Yes, I've googled it, but there are many different approaches. Which one is used in domestic LED bulbs?

On Tue, 25 Apr 2017 12:25:35 +0100, "James Wilkinson Sword"
wrote:

Yes, I've googled it, but there are many different approaches. Which one is used in domestic LED bulbs?

Ultra-violet LED exciting a white phosphor, much the same principle
used in florescents.

--

Graham.
%Profound_observation%

On Tue, 25 Apr 2017 13:27:49 +0100, Graham. wrote:

On Tue, 25 Apr 2017 12:25:35 +0100, "James Wilkinson Sword"
wrote:

Yes, I've googled it, but there are many different approaches. Which one is used in domestic LED bulbs?

Ultra-violet LED exciting a white phosphor, much the same principle
used in florescents.

That's what I would have assumed, but when you look at a switched off white LED, it's not white. I would have expected it to have a white coating that can be seen like on a switched off fluorescent tube.

--
When you want a man to play with you, wear a full-length black nightgown with buttons all over it.
Sure it's uncomfortable, but it makes you look just like his remote control.

On Tue, 25 Apr 2017 13:38:40 +0100, "James Wilkinson Sword"
wrote:

On Tue, 25 Apr 2017 13:27:49 +0100, Graham. wrote:

On Tue, 25 Apr 2017 12:25:35 +0100, "James Wilkinson Sword"
wrote:

Yes, I've googled it, but there are many different approaches. Which one is used in domestic LED bulbs?

Ultra-violet LED exciting a white phosphor, much the same principle
used in florescents.

That's what I would have assumed, but when you look at a switched off white LED, it's not white. I would have expected it to have a white coating that can be seen like on a switched off fluorescent tube.


Perhaps the phosphor just surrounds the die, with a clear epoxy
envelope surrounding it.
--

Graham.
%Profound_observation%

On 25/04/2017 13:58, Graham. wrote:
On Tue, 25 Apr 2017 13:38:40 +0100, "James Wilkinson Sword"
wrote:

On Tue, 25 Apr 2017 13:27:49 +0100, Graham. wrote:

On Tue, 25 Apr 2017 12:25:35 +0100, "James Wilkinson Sword"
wrote:

Yes, I've googled it, but there are many different approaches. Which one is used in domestic LED bulbs?

Ultra-violet LED exciting a white phosphor, much the same principle
used in florescents.

That's what I would have assumed, but when you look at a switched off white LED, it's not white. I would have expected it to have a white coating that can be seen like on a switched off fluorescent tube.


Perhaps the phosphor just surrounds the die, with a clear epoxy
envelope surrounding it.

I thought a thousand people would leap on this, but it's a blue LED with
a yellow phosphor. Maybe not always, but as near as makes no difference.

Cheers
--
Clive

On 25/04/2017 13:27, Graham. wrote:
On Tue, 25 Apr 2017 12:25:35 +0100, "James Wilkinson Sword"
wrote:

Yes, I've googled it, but there are many different approaches. Which one is used in domestic LED bulbs?

Ultra-violet LED exciting a white phosphor, much the same principle
used in florescents.

It is usually a high efficiency blue LED pump exciting a yellow phosphor
with that mix determining the nominal colour temperature. It is quite
peaky in the blue and more of a wide hump around the yellow. The
phosphor usually looks yellow and sits on top of the LED.

http://i.stack.imgur.com/lkyXG.png

The visible light flux out of an LED die on a high efficiency LED these
days is about the same order of magnitude as the sun's photosphere.

It is a lot more obvious on the devices which use a remote phosphor.

http://www.cree.com/led-components/m...e-Phosphor.pdf

--
Regards,
Martin Brown

On Tue, 25 Apr 2017 14:27:29 +0100, Martin Brown wrote:

On 25/04/2017 13:27, Graham. wrote:
On Tue, 25 Apr 2017 12:25:35 +0100, "James Wilkinson Sword"
wrote:

Yes, I've googled it, but there are many different approaches. Which one is used in domestic LED bulbs?

Ultra-violet LED exciting a white phosphor, much the same principle
used in florescents.

It is usually a high efficiency blue LED pump exciting a yellow phosphor
with that mix determining the nominal colour temperature. It is quite
peaky in the blue and more of a wide hump around the yellow. The
phosphor usually looks yellow and sits on top of the LED.

http://i.stack.imgur.com/lkyXG.png

That's not as even as I thought. I thought they'd made it similar to the sun, which looks like this:
https://i.publiclab.org/system/image...ctrumGraph.jpg
Maybe we should be using the controllable colour RGB ones.

The visible light flux out of an LED die on a high efficiency LED these
days is about the same order of magnitude as the sun's photosphere.

It is a lot more obvious on the devices which use a remote phosphor.

http://www.cree.com/led-components/m...e-Phosphor.pdf

--
You never really learn to swear until you learn to drive.

On 25/04/2017 14:54, James Wilkinson Sword wrote:
On Tue, 25 Apr 2017 14:27:29 +0100, Martin Brown
wrote:

On 25/04/2017 13:27, Graham. wrote:
On Tue, 25 Apr 2017 12:25:35 +0100, "James Wilkinson Sword"
wrote:

Yes, I've googled it, but there are many different approaches.
Which one is used in domestic LED bulbs?

Ultra-violet LED exciting a white phosphor, much the same principle
used in florescents.

It is usually a high efficiency blue LED pump exciting a yellow phosphor
with that mix determining the nominal colour temperature. It is quite
peaky in the blue and more of a wide hump around the yellow. The
phosphor usually looks yellow and sits on top of the LED.

http://i.stack.imgur.com/lkyXG.png

That's not as even as I thought. I thought they'd made it similar to
the sun, which looks like this:
https://i.publiclab.org/system/image...ctrumGraph.jpg

Maybe we should be using the controllable colour RGB ones.

They would be even worse at approximating the solar spectrum.

https://s-media-cache-ak0.pinimg.com...07cc796e89.jpg

RGB LED emissions have a fwhm of 50nm so would have a very peaky
spectrum. It doesn't normally matter except for colour matching or where
you have unusually narrow band pigments.

Materials that have very different colour depending on the white light
source you use are called after the semiprecious stone Alexandrite.

https://en.wikipedia.org/wiki/Chrysoberyl#Alexandrite

The other common one is neodymium doped glass used by glassblowers to
see into a gas flame against the yellow-orange glare of sodium emission.

--
Regards,
Martin Brown

On Tue, 25 Apr 2017 15:34:15 +0100, Martin Brown wrote:

On 25/04/2017 14:54, James Wilkinson Sword wrote:
On Tue, 25 Apr 2017 14:27:29 +0100, Martin Brown
wrote:

On 25/04/2017 13:27, Graham. wrote:
On Tue, 25 Apr 2017 12:25:35 +0100, "James Wilkinson Sword"
wrote:

Yes, I've googled it, but there are many different approaches.
Which one is used in domestic LED bulbs?

Ultra-violet LED exciting a white phosphor, much the same principle
used in florescents.

It is usually a high efficiency blue LED pump exciting a yellow phosphor
with that mix determining the nominal colour temperature. It is quite
peaky in the blue and more of a wide hump around the yellow. The
phosphor usually looks yellow and sits on top of the LED.

http://i.stack.imgur.com/lkyXG.png

That's not as even as I thought. I thought they'd made it similar to
the sun, which looks like this:
https://i.publiclab.org/system/image...ctrumGraph.jpg

Maybe we should be using the controllable colour RGB ones.

They would be even worse at approximating the solar spectrum.

https://s-media-cache-ak0.pinimg.com...07cc796e89.jpg

RGB LED emissions have a fwhm of 50nm so would have a very peaky
spectrum. It doesn't normally matter except for colour matching or where
you have unusually narrow band pigments.

Actually, they seem to be sold as RGBW, so they probably ave white LEDs too. But you can add a bit of R G B as necessary to make it closer to sunlight or whatever tone you prefer.

Clearly the best thing would be a phosphor mix that makes precisely the levels you get from sunlight, or many different wavelength LEDs which can be individually adjusted by the user to give the preferred output.

Materials that have very different colour depending on the white light
source you use are called after the semiprecious stone Alexandrite.

https://en.wikipedia.org/wiki/Chrysoberyl#Alexandrite

The other common one is neodymium doped glass used by glassblowers to
see into a gas flame against the yellow-orange glare of sodium emission.

--
The opposite of courage in our society is not cowardice, it is conformity; and there you have the trouble today is conformity: People acting like everyone else without knowing why, without knowing where they're going. -- Earl Nightingale

James Wilkinson Sword wrote

Yes, I've googled it, but there are many different
approaches. Which one is used in domestic LED bulbs?

Varys with who is doing the bulbs. The cheapest ****
does it differently to the stuff with the long warrantys.

James Wilkinson Sword wrote
Graham. wrote
James Wilkinson Sword wrote

Yes, I've googled it, but there are many different approaches.
Which one is used in domestic LED bulbs?

Ultra-violet LED exciting a white phosphor,
much the same principle used in florescents.

That's what I would have assumed, but when you
look at a switched off white LED, it's not white.

All that means is that it isnt white when it doesn't have UV falling
on it and that the protective outer isnt the phosphor itself.

I would have expected it to have a white coating that
can be seen like on a switched off fluorescent tube.

The difference is that leds don't have glass as the protective outer.

On Tue, 25 Apr 2017 19:34:38 +0100, Rod Speed wrote:

James Wilkinson Sword wrote
Graham. wrote
James Wilkinson Sword wrote

Yes, I've googled it, but there are many different approaches.
Which one is used in domestic LED bulbs?

Ultra-violet LED exciting a white phosphor,
much the same principle used in florescents.

That's what I would have assumed, but when you
look at a switched off white LED, it's not white.

All that means is that it isnt white when it doesn't have UV falling
on it and that the protective outer isnt the phosphor itself.

I would have expected it to have a white coating that
can be seen like on a switched off fluorescent tube.

The difference is that leds don't have glass as the protective outer.

Those adjustable-by-remote ones you have, just how many colours can you make? Do they only have R G and B emitters, or could you make a spectrum similar to sunlight?

--
"One dies in Istanbul suicide attack"

"James Wilkinson Sword" wrote in message
news
On Tue, 25 Apr 2017 15:34:15 +0100, Martin Brown
wrote:

On 25/04/2017 14:54, James Wilkinson Sword wrote:
On Tue, 25 Apr 2017 14:27:29 +0100, Martin Brown
wrote:

On 25/04/2017 13:27, Graham. wrote:
On Tue, 25 Apr 2017 12:25:35 +0100, "James Wilkinson Sword"
wrote:

Yes, I've googled it, but there are many different approaches.
Which one is used in domestic LED bulbs?

Ultra-violet LED exciting a white phosphor, much the same principle
used in florescents.

It is usually a high efficiency blue LED pump exciting a yellow
phosphor
with that mix determining the nominal colour temperature. It is quite
peaky in the blue and more of a wide hump around the yellow. The
phosphor usually looks yellow and sits on top of the LED.

http://i.stack.imgur.com/lkyXG.png

That's not as even as I thought. I thought they'd made it similar to
the sun, which looks like this:
https://i.publiclab.org/system/image...ctrumGraph.jpg

Maybe we should be using the controllable colour RGB ones.

They would be even worse at approximating the solar spectrum.

https://s-media-cache-ak0.pinimg.com...07cc796e89.jpg

RGB LED emissions have a fwhm of 50nm so would have a very peaky
spectrum. It doesn't normally matter except for colour matching or where
you have unusually narrow band pigments.

Actually, they seem to be sold as RGBW, so they probably ave white LEDs
too.

That's for brightness reasons.

But you can add a bit of R G B as necessary to make it closer to sunlight
or whatever tone you prefer.

Yep, that's what they do.

Clearly the best thing would be a phosphor mix that makes precisely the
levels you get from sunlight,

There is no such animal. Sunlight varys tremendously.

The sunlight you get on that soggy little
frigid island is nothing like what we get here.

or many different wavelength LEDs which can be individually adjusted by
the user to give the preferred output.

Yep, that's what the best of the led bulbs do, so you can have any
color temp you like, and different color temps at different times too.

Considerably more expensive to do it that way tho.

Materials that have very different colour depending on the white light
source you use are called after the semiprecious stone Alexandrite.

https://en.wikipedia.org/wiki/Chrysoberyl#Alexandrite

The other common one is neodymium doped glass used by glassblowers to
see into a gas flame against the yellow-orange glare of sodium emission.

On Tue, 25 Apr 2017 19:11:49 +0100, Rod Speed wrote:

James Wilkinson Sword wrote

Yes, I've googled it, but there are many different
approaches. Which one is used in domestic LED bulbs?

Varys with who is doing the bulbs. The cheapest ****
does it differently to the stuff with the long warrantys.

Don't they all use something similar to CREE LEDs?

--
A backward poet writes inverse.

