Is there such an animal?

Mary

While you can get very high output white LEDs (50Cd+), and you
can get assemblies of LEDs to replace conventional low voltage
bulbs, I haven't seen them applied to domestic lighting yet.

One of the biggest challenges is going to be getting the colour
temperature right - people are very fussy about that, and white
LEDs are very harsh.

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

Mary Fisher wrote:

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.

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.

--
Grunff

In uk.d-i-y, Grunff wrote:
Mary Fisher wrote:

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.

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

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

--
Mike Barnes

Mike Barnes wrote:

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


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

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

--
Grunff

"Grunff" wrote in message
...
Mike Barnes wrote:

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


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

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

--
Grunff


http://www.absolutelylights.co.uk/ledtech.htm


---
BigWallop

http://basecuritysystems.no-ip.com

Outgoing mail is certified Virus Free.
Checked by AVG anti-virus system (http://www.grisoft.com).
Version: 6.0.500 / Virus Database: 298 - Release Date: 10/07/03

"Mary Fisher" wrote in message
t...


Is there such an animal?

Mary




http://www.visionelements.co.uk/illu.../led_home.html


---
BigWallop

http://basecuritysystems.no-ip.com

Outgoing mail is certified Virus Free.
Checked by AVG anti-virus system (http://www.grisoft.com).
Version: 6.0.500 / Virus Database: 298 - Release Date: 10/07/03

"Mary Fisher" wrote in message
t...


Is there such an animal?

Mary

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.

http://www.bltdirect.co.uk/item562.htm

Have seen them advertised for £12.00 but lost the URL

Dave

"Grunff" wrote in message
...
BigWallop wrote:

http://www.absolutelylights.co.uk/ledtech.htm

Erm...Whatever...

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

It IS worthy of a mindless adolescent ...

Mary
Who has several of those a grandchildren.

--
Grunff

In message ,
Mike Barnes wrote:

In uk.d-i-y, Grunff wrote:
Mary Fisher wrote:

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.

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

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


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" (http://www.qvsdirect.co.uk/ ): 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.

--
Martin Angove (it's Cornish for "Smith") - ARM/Digital SA110 RPC
See the Aber Valley -- http://www.tridwr.demon.co.uk/abervalley.html
.... In case of fire, yell FIRE!

In article ,
Grunff writes:
Mary Fisher wrote:

Is there such an animal?

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.

While you can get very high output white LEDs (50Cd+), and you
can get assemblies of LEDs to replace conventional low voltage
bulbs, I haven't seen them applied to domestic lighting yet.

One of the biggest challenges is going to be getting the colour
temperature right - people are very fussy about that, and white
LEDs are very harsh.

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.

--
Andrew Gabriel

Is there such an animal?

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.

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.


One of the biggest challenges is going to be getting the colour
temperature right - people are very fussy about that, and white
LEDs are very harsh.

Filters?

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.

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

--
Andrew Gabriel

"Mary Fisher" wrote in message
t...

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 wrote:

What about enviro types who DO have a mind?

Like me.

And me - the only sensible thing to do is weigh up all pros and
cons, and make a decision based on all the evidence.

I'm not having a go at all greenies, not in any way. I try to
lead as 'green' a life as I can. What I do have a problem with
is the very vocal group of greenies who shout about issues they
don't understand. And please don't think I mean you (or anyone
else on this group) - I don't.

--
Grunff

"Grunff" wrote in message
...
Mary Fisher wrote:

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

It IS worthy of a mindless adolescent ...

I feel well and truly told off :-( But since it's you, I don't
mind too much.

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

However, there's only so many slightly relevant links one can
take. BigW has a habit of googling for every discussion topic,
and posting any links (s)he thinks are relevant, regardless of
how relevant they really are. It gets tiresome after a while.

I hadn't noticed but I believe you.

Mary

--
Grunff

"Steve" wrote in message
.. .
The efficiency is still only around 20 Lumens/Watt, compared to fluoros
at 95 lumens/watt. We use the Luxeon Star LEDS at work on some projects
- incredibly, painfully bright beams, but as has been said, rather
narrow. An LED drawing 300mA is quite a beastie.

Sounds frightening - but it will get better?

I hope in my time ...

Mary

Steve

"Grunff" wrote in message
...
Mary Fisher wrote:

What about enviro types who DO have a mind?

Like me.

And me - the only sensible thing to do is weigh up all pros and
cons, and make a decision based on all the evidence.

I'm not having a go at all greenies, not in any way. I try to
lead as 'green' a life as I can. What I do have a problem with
is the very vocal group of greenies who shout about issues they
don't understand. And please don't think I mean you (or anyone
else on this group) - I don't.

I didn't think that.

As for me, I could have written that last paragraph. But I ask questions
before I shout - which was why I posted the question. It's been very
interesting.

Mary

--
Grunff

"Mary Fisher" wrote in message
t...

