder if the compromises of miniaturisation might mean that this might be more vulnerable to failure? Whereas a separate LED driver unit (for 12 V bulbs) is bigger, so it might be more robust?

JC_Derby

has most of this thread been removed?

can anyone give any advice on these?
http://www.amazon.co.uk/gp/product/B005DETSPQ/ref=s9_simh_gw_p79_d6_g79_i3?pf_rd_m=A3P5ROKL5A1OLE&pf_rd_s=center-2&pf_rd_r=0X92A1JGNKZ2T4D4SN8A&pf_rd_t=101&pf_rd_p=467128533&pf_rd_i=468294

or suggest a cheaper/ equally good alternative?

JC_Derby

no one has an opinion?:(