On Tue, 25 Apr 2017 20:13:13 +0100, Rod Speed wrote:



"James Wilkinson Sword" wrote in message
news
On Tue, 25 Apr 2017 15:34:15 +0100, Martin Brown
wrote:

On 25/04/2017 14:54, James Wilkinson Sword wrote:
On Tue, 25 Apr 2017 14:27:29 +0100, Martin Brown
wrote:

On 25/04/2017 13:27, Graham. wrote:
On Tue, 25 Apr 2017 12:25:35 +0100, "James Wilkinson Sword"
wrote:

Yes, I've googled it, but there are many different approaches.
Which one is used in domestic LED bulbs?

Ultra-violet LED exciting a white phosphor, much the same principle
used in florescents.

It is usually a high efficiency blue LED pump exciting a yellow
phosphor
with that mix determining the nominal colour temperature. It is quite
peaky in the blue and more of a wide hump around the yellow. The
phosphor usually looks yellow and sits on top of the LED.

http://i.stack.imgur.com/lkyXG.png

That's not as even as I thought. I thought they'd made it similar to
the sun, which looks like this:
https://i.publiclab.org/system/image...ctrumGraph.jpg

Maybe we should be using the controllable colour RGB ones.

They would be even worse at approximating the solar spectrum.

https://s-media-cache-ak0.pinimg.com...07cc796e89.jpg

RGB LED emissions have a fwhm of 50nm so would have a very peaky
spectrum. It doesn't normally matter except for colour matching or where
you have unusually narrow band pigments.

Actually, they seem to be sold as RGBW, so they probably ave white LEDs
too.

That's for brightness reasons.

But you can add a bit of R G B as necessary to make it closer to sunlight
or whatever tone you prefer.

Yep, that's what they do.

So you can create a very even spectrum like with sunlight?

Give me a link to such a bulb, I want to try one.

Clearly the best thing would be a phosphor mix that makes precisely the
levels you get from sunlight,

There is no such animal. Sunlight varys tremendously.

The sunlight you get on that soggy little
frigid island is nothing like what we get here.

When the sky is blue, I would think it's similar everywhere all over the globe. Just a different intensity.

or many different wavelength LEDs which can be individually adjusted by
the user to give the preferred output.

Yep, that's what the best of the led bulbs do, so you can have any
color temp you like, and different color temps at different times too.

Considerably more expensive to do it that way tho.

Materials that have very different colour depending on the white light
source you use are called after the semiprecious stone Alexandrite.

https://en.wikipedia.org/wiki/Chrysoberyl#Alexandrite

The other common one is neodymium doped glass used by glassblowers to
see into a gas flame against the yellow-orange glare of sodium emission.

--
Connecticut police are investigating a string of shootings where clues are reportedly contained in a rap CD.
They are also questioning Bob Marley about the shooting of a sheriff.

"James Wilkinson Sword" wrote in message
news
On Tue, 25 Apr 2017 19:34:38 +0100, Rod Speed
wrote:

James Wilkinson Sword wrote
Graham. wrote
James Wilkinson Sword wrote

Yes, I've googled it, but there are many different approaches.
Which one is used in domestic LED bulbs?

Ultra-violet LED exciting a white phosphor,
much the same principle used in florescents.

That's what I would have assumed, but when you
look at a switched off white LED, it's not white.

All that means is that it isnt white when it doesn't have UV falling
on it and that the protective outer isnt the phosphor itself.

I would have expected it to have a white coating that
can be seen like on a switched off fluorescent tube.

The difference is that leds don't have glass as the protective outer.

Those adjustable-by-remote ones you have, just how many colours can you
make?

They claim 16M

Do they only have R G and B emitters,

Nope. The strips where the leds are visible have one big led and a couple
of smaller RGB ones. Not clear why there is more than one RGB one,
presumably because they arent anything like as bright as the white one.

Just discovered I can't actually take a photo of the strip with the leds
lit in the dark it completely ****s the exposure system in the phone.

or could you make a spectrum similar to sunlight?

--
"One dies in Istanbul suicide attack"

James Wilkinson Sword wrote
Rod Speed wrote
James Wilkinson Sword wrote

Yes, I've googled it, but there are many different
approaches. Which one is used in domestic LED bulbs?

Varys with who is doing the bulbs. The cheapest ****
does it differently to the stuff with the long warrantys.

Don't they all use something similar to CREE LEDs?

Nope, the cheapest **** has the individual leds clearly visible.

The fancy **** does indeed have what CREE calls remote phosphors.

But those don't work where you want a bulb that you
can vary the color temperature to anything you like.

"James Wilkinson Sword" wrote in message
news
On Tue, 25 Apr 2017 20:13:13 +0100, Rod Speed
wrote:



"James Wilkinson Sword" wrote in message
news
On Tue, 25 Apr 2017 15:34:15 +0100, Martin Brown
wrote:

On 25/04/2017 14:54, James Wilkinson Sword wrote:
On Tue, 25 Apr 2017 14:27:29 +0100, Martin Brown
wrote:

On 25/04/2017 13:27, Graham. wrote:
On Tue, 25 Apr 2017 12:25:35 +0100, "James Wilkinson Sword"
wrote:

Yes, I've googled it, but there are many different approaches.
Which one is used in domestic LED bulbs?

Ultra-violet LED exciting a white phosphor, much the same principle
used in florescents.

It is usually a high efficiency blue LED pump exciting a yellow
phosphor
with that mix determining the nominal colour temperature. It is quite
peaky in the blue and more of a wide hump around the yellow. The
phosphor usually looks yellow and sits on top of the LED.

http://i.stack.imgur.com/lkyXG.png

That's not as even as I thought. I thought they'd made it similar to
the sun, which looks like this:
https://i.publiclab.org/system/image...ctrumGraph.jpg

Maybe we should be using the controllable colour RGB ones.

They would be even worse at approximating the solar spectrum.

https://s-media-cache-ak0.pinimg.com...07cc796e89.jpg

RGB LED emissions have a fwhm of 50nm so would have a very peaky
spectrum. It doesn't normally matter except for colour matching or
where
you have unusually narrow band pigments.

Actually, they seem to be sold as RGBW, so they probably ave white LEDs
too.

That's for brightness reasons.

But you can add a bit of R G B as necessary to make it closer to
sunlight or whatever tone you prefer.

Yep, that's what they do.

So you can create a very even spectrum like with sunlight?

Nope, that's very difficult to do with leds.

Give me a link to such a bulb, I want to try one.

Clearly the best thing would be a phosphor mix that makes precisely the
levels you get from sunlight,

There is no such animal. Sunlight varys tremendously.

The sunlight you get on that soggy little
frigid island is nothing like what we get here.

When the sky is blue, I would think it's similar everywhere all over the
globe. Just a different intensity.

Fraid not. And you don't get the same blue sky everywhere either.

or many different wavelength LEDs which can be individually adjusted by
the user to give the preferred output.

Yep, that's what the best of the led bulbs do, so you can have any
color temp you like, and different color temps at different times too.

Considerably more expensive to do it that way tho.

Materials that have very different colour depending on the white light
source you use are called after the semiprecious stone Alexandrite.

https://en.wikipedia.org/wiki/Chrysoberyl#Alexandrite

The other common one is neodymium doped glass used by glassblowers to
see into a gas flame against the yellow-orange glare of sodium
emission.

On Tue, 25 Apr 2017 21:01:37 +0100, Rod Speed wrote:



"James Wilkinson Sword" wrote in message
news
On Tue, 25 Apr 2017 19:34:38 +0100, Rod Speed
wrote:

James Wilkinson Sword wrote
Graham. wrote
James Wilkinson Sword wrote

Yes, I've googled it, but there are many different approaches.
Which one is used in domestic LED bulbs?

Ultra-violet LED exciting a white phosphor,
much the same principle used in florescents.

That's what I would have assumed, but when you
look at a switched off white LED, it's not white.

All that means is that it isnt white when it doesn't have UV falling
on it and that the protective outer isnt the phosphor itself.

I would have expected it to have a white coating that
can be seen like on a switched off fluorescent tube.

The difference is that leds don't have glass as the protective outer.

Those adjustable-by-remote ones you have, just how many colours can you
make?

They claim 16M

Do they only have R G and B emitters,

Nope. The strips where the leds are visible have one big led and a couple
of smaller RGB ones. Not clear why there is more than one RGB one,
presumably because they arent anything like as bright as the white one.

Just discovered I can't actually take a photo of the strip with the leds
lit in the dark it completely ****s the exposure system in the phone.

Use a real camera and put it on manual exposure?

or could you make a spectrum similar to sunlight?

--
A can of diet coke floats in water, but a can of regular coke sinks.

On Tue, 25 Apr 2017 21:14:46 +0100, Rod Speed wrote:

James Wilkinson Sword wrote
Rod Speed wrote
James Wilkinson Sword wrote

Yes, I've googled it, but there are many different
approaches. Which one is used in domestic LED bulbs?

Varys with who is doing the bulbs. The cheapest ****
does it differently to the stuff with the long warrantys.

Don't they all use something similar to CREE LEDs?

Nope, the cheapest **** has the individual leds clearly visible.

What do you mean by that? You can always se individual LEDs can't you?

The fancy **** does indeed have what CREE calls remote phosphors.

But those don't work where you want a bulb that you
can vary the color temperature to anything you like.

--
What's the fastest thing in Wales?
A virgin sheep.

On Tue, 25 Apr 2017 21:18:11 +0100, Rod Speed wrote:



"James Wilkinson Sword" wrote in message
news
On Tue, 25 Apr 2017 20:13:13 +0100, Rod Speed
wrote:



"James Wilkinson Sword" wrote in message
news On Tue, 25 Apr 2017 15:34:15 +0100, Martin Brown
wrote:

On 25/04/2017 14:54, James Wilkinson Sword wrote:
On Tue, 25 Apr 2017 14:27:29 +0100, Martin Brown
wrote:

On 25/04/2017 13:27, Graham. wrote:
On Tue, 25 Apr 2017 12:25:35 +0100, "James Wilkinson Sword"
wrote:

Yes, I've googled it, but there are many different approaches.
Which one is used in domestic LED bulbs?

Ultra-violet LED exciting a white phosphor, much the same principle
used in florescents.

It is usually a high efficiency blue LED pump exciting a yellow
phosphor
with that mix determining the nominal colour temperature. It is quite
peaky in the blue and more of a wide hump around the yellow. The
phosphor usually looks yellow and sits on top of the LED.

http://i.stack.imgur.com/lkyXG.png

That's not as even as I thought. I thought they'd made it similar to
the sun, which looks like this:
https://i.publiclab.org/system/image...ctrumGraph.jpg

Maybe we should be using the controllable colour RGB ones.

They would be even worse at approximating the solar spectrum.

https://s-media-cache-ak0.pinimg.com...07cc796e89.jpg

RGB LED emissions have a fwhm of 50nm so would have a very peaky
spectrum. It doesn't normally matter except for colour matching or
where
you have unusually narrow band pigments.

Actually, they seem to be sold as RGBW, so they probably ave white LEDs
too.

That's for brightness reasons.

But you can add a bit of R G B as necessary to make it closer to
sunlight or whatever tone you prefer.

Yep, that's what they do.

So you can create a very even spectrum like with sunlight?

Nope, that's very difficult to do with leds.

Surely you can at least make the R G and B frequencies that the LEDs produce be the right levels for sunlight?

Give me a link to such a bulb, I want to try one.

Clearly the best thing would be a phosphor mix that makes precisely the
levels you get from sunlight,

There is no such animal. Sunlight varys tremendously.

The sunlight you get on that soggy little
frigid island is nothing like what we get here.

When the sky is blue, I would think it's similar everywhere all over the
globe. Just a different intensity.

Fraid not. And you don't get the same blue sky everywhere either.

Cite?

--
She was as easy as the Daily Star crossword.

James Wilkinson Sword wrote:
On Tue, 25 Apr 2017 21:18:11 +0100, Rod Speed
wrote:


"James Wilkinson Sword" wrote in message
news
On Tue, 25 Apr 2017 20:13:13 +0100, Rod Speed
wrote:



"James Wilkinson Sword" wrote in message
news On Tue, 25 Apr 2017 15:34:15 +0100, Martin Brown
wrote:

On 25/04/2017 14:54, James Wilkinson Sword wrote:
On Tue, 25 Apr 2017 14:27:29 +0100, Martin Brown
wrote:

On 25/04/2017 13:27, Graham. wrote:
On Tue, 25 Apr 2017 12:25:35 +0100, "James Wilkinson Sword"
wrote:

Yes, I've googled it, but there are many different
approaches. Which one is used in domestic LED bulbs?

Ultra-violet LED exciting a white phosphor, much the same
principle used in florescents.

