No Luxeon TFFC LEDs for a while

[Kevin McMurtrie]

Philips has recalled TFFC versions of the Rebel and K2 Luxeon LEDs. The
epoxy under the die has a mismatched thermal expansion that will cause
10% to 30% of them to crack upon heating. Shipments will resume in
early March.

This might cause shortages of high-end LED lights. (It's keeping me
from building my home-made light.)

--
I don't read Google's spam. Reply with another service.

[Chalo]

Kevin McMurtrie wrote:
>
> Philips has recalled TFFC versions of the Rebel and K2 Luxeon LEDs. The
> epoxy under the die has a mismatched thermal expansion that will cause
> 10% to 30% of them to crack upon heating. Shipments will resume in
> early March.
>
> This might cause shortages of high-end LED lights. (It's keeping me
> from building my home-made light.)

Cree Xlamp XR-E and Seoul Semiconductor P4 LEDs are at least as good
performance-wise as Luxeon Rebels and better than Luxeon K2s. They
are so good that I've begun to use up my precious stash of Luxeon I
and Luxeon III LEDs in junk projects, because any labor-intensive
project warrants the use of a cheaper, brighter, more efficient, up-to-
date emitter.

What do you have in mind for your own light?

Chalo

[Chalo]

Kevin McMurtrie wrote:
>
> I don't read Google's spam. Reply with another service.

Tough luck, by the way. If you want that, maybe you should provide
the public with another free Usenet web interface that folks can
access from whatever machine and OS they happen to be using.

Chalo

[Ryan Cousineau]

In article
<11f39675-2901-4c61-99f7-56e70dd1ba72@k39g2000hsf.googlegroups.com>,
Chalo <chalo.colina@gmail.com> wrote:

> Kevin McMurtrie wrote:
> >
> > Philips has recalled TFFC versions of the Rebel and K2 Luxeon LEDs. The
> > epoxy under the die has a mismatched thermal expansion that will cause
> > 10% to 30% of them to crack upon heating. Shipments will resume in
> > early March.
> >
> > This might cause shortages of high-end LED lights. (It's keeping me
> > from building my home-made light.)
>
> Cree Xlamp XR-E and Seoul Semiconductor P4 LEDs are at least as good
> performance-wise as Luxeon Rebels and better than Luxeon K2s. They
> are so good that I've begun to use up my precious stash of Luxeon I
> and Luxeon III LEDs in junk projects, because any labor-intensive
> project warrants the use of a cheaper, brighter, more efficient, up-to-
> date emitter.
>
> What do you have in mind for your own light?
>
> Chalo

Interresting...I'm at the point where, having acquired a few MR11-based
lights (complete with batteries) I'm realizing that dumping in one of
these new super-LEDs might be a nice upgrade.

These wild and crazy kids seem to offer a not-quite drop-in kit for MR11
conversion:

http://www.cutter.com.au/products.php?cat=41

US$30, a pretty good deal if it works. Since I have a bottle-sized NiMH
battery, my goal would be to get something like 4 hours of
super-lighting, enough for any night ride I'm likely to undertake.

--
Ryan Cousineau rcousine@gmail.com http://www.wiredcola.com/
"In other newsgroups, they killfile trolls."
"In rec.bicycles.racing, we coach them."

[Kevin McMurtrie]

In article
<11f39675-2901-4c61-99f7-56e70dd1ba72@k39g2000hsf.googlegroups.com>,
Chalo <chalo.colina@gmail.com> wrote:

> Kevin McMurtrie wrote:
> >
> > Philips has recalled TFFC versions of the Rebel and K2 Luxeon LEDs. The
> > epoxy under the die has a mismatched thermal expansion that will cause
> > 10% to 30% of them to crack upon heating. Shipments will resume in
> > early March.
> >
> > This might cause shortages of high-end LED lights. (It's keeping me
> > from building my home-made light.)
>
> Cree Xlamp XR-E and Seoul Semiconductor P4 LEDs are at least as good
> performance-wise as Luxeon Rebels and better than Luxeon K2s. They
> are so good that I've begun to use up my precious stash of Luxeon I
> and Luxeon III LEDs in junk projects, because any labor-intensive
> project warrants the use of a cheaper, brighter, more efficient, up-to-
> date emitter.
>
> What do you have in mind for your own light?
>
> Chalo

(I found your post through a reference. I filter Google because some
groups that I read are nearly 50% Google spam.)

I built a prototype using an array of 12 LXML-PWC1-0090 Rebels and 18mm
lenses. A switching power supply adjusted the power smoothly from about
0.1mA to 950mA per LED. It electrically worked perfectly. At 5W, it
totally blew away a 5W CCFL headlight I had built before. It could
momentarily be cranked up brighter than a car high-beam.

When it came to the mechanics, I screwed up big-time. I had mounted the
LEDs on the edge of a copper plate that was formed into a chassis. It
was heavy and weak. I tried to trade a bit of copper for carbon fiber
then things really got ugly.