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)

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

Mary

In article ,
Mike Barnes wrote:
Well, yes, but they'd only need to be replaced every few decades. The
lamps, that is.

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.

--
*Make it idiot-proof and someone will make a better idiot.

Dave Plowman London SW 12
RIP Acorn

Grunff wrote:
Mary Fisher wrote:

Is there such an animal?

While you can get very high output white LEDs (50Cd+), and you
can get assemblies of LEDs to replace conventional low voltage
bulbs, I haven't seen them applied to domestic lighting yet.

One of the biggest challenges is going to be getting the colour
temperature right - people are very fussy about that, and white
LEDs are very harsh.

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.

--
Chris Green )

Andrew Gabriel wrote:
In article ,
Grunff writes:
Mary Fisher wrote:

Is there such an animal?

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.

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.

--
Chris Green )

The efficiency is still only around 20 Lumens/Watt, compared to fluoros
at 95 lumens/watt. We use the Luxeon Star LEDS at work on some projects
- incredibly, painfully bright beams, but as has been said, rather
narrow. An LED drawing 300mA is quite a beastie.

Steve

In article ,
"Mary Fisher" writes:

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.

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.

http://ateam.lbl.gov/Design-Guide/DG...ingsources.htm

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

In article ,
Dave Plowman writes:

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.

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

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.

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.

driving them like this also means you can pump more current through them
thus making them brighter (maybe this is the reason rather than saving
battery life?)

Dave wrote:

I dont know how dangerous the arsenic in LEDs is though. I suspect the
amount of arsenic is miniscule - and can it leach out of the semiconductor,
I doubt it?

But think of all those used LEDs being binned and ending up
being incinerated with your domestic waste.

I'm not in any way suggesting that this poses a danger - I'm
just saying that this is the type of environmental argument that
could be put forward.

--
Grunff

In article ,
writes:
Andrew Gabriel wrote:
In article ,
Grunff writes:
Mary Fisher wrote:

Is there such an animal?

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.

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.

Sorry, but this is a very common misconception.
They can produce excellent high brightness narrow beams of light,
which a filament lamp can't. This can be an advantage in some
applications like spotlamps so the beam might look brighter than
a filament lamp. However, if you take something like a 10º beam
angle, which is 78 square degrees, and divide by the 41253
square degrees in the sphere which a filament lamp lights, this
shows that the LED is only lighting up 0.2% of the area which
the filament lamp did. That's why they appear so efficient, but
in fact they aren't.

Nobody can currently get 30 lumens/watt from a white LED, which
is what you get from highest efficiency halogen lamp. Nichia are
predicting 60 lumens/watt for a product they expect to ship in
2005, which is still less than a fluorescent lamp. The efficiency
improvement manufacturers have managed over the last couple of
years is very disappointing compared with what went before, so
it may be that some type of limit has now been reached without
a significant change in technology.

--
Andrew Gabriel

Dave wrote:
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.

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.


driving them like this also means you can pump more current through them
thus making them brighter (maybe this is the reason rather than saving
battery life?)


The mean brightness is still the same, since the mean current must be
the same, because you can't leave the LED on at the current used when on
or it will burn out. However driving them switch mode allows the circuit
to run more efficiently which IS why they are pulsed.

Steve

Mary Fisher wrote:


"Mary Fisher" wrote in message
t...

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)

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

Mary

Mary: I agree. I don't think I can even speleologically spell
that anyway! Terry.

In message ,
writes

Nobody can currently get 30 lumens/watt from a white LED, which
is what you get from highest efficiency halogen lamp. Nichia are

Er, but, cycle lamp bulbs aren't halogen bulbs are they? The sort of
bulbs producing comparable light outputs to the LED cycle lamps are
tiny little bulbs which probably don't get to the sort of temperature
(and thus efficiency) of halogen bulbs.

You can certainly buy cycle lamps with what are described as halogen
bulbs - btw, has the law been updated yet to allow cyclists to use
non-filament bulbs?

--
dave @ stejonda

Steve wrote:

The efficiency is still only around 20 Lumens/Watt, compared to fluoros
at 95 lumens/watt. We use the Luxeon Star LEDS at work on some projects
- incredibly, painfully bright beams, but as has been said, rather
narrow. An LED drawing 300mA is quite a beastie.

Steve


There are some new EL materials coming up that are between LED and
fluoro efficiency. see www.elam-T.com - but the most lucrative potential
market is in replacing LCD display technology, so don't expect to see
flat screen lighting yet awhile.

Right now, fluoro is the best there is for GP lighting, according to the
research director there...however their 'phosphors' might make it into
those yet, for a tad more efficiency and better color balance.

Grunff wrote:

Dave wrote:

I dont know how dangerous the arsenic in LEDs is though. I suspect the
amount of arsenic is miniscule - and can it leach out of the
semiconductor,
I doubt it?