It is usually a high efficiency blue LED pump exciting a yellow
phosphor
with that mix determining the nominal colour temperature. It
is quite peaky in the blue and more of a wide hump around the
yellow. The phosphor usually looks yellow and sits on top of
the LED. http://i.stack.imgur.com/lkyXG.png

That's not as even as I thought. I thought they'd made it
similar to the sun, which looks like this:
https://i.publiclab.org/system/image...ctrumGraph.jpg

Maybe we should be using the controllable colour RGB ones.

They would be even worse at approximating the solar spectrum.

https://s-media-cache-ak0.pinimg.com...07cc796e89.jpg

RGB LED emissions have a fwhm of 50nm so would have a very peaky
spectrum. It doesn't normally matter except for colour matching
or where
you have unusually narrow band pigments.

Actually, they seem to be sold as RGBW, so they probably ave
white LEDs too.

That's for brightness reasons.

But you can add a bit of R G B as necessary to make it closer to
sunlight or whatever tone you prefer.

Yep, that's what they do.

So you can create a very even spectrum like with sunlight?

Nope, that's very difficult to do with leds.

Surely you can at least make the R G and B frequencies that the LEDs
produce be the right levels for sunlight?
Give me a link to such a bulb, I want to try one.

Clearly the best thing would be a phosphor mix that makes
precisely the levels you get from sunlight,

There is no such animal. Sunlight varys tremendously.

The sunlight you get on that soggy little
frigid island is nothing like what we get here.

When the sky is blue, I would think it's similar everywhere all
over the globe. Just a different intensity.

Fraid not. And you don't get the same blue sky everywhere either.

Cite?

Long thread.
How many wanks will you get out of this one, you little piece of benefit
claiming ****?

"James Wilkinson Sword" wrote in message
news
On Tue, 25 Apr 2017 21:01:37 +0100, Rod Speed
wrote:



"James Wilkinson Sword" wrote in message
news
On Tue, 25 Apr 2017 19:34:38 +0100, Rod Speed
wrote:

James Wilkinson Sword wrote
Graham. wrote
James Wilkinson Sword wrote

Yes, I've googled it, but there are many different approaches.
Which one is used in domestic LED bulbs?

Ultra-violet LED exciting a white phosphor,
much the same principle used in florescents.

That's what I would have assumed, but when you
look at a switched off white LED, it's not white.

All that means is that it isnt white when it doesn't have UV falling
on it and that the protective outer isnt the phosphor itself.

I would have expected it to have a white coating that
can be seen like on a switched off fluorescent tube.

The difference is that leds don't have glass as the protective outer.

Those adjustable-by-remote ones you have, just how many colours can you
make?

They claim 16M

Do they only have R G and B emitters,

Nope. The strips where the leds are visible have one big led and a couple
of smaller RGB ones. Not clear why there is more than one RGB one,
presumably because they arent anything like as bright as the white one.

Just discovered I can't actually take a photo of the strip with the leds
lit in the dark it completely ****s the exposure system in the phone.

Use a real camera

Don't have one anymore and wouldn't have any film for it even if I did.

and put it on manual exposure?

or could you make a spectrum similar to sunlight?

On Tue, 25 Apr 2017 14:27:29 +0100, Martin Brown wrote:

On 25/04/2017 13:27, Graham. wrote:
On Tue, 25 Apr 2017 12:25:35 +0100, "James Wilkinson Sword"
wrote:

Yes, I've googled it, but there are many different approaches. Which
one is used in domestic LED bulbs?

Ultra-violet LED exciting a white phosphor, much the same principle
used in florescents.

It is usually a high efficiency blue LED pump exciting a yellow phosphor
with that mix determining the nominal colour temperature. It is quite
peaky in the blue and more of a wide hump around the yellow. The
phosphor usually looks yellow and sits on top of the LED.

http://i.stack.imgur.com/lkyXG.png

The visible light flux out of an LED die on a high efficiency LED these
days is about the same order of magnitude as the sun's photosphere.

It is a lot more obvious on the devices which use a remote phosphor.

http://www.cree.com/led-components/m...e-Phosphor.pdf

An interesting read (note the use of the expression "loosing efficiency"
on page 8 regarding Fig 7a). Also of note is the copyright date of this
document which is the year of their record breaking 303Lm/W led efficacy
achievement in February/March of that year when the Cree Spokesperson let
slip to the trade press that such laboratory achievements typically took
a further 18 to 24 months of development before making their début on
store shelves for public consumption.

A simple arithmetic calculation reveals that this scheduled development
has slipped by a rather conservatively estimated 13 months. :-( The best
Lm/W efficacy figures I've noted recently have been around the 125 to 145
Lm/W mark. The former being a 1500Lm 12W GLS B22 2700K Warm White lamp I
sampled from a Home Bargains store for the princely sum of £2.99 which
turned out to have an *actual* consumption figure of 14 watts.

Since its illumination power doesn't seem as impressively bright as I
was expecting (even making allowances for the eye's logarithmic response
to brightness), I rather doubt the additional 2 watts is hiking the
claimed 1500Lm to 1750Lms as one might expect if the additional 2 watts
was simply the result of overly wide tolerances in the 'electronic
ballast circuit' causing the LEDs to be overdriven to a higher than
designed Lumens output.

I have a sneaking suspicion that the claims of "1500 Lumens at 12W (100W
eqv)" have been based on the best of a sampling of these lamps off the
production line, possibly based on the maximum positive tolerance limit
of the 'nominal' power consumption to boot for good measure (+10%? =
13.2W) so might more typically be nearer the 110Lm/W mark than to the
claimed 125Lm/W figure. Even the claimed efficacy is not a particularly
massive improvement over the 81Lm/W efficacy figures typical of many LED
GLS lamps of just over three years ago.

The 145Lm/W lamps I saw were the grossly overpriced 1600Lm LES 11W
examples being offered by Asda. I might have considered buying one if
they'd been more sanely priced but at something like 10 to 18 quid a pop
(I didn't bother trying to pin the confusing shelf price labelling down
any tighter than that - it was enough to know that it was at least 3
times pricier than I'd been prepared to pay in Home and Bargain), I
wasn't in the least bit tempted.

It's not so much the electrical consumption cost savings that interest
me so much as the service life endurance promise standing a much better
chance of being fulfilled outside of a laboratory test environment in the
more demanding conditions typical of a domestic pendant light fitting
complete with fancy draught excluding shade dangling in the warmest
layers of air to be found in a room basking in the warmth of a centrally
heated radiator or two.

I'm happy enough with the current crop of "60W 806Lm 120v 750 Hour life
rated" American tungsten GLS lamp equivalent 9W LEDs where an 806 Lm lamp
can provide the required illumination level (effectively replacing a 73W
240v 1000 hour tungsten filament GLS lamp in UK housing). It's all these
15 and 18 watt 1500Lm LED GLS replacements for the 100W tungsten filament
GLS lamps with their more marginal temperature tolerance that give me
pause in their deployment as a GLS alternative.

The LED version of the "100W GLS tungsten filament lamps now starting to
appear would seem to be a viable GLS candidate if their claimed
efficacies of 145 and 150 Lm per watt are based in reality rather than
best hoped for efficacy.

It's been a rather disappointing wait for Cree to begin fulfilling that
(probably ill advised) promise made by their spokesperson just over three
years ago when they announced their record breaking achievement in LED
efficacy. Here we are, some 50 percent further along than their upper
timescale to get 300Lm/W lamps to market, with lamps of only half that
efficacy to show for their efforts thus far.

Still, at least *some* progress has finally materialised at long last,
so I suppose we ought to be grateful to finally be free of the 2013 'Time
Warp' we seem to have been living in for the past 3 or 4 years. :-)
Better late than never.

At this rate of development, we'll be lucky to see the next efficacy
milestone of 200Lm/W being achieved within the next three years or so.
Who knows? We may see a sudden spurt from Cree whereby the 200Lm/W
milestone in commercially available lamps is reached within the next 12
months. Either that or else an admission that the 303Lm/W lab results
were faked just to pressurise Philips Lighting into quitting the LED lamp
business. :-(

--
Johnny B Good

"James Wilkinson Sword" wrote in message
news
On Tue, 25 Apr 2017 21:14:46 +0100, Rod Speed
wrote:

James Wilkinson Sword wrote
Rod Speed wrote
James Wilkinson Sword wrote

Yes, I've googled it, but there are many different
approaches. Which one is used in domestic LED bulbs?

Varys with who is doing the bulbs. The cheapest ****
does it differently to the stuff with the long warrantys.

Don't they all use something similar to CREE LEDs?

Nope, the cheapest **** has the individual leds clearly visible.

What do you mean by that? You can always se individual LEDs can't you?

Nope, no visible individual leds with the high end led bulbs.
https://www.cnet.com/products/philip...er-kit/review/

The fancy **** does indeed have what CREE calls remote phosphors.

But those don't work where you want a bulb that you
can vary the color temperature to anything you like.

"James Wilkinson Sword" wrote in message
news
On Tue, 25 Apr 2017 21:18:11 +0100, Rod Speed
wrote:



"James Wilkinson Sword" wrote in message
news
On Tue, 25 Apr 2017 20:13:13 +0100, Rod Speed
wrote:



"James Wilkinson Sword" wrote in message
news On Tue, 25 Apr 2017 15:34:15 +0100, Martin Brown
wrote:

On 25/04/2017 14:54, James Wilkinson Sword wrote:
On Tue, 25 Apr 2017 14:27:29 +0100, Martin Brown
wrote:

On 25/04/2017 13:27, Graham. wrote:
On Tue, 25 Apr 2017 12:25:35 +0100, "James Wilkinson Sword"
wrote:

Yes, I've googled it, but there are many different approaches.
Which one is used in domestic LED bulbs?

Ultra-violet LED exciting a white phosphor, much the same
principle
used in florescents.

It is usually a high efficiency blue LED pump exciting a yellow
phosphor
with that mix determining the nominal colour temperature. It is
quite
peaky in the blue and more of a wide hump around the yellow. The
phosphor usually looks yellow and sits on top of the LED.

http://i.stack.imgur.com/lkyXG.png

That's not as even as I thought. I thought they'd made it similar
to
the sun, which looks like this:
https://i.publiclab.org/system/image...ctrumGraph.jpg

Maybe we should be using the controllable colour RGB ones.

They would be even worse at approximating the solar spectrum.

https://s-media-cache-ak0.pinimg.com...07cc796e89.jpg

RGB LED emissions have a fwhm of 50nm so would have a very peaky
spectrum. It doesn't normally matter except for colour matching or
where
you have unusually narrow band pigments.

Actually, they seem to be sold as RGBW, so they probably ave white
LEDs
too.

That's for brightness reasons.

But you can add a bit of R G B as necessary to make it closer to
sunlight or whatever tone you prefer.

Yep, that's what they do.

So you can create a very even spectrum like with sunlight?

Nope, that's very difficult to do with leds.

Surely you can at least make the R G and B frequencies that the LEDs
produce be the right levels for sunlight?

Yes, but the SPECTRUM is nothing even remotely like real sunlight.

Give me a link to such a bulb, I want to try one.

Clearly the best thing would be a phosphor mix that makes precisely
the
levels you get from sunlight,

There is no such animal. Sunlight varys tremendously.

The sunlight you get on that soggy little
frigid island is nothing like what we get here.

When the sky is blue, I would think it's similar everywhere all over the
globe. Just a different intensity.

Fraid not. And you don't get the same blue sky everywhere either.

Cite?

Don't need a cite, look at the photos.

On Tue, 25 Apr 2017 22:16:46 +0100, Rod Speed wrote:



"James Wilkinson Sword" wrote in message
news
On Tue, 25 Apr 2017 21:18:11 +0100, Rod Speed
wrote:



"James Wilkinson Sword" wrote in message
news On Tue, 25 Apr 2017 20:13:13 +0100, Rod Speed
wrote:



"James Wilkinson Sword" wrote in message
news On Tue, 25 Apr 2017 15:34:15 +0100, Martin Brown
wrote:

On 25/04/2017 14:54, James Wilkinson Sword wrote:
On Tue, 25 Apr 2017 14:27:29 +0100, Martin Brown
wrote:

On 25/04/2017 13:27, Graham. wrote:
On Tue, 25 Apr 2017 12:25:35 +0100, "James Wilkinson Sword"
wrote:

Yes, I've googled it, but there are many different approaches.
Which one is used in domestic LED bulbs?

Ultra-violet LED exciting a white phosphor, much the same
principle
used in florescents.

It is usually a high efficiency blue LED pump exciting a yellow
phosphor
with that mix determining the nominal colour temperature. It is
quite
peaky in the blue and more of a wide hump around the yellow. The
phosphor usually looks yellow and sits on top of the LED.

http://i.stack.imgur.com/lkyXG.png

That's not as even as I thought. I thought they'd made it similar
to
the sun, which looks like this:
https://i.publiclab.org/system/image...ctrumGraph.jpg

Maybe we should be using the controllable colour RGB ones.

