I've been following the various discussions about how LED low-energy
lamps are steadily improving. Bought a couple of GU10 replacements from
B&Q recently and was very disappointed - a cold blueish light with a
poor colour spectrum.

I recently grabbed one of these from fleabay:

http://cgi.ebay.co.uk/ws/eBayISAPI.d...m=180500589677

it's a 108 LED low-energy lamp. Came from Hong Kong in about a week.
Worth a look for $1. Described a 'corn bulb' which works, it feels just
like holding a cob of corn.

Counted the LEDs - yes, 108. Smaller than it looks in the pics. The
'bulb' is octagonal, presumably to evenly distribute the direct light
emitted by the LEDs. There are 12 LEDs on the end to provide downward
as well as sideways light.

Seems well made, though I haven't opened it. Not expecting wonders,
some of these Chinese-made things are real horrors. There is a dodgy-
looking CE sticker (I don't believe for one second that it's been
tested) and no other markings or approval/safety stickers. Doubt I
would use those unattended in the house until quality branded and safety
tested ones come on the market, but would be OK with it in an enclosed
outdoor fitting where it wouldn't do any damage if it decided to self-
combust.

Draws 25mA at 240V, so about 6.5W as opposed to the claimed 5W at
200-220V. The ebay ad doesn't make a claim for incandescent equivalent,
but after testing it I'd guess at 40W.

The light is a very cold white with a slight blue tinge, but not as bad
as some I have seen. The LEDs are uncomfortably bright to look at
directly. Don't have much of a feel for colour spectrum yet but don't
think it is good.

I wouldn't use these where they could be seen by the naked eye, but
could see them working well in shades, particularly frosted glass shades
which would diffuse the light.

On a related topic, CFLs are also improving. Bought half a dozen 7W
twisted-candle CFLs from Tesco for 20p each recently and they are
excellent. These are the first CFLs I've used that I would be happy to
fit around the house. I've lightly sprayed a couple with red enamel
paint to replace fireglow bulbs and they look good.

That said, I don't think CFLs are a universal panacea. There are
occasions when you just want the warm glow of an incandescent. My
contribution to energy saving is to turn lights off when I don't need
them. Simple, eh?

--
(\__/)
(='.'=)
(")_(")

On Aug 4, 5:54 pm, Mike Tomlinson wrote:

http://cgi.ebay.co.uk/ws/eBayISAPI.d...m=180500589677

it's a 108 LED low-energy lamp. Came from Hong Kong in about a week.
Worth a look for $1.

I've had around 50 LEDs running outside in my imitation gaslamp for a
couple of years.They seem very reliable and don't give out much heat.
At the rate the price is dropping I hereby predict that LEDs will take
over from all other lights in the next few years. In NZ we are using
them for traffic lights, and most new cars seem to use them for tail
lights and sidelights.
I don't see why there isn't a mixture of different coloured LEDs in
the cluster, if people are really worried about a cold white light.
Which I am not. Low power usage and long life are the most inportant
factors to me.

On Aug 4, 8:04*am, Matty F wrote:
On Aug 4, 5:54 pm, Mike Tomlinson wrote:

http://cgi.ebay.co.uk/ws/eBayISAPI.d...m=180500589677



it's a 108 LED low-energy lamp. *Came from Hong Kong in about a week.
Worth a look for $1.

I've had around 50 LEDs running outside in my imitation gaslamp for a
couple of years.They seem very reliable and don't give out much heat.

The device from Ebay looks like it is just a load of 5mm white LEDs, a
completely different beast to LEDs designed for incandescent
replacement. The latter *do* give out a lot of heat when driven hard
enough to be effective as lighting.

MBQ

In article ,
Mike Tomlinson wrote:
That said, I don't think CFLs are a universal panacea. There are
occasions when you just want the warm glow of an incandescent. My
contribution to energy saving is to turn lights off when I don't need
them. Simple, eh?

It's possible today to make a fluorescent tube with pretty well any colour
temperature you want. And you can get them for ordinary fittings, although
only from a specialist. CFLs tend to be built down to a price.

LEDs are a long way from this - and IMHO will never achieve it. As the
efficiency goes down with each attempt.

--
*What was the best thing before sliced bread? *

Dave Plowman London SW
To e-mail, change noise into sound.

In article ,
Matty F writes:
On Aug 4, 5:54 pm, Mike Tomlinson wrote:

http://cgi.ebay.co.uk/ws/eBayISAPI.d...m=180500589677

it's a 108 LED low-energy lamp. Came from Hong Kong in about a week.
Worth a look for $1.

I've had around 50 LEDs running outside in my imitation gaslamp for a
couple of years.They seem very reliable and don't give out much heat.
At the rate the price is dropping I hereby predict that LEDs will take
over from all other lights in the next few years. In NZ we are using

I think that prediction has been continuous for last 20 years,
and so far, 100% wrong. The reasons it's been wrong for last 20
years haven't gone away. What is perhaps changing is the realisation
that these issues probably aren't going to get fixed (e.g. making an
LED which will work efficiently at 200C, or even at all, which can
replace existing lamps) and different solutions are required.

them for traffic lights, and most new cars seem to use them for tail
lights and sidelights.

They certainly have niches where they're ideal - single colour
directional lighting being top of the list.

I don't see why there isn't a mixture of different coloured LEDs in
the cluster, if people are really worried about a cold white light.