But think of all those used LEDs being binned and ending up being
incinerated with your domestic waste.

I'm not in any way suggesting that this poses a danger - I'm just saying
that this is the type of environmental argument that could be put forward.


Arsenic is a medicine in small enough doses.

"Dave Plowman" wrote
| Mike Barnes wrote:
| Well, yes, but they'd only need to be replaced every few decades. The
| lamps, that is.
| 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.

I noticed last time I was passing through Waverley that the solari-style
LEDboards had some characters missing.

The main concourse ones were advertising trains calling at Newcas and
Leices and the ticket hall ones were welcoming passengers to the First
ass Lounge.

Owain

"Steve" wrote
| 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.
| The mean brightness is still the same, since the mean current must be
| the same, because you can't leave the LED on at the current used when on
| or it will burn out. However driving them switch mode allows the circuit
| to run more efficiently which IS why they are pulsed.

Is there a certain frequency above which this pulsed light is considered a
continuous light and therefore acceptable as the continuous light required
under the Road Traffic Act or whatever legislation says that flashing lights
on bicycles are verboten?

Owain

dave @ stejonda wrote:
In message ,
writes

Nobody can currently get 30 lumens/watt from a white LED, which
is what you get from highest efficiency halogen lamp. Nichia are

Er, but, cycle lamp bulbs aren't halogen bulbs are they? The sort of
bulbs producing comparable light outputs to the LED cycle lamps are
tiny little bulbs which probably don't get to the sort of temperature
(and thus efficiency) of halogen bulbs.

You can certainly buy cycle lamps with what are described as halogen
bulbs - btw, has the law been updated yet to allow cyclists to use
non-filament bulbs?

Well LED rear lights have had BS markings for a while and now the new
LED front ones do as well so presumably they're legal as they conform
to the required British Standard.

--
Chris Green )

Huge wrote:

Only recent TVRs, if they have them at all. Griffiths & Chimaeras have
filament lamps.

Don't know about TVRs, but the latest crop of Range Rovers have
LED brake lights.

--
Grunff

In article ,
RichardS noaccess@invalid wrote:
Perhaps the law has changed, however, because I think that TVRs have LED
brake light clusters, don't they? (unless this didn't apply to the rear
lighting).

They're common as centre stop lights on cars. And as all the various tail
lights and indicators on buses. Oh - and the taillights on my BMW. And of
course there are HID headlamps (xenon) which aren't filament lamps either.

--
*60-year-old, one owner - needs parts, make offer

Dave Plowman London SW 12
RIP Acorn

In article ,
Steve writes:
Dave wrote:
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.

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.


driving them like this also means you can pump more current through them
thus making them brighter (maybe this is the reason rather than saving
battery life?)


The mean brightness is still the same, since the mean current must be
the same,

Actually LEDs get slightly more efficient at higher current, so
the mean brightness is higher.

Furthermore, it appears that eyes don't perceive mean brightness,
but perceive something which is between the mean and peak brightness,
so a flashing light will appear brighter than a steady light of the
same mean brightness (over some frequency range).

Neither of these effects is very large though. I've seen conflicting
reports of which of these effects first resulted in pulsed operation
of visible LEDs, although the high pulse current techneque was used
to drive infra-red LEDs before visible LEDs were invented.

because you can't leave the LED on at the current used when on
or it will burn out. However driving them switch mode allows the circuit
to run more efficiently which IS why they are pulsed.

--
Andrew Gabriel

In message , Huge
writes
"dave @ stejonda" writes:
In message ,
writes

Nobody can currently get 30 lumens/watt from a white LED, which
is what you get from highest efficiency halogen lamp. Nichia are

Er, but, cycle lamp bulbs aren't halogen bulbs are they? The sort of
bulbs producing comparable light outputs to the LED cycle lamps are
tiny little bulbs which probably don't get to the sort of temperature
(and thus efficiency) of halogen bulbs.

You can certainly buy cycle lamps with what are described as halogen
bulbs - btw, has the law been updated yet to allow cyclists to use
non-filament bulbs?

Since no other laws applicable to cyclists are actually enforced, you
really think this one os going to be?

The police are probably just happy that a bike actually has lights
--
geoff

Andrew Gabriel wrote:

The mean brightness is still the same, since the mean current must be
the same,


Actually LEDs get slightly more efficient at higher current, so
the mean brightness is higher.

That certainly used to be true, but again for the Luxeon jobbies we use,
it ain't anymore.

Furthermore, it appears that eyes don't perceive mean brightness,
but perceive something which is between the mean and peak brightness,
so a flashing light will appear brighter than a steady light of the
same mean brightness (over some frequency range).

Neither of these effects is very large though.

Is this a medical fact ? In recent discussion on sci.elect.design, this
effect was poo-poohed by several of the engineers in there whose
opinions I would trust.

Steve