They would be even worse at approximating the solar spectrum.

https://s-media-cache-ak0.pinimg.com...07cc796e89.jpg

RGB LED emissions have a fwhm of 50nm so would have a very peaky
spectrum. It doesn't normally matter except for colour matching or
where
you have unusually narrow band pigments.

Actually, they seem to be sold as RGBW, so they probably ave white
LEDs
too.

That's for brightness reasons.

But you can add a bit of R G B as necessary to make it closer to
sunlight or whatever tone you prefer.

Yep, that's what they do.

So you can create a very even spectrum like with sunlight?

Nope, that's very difficult to do with leds.

Surely you can at least make the R G and B frequencies that the LEDs
produce be the right levels for sunlight?

Yes, but the SPECTRUM is nothing even remotely like real sunlight.

But it has to be an improvement over white LEDs.

Give me a link to such a bulb, I want to try one.

Clearly the best thing would be a phosphor mix that makes precisely
the
levels you get from sunlight,

There is no such animal. Sunlight varys tremendously.

The sunlight you get on that soggy little
frigid island is nothing like what we get here.

When the sky is blue, I would think it's similar everywhere all over the
globe. Just a different intensity.

Fraid not. And you don't get the same blue sky everywhere either.

Cite?

Don't need a cite, look at the photos.

Never seen a difference.

--
Say it with flowers - send her a triffid.

On Tue, 25 Apr 2017 22:15:15 +0100, Rod Speed wrote:



"James Wilkinson Sword" wrote in message
news
On Tue, 25 Apr 2017 21:14:46 +0100, Rod Speed
wrote:

James Wilkinson Sword wrote
Rod Speed wrote
James Wilkinson Sword wrote

Yes, I've googled it, but there are many different
approaches. Which one is used in domestic LED bulbs?

Varys with who is doing the bulbs. The cheapest ****
does it differently to the stuff with the long warrantys.

Don't they all use something similar to CREE LEDs?

Nope, the cheapest **** has the individual leds clearly visible.

What do you mean by that? You can always se individual LEDs can't you?

Nope, no visible individual leds with the high end led bulbs.
https://www.cnet.com/products/philip...er-kit/review/

There's a plastic over over it. What's your point?

--
A single blonde pregnant girl goes to the grocery store. A couple that she knows notices she's pregnant.
The lady asks her, "Whose baby is it?"
The blonde says, "Well, I don't know they are going to do blood tests, but I think it's mine."

On Tue, 25 Apr 2017 22:12:37 +0100, Johnny B Good wrote:

On Tue, 25 Apr 2017 14:27:29 +0100, Martin Brown wrote:

On 25/04/2017 13:27, Graham. wrote:
On Tue, 25 Apr 2017 12:25:35 +0100, "James Wilkinson Sword"
wrote:

Yes, I've googled it, but there are many different approaches. Which
one is used in domestic LED bulbs?

Ultra-violet LED exciting a white phosphor, much the same principle
used in florescents.

It is usually a high efficiency blue LED pump exciting a yellow phosphor
with that mix determining the nominal colour temperature. It is quite
peaky in the blue and more of a wide hump around the yellow. The
phosphor usually looks yellow and sits on top of the LED.

http://i.stack.imgur.com/lkyXG.png

The visible light flux out of an LED die on a high efficiency LED these
days is about the same order of magnitude as the sun's photosphere.

It is a lot more obvious on the devices which use a remote phosphor.

http://www.cree.com/led-components/m...e-Phosphor.pdf

An interesting read (note the use of the expression "loosing efficiency"
on page 8 regarding Fig 7a). Also of note is the copyright date of this
document which is the year of their record breaking 303Lm/W led efficacy
achievement in February/March of that year when the Cree Spokesperson let
slip to the trade press that such laboratory achievements typically took
a further 18 to 24 months of development before making their début on
store shelves for public consumption.

A simple arithmetic calculation reveals that this scheduled development
has slipped by a rather conservatively estimated 13 months. :-( The best
Lm/W efficacy figures I've noted recently have been around the 125 to 145
Lm/W mark. The former being a 1500Lm 12W GLS B22 2700K Warm White lamp I
sampled from a Home Bargains store for the princely sum of £2.99 which
turned out to have an *actual* consumption figure of 14 watts.

I thought the best LEDs were equivalent to 10W out per 1W in. Eg a 10W LED bulb should be equivalent to a 100W incandescent. A 100W incandescent is 1435 lumens. So your bulb is consuming 14W to give out about 105W.. Not as good as I thought.

Since its illumination power doesn't seem as impressively bright as I
was expecting (even making allowances for the eye's logarithmic response
to brightness), I rather doubt the additional 2 watts is hiking the
claimed 1500Lm to 1750Lms as one might expect if the additional 2 watts
was simply the result of overly wide tolerances in the 'electronic
ballast circuit' causing the LEDs to be overdriven to a higher than
designed Lumens output.

I have a sneaking suspicion that the claims of "1500 Lumens at 12W (100W
eqv)" have been based on the best of a sampling of these lamps off the
production line, possibly based on the maximum positive tolerance limit
of the 'nominal' power consumption to boot for good measure (+10%? =
13.2W) so might more typically be nearer the 110Lm/W mark than to the
claimed 125Lm/W figure. Even the claimed efficacy is not a particularly
massive improvement over the 81Lm/W efficacy figures typical of many LED
GLS lamps of just over three years ago.

Companies lie, they always do. Cameras state x MP, and if you take a photo at full resolution, it's ****. Hard disks don't use gigabytes, but billions of bytes, shaving off a little.

The 145Lm/W lamps I saw were the grossly overpriced 1600Lm LES 11W
examples being offered by Asda. I might have considered buying one if
they'd been more sanely priced but at something like 10 to 18 quid a pop
(I didn't bother trying to pin the confusing shelf price labelling down
any tighter than that - it was enough to know that it was at least 3
times pricier than I'd been prepared to pay in Home and Bargain), I
wasn't in the least bit tempted.

I'm currently using this sort of thing:
http://www.ebay.co.uk/itm/231644564446
Might not be the best price, I just linked to the first one I found, not where I bought them from.
The LEDs are well spaced and they don't exceed body temperature, so they don't fail like most LED bulbs.

It's not so much the electrical consumption cost savings that interest
me so much as the service life endurance promise standing a much better
chance of being fulfilled outside of a laboratory test environment in the
more demanding conditions typical of a domestic pendant light fitting
complete with fancy draught excluding shade dangling in the warmest
layers of air to be found in a room basking in the warmth of a centrally
heated radiator or two.

I'm happy enough with the current crop of "60W 806Lm 120v 750 Hour life
rated" American tungsten GLS lamp equivalent 9W LEDs where an 806 Lm lamp
can provide the required illumination level (effectively replacing a 73W
240v 1000 hour tungsten filament GLS lamp in UK housing). It's all these
15 and 18 watt 1500Lm LED GLS replacements for the 100W tungsten filament
GLS lamps with their more marginal temperature tolerance that give me
pause in their deployment as a GLS alternative.

The LED version of the "100W GLS tungsten filament lamps now starting to
appear would seem to be a viable GLS candidate if their claimed
efficacies of 145 and 150 Lm per watt are based in reality rather than
best hoped for efficacy.

It's been a rather disappointing wait for Cree to begin fulfilling that
(probably ill advised) promise made by their spokesperson just over three
years ago when they announced their record breaking achievement in LED
efficacy. Here we are, some 50 percent further along than their upper
timescale to get 300Lm/W lamps to market, with lamps of only half that
efficacy to show for their efforts thus far.

Still, at least *some* progress has finally materialised at long last,
so I suppose we ought to be grateful to finally be free of the 2013 'Time
Warp' we seem to have been living in for the past 3 or 4 years. :-)
Better late than never.

At this rate of development, we'll be lucky to see the next efficacy
milestone of 200Lm/W being achieved within the next three years or so.
Who knows? We may see a sudden spurt from Cree whereby the 200Lm/W
milestone in commercially available lamps is reached within the next 12
months. Either that or else an admission that the 303Lm/W lab results
were faked just to pressurise Philips Lighting into quitting the LED lamp
business. :-(

They really should put sensible ratings on each LED bulb they sell. It should clearly state the actual electrical consumption (it's been mentioned in this thread that they lie), and equivalent output (eg "=60W incandescent". The general public don't know what a bloody lumen is.

--
I took a vow of faith, I don't shoot any more.
You don't shoot any less either.
-- Machete, film, 2010.

On Tue, 25 Apr 2017 22:08:34 +0100, Rod Speed wrote:



"James Wilkinson Sword" wrote in message
news
On Tue, 25 Apr 2017 21:01:37 +0100, Rod Speed
wrote:



"James Wilkinson Sword" wrote in message
news On Tue, 25 Apr 2017 19:34:38 +0100, Rod Speed
wrote:

James Wilkinson Sword wrote
Graham. wrote
James Wilkinson Sword wrote

Yes, I've googled it, but there are many different approaches.
Which one is used in domestic LED bulbs?

Ultra-violet LED exciting a white phosphor,
much the same principle used in florescents.

That's what I would have assumed, but when you
look at a switched off white LED, it's not white.

All that means is that it isnt white when it doesn't have UV falling
on it and that the protective outer isnt the phosphor itself.

I would have expected it to have a white coating that
can be seen like on a switched off fluorescent tube.

The difference is that leds don't have glass as the protective outer.

Those adjustable-by-remote ones you have, just how many colours can you
make?

They claim 16M

Do they only have R G and B emitters,

Nope. The strips where the leds are visible have one big led and a couple
of smaller RGB ones. Not clear why there is more than one RGB one,
presumably because they arent anything like as bright as the white one.

Just discovered I can't actually take a photo of the strip with the leds
lit in the dark it completely ****s the exposure system in the phone.

Use a real camera

Don't have one anymore and wouldn't have any film for it even if I did.

I meant a real digital camera, with proper options like manual control of focussing and aperture for situations like this. A phone is not a camera, it's a handy thing which can take a dodgy photo at a push.

--
You wag your tail like your mother, you repugnant, hairball engorging, cat buggering, pseudo-human android spawn of a foul-smelling telephone solicitor!

"James Wilkinson Sword" wrote in message
news
On Tue, 25 Apr 2017 22:15:15 +0100, Rod Speed
wrote:



"James Wilkinson Sword" wrote in message
news
On Tue, 25 Apr 2017 21:14:46 +0100, Rod Speed
wrote:

James Wilkinson Sword wrote
Rod Speed wrote
James Wilkinson Sword wrote

Yes, I've googled it, but there are many different
approaches. Which one is used in domestic LED bulbs?

Varys with who is doing the bulbs. The cheapest ****
does it differently to the stuff with the long warrantys.

Don't they all use something similar to CREE LEDs?

Nope, the cheapest **** has the individual leds clearly visible.

What do you mean by that? You can always se individual LEDs can't you?

Nope, no visible individual leds with the high end led bulbs.
https://www.cnet.com/products/philip...er-kit/review/

There's a plastic over over it.

That's actually what CREE calls a remote phosphor.

What's your point?

That you cant SEE the individual leds.

"James Wilkinson Sword" wrote in message
news
On Tue, 25 Apr 2017 22:12:37 +0100, Johnny B Good
wrote:

On Tue, 25 Apr 2017 14:27:29 +0100, Martin Brown wrote:

On 25/04/2017 13:27, Graham. wrote:
On Tue, 25 Apr 2017 12:25:35 +0100, "James Wilkinson Sword"
wrote:

Yes, I've googled it, but there are many different approaches. Which
one is used in domestic LED bulbs?

Ultra-violet LED exciting a white phosphor, much the same principle
used in florescents.

It is usually a high efficiency blue LED pump exciting a yellow phosphor
with that mix determining the nominal colour temperature. It is quite
peaky in the blue and more of a wide hump around the yellow. The
phosphor usually looks yellow and sits on top of the LED.

http://i.stack.imgur.com/lkyXG.png

The visible light flux out of an LED die on a high efficiency LED these
days is about the same order of magnitude as the sun's photosphere.

It is a lot more obvious on the devices which use a remote phosphor.

http://www.cree.com/led-components/m...e-Phosphor.pdf

An interesting read (note the use of the expression "loosing efficiency"
on page 8 regarding Fig 7a). Also of note is the copyright date of this
document which is the year of their record breaking 303Lm/W led efficacy
achievement in February/March of that year when the Cree Spokesperson let
slip to the trade press that such laboratory achievements typically took
a further 18 to 24 months of development before making their début on
store shelves for public consumption.

A simple arithmetic calculation reveals that this scheduled development
has slipped by a rather conservatively estimated 13 months. :-( The best
Lm/W efficacy figures I've noted recently have been around the 125 to 145
Lm/W mark. The former being a 1500Lm 12W GLS B22 2700K Warm White lamp I
sampled from a Home Bargains store for the princely sum of £2.99 which
turned out to have an *actual* consumption figure of 14 watts.

