LED lighting

Scrat

Definitely contains acorns
Anyone had any success with this? Having tried various combinations of corn bulb with hundreds of LEDs in them, I have given up, in the lounge at least. They make the room both light and dark at the same time. Is it their narrow spectrum?

They are fine as reading lights and adequate but not wonderful in the bathroom and kitchen, but otherwise I have returned to CFLs.

Any thoughts?
 

Black Hole

May contain traces of nut
I have just one in the house, bought it the other day for a look-see (£8 at Aldi). It replaces a 40W mini spot bulb. At 5W it seems dimmer than the spot it replaces, but that could be because the beam is not confined - overall it has a greater spread and possibly an greater total luminance. The colour is whiter than the incandescent (but is supposed to be on the warm side).

Overall I am underwhelmed, but with a 25,000 hour life I look forward to never replacing it.
 

Wallace

Traveler 34122
I can now say I have replaced all of my 'old' bulbs with LED. Even down to our bedside lamps. It has cost me quite a lot to do so, but the plan is to save money in the long term.

I previously tried the CFL lamps but they seem to have an 'unnatural' colour tone, plus they don't start with maximum brightness.

The LED's are as close to the colour tone of my tungsten bulbs as doesn't matter, plus the come on with instant maximum brightness.

No problem with light 'spread' either.

As for energy (therefore money) saving, I would give this as an example:

Previously we had six (6) 50 watt halogen down lighters in our bathroom. We now have six 3 watt LED down lighters. There is a slight noticeable drop on light level as you might imagine, but the long term cost saving is self evident.


Sent from my iPad using Tapatalk HD
 

MartinLiddle

Super Moderator
Staff member
Overall I am underwhelmed, but with a 25,000 hour life I look forward to never replacing it.
I was similarly interested and purchased a pack of four GU10 spotlights from an eBay seller for £12 delivered. They are 6W lights and I don't think the light output is quite as much as the 50W lights they replace (maybe 20% down) but adequate. More worryingly one of the lights failed catastrophically with quite a loud bang after only a few hours use, with a power supply problem (the case of a small capacitor had been blown off) and ejected small amounts of solder onto the kitchen table below. So much for the claimed life time. The eBay seller has been bending over backwards to avoid negative feedback with a refund for the failed bulb and another pack of bulbs turning up FOC. No problems with the other bulbs so far.
 

Black Hole

May contain traces of nut
With such a thing from eBay, I would worry whether it was standards compliant (eg CE marked), and if so marked whether it had actually been properly approved or just marked without approval.

At least I'm pretty sure my Aldi lamp hasn't got any horse meat in it.
 

Ezra Pound

Well-Known Member
With such a thing from eBay, I would worry whether it was standards compliant (eg CE marked), and if so marked whether it had actually been properly approved or just marked without approval.

The Mains dropper is likely to be a single capacitor and if you're lucky maybe an in-line resistor
 

Black Hole

May contain traces of nut
Yup, and who knows (from the outside) whether the capacitor is adequately rated, in addition to other factors such as insulation thickness, creep distances, mechanical integrity...

Something available from a shop (and I don't mean the bargain basements of dubious origin, eg B&M) is open to spot checks from Trading Standards. I would not be too concerned about Aldi & Lidl or any of the major retailers.
 

MartinLiddle

Super Moderator
Staff member
The Mains dropper is likely to be a single capacitor and if you're lucky maybe an in-line resistor
There is a circuit board with a large capacitor on one side and a resistor and five or six other components (hard to tell under the mess from the failed capacitor) on the other side. The bulbs are CE marked.
 

Ezra Pound

Well-Known Member
Blimey, that's about as sophisticated as they get, with 7-8 components, I'd say that's the deluxe model :), with a real LED driver
 

Black Hole

May contain traces of nut
You can't run 1W+ LEDs without some kind of controller (not from mains anyway). Battery solutions rely on the internal resistance of the battery to limit the current.
 
OP
Scrat

Scrat

Definitely contains acorns
Not if you want it last any length if time, no



What I don't get is that an LED light rated at 1500lm can be dimmer than a CFL rated at 1200lm.

I agree that there is a substantial saving in replacing halogen bulbs with LED or CFL. We now have no halogen or tungsten bulbs in the house. However, modern CFLs such as the Philips tornado are instant-on. Plus, what with replacing very dim LEDs with dim LEDs, I don't think I have had the benefit of their long life relative to CFLs either. I just seem to have spent money on very expensive LEDs that were not up to the job!

I understand there is a fire hazard with cheap LEDs from China, too.

I have been trying out these recently:

http://www.ebay.co.uk/itm/4W-6W-9W-...85?pt=UK_Light_Bulbs&var=&hash=item870f8a2697

The 20w bulb at 1600lm I would rate at roughly the brightness of a 60w incandescent bulb. The 11w at 900lm is about the same as a 40w incandescent.

With GU10s, I have 8 of these:

http://www.amazon.co.uk/gp/product/B004KRB7XS/ref=oh_details_o00_s00_i00

I would say that they were roughly as bright as 20--30w incandescents. Three are just OK in a small bathroom. Five in our kitchen are pretty inadequate!

I am now writing this bathed in the light of 4 20w Philips Tornados. Bliss!
 