1) Patents. In the lighting industry outside of LEDs, cross licensing
of patents has been pretty universal for almost 100 years. LED
lighting is coming from different players, and they just don't do
it. This means you have to wait 25 years for patents to expire
before technology becomes widespread enough to drop to consumer
level pricing.
2) Separation of colour light sources generates quite difficult design
challenges. Firstly, you get an effect which looks like chromatic
aberration on steroids. Also you have to mix evenly in all directions
or the colour changes by angle. Neither are easy to solve efficiently.

Which I am not. Low power usage and long life are the most inportant
factors to me.

--
Andrew Gabriel
[email address is not usable -- followup in the newsgroup]

On 04/08/2010 08:04, Matty F wrote:
On Aug 4, 5:54 pm, Mike Tomlinson wrote:

http://cgi.ebay.co.uk/ws/eBayISAPI.d...m=180500589677

it's a 108 LED low-energy lamp. Came from Hong Kong in about a week.
Worth a look for $1.

I've had around 50 LEDs running outside in my imitation gaslamp for a
couple of years.They seem very reliable and don't give out much heat.
At the rate the price is dropping I hereby predict that LEDs will take
over from all other lights in the next few years. In NZ we are using
them for traffic lights, and most new cars seem to use them for tail
lights and sidelights.

LEDs have a huge efficiency advantage where you want coloured light;
they produce the colour you actually want rather than producing white
and filtering it. The increased reliability will reduce maintenance
costs significantly for things like traffic lights.

I don't see why there isn't a mixture of different coloured LEDs in
the cluster, if people are really worried about a cold white light.
Which I am not. Low power usage and long life are the most inportant
factors to me.

I still like the light from conventional bulbs and I find the time it
takes CFLs to warm up really annoying. I recently bought some halogen
bulb replacements for ordinary light bulbs. Though not as efficient as
CFLs or LEDs these claim to be more efficient than ordinary filament
lamps, give a nice light, come on instantly and work with dimmer
switches. To me these seem like a good compromise, especially as they
were 10p each in the "reduced to clear" bin.

In article
s.com, Man at B&Q writes

The device from Ebay looks like it is just a load of 5mm white LEDs

Pretty sure they are, yes.

--
(\__/)
(='.'=)
(")_(")

In article , John
Rumm writes

You can't really predict the actual power consumed on these just from a
voltage and current measurement. So there is a fair chance it is 5W or
even less...

http://wiki.diyfaq.org.uk/index.php?..._of_low_p owe
r
_factor

Thanks for the link. I do actually have a plug-in power meter which
indicates power factor, so will bung the lamp on that and report back.

I have seen some LED lights where the light quality is as good as a CFL,
which admittedly is not saying much, but sounds better than this example.

Well, it was only $1. worth it for a play.

old-fart I can remember when LEDs were $1/£1 *each* /old-fart

--
(\__/)
(='.'=)
(")_(")

On Aug 4, 11:18*pm, Gareth wrote:
On 04/08/2010 08:04, Matty F wrote:

On Aug 4, 5:54 pm, Mike Tomlinson wrote:

http://cgi.ebay.co.uk/ws/eBayISAPI.d...m=180500589677

it's a 108 LED low-energy lamp. *Came from Hong Kong in about a week..
Worth a look for $1.

I've had around 50 LEDs running outside in my imitation gaslamp for a
couple of years.They seem very reliable and don't give out much heat.
At the rate the price is dropping I hereby predict that LEDs will take
over from all other lights in the next few years. In NZ we are using
them for traffic lights, and most new cars seem to use them for tail
lights and sidelights.

LEDs have a huge efficiency advantage where you want coloured light;
they produce the colour you actually want rather than producing white
and filtering it.

Except when you actually want white.

Or you need a wavelenght that cannot be produced using any of the
materials used to make LEDs. For some time it was simply not possible
to replace the warning lights at level crossings with LEDs, as they
simply couldn't produce the colour that was laid down in regulations.
That may have changed now.

MBQ

On Aug 5, 5:12*am, Mike Tomlinson wrote:
In article , John
Rumm writes

You can't really predict the actual power consumed on these just from a
voltage and current measurement. So there is a fair chance it is 5W or
even less...

http://wiki.diyfaq.org.uk/index.php?...Other_causes_o....
r
_factor

Thanks for the link. *I do actually have a plug-in power meter which
indicates power factor, so will bung the lamp on that and report back.

I have seen some LED lights where the light quality is as good as a CFL,
which admittedly is not saying much, but sounds better than this example..

Well, it was only $1. *worth it for a play.

old-fart I can remember when LEDs were $1/£1 *each* /old-fart

You're not that old if they were only $1/£1!

MBQ

In article ,
John Rumm writes:
On 04/08/2010 06:54, Mike Tomlinson wrote:

Draws 25mA at 240V, so about 6.5W as opposed to the claimed 5W at

You can't really predict the actual power consumed on these just from a
voltage and current measurement. So there is a fair chance it is 5W or
even less...

http://wiki.diyfaq.org.uk/index.php?...p ower_factor

Some interactive toys to play with this at:
http://blogs.sun.com/agabriel/entry/...ctor_explained

These will either be simple capacitive dropper (which is example 1),
or switched mode PSU (which is example 3).

--
Andrew Gabriel
[email address is not usable -- followup in the newsgroup]