I thought the best LEDs were equivalent to 10W out per 1W in. Eg a 10W
LED bulb should be equivalent to a 100W incandescent. A 100W incandescent
is 1435 lumens. So your bulb is consuming 14W to give out about 105W.
Not as good as I thought.

Since its illumination power doesn't seem as impressively bright as I
was expecting (even making allowances for the eye's logarithmic response
to brightness), I rather doubt the additional 2 watts is hiking the
claimed 1500Lm to 1750Lms as one might expect if the additional 2 watts
was simply the result of overly wide tolerances in the 'electronic
ballast circuit' causing the LEDs to be overdriven to a higher than
designed Lumens output.

I have a sneaking suspicion that the claims of "1500 Lumens at 12W (100W
eqv)" have been based on the best of a sampling of these lamps off the
production line, possibly based on the maximum positive tolerance limit
of the 'nominal' power consumption to boot for good measure (+10%? =
13.2W) so might more typically be nearer the 110Lm/W mark than to the
claimed 125Lm/W figure. Even the claimed efficacy is not a particularly
massive improvement over the 81Lm/W efficacy figures typical of many LED
GLS lamps of just over three years ago.

Companies lie, they always do. Cameras state x MP, and if you take a
photo at full resolution, it's ****. Hard disks don't use gigabytes, but
billions of bytes, shaving off a little.

The 145Lm/W lamps I saw were the grossly overpriced 1600Lm LES 11W
examples being offered by Asda. I might have considered buying one if
they'd been more sanely priced but at something like 10 to 18 quid a pop
(I didn't bother trying to pin the confusing shelf price labelling down
any tighter than that - it was enough to know that it was at least 3
times pricier than I'd been prepared to pay in Home and Bargain), I
wasn't in the least bit tempted.

I'm currently using this sort of thing:
http://www.ebay.co.uk/itm/231644564446

I want complete remote control of on/off, color temp and dimming, by voice.

And much more convenient physically too. The Hue Lightstrip Plus starts
with a 2M strip and has 1M plug in extensions with up to 8 allowed and
they go in the standard led strip extrusions that are much less bulky than
yours and you can get in single lengths up to 10m or more in length so
you can have the one thing covering the entire long axis of even the
longest room and with joiners to go for 100m in total if you need to.

Might not be the best price, I just linked to the first one I found, not
where I bought them from. The LEDs are well spaced and they don't exceed
body temperature, so they don't fail like most LED bulbs.

Yeah, that's one big plus. Dunno what they look like
when one led dies tho as they must eventually.

No big deal with the Hue Lightstrip Plus with
1m extensions, but the price is a bit high currently.

Not that I care, I'm rolling in it and convenience is what matters.

It's not so much the electrical consumption cost savings that interest
me so much as the service life endurance promise standing a much better
chance of being fulfilled outside of a laboratory test environment in the
more demanding conditions typical of a domestic pendant light fitting
complete with fancy draught excluding shade dangling in the warmest
layers of air to be found in a room basking in the warmth of a centrally
heated radiator or two.

I'm happy enough with the current crop of "60W 806Lm 120v 750 Hour life
rated" American tungsten GLS lamp equivalent 9W LEDs where an 806 Lm lamp
can provide the required illumination level (effectively replacing a 73W
240v 1000 hour tungsten filament GLS lamp in UK housing). It's all these
15 and 18 watt 1500Lm LED GLS replacements for the 100W tungsten filament
GLS lamps with their more marginal temperature tolerance that give me
pause in their deployment as a GLS alternative.

The LED version of the "100W GLS tungsten filament lamps now starting to
appear would seem to be a viable GLS candidate if their claimed
efficacies of 145 and 150 Lm per watt are based in reality rather than
best hoped for efficacy.

It's been a rather disappointing wait for Cree to begin fulfilling that
(probably ill advised) promise made by their spokesperson just over three
years ago when they announced their record breaking achievement in LED
efficacy. Here we are, some 50 percent further along than their upper
timescale to get 300Lm/W lamps to market, with lamps of only half that
efficacy to show for their efforts thus far.

Still, at least *some* progress has finally materialised at long last,
so I suppose we ought to be grateful to finally be free of the 2013 'Time
Warp' we seem to have been living in for the past 3 or 4 years. :-)
Better late than never.

At this rate of development, we'll be lucky to see the next efficacy
milestone of 200Lm/W being achieved within the next three years or so.
Who knows? We may see a sudden spurt from Cree whereby the 200Lm/W
milestone in commercially available lamps is reached within the next 12
months. Either that or else an admission that the 303Lm/W lab results
were faked just to pressurise Philips Lighting into quitting the LED lamp
business. :-(

They really should put sensible ratings on each LED bulb they sell. It
should clearly state the actual electrical consumption

The high end stuff does. And states the lumens at various color temps too.
http://www2.meethue.com/en-au/produc...specifications

(it's been mentioned in this thread that they lie), and equivalent output
(eg "=60W incandescent". The general public don't know what a bloody
lumen is.

Sure, but when you have one already, you know if that amount of lumens is
enough there or not.

"James Wilkinson Sword" wrote in message
news
On Tue, 25 Apr 2017 22:08:34 +0100, Rod Speed
wrote:



"James Wilkinson Sword" wrote in message
news
On Tue, 25 Apr 2017 21:01:37 +0100, Rod Speed
wrote:



"James Wilkinson Sword" wrote in message
news On Tue, 25 Apr 2017 19:34:38 +0100, Rod Speed

wrote:

James Wilkinson Sword wrote
Graham. wrote
James Wilkinson Sword wrote

Yes, I've googled it, but there are many different approaches.
Which one is used in domestic LED bulbs?

Ultra-violet LED exciting a white phosphor,
much the same principle used in florescents.

That's what I would have assumed, but when you
look at a switched off white LED, it's not white.

All that means is that it isnt white when it doesn't have UV falling
on it and that the protective outer isnt the phosphor itself.

I would have expected it to have a white coating that
can be seen like on a switched off fluorescent tube.

The difference is that leds don't have glass as the protective outer.

Those adjustable-by-remote ones you have, just how many colours can
you
make?

They claim 16M

Do they only have R G and B emitters,

Nope. The strips where the leds are visible have one big led and a
couple
of smaller RGB ones. Not clear why there is more than one RGB one,
presumably because they arent anything like as bright as the white one.

Just discovered I can't actually take a photo of the strip with the
leds
lit in the dark it completely ****s the exposure system in the phone.

Use a real camera

Don't have one anymore and wouldn't have any film for it even if I did.

I meant a real digital camera, with proper options like manual control of
focussing and aperture for situations like this.

Don't bother with those, stupid waste of money given that the
phone does almost all I ever need and is with me all the time.

A phone is not a camera, it's a handy thing which can take a dodgy photo
at a push.

Nothing dodgy about any of the ones I have taken.

On Tue, 25 Apr 2017 23:04:08 +0100, Rod Speed wrote:



"James Wilkinson Sword" wrote in message
news
On Tue, 25 Apr 2017 22:12:37 +0100, Johnny B Good
wrote:

On Tue, 25 Apr 2017 14:27:29 +0100, Martin Brown wrote:

On 25/04/2017 13:27, Graham. wrote:
On Tue, 25 Apr 2017 12:25:35 +0100, "James Wilkinson Sword"
wrote:

Yes, I've googled it, but there are many different approaches. Which
one is used in domestic LED bulbs?

Ultra-violet LED exciting a white phosphor, much the same principle
used in florescents.

It is usually a high efficiency blue LED pump exciting a yellow phosphor
with that mix determining the nominal colour temperature. It is quite
peaky in the blue and more of a wide hump around the yellow. The
phosphor usually looks yellow and sits on top of the LED.

http://i.stack.imgur.com/lkyXG.png

The visible light flux out of an LED die on a high efficiency LED these
days is about the same order of magnitude as the sun's photosphere.

It is a lot more obvious on the devices which use a remote phosphor..

http://www.cree.com/led-components/m...e-Phosphor.pdf

An interesting read (note the use of the expression "loosing efficiency"
on page 8 regarding Fig 7a). Also of note is the copyright date of this
document which is the year of their record breaking 303Lm/W led efficacy
achievement in February/March of that year when the Cree Spokesperson let
slip to the trade press that such laboratory achievements typically took
a further 18 to 24 months of development before making their début on
store shelves for public consumption.

A simple arithmetic calculation reveals that this scheduled development
has slipped by a rather conservatively estimated 13 months. :-( The best
Lm/W efficacy figures I've noted recently have been around the 125 to 145
Lm/W mark. The former being a 1500Lm 12W GLS B22 2700K Warm White lamp I
sampled from a Home Bargains store for the princely sum of £2.99 which
turned out to have an *actual* consumption figure of 14 watts.

I thought the best LEDs were equivalent to 10W out per 1W in. Eg a 10W
LED bulb should be equivalent to a 100W incandescent. A 100W incandescent
is 1435 lumens. So your bulb is consuming 14W to give out about 105W..
Not as good as I thought.

Since its illumination power doesn't seem as impressively bright as I
was expecting (even making allowances for the eye's logarithmic response
to brightness), I rather doubt the additional 2 watts is hiking the
claimed 1500Lm to 1750Lms as one might expect if the additional 2 watts
was simply the result of overly wide tolerances in the 'electronic
ballast circuit' causing the LEDs to be overdriven to a higher than
designed Lumens output.

I have a sneaking suspicion that the claims of "1500 Lumens at 12W (100W
eqv)" have been based on the best of a sampling of these lamps off the
production line, possibly based on the maximum positive tolerance limit
of the 'nominal' power consumption to boot for good measure (+10%? =
13.2W) so might more typically be nearer the 110Lm/W mark than to the
claimed 125Lm/W figure. Even the claimed efficacy is not a particularly
massive improvement over the 81Lm/W efficacy figures typical of many LED
GLS lamps of just over three years ago.

Companies lie, they always do. Cameras state x MP, and if you take a
photo at full resolution, it's ****. Hard disks don't use gigabytes, but
billions of bytes, shaving off a little.

The 145Lm/W lamps I saw were the grossly overpriced 1600Lm LES 11W
examples being offered by Asda. I might have considered buying one if
they'd been more sanely priced but at something like 10 to 18 quid a pop
(I didn't bother trying to pin the confusing shelf price labelling down
any tighter than that - it was enough to know that it was at least 3
times pricier than I'd been prepared to pay in Home and Bargain), I
wasn't in the least bit tempted.

I'm currently using this sort of thing:
http://www.ebay.co.uk/itm/231644564446

I want complete remote control of on/off, color temp and dimming, by voice.

I don't see the need for that. All my rooms have one or more PIR/daylight sensors. They come on if it's dark and someone (or a pet) is moving in the room. I never manually turn on a light.

And much more convenient physically too. The Hue Lightstrip Plus starts
with a 2M strip and has 1M plug in extensions with up to 8 allowed and
they go in the standard led strip extrusions that are much less bulky than
yours and you can get in single lengths up to 10m or more in length so
you can have the one thing covering the entire long axis of even the
longest room and with joiners to go for 100m in total if you need to.

Mine are very easy. You plug in one strip to the power. Then they all join to that one. As for physical mounting, ONE single screw in a little clip supports each strip.

Might not be the best price, I just linked to the first one I found, not
where I bought them from. The LEDs are well spaced and they don't exceed
body temperature, so they don't fail like most LED bulbs.

Yeah, that's one big plus. Dunno what they look like
when one led dies tho as they must eventually.

As they run cool, they may well get the 50,000 hour life an LED is meant to. And easy enough to replace a dodgy LED if one ever did fail. I've got about 30 of them and have run them for 2 years. Only one flickered, about a week after I bought it. The seller sent me a free unit to replace it. I fixed the original by putting a smoothing capacitor in it.

No big deal with the Hue Lightstrip Plus with
1m extensions, but the price is a bit high currently.

Not that I care, I'm rolling in it and convenience is what matters.

What was you job before you retired? (Yes I know you've probably told me before, but my memory sux).

It's not so much the electrical consumption cost savings that interest
me so much as the service life endurance promise standing a much better
chance of being fulfilled outside of a laboratory test environment in the
more demanding conditions typical of a domestic pendant light fitting
complete with fancy draught excluding shade dangling in the warmest
layers of air to be found in a room basking in the warmth of a centrally
heated radiator or two.

I'm happy enough with the current crop of "60W 806Lm 120v 750 Hour life
rated" American tungsten GLS lamp equivalent 9W LEDs where an 806 Lm lamp
can provide the required illumination level (effectively replacing a 73W
240v 1000 hour tungsten filament GLS lamp in UK housing). It's all these
15 and 18 watt 1500Lm LED GLS replacements for the 100W tungsten filament
GLS lamps with their more marginal temperature tolerance that give me
pause in their deployment as a GLS alternative.

The LED version of the "100W GLS tungsten filament lamps now starting to
appear would seem to be a viable GLS candidate if their claimed
efficacies of 145 and 150 Lm per watt are based in reality rather than
best hoped for efficacy.