Black Hole

May contain traces of nut
Figures to do with photometry (the response of the human eye to light) are notoriously difficult.

For example, the "Lumen" is a measure of the total amount of light emitted (summed over the whole sphere), spectrally weighted using a standardised notion of the spectral response of the eye. The intention is that the same number of lumens (emitted over the same area) should appear the same brightness if they are in one colour as they would in another.

That should take care of differences in the warmth of light emitted by the various types of bulb - but the dispersion is another matter. A 1000 lumen lamp emitting all it's energy in a spot will be brighter (in that spot) than a 1000 lumen lamp that emits in all directions.

Ultimately I take the figures with a pinch of salt and just try it and see.
 

socrates

Member
I wouldn't be too confident about buying from major retailers - I bought 2 LED spots from Homebase, neither worked so back to CFLs.

That bad experience aside it still seems to be the case that LEDs are not yet a good option for general lighting. Current CFLs are pretty good. We also have 4 Powerstar metal halide lamps in the library, total 280 watts which sounds a lot but I worked out that the equivalent output with CFLs would require at least 400 watt. Still going strong after 10 years. Drawbacks are the 10 minute warm up and the 30 minute restrike time so not suitable for most locations.
 

AndrewB

New Member
They make the room both light and dark at the same time. Is it their narrow spectrum?

Most nights our house is 100% LED lit now. But I've found enormous variation in the light "quality" (for want of a better word). Aside from the brightness and colour temperature, I think colour rendering index (CRI) is an important thing to consider, which seems to describe the "narrow spectrum" that you mentioned - but most LED bulbs don't quote their CRI.

Worst: at the budget end, we've got some B&Q own-make GU10s that come in a 3-pack. These have multiple (12 ish) surface mount LEDs visible. Brightness is OK; but they seem to strobe (although I'm quite susceptible to it - some people don't see it). OK, but I wouldn't buy again.

Medium: in the middle budget, we've got some of the Ikea small screw (SES) own brand. Made in India is the only clue to manufacturer. Colour temp and CRI is good; no strobing either; just a tiny bit on the dim side if anything. But I'd recommend them.

Best: invested in some Philips gear for the lounge, namely this one. Highly recommended. I couldn't fault it at all. The construction seems to rely on a heavy phosphorescent coating on the inside of the bulb (much like a normal CFL, I guess), which seems to give off a very natural light. You can even see it glow for about one second while it "cools down" after being turned off - which maybe gives some idea to the thickness of the coating? This one isn't dimmable though - that's even more cash.

Cheers
 

socrates

Member
Looking at the spec of the Phillips bulbs recommended above what strikes me is that the high efficiency originally claimed for LED seems lacking. I find a 50 watt GLS equivalent bulb totally inadequate for main lighting. A 100 watt is about right and equates to a CFL of between 18 and 21 watts. Thus the Phillips bulb at 9.5 watts ( = 48 GLS ) is no more efficient and much more expensive.

I agree there are other advantages but at present for general lighting they do not seem viable. Maybe reading or bedside lamps are a different matter, but not a priority in terms of running cost.
 
OP
Scrat

Scrat

Definitely contains acorns
Looking at the spec of the Phillips bulbs recommended above what strikes me is that the high efficiency originally claimed for LED seems lacking. I find a 50 watt GLS equivalent bulb totally inadequate for main lighting. A 100 watt is about right and equates to a CFL of between 18 and 21 watts. Thus the Phillips bulb at 9.5 watts ( = 48 GLS ) is no more efficient and much more expensive.

I agree there are other advantages but at present for general lighting they do not seem viable. Maybe reading or bedside lamps are a different matter, but not a priority in terms of running cost.


I agree. I have tried the Philips bulbs and found them wanting in brightness. To get the equivalent light to CFLs you seem to need the same wattage, but even then the light is of a poor quality compared with the best CFLs. So, for the foreseeable future I will be stuck with buying medium priced Philips Tornado CFL bulbs, rather than their ultra-dim LEDs. (One of which LEDs lasted 6 months and took a further 6 months for Philips to provide a replacement!)
 

socrates

Member
I've just come home from a short break in Northumberland ( Landmark Trust - Brinkburn Mill. Highly recommended ). The house was fitted throughout with Tesco frosted globe CFLs rated I think at 20 watts. I can't see them on the Tesco website but would assume they were pretty cheap. Anyway, although they took about 3 - 4 minutes to achieve full brightness the quality then was very good - flicker free, warm and at least as bright as a 100 watt GLS lamp. Not ideal for bathrooms perhaps where on/off times are short but perfect for living rooms.
 
OP
Scrat

Scrat

Definitely contains acorns
Developments!

The following are available in the US, not here.

http://www.geek.com/news/crees-new-100w-led-bulb-looks-like-a-bulb-and-its-just-20-1587558/

The article mentions an equivalent Philips bulb that I couldn't see on their web site.

The other development is some excellent bright GU10 LEDs that really are the business. I have replaced the 5 in our kitchen with these and the difference is stunning. Mind you, constantly replacing LED bulbs is becoming expensive, but at least these are at a reasonable price point.

http://www.amazon.co.uk/gp/product/B007DIJDVE/

These are the first I have seen that match halogens in brightness. Let's just hope they don't blow prematurely!
 
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