GU10 Mains Halogens

[Slurp]

Fitted several of those GU10 lighting units to the kids bedrooms - 4 GU10's in each! - after the honeymoon period of about 2 months when all the el cheapo GU10's that come with the units started to pop, discovered GU10's where about a fiver each in the local sheds...

then discovered screwfix do the cheapo 1500 hour (LOL) ones for about 3 quid .....

then discovered Tesco's do a 'value' version (1500 hour - LOL) for

1.98.......

Today I was in the local B&Q - they are flogging six packs for £5.98 ...... yep .... couldn't believe it, and they are pukka 2000 hour units ... so chuffed I bought two six packs.

Hope this info helps

Slurp

[Andy Hall]

What they don't tell you is that it's 2000 hours total for all six :-)

[Slurp]

.... you may well be right - only time will tell!

I will say though that the units seem like the high quality 2000 hour units, with ceramic base rather than the cheaper - er I mean lesser life - all glass units.

Slurp

[Doctor Drivel]

Thanks. I'm just about to buy a few.

[Chip]

On Tue, 2 Aug 2005 21:02:26 +0100,it is alleged that "Slurp" spake thusly in uk.d-i-y:

[snip]

Hmm, I should tell this to the ceramic base one that blew with less than 1 week of normal use on it :(

OTOH, it spurred me to get the LED GU10s, they are *very* blue, even the ones specified as 'bluish white' but more than adequate for general room lighting and use close to unmeasurably small amounts of power.

[Ed Sirett]

IME the better s/fix ones (branded Osram IIRC) do actually last. The cheaper ones don't.

If you are a man with some time available then it should be possible to buy a batch of bulbs and prove the 2000 hours is a lie. Then get trading standards to take on B&Q and Tesco.

It's outside of my knowledge of statistics but does anyone know how many bulbs you would have to get and how short their lives would have to be to get, say, 99% certain that the bulb are being misrepresented? How certain would you have to be to put the matter 'beyond reasonable doubt'?

[John Cartmell]

Where do you get LED GU10s and at what price? Can you mix 'n' match 'ordinary' and LED GU10s on the same fixture to give a mix ofblue and ordinary yellow light?

[Andy Hall]

Yes. I've had some of the bulk packed own label ones from B&Q before, and fitted three of them and then three Osram ones.

The B&Q ones failed within a day or two of each other, and the Osram ones lasted about three times as long.

[Mr Fizzion]

Reminds me of the coffee machine I bought from Makro at GBP 14.99. The packaging stated "makes 12 cups".

Sure enough it made 12 cups.

Mr F.

[Tim Mitchell]

In article , Chip writes

Are they really bright enough? the ones I have seen are not very bright at all - probably about 10% of a real GU10. They are nice if you want pretty-pretty but not much good for lighting anything up.

[Chip]

On Tue, 02 Aug 2005 21:48:33 +0100,it is alleged that John Cartmell spake thusly in uk.d-i-y:

TLC electrical for around 6 pounds each. (less than their list price, don't know how come that happened and didn't ask )

Yes you can mix and match them, the light output is dim compared with a 50W, and only a little dimmer than a 20W, if this helps.

[Chip]

On Wed, 3 Aug 2005 08:45:33 +0100,it is alleged that Tim Mitchell spake thusly in uk.d-i-y:

[snip]

The ones I have are very slightly dimmer than a 20W Halogen. I agree re: them not being bright enough on their own for most purposes, but for our conservatory they seem to work fine. Being LED they are _very_ directional compared to even the narrow beam halogens, but after over a week of them, I think I like them.

We have 2 fixtures in the 'leanto' conservatory (about 18ft by 8ft), one at each end. One end contains the dining table, that has retained its 3x50w Xenon lamps, and the other end with the TV has the 3x1.8w LEDs. They provide fairly reasonable functional light without too much glare.

I would agree with the fact that right now, they are best in most cases for 'accent' lighting, we were unusual in only requiring a fairly low level of light. Give it another couple of years and I expect they'll be as good as compact fluorescents.

[Tim Mitchell]

In article , Chip writes

xenon, blimey, do you really mean halogen?

Yes, LEDs are definitely on the up. They are not as energy efficient as the manufacturers would have you believe though.

[Chip]

On Wed, 3 Aug 2005 12:08:35 +0100,it is alleged that Tim Mitchell spake thusly in uk.d-i-y:

[snip]

Yes, halogen but with the inert gas being xenon rather than argon (as in

), not to be confused with a xenon arc lamp

[snip]

This also is true. I am not quite sure of the circuit arrangement in the GU10s, but blue/white LEDs have a forward voltage of around 4.5 volts, and there are 15 in the lamp, meaning the efficiency would be highest at around 70v ac, there must be significant loss at 240v in the dropper circuitry (I believe this to consist of a capacitor and resistor chain). Their main advantage to me stems from the fact they don't (short of circuit failure or large voltage spikes) have a 'single point of failure' but rather dim gradually over a period of time. Of course, the life could be extended greatly by using twice as many and *not* overdriving them as they do, but then the lamp manufacturer would very shortly cease to sell very many, can't see them doing that.

[Andrew Gabriel]

They are about the same energy efficiency as a 12V halogen (maybe nearly twice that of a mains halogen). So the 1.8W one mentioned (assuming that all goes into the LED's) will be about the same light output as 3W worth of mains halogen.

LED's are very directional. The area of the spot is probably less than 1/100th of that of a mains halogen, so if you consider only the intensity on-beam when comparing light output, you will be out by something over 2 orders of magnitude.

[Mathew J. Newton]

.=2Eand that the clock started ticking straight after manufacture. ;-)

[Doctor Drivel]

Not in the B&Q I passed this morning.

[Doctor Drivel]

They have them in Homebase on display, yet are not for sale. They are there to stop people burning themselves. Yellow, blue and I think green coloured GU10 are available in Homebase for £7 plus, for two.

[Brian Sharrock]

... but AIUI, the nnnn hours life is predicated on the 50% 'Life'; one gets say 100 units and power them 'ON' simultaneously, _when_ the 50th unit fails that's the nnnn hour "Life". Note this doesn't mean that _your_ bunch of things will last nnnn hours! Someone, somewhere, somewhen will end up saying;- 'I bought these in YYYY and they've lasted eons - while someone else is saying; - "I bought these yesterday and they've failed already" {The retailer/manufacturer is still saying truthfully ; 'the life is nnnn hours".

[Ed Sirett]

OK. I'm sure that if I were to buy a reasonable quantity of budget bulbs I won't get anywhere near the figure. How short a life for the 50th bulb is significant to prove that bulbs on average don't have the life stated?

Example:

3 years ago I bought a kitchen light fitting for one of the flats I run. the bulbs were all out in 6 weeks. (say 8 hours a day max - winter) That's about 350 hours tops. Since then I've replaced them once. Even allowing for summer usage of nothing so say 4 hours a day over the whole year. Say 18 months life (at least) say that's about 500 days at 4 hours /day = that's about 2000 hours.