It's been a rather disappointing wait for Cree to begin fulfilling that
(probably ill advised) promise made by their spokesperson just over three
years ago when they announced their record breaking achievement in LED
efficacy. Here we are, some 50 percent further along than their upper
timescale to get 300Lm/W lamps to market, with lamps of only half that
efficacy to show for their efforts thus far.

Still, at least *some* progress has finally materialised at long last,
so I suppose we ought to be grateful to finally be free of the 2013 'Time
Warp' we seem to have been living in for the past 3 or 4 years. :-)
Better late than never.

At this rate of development, we'll be lucky to see the next efficacy
milestone of 200Lm/W being achieved within the next three years or so.
Who knows? We may see a sudden spurt from Cree whereby the 200Lm/W
milestone in commercially available lamps is reached within the next 12
months. Either that or else an admission that the 303Lm/W lab results
were faked just to pressurise Philips Lighting into quitting the LED lamp
business. :-(

They really should put sensible ratings on each LED bulb they sell. It
should clearly state the actual electrical consumption

The high end stuff does. And states the lumens at various color temps too.
http://www2.meethue.com/en-au/produc...specifications

(it's been mentioned in this thread that they lie), and equivalent output
(eg "=60W incandescent". The general public don't know what a bloody
lumen is.

Sure, but when you have one already, you know if that amount of lumens is
enough there or not.

I think in watts. I know what a 100W lightbulb is like. Lumens means nothing to me, it's like telling me something is 57km away, I have to calculate it into miles first.

--
Old statisticians never die. They just get broken down by age and sex.

On Tue, 25 Apr 2017 22:49:40 +0100, Rod Speed wrote:



"James Wilkinson Sword" wrote in message
news
On Tue, 25 Apr 2017 22:15:15 +0100, Rod Speed
wrote:



"James Wilkinson Sword" wrote in message
news On Tue, 25 Apr 2017 21:14:46 +0100, Rod Speed
wrote:

James Wilkinson Sword wrote
Rod Speed wrote
James Wilkinson Sword wrote

Yes, I've googled it, but there are many different
approaches. Which one is used in domestic LED bulbs?

Varys with who is doing the bulbs. The cheapest ****
does it differently to the stuff with the long warrantys.

Don't they all use something similar to CREE LEDs?

Nope, the cheapest **** has the individual leds clearly visible.

What do you mean by that? You can always se individual LEDs can't you?

Nope, no visible individual leds with the high end led bulbs.
https://www.cnet.com/products/philip...er-kit/review/

There's a plastic over over it.

That's actually what CREE calls a remote phosphor.

What's your point?

That you cant SEE the individual leds.

I thought you were talking about the actual LEDs, not the covered unit. I asked if everyone used CREE LEDs, then for some reason you started talking about if you could see them or not.

--
TV takes over your life when you could be doing useful things like smoking crack and stealing car stereos.

"James Wilkinson Sword" wrote in message
news
On Tue, 25 Apr 2017 23:07:38 +0100, Rod Speed
wrote:



"James Wilkinson Sword" wrote in message
news
On Tue, 25 Apr 2017 22:08:34 +0100, Rod Speed
wrote:



"James Wilkinson Sword" wrote in message
news On Tue, 25 Apr 2017 21:01:37 +0100, Rod Speed

wrote:



"James Wilkinson Sword" wrote in message
news On Tue, 25 Apr 2017 19:34:38 +0100, Rod Speed

wrote:

James Wilkinson Sword wrote
Graham. wrote
James Wilkinson Sword wrote

Yes, I've googled it, but there are many different approaches.
Which one is used in domestic LED bulbs?

Ultra-violet LED exciting a white phosphor,
much the same principle used in florescents.

That's what I would have assumed, but when you
look at a switched off white LED, it's not white.

All that means is that it isnt white when it doesn't have UV
falling
on it and that the protective outer isnt the phosphor itself.

I would have expected it to have a white coating that
can be seen like on a switched off fluorescent tube.

The difference is that leds don't have glass as the protective
outer.

Those adjustable-by-remote ones you have, just how many colours can
you
make?

They claim 16M

Do they only have R G and B emitters,

Nope. The strips where the leds are visible have one big led and a
couple
of smaller RGB ones. Not clear why there is more than one RGB one,
presumably because they arent anything like as bright as the white
one.

Just discovered I can't actually take a photo of the strip with the
leds
lit in the dark it completely ****s the exposure system in the phone.

Use a real camera

Don't have one anymore and wouldn't have any film for it even if I did.

I meant a real digital camera, with proper options like manual control
of
focussing and aperture for situations like this.

Don't bother with those, stupid waste of money given that the
phone does almost all I ever need and is with me all the time.

It's a child's toy compared to a proper camera.

Couldn't care less. It does what I want to do almost all of
the time and the times when it doesn't as so few that its not
worth having something more capable for those situation.

There likely is an app that allows full manual control
of the exposure but I havent bothered to look because
its not worth my time to even look for one.

Only any good to take a photo to show someone something, prove something
happened etc.

Its good for a hell of a lot more than that, like being a handy
video recorder that's with me all the time, handy for taking a
photo of shelf price stickers instead of recording prices any
other way, handy for taking photos of ID plates, handy for
taking photos of stuff that I would otherwise have to lie
flat on my face on the ground to see, handy for stuff with
print on it so fine and such poor contrast that I cant even
read, etc etc etc.

The quality is awful.

Even sillier than you usually manage.

Simply not room on a phone for a proper lens.

Don't need a proper lens, I don't take that sort of photo.

A phone is not a camera, it's a handy thing which can take a dodgy photo
at a push.

Nothing dodgy about any of the ones I have taken.

Show me an example of a quality photo from your phone.

I don't bother with that sort of photo. There are plenty online.

And show me something like an animal in the distance you've zoomed in on.

Don't take that sort of photo.

Take a picture of a galah in a tree etc.

No galahs in my trees currently.

"James Wilkinson Sword" wrote in message
news
On Tue, 25 Apr 2017 23:04:08 +0100, Rod Speed
wrote:



"James Wilkinson Sword" wrote in message
news
On Tue, 25 Apr 2017 22:12:37 +0100, Johnny B Good
wrote:

On Tue, 25 Apr 2017 14:27:29 +0100, Martin Brown wrote:

On 25/04/2017 13:27, Graham. wrote:
On Tue, 25 Apr 2017 12:25:35 +0100, "James Wilkinson Sword"
wrote:

Yes, I've googled it, but there are many different approaches.
Which
one is used in domestic LED bulbs?

Ultra-violet LED exciting a white phosphor, much the same principle
used in florescents.

It is usually a high efficiency blue LED pump exciting a yellow
phosphor
with that mix determining the nominal colour temperature. It is quite
peaky in the blue and more of a wide hump around the yellow. The
phosphor usually looks yellow and sits on top of the LED.

http://i.stack.imgur.com/lkyXG.png

The visible light flux out of an LED die on a high efficiency LED
these
days is about the same order of magnitude as the sun's photosphere.

It is a lot more obvious on the devices which use a remote phosphor.

http://www.cree.com/led-components/m...e-Phosphor.pdf

An interesting read (note the use of the expression "loosing
efficiency"
on page 8 regarding Fig 7a). Also of note is the copyright date of this
document which is the year of their record breaking 303Lm/W led
efficacy
achievement in February/March of that year when the Cree Spokesperson
let
slip to the trade press that such laboratory achievements typically
took
a further 18 to 24 months of development before making their début on
store shelves for public consumption.

A simple arithmetic calculation reveals that this scheduled
development
has slipped by a rather conservatively estimated 13 months. :-( The
best
Lm/W efficacy figures I've noted recently have been around the 125 to
145
Lm/W mark. The former being a 1500Lm 12W GLS B22 2700K Warm White lamp
I
sampled from a Home Bargains store for the princely sum of £2.99 which
turned out to have an *actual* consumption figure of 14 watts.

I thought the best LEDs were equivalent to 10W out per 1W in. Eg a 10W
LED bulb should be equivalent to a 100W incandescent. A 100W
incandescent
is 1435 lumens. So your bulb is consuming 14W to give out about 105W.
Not as good as I thought.

Since its illumination power doesn't seem as impressively bright as I
was expecting (even making allowances for the eye's logarithmic
response
to brightness), I rather doubt the additional 2 watts is hiking the
claimed 1500Lm to 1750Lms as one might expect if the additional 2 watts
was simply the result of overly wide tolerances in the 'electronic
ballast circuit' causing the LEDs to be overdriven to a higher than
designed Lumens output.

I have a sneaking suspicion that the claims of "1500 Lumens at 12W
(100W
eqv)" have been based on the best of a sampling of these lamps off the
production line, possibly based on the maximum positive tolerance limit
of the 'nominal' power consumption to boot for good measure (+10%? =
13.2W) so might more typically be nearer the 110Lm/W mark than to the
claimed 125Lm/W figure. Even the claimed efficacy is not a particularly
massive improvement over the 81Lm/W efficacy figures typical of many
LED
GLS lamps of just over three years ago.

Companies lie, they always do. Cameras state x MP, and if you take a
photo at full resolution, it's ****. Hard disks don't use gigabytes,
but
billions of bytes, shaving off a little.

The 145Lm/W lamps I saw were the grossly overpriced 1600Lm LES 11W
examples being offered by Asda. I might have considered buying one if
they'd been more sanely priced but at something like 10 to 18 quid a
pop
(I didn't bother trying to pin the confusing shelf price labelling down
any tighter than that - it was enough to know that it was at least 3
times pricier than I'd been prepared to pay in Home and Bargain), I
wasn't in the least bit tempted.

I'm currently using this sort of thing:
http://www.ebay.co.uk/itm/231644564446

I want complete remote control of on/off, color temp and dimming, by
voice.

I don't see the need for that.

I do, I don't want the same light level all the time that its useful to have
the light on.

I prefer a brighter light on what I am eating than when I am typing after
eating and a different light level when watching recorded videos etc.

All my rooms have one or more PIR/daylight sensors. They come on if it's
dark and someone (or a pet) is moving in the room. I never manually turn
on a light.

Too crude. I don't want the same light level all the time when its dark.

Don't when I get up either. I prefer to light to fade up over a
second or so it isnt too bright initially but is full brightness a
bit later when I weigh myself so I can see the scale properly.

And much more convenient physically too. The Hue Lightstrip Plus starts
with a 2M strip and has 1M plug in extensions with up to 8 allowed and
they go in the standard led strip extrusions that are much less bulky
than
yours and you can get in single lengths up to 10m or more in length so
you can have the one thing covering the entire long axis of even the
longest room and with joiners to go for 100m in total if you need to.

Mine are very easy. You plug in one strip to the power. Then they all
join to that one. As for physical mounting, ONE single screw in a little
clip supports each strip.

Useless for me because the only sensible place to attach
anything is to the base flange of the galvanised steel beams
that form the entire roof/ceiling structure at ceiling level.

Might not be the best price, I just linked to the first one I found, not
where I bought them from. The LEDs are well spaced and they don't exceed
body temperature, so they don't fail like most LED bulbs.

Yeah, that's one big plus. Dunno what they look like
when one led dies tho as they must eventually.

As they run cool, they may well get the 50,000 hour life an LED is meant
to.

Sure, but that's still going to see some failures eventually.

And easy enough to replace a dodgy LED if one ever did fail.

Dunno, not clear how easy it is to actually change one of those
LEDs in a strip even if you say have an entire extension that you
use as a source of individual leds as they fail.

I've got about 30 of them and have run them for 2 years.

Sure, but 2 years is **** all in the life of a house.

Only one flickered, about a week after I bought it. The seller sent me a
free unit to replace it. I fixed the original by putting a smoothing
capacitor in it.

Like I said, its less clear how easy it is to change a led in a strip.

No big deal with the Hue Lightstrip Plus with
1m extensions, but the price is a bit high currently.

Not that I care, I'm rolling in it and convenience is what matters.

What was you job before you retired?

I ran all the computers in the place I worked for, minis, pcs, and
the node for the countrywide network, doing all the maintenance and
lots of software, right up to a full multitasking OS for the first mini.

(Yes I know you've probably told me before, but my memory sux).

It's not so much the electrical consumption cost savings that interest
me so much as the service life endurance promise standing a much better
chance of being fulfilled outside of a laboratory test environment in
the
more demanding conditions typical of a domestic pendant light fitting
complete with fancy draught excluding shade dangling in the warmest
layers of air to be found in a room basking in the warmth of a
centrally
heated radiator or two.

I'm happy enough with the current crop of "60W 806Lm 120v 750 Hour
life
rated" American tungsten GLS lamp equivalent 9W LEDs where an 806 Lm
lamp
can provide the required illumination level (effectively replacing a
73W
240v 1000 hour tungsten filament GLS lamp in UK housing). It's all
these
15 and 18 watt 1500Lm LED GLS replacements for the 100W tungsten
filament
GLS lamps with their more marginal temperature tolerance that give me
pause in their deployment as a GLS alternative.

