LED domestic lighting

[Mary Fisher]

Is there such an animal?

Mary

[Mary Fisher]

Thank you. I asked because of a question on radio this afternoon - someone asked what to do with defunct low energy 'bulbs' and a panellist said that they could be an environmental hazard and implied that the future was in LEDs.

But I'd still be interested in trying them ... one ... :-)

Mary

[Grunff]

Ha! Nothing is a hazard if recycled correctly. You wait til the enviro-winers find out that LEDs contain arsenic!

FWIW, I think the future is in LEDs, but polymer based ones. These only exist in labs at the moment, but when high brightenss polymer LEDs make it into production, you'll see a whole range of new applications.

[Mike Barnes]

Well, yes, but they'd only need to be replaced every few decades. The lamps, that is.

[Grunff]

I know that - you know that - but that is exactly the kind of logic that doesn't work on mindless enviro types.

[BigWallop]

[BigWallop]

[Emeritius Cornflea]

Yes, I have just replaced all the GU10 fittings I had. The GU10 is a 230V 50W mains halogen and the LED version is a direct replacement, although a slightly reduced light output. I had been paying around £4.50 for 4000 hour halogen GU10's but managed to get a load of LED replacements at trade cost, and figure they are more cost effective as they only consume 4W and last 12 time longer.

seen them advertised for £12.00 but lost the URL

Dave

[Mary Fisher]

Oh come on! That's not worthy of you.

It IS worthy of a mindless adolescent ...

Mary Who has several of those a grandchildren.

[Martin Angove]

We had *loads* of these at a previous place of employment. Large ones, small ones, round ones, square ones, red ones, blue ones, white ones... and they are *not* indestructible. The LEDs are arranged in a matrix, and a failure of just one will take out a whole row. Out of some 40 (ish?) in the ramp outside the main entrance, at the time I left there were a good 8 or 9 with a fault like this. In others the whole thing was off, but in this case it was usually the transformer which is easily replaced.

As for domestic suppliers, there are a few in a catalogue I have from a company called "QVS"

): 240V versions with

15 LEDs in white, blue, green, red, orange from £12 upwards. Also other versions of similar products including some outdoor (IP68) "floorlights" with 4 or 9 LEDs in blue or white for £22.50 or £29.95 and which require transformers.

As for power consumption, the 240V things are 1.8W, but quite how much illumination that gives is anyone's guess.

Hwyl!

M.

[Andrew Gabriel]

They exist, but the best LEDs are currently only around the same efficiency as filament lamps, which means they get just as hot and die quickly or are lower power and lower light output (if you are thinking along the lines of retrofit lamps). They don't get to the efficiency of fluorescent lamps yet.

The area where I expect they will initially make inroads is where their very narrow beam angle can be used to advantage. In such applications they can exceed filament lamps in overall system efficiency because they don't spill light where it's not wanted.

The white ones are UV with fluorescent phosphors, so they can be made same colours as fluorescent lamps in theory, but I suspect there's no demand for 2700K ones. Also, the efficiency of the phosphor will reduce slightly for lower colour temperature and at the moment everyone is after highest brightness, so that would not be a lot of interest to manufacturers.

[Mary Fisher]

But efficiency and acceptability aren't the same thing. I dislike the quality of light produced by fluorescent 'bulbs', no matter how they are modified to produce 'daylight', 'warm' or other qualities.

Filters?

Hmm. I didn't think my simple question would be answered so quickly, fully or technically but I'm grateful to everyone who has joined the conversation. If it continues I shall too :-)

Mary

[Malc]

I use LED lamps when caving and TBH they aren't brilliant (well they are but they aren't too). They are ok if you haven't got to see very far (fine in a cave cos the wall isn't usually more than a few feet away) but to get the brilliance they narrow the projection angle somehow so they don't light a huge area. You'd need an awful lot in a domestic setting and whilst it's possible to do and very economic with the juice, the cost would be prohibitive.

-- Malc Wond'ring Aloud

Get me out of my tree to reply

[Mary Fisher]

Aaww ..... :-) I wasn't being nasty!

I hadn't noticed but I believe you.

Mary

[Mary Fisher]

Er - I think I'd prefer to leave that activity to you :-)

Mary

[Dave Plowman]

I'm not so sure. Once you start driving LEDs hard as a light source rather than just an indicator, their life span reduces dramatically.

[usenet]

Our local Denmans are advertising LED GU10 lamps now, 240 volts, "Very Long Life". The cost £8.50 each though which is a bit pricey.

[usenet]

They are *far* more efficient in bicycle lamps, the latest LED cycle lamp (the CatEye LED300) is just as bright as their old standard krypton bulbed lamp (the HL-500 was it?) and runs several times as long.

I don't know whether this is down to them being efficient at low voltages or what but has revolutionised cycle lighting, front lamps can now realistically be run on AA cells.

[John Schmitt]

There is also the sulphur-microwave system although this is aimed at industrial applications. While it achieves about 70% efficiency, less than LED, it does give continuous spectrum. I understand that the idea is that you distribute it with fibre optics, as several kilowatts of illumination are a little excessive even for reading fine print.

Schmitt

-- If you have nothing to say, or rather, something extremely stupid and obvious, say it, but in a 'plonking' tone of voice - i.e. roundly, but hollowly and dogmatically. - Stephen Potter

[John Schmitt]

My curiosity knows no bounds, it appears. When I bought one of those LED cycle lights, I hooked up a sillyscope to it and discovered that on the "steady" setting, it actually spent 3/4 of the time switched off. 100 Hz square wave mark to space 1:3. A clever way of stretching battery life. If you own one, you simply have to move it rapidly across your field of vision to demonstrate this.

John Schmitt

-- If you have nothing to say, or rather, something extremely stupid and obvious, say it, but in a 'plonking' tone of voice - i.e. roundly, but hollowly and dogmatically. - Stephen Potter