The LED version of the "100W GLS tungsten filament lamps now starting
to
appear would seem to be a viable GLS candidate if their claimed
efficacies of 145 and 150 Lm per watt are based in reality rather than
best hoped for efficacy.

It's been a rather disappointing wait for Cree to begin fulfilling
that
(probably ill advised) promise made by their spokesperson just over
three
years ago when they announced their record breaking achievement in LED
efficacy. Here we are, some 50 percent further along than their upper
timescale to get 300Lm/W lamps to market, with lamps of only half that
efficacy to show for their efforts thus far.

Still, at least *some* progress has finally materialised at long last,
so I suppose we ought to be grateful to finally be free of the 2013
'Time
Warp' we seem to have been living in for the past 3 or 4 years. :-)
Better late than never.

At this rate of development, we'll be lucky to see the next efficacy
milestone of 200Lm/W being achieved within the next three years or so.
Who knows? We may see a sudden spurt from Cree whereby the 200Lm/W
milestone in commercially available lamps is reached within the next 12
months. Either that or else an admission that the 303Lm/W lab results
were faked just to pressurise Philips Lighting into quitting the LED
lamp
business. :-(

They really should put sensible ratings on each LED bulb they sell. It
should clearly state the actual electrical consumption

The high end stuff does. And states the lumens at various color temps
too.
http://www2.meethue.com/en-au/produc...specifications

(it's been mentioned in this thread that they lie), and equivalent
output
(eg "=60W incandescent". The general public don't know what a bloody
lumen is.

Sure, but when you have one already, you know if that amount of lumens is
enough there or not.

I think in watts. I know what a 100W lightbulb is like.

I used to, but that doesn't work anymore with modern led bulbs that
you can change the color temp of to anything you like remotely.

Lumens means nothing to me,

It does when you have something that produces known lumens
to try there and decide if that location needs more than that or
less than that and can remotely dim it to any level you like so
you can decided that you need xx lumens there.

Even with watts, the number of watts you need depends on
where the bulb will go and the housing/luminaire you put it in.

it's like telling me something is 57km away, I have to calculate it into
miles first.

Not anymore with fully controllable bulbs.

On Tue, 25 Apr 2017 23:56:44 +0100, Rod Speed wrote:



"James Wilkinson Sword" wrote in message
news
On Tue, 25 Apr 2017 23:04:08 +0100, Rod Speed
wrote:



"James Wilkinson Sword" wrote in message
news On Tue, 25 Apr 2017 22:12:37 +0100, Johnny B Good
wrote:

On Tue, 25 Apr 2017 14:27:29 +0100, Martin Brown wrote:

On 25/04/2017 13:27, Graham. wrote:
On Tue, 25 Apr 2017 12:25:35 +0100, "James Wilkinson Sword"
wrote:

Yes, I've googled it, but there are many different approaches.
Which
one is used in domestic LED bulbs?

Ultra-violet LED exciting a white phosphor, much the same principle
used in florescents.

It is usually a high efficiency blue LED pump exciting a yellow
phosphor
with that mix determining the nominal colour temperature. It is quite
peaky in the blue and more of a wide hump around the yellow. The
phosphor usually looks yellow and sits on top of the LED.

http://i.stack.imgur.com/lkyXG.png

The visible light flux out of an LED die on a high efficiency LED
these
days is about the same order of magnitude as the sun's photosphere.

It is a lot more obvious on the devices which use a remote phosphor.

http://www.cree.com/led-components/m...e-Phosphor.pdf

An interesting read (note the use of the expression "loosing
efficiency"
on page 8 regarding Fig 7a). Also of note is the copyright date of this
document which is the year of their record breaking 303Lm/W led
efficacy
achievement in February/March of that year when the Cree Spokesperson
let
slip to the trade press that such laboratory achievements typically
took
a further 18 to 24 months of development before making their début on
store shelves for public consumption.

A simple arithmetic calculation reveals that this scheduled
development
has slipped by a rather conservatively estimated 13 months. :-( The
best
Lm/W efficacy figures I've noted recently have been around the 125 to
145
Lm/W mark. The former being a 1500Lm 12W GLS B22 2700K Warm White lamp
I
sampled from a Home Bargains store for the princely sum of £2.99 which
turned out to have an *actual* consumption figure of 14 watts.

I thought the best LEDs were equivalent to 10W out per 1W in. Eg a 10W
LED bulb should be equivalent to a 100W incandescent. A 100W
incandescent
is 1435 lumens. So your bulb is consuming 14W to give out about 105W.
Not as good as I thought.

Since its illumination power doesn't seem as impressively bright as I
was expecting (even making allowances for the eye's logarithmic
response
to brightness), I rather doubt the additional 2 watts is hiking the
claimed 1500Lm to 1750Lms as one might expect if the additional 2 watts
was simply the result of overly wide tolerances in the 'electronic
ballast circuit' causing the LEDs to be overdriven to a higher than
designed Lumens output.

I have a sneaking suspicion that the claims of "1500 Lumens at 12W
(100W
eqv)" have been based on the best of a sampling of these lamps off the
production line, possibly based on the maximum positive tolerance limit
of the 'nominal' power consumption to boot for good measure (+10%? =
13.2W) so might more typically be nearer the 110Lm/W mark than to the
claimed 125Lm/W figure. Even the claimed efficacy is not a particularly
massive improvement over the 81Lm/W efficacy figures typical of many
LED
GLS lamps of just over three years ago.

Companies lie, they always do. Cameras state x MP, and if you take a
photo at full resolution, it's ****. Hard disks don't use gigabytes,
but
billions of bytes, shaving off a little.

The 145Lm/W lamps I saw were the grossly overpriced 1600Lm LES 11W
examples being offered by Asda. I might have considered buying one if
they'd been more sanely priced but at something like 10 to 18 quid a
pop
(I didn't bother trying to pin the confusing shelf price labelling down
any tighter than that - it was enough to know that it was at least 3
times pricier than I'd been prepared to pay in Home and Bargain), I
wasn't in the least bit tempted.

I'm currently using this sort of thing:
http://www.ebay.co.uk/itm/231644564446

I want complete remote control of on/off, color temp and dimming, by
voice.

I don't see the need for that.

I do, I don't want the same light level all the time that its useful to have
the light on.

I prefer a brighter light on what I am eating than when I am typing after
eating and a different light level when watching recorded videos etc.

Odd, I just like it bright all the time so I can see what I'm doing. I make the TV/monitor bright enough to see in that amount of ambient light.. The exception is my bedroom where I have a dimmer light so I don't wake up and get dazzled.

All my rooms have one or more PIR/daylight sensors. They come on if it's
dark and someone (or a pet) is moving in the room. I never manually turn
on a light.

Too crude. I don't want the same light level all the time when its dark.

Don't when I get up either. I prefer to light to fade up over a
second or so it isnt too bright initially but is full brightness a
bit later when I weigh myself so I can see the scale properly.

Bedroom dim, every other room bright. Simpler that way.

And much more convenient physically too. The Hue Lightstrip Plus starts
with a 2M strip and has 1M plug in extensions with up to 8 allowed and
they go in the standard led strip extrusions that are much less bulky
than
yours and you can get in single lengths up to 10m or more in length so
you can have the one thing covering the entire long axis of even the
longest room and with joiners to go for 100m in total if you need to..

Mine are very easy. You plug in one strip to the power. Then they all
join to that one. As for physical mounting, ONE single screw in a little
clip supports each strip.

Useless for me because the only sensible place to attach
anything is to the base flange of the galvanised steel beams
that form the entire roof/ceiling structure at ceiling level.

These things are so light they will affix to plasterboard or wood panels or whatever your ceiling is made of.

Might not be the best price, I just linked to the first one I found, not
where I bought them from. The LEDs are well spaced and they don't exceed
body temperature, so they don't fail like most LED bulbs.

Yeah, that's one big plus. Dunno what they look like
when one led dies tho as they must eventually.

As they run cool, they may well get the 50,000 hour life an LED is meant
to.

Sure, but that's still going to see some failures eventually.

Considering incandescent is 2000 hours and CFL is 8000 hours, 50000 is a very long time indeed. And at £4 a strip, they're cheap to replace.

And easy enough to replace a dodgy LED if one ever did fail.

Dunno, not clear how easy it is to actually change one of those
LEDs in a strip

As simple as changing any component on a circuit board. They're well spaced.

even if you say have an entire extension that you
use as a source of individual leds as they fail.

What? I cannot interpret that sentence.

I've got about 30 of them and have run them for 2 years.

Sure, but 2 years is **** all in the life of a house.

None in 2 years is better than other types of light. And definitely better than any other LED I've used.

It's not so much the electrical consumption cost savings that interest
me so much as the service life endurance promise standing a much better
chance of being fulfilled outside of a laboratory test environment in
the
more demanding conditions typical of a domestic pendant light fitting
complete with fancy draught excluding shade dangling in the warmest
layers of air to be found in a room basking in the warmth of a
centrally
heated radiator or two.

I'm happy enough with the current crop of "60W 806Lm 120v 750 Hour
life
rated" American tungsten GLS lamp equivalent 9W LEDs where an 806 Lm
lamp
can provide the required illumination level (effectively replacing a
73W
240v 1000 hour tungsten filament GLS lamp in UK housing). It's all
these
15 and 18 watt 1500Lm LED GLS replacements for the 100W tungsten
filament
GLS lamps with their more marginal temperature tolerance that give me
pause in their deployment as a GLS alternative.

The LED version of the "100W GLS tungsten filament lamps now starting
to
appear would seem to be a viable GLS candidate if their claimed
efficacies of 145 and 150 Lm per watt are based in reality rather than
best hoped for efficacy.

It's been a rather disappointing wait for Cree to begin fulfilling
that
(probably ill advised) promise made by their spokesperson just over
three
years ago when they announced their record breaking achievement in LED
efficacy. Here we are, some 50 percent further along than their upper
timescale to get 300Lm/W lamps to market, with lamps of only half that
efficacy to show for their efforts thus far.

Still, at least *some* progress has finally materialised at long last,
so I suppose we ought to be grateful to finally be free of the 2013
'Time
Warp' we seem to have been living in for the past 3 or 4 years. :-)
Better late than never.

At this rate of development, we'll be lucky to see the next efficacy
milestone of 200Lm/W being achieved within the next three years or so.
Who knows? We may see a sudden spurt from Cree whereby the 200Lm/W
milestone in commercially available lamps is reached within the next 12
months. Either that or else an admission that the 303Lm/W lab results
were faked just to pressurise Philips Lighting into quitting the LED
lamp
business. :-(

They really should put sensible ratings on each LED bulb they sell. It
should clearly state the actual electrical consumption

The high end stuff does. And states the lumens at various color temps
too.
http://www2.meethue.com/en-au/produc...specifications

(it's been mentioned in this thread that they lie), and equivalent
output
(eg "=60W incandescent". The general public don't know what a bloody
lumen is.

Sure, but when you have one already, you know if that amount of lumens is
enough there or not.

I think in watts. I know what a 100W lightbulb is like.

I used to, but that doesn't work anymore with modern led bulbs that
you can change the color temp of to anything you like remotely.

Why not? 100W equivalent is easy to understand.

Lumens means nothing to me,

It does when you have something that produces known lumens
to try there and decide if that location needs more than that or
less than that and can remotely dim it to any level you like so
you can decided that you need xx lumens there.

Even with watts, the number of watts you need depends on
where the bulb will go and the housing/luminaire you put it in.

Watts and lumens are the same thing. Like km and miles.

--
A daughter asked her mother how to spell penis, her mum said you should have asked me last night it was on the tip of my tongue.

"James Wilkinson Sword" wrote in message
news
On Tue, 25 Apr 2017 23:56:44 +0100, Rod Speed
wrote:



"James Wilkinson Sword" wrote in message
news
On Tue, 25 Apr 2017 23:04:08 +0100, Rod Speed
wrote:



"James Wilkinson Sword" wrote in message
news On Tue, 25 Apr 2017 22:12:37 +0100, Johnny B Good
wrote:

On Tue, 25 Apr 2017 14:27:29 +0100, Martin Brown wrote:

On 25/04/2017 13:27, Graham. wrote:
On Tue, 25 Apr 2017 12:25:35 +0100, "James Wilkinson Sword"
wrote:

Yes, I've googled it, but there are many different approaches.
Which
one is used in domestic LED bulbs?

Ultra-violet LED exciting a white phosphor, much the same principle
used in florescents.

It is usually a high efficiency blue LED pump exciting a yellow
phosphor
with that mix determining the nominal colour temperature. It is
quite
peaky in the blue and more of a wide hump around the yellow. The
phosphor usually looks yellow and sits on top of the LED.

http://i.stack.imgur.com/lkyXG.png

The visible light flux out of an LED die on a high efficiency LED
these
days is about the same order of magnitude as the sun's photosphere.

It is a lot more obvious on the devices which use a remote phosphor.

http://www.cree.com/led-components/m...e-Phosphor.pdf

An interesting read (note the use of the expression "loosing
efficiency"
on page 8 regarding Fig 7a). Also of note is the copyright date of
this
document which is the year of their record breaking 303Lm/W led
efficacy
achievement in February/March of that year when the Cree Spokesperson
let
slip to the trade press that such laboratory achievements typically
took
a further 18 to 24 months of development before making their début on
store shelves for public consumption.

A simple arithmetic calculation reveals that this scheduled
development
has slipped by a rather conservatively estimated 13 months. :-( The
best
Lm/W efficacy figures I've noted recently have been around the 125 to
145
Lm/W mark. The former being a 1500Lm 12W GLS B22 2700K Warm White
lamp
I
sampled from a Home Bargains store for the princely sum of £2.99
which
turned out to have an *actual* consumption figure of 14 watts.

I thought the best LEDs were equivalent to 10W out per 1W in. Eg a
10W
LED bulb should be equivalent to a 100W incandescent. A 100W
incandescent
is 1435 lumens. So your bulb is consuming 14W to give out about 105W.
Not as good as I thought.

Since its illumination power doesn't seem as impressively bright as
I
was expecting (even making allowances for the eye's logarithmic
response
to brightness), I rather doubt the additional 2 watts is hiking the
claimed 1500Lm to 1750Lms as one might expect if the additional 2
watts
was simply the result of overly wide tolerances in the 'electronic
ballast circuit' causing the LEDs to be overdriven to a higher than
designed Lumens output.

I have a sneaking suspicion that the claims of "1500 Lumens at 12W
(100W
eqv)" have been based on the best of a sampling of these lamps off
the
production line, possibly based on the maximum positive tolerance
limit
of the 'nominal' power consumption to boot for good measure (+10%? =
13.2W) so might more typically be nearer the 110Lm/W mark than to the
claimed 125Lm/W figure. Even the claimed efficacy is not a
particularly
massive improvement over the 81Lm/W efficacy figures typical of many
LED
GLS lamps of just over three years ago.

Companies lie, they always do. Cameras state x MP, and if you take a
photo at full resolution, it's ****. Hard disks don't use gigabytes,
but
billions of bytes, shaving off a little.

The 145Lm/W lamps I saw were the grossly overpriced 1600Lm LES 11W
examples being offered by Asda. I might have considered buying one if
they'd been more sanely priced but at something like 10 to 18 quid a
pop
(I didn't bother trying to pin the confusing shelf price labelling
down
any tighter than that - it was enough to know that it was at least 3
times pricier than I'd been prepared to pay in Home and Bargain), I
wasn't in the least bit tempted.

I'm currently using this sort of thing:
http://www.ebay.co.uk/itm/231644564446

I want complete remote control of on/off, color temp and dimming, by
voice.

I don't see the need for that.

I do, I don't want the same light level all the time that its useful to
have
the light on.

I prefer a brighter light on what I am eating than when I am typing after
eating and a different light level when watching recorded videos etc.

Odd, I just like it bright all the time so I can see what I'm doing.

I do want to do that when eating or repairing stuff,
but not when using the computer or watching videos.

I make the TV/monitor bright enough to see in that amount of ambient
light. The exception is my bedroom where I have a dimmer light so I don't
wake up and get dazzled.

Yeah, tho I prefer a soft start there, but want full
brightness so I can read the non backlit scales better.

I should get some automatically recording scales
but currently havent found any that are even that
reproducible so they read the same thing if you
weigh yourself say 5 times in a row. Had a hell
of a job finding a decent set of digital scales
that don't have any recording capability at all.

All my rooms have one or more PIR/daylight sensors. They come on if
it's dark and someone (or a pet) is moving in the room. I never
manually turn on a light.

Too crude. I don't want the same light level all the time when its dark.

Don't when I get up either. I prefer to light to fade up over a
second or so it isnt too bright initially but is full brightness a
bit later when I weigh myself so I can see the scale properly.

Bedroom dim, every other room bright. Simpler that way.

Not viable when you want full brightness for reading the scales.

And much more convenient physically too. The Hue Lightstrip Plus starts
with a 2M strip and has 1M plug in extensions with up to 8 allowed and
they go in the standard led strip extrusions that are much less bulky
than
yours and you can get in single lengths up to 10m or more in length so
you can have the one thing covering the entire long axis of even the
longest room and with joiners to go for 100m in total if you need to.

Mine are very easy. You plug in one strip to the power. Then they all
join to that one. As for physical mounting, ONE single screw in a
little
clip supports each strip.

Useless for me because the only sensible place to attach
anything is to the base flange of the galvanised steel beams
that form the entire roof/ceiling structure at ceiling level.

These things are so light they will affix to plasterboard or wood panels
or whatever your ceiling is made of.

I have immense great sheets of paper faced on the bottom
and foil faced on the top, pollyfoam sheets that drop into
those galvanised steel beams that span the entire house
on the short axis. Not viable to screw anything into and
that leaves a hole with the spring toggle things. Much
more viable to double sided tape to the bottom flange
of the beams.

Might not be the best price, I just linked to the first one I found,
not
where I bought them from. The LEDs are well spaced and they don't
exceed body temperature, so they don't fail like most LED bulbs.

Yeah, that's one big plus. Dunno what they look like
when one led dies tho as they must eventually.

As they run cool, they may well get the 50,000 hour life an LED is meant
to.

Sure, but that's still going to see some failures eventually.

Considering incandescent is 2000 hours and CFL is 8000 hours, 50000 is a
very long time indeed.

Trouble is with leds you are likely to not care about the
power used and leave them on more than you would usually.

And at £4 a strip, they're cheap to replace.

Those fully controllable led strips cost a lot more than that.

And easy enough to replace a dodgy LED if one ever did fail.

Dunno, not clear how easy it is to actually change one of those LEDs in a
strip

As simple as changing any component on a circuit board.

Nope, there is no pcb with led strips.

They're well spaced.

Yes, but there is no pcb with a led strip.

even if you say have an entire extension that you
use as a source of individual leds as they fail.

What? I cannot interpret that sentence.

To have identical leds to the original, you could buy an
extra extension strip and take the leds off that to replace
the ones that fail. But since they don't have a pcb, it isnt
as simple as that to move a led from the one used for
the spare leds to the one you have installed in the house.

I've got about 30 of them and have run them for 2 years.

Sure, but 2 years is **** all in the life of a house.

None in 2 years is better than other types of light.

Like hell it is with long tube fluoros. I got a lot longer
than that out of the PAR38 floods I used previously too.

And the single CFL on the bed head too.

And definitely better than any other LED I've used.

Sure, the cheap **** from china is notorious for short life.

It's not so much the electrical consumption cost savings that
interest me so much as the service life endurance promise standing a
much better chance of being fulfilled outside of a laboratory test
environment in the more demanding conditions typical of a domestic
pendant light fitting
complete with fancy draught excluding shade dangling in the warmest
layers of air to be found in a room basking in the warmth of a
centrally heated radiator or two.

I'm happy enough with the current crop of "60W 806Lm 120v 750 Hour
life
rated" American tungsten GLS lamp equivalent 9W LEDs where an 806 Lm
lamp
can provide the required illumination level (effectively replacing a
73W
240v 1000 hour tungsten filament GLS lamp in UK housing). It's all
these
15 and 18 watt 1500Lm LED GLS replacements for the 100W tungsten
filament
GLS lamps with their more marginal temperature tolerance that give me
pause in their deployment as a GLS alternative.

The LED version of the "100W GLS tungsten filament lamps now
starting
to
appear would seem to be a viable GLS candidate if their claimed
efficacies of 145 and 150 Lm per watt are based in reality rather
than
best hoped for efficacy.

It's been a rather disappointing wait for Cree to begin fulfilling
that
(probably ill advised) promise made by their spokesperson just over
three
years ago when they announced their record breaking achievement in
LED
efficacy. Here we are, some 50 percent further along than their upper
timescale to get 300Lm/W lamps to market, with lamps of only half
that
efficacy to show for their efforts thus far.

Still, at least *some* progress has finally materialised at long
last,
so I suppose we ought to be grateful to finally be free of the 2013
'Time
Warp' we seem to have been living in for the past 3 or 4 years. :-)
Better late than never.

At this rate of development, we'll be lucky to see the next efficacy
milestone of 200Lm/W being achieved within the next three years or
so.
Who knows? We may see a sudden spurt from Cree whereby the 200Lm/W
milestone in commercially available lamps is reached within the next
12
months. Either that or else an admission that the 303Lm/W lab results
were faked just to pressurise Philips Lighting into quitting the LED
lamp
business. :-(

They really should put sensible ratings on each LED bulb they sell.
It
should clearly state the actual electrical consumption

The high end stuff does. And states the lumens at various color temps
too.
http://www2.meethue.com/en-au/produc...specifications

(it's been mentioned in this thread that they lie), and equivalent
output
(eg "=60W incandescent". The general public don't know what a bloody
lumen is.

Sure, but when you have one already, you know if that amount of lumens
is
enough there or not.

I think in watts. I know what a 100W lightbulb is like.

I used to, but that doesn't work anymore with modern led bulbs that
you can change the color temp of to anything you like remotely.

Why not?

Because the lumens change dramatically with the color temp.
http://www2.meethue.com/en-au/produc...specifications

100W equivalent is easy to understand.

Not when the color temp changes.

Lumens means nothing to me,

It does when you have something that produces known lumens
to try there and decide if that location needs more than that or
less than that and can remotely dim it to any level you like so
you can decided that you need xx lumens there.

Even with watts, the number of watts you need depends on
where the bulb will go and the housing/luminaire you put it in.

Watts and lumens are the same thing.

Nope, the lumens change dramatically with color temp.
http://www2.meethue.com/en-au/produc...specifications

Like km and miles.

Nothing like.

On Tue, 25 Apr 2017 21:12:37 +0000, Johnny B Good wrote:

====snip====

I thought a quick follow up with some references would be in order.

It's been a rather disappointing wait for Cree to begin fulfilling that
(probably ill advised) promise made by their spokesperson just over
three years ago when they announced their record breaking achievement in
LED efficacy. Here we are, some 50 percent further along than their
upper timescale to get 300Lm/W lamps to market, with lamps of only half
that efficacy to show for their efforts thus far.

If you google for "303Lm/W LED Cree" you'll be swamped by Cree's own web
page hits where they seem to be trying to re-write history. However, I
did manage to find an original trade press report:

https://www.forbes.com/sites/peterde...will-get-even-
more-efficient-cree-passes-300-lumens-per-watt/#374ac9112611

Apologies for the line wrap.

Interestingly, the 'spokesperson' turned out to be no less a personage
than Cree's vice president for product strategy, Mike Watson himself who
was quoted as saying,

"While some of these performance improvements already impact our current
developments, commercializing products with this level of performance
typically takes between 18 to 24 months from when we announce a research
and development result."


Still, at least *some* progress has finally materialised at long last,
so I suppose we ought to be grateful to finally be free of the 2013
'Time Warp' we seem to have been living in for the past 3 or 4 years.
:-) Better late than never.


Having re-read that article, it is only now, with the benefit of
hindsight, that I recognise the skilful use of Marketing Weasel Speak by
Cree's VP for Product Strategy.

I'm guessing the hope was that their one and only competitor, Philips
Lighting, would give up trying to win the race and drop out of the game
(as they subsequently did), allowing Cree to just coast along and milk
this promise of improved LED lamps for as long as the (technically
ignorant) consumer masses would tolerate the tiny incremental
improvements being drip fed into the market place.

With Philips Lighting gone, it's no wonder we seem to have been "Stuck
in 2013" for the past four years as far as LED lighting products are
concerned. I suppose we should eventually see 250 LPW lamps make an
appearance since Cree will have no choice but to spend that margin
between their best achieved 303LPW laboratory example and the current
marketing period's "Best LPW offering to date".

Before anyone else jumps in with a best guess at when we're likely to
see 250LPW LED GLS lamps finally make an appearance, I'll offer mine.

I reckon Cree could get away with a 20LPW improvement per marketing
season which, given the size of the worldwide market they have exclusive
access to, is likely to straddle a two year interval. Assuming the
current LPW is now at the 150 mark, I reckon this gives Cree another
decade's worth of high living before they're finally obliged to offer a
250LPW lamp sometime towards the end of the third decade of this current
millenium (assuming Trump hasn't plunged the whole world into Nuclear
Armageddon during the next 4 or 8 years of his presidency[1]).

[1] In which case, I can foresee Cree diversifying into tallow and wick
based lighting technology, always, of course, assuming enough of their
board of directors survive "The Event" to keep the operation going as a
vital part of the business of rebuilding a post apocalyptic society (and
thereby get their snouts back into the trough).

--
Johnny B Good