My next attempt will probably use Rebels on a thin film PCB over an
aluminum heatsink. I see that the Xlamp XR-E matches the specs and
price of the TFFC Rebels and K2s. How is the color uniformity?

--
I don't read Google's spam. Reply with another service.

[Tom Sherman]

Chalo Colina wrote:
> Kevin McMurtrie wrote:
>> I don't read Google's spam. Reply with another service.
>
> Tough luck, by the way. If you want that, maybe you should provide
> the public with another free Usenet web interface that folks can
> access from whatever machine and OS they happen to be using.
>
Can someone PLEASE, PLEASE, PLEASE convince Google to honor the
signature separator, use the display name in the attribution line, not
change quotation marks to forward slashes in display names, and to stop
deleting blank lines when quoting text!!!

--
Tom Sherman - Holstein-Friesland Bovinia
The weather is here, wish you were beautiful

[Chalo]

Ryan Cousineau wrote:
>
> These wild and crazy kids seem to offer a not-quite drop-in kit for MR11
> conversion:
>
> http://www.cutter.com.au/products.php?cat=41
>
> US$30, a pretty good deal if it works. Since I have a bottle-sized NiMH
> battery, my goal would be to get something like 4 hours of
> super-lighting, enough for any night ride I'm likely to undertake.

I like the 3- and 4-emitter packaging. Even when overdriven at
1000mA, meaning almost 4W per LED, single emitters are going to have a
tough time meeting expectations established by halogen and xenon
lights operating at much higher per-unit wattages. Stuffing a few
LEDs together in the same volume should accomplish a couple of
things-- getting the total lumens output up to a satisfying amount,
and running each individual emitter at a lower, more efficient power
level. (Although incandescent bulbs become more efficient with
escalating power, LEDs make more light per watt when underdriven.)

I don't know if you are into rolling your own, but there are places
where you can get the subcomponents for a song. They're in Hong Kong,
which spooked me at first-- but after a couple of satisfactory
transactions with them, I've decided they are a good resource:

http://www.kaidomain.com/WEBUI/ProductDetail.aspx?TranID=2982
http://www.dealextreme.com/details.dx/sku.3417
http://www.dealextreme.com/details.dx/sku.3257

If you're not entertained by the idea of puzzling out and fussily
constructing small electronic devices, then by all means you should
pay a little more and get something closer to a plug-and-play
solution. But I have really been enjoying this stuff. I guess I
didn't build enough model airplanes when I was a kid to get such
things out of my system.

Chalo

[Ryan Cousineau]

In article
<195e56b1-d12f-4c61-b239-9fa3417d1e76@e4g2000hsg.googlegroups.com>,
Chalo <chalo.colina@gmail.com> wrote:

> Ryan Cousineau wrote:
> >
> > These wild and crazy kids seem to offer a not-quite drop-in kit for MR11
> > conversion:
> >
> > http://www.cutter.com.au/products.php?cat=41
> >
> > US$30, a pretty good deal if it works. Since I have a bottle-sized NiMH
> > battery, my goal would be to get something like 4 hours of
> > super-lighting, enough for any night ride I'm likely to undertake.
>
> I like the 3- and 4-emitter packaging. Even when overdriven at
> 1000mA, meaning almost 4W per LED, single emitters are going to have a
> tough time meeting expectations established by halogen and xenon
> lights operating at much higher per-unit wattages. Stuffing a few
> LEDs together in the same volume should accomplish a couple of
> things-- getting the total lumens output up to a satisfying amount,
> and running each individual emitter at a lower, more efficient power
> level. (Although incandescent bulbs become more efficient with
> escalating power, LEDs make more light per watt when underdriven.)

Looking down below, I see the parts you've suggested are for a
single-LED reflector/module, though the power board can handle multiple
LEDs.

Since I already have some nice MR-11-sized housings (two BLTs, one
Sigma), I'd like to make use of them. It looks like the current
available LED mounts for the Cree/Seoul/Luxeon super-LEDs all feature
sufficiently large bases (for cooling) that it's strictly a case of
one-per-housing. Do you know otherwise? Similarly, it looks like the
replacement reflector kits shown there are designed for only one LED,
too.

I guess the solutions is to abandon my current housings, and fill
something like this with LEDs:

http://www.dealextreme.com/details.dx/sku.1915

And make the emitter of the gods! It would work with the controller
board below. This housing seems to be intended to fit inside a
C-cell-sized Maglite head.

> I don't know if you are into rolling your own, but there are places
> where you can get the subcomponents for a song. They're in Hong Kong,
> which spooked me at first-- but after a couple of satisfactory
> transactions with them, I've decided they are a good resource:
>
> http://www.kaidomain.com/WEBUI/ProductDetail.aspx?TranID=2982
> http://www.dealextreme.com/details.dx/sku.3417
> http://www.dealextreme.com/details.dx/sku.3257

Oooh er. Such pretty prices!

> If you're not entertained by the idea of puzzling out and fussily
> constructing small electronic devices, then by all means you should
> pay a little more and get something closer to a plug-and-play
> solution. But I have really been enjoying this stuff. I guess I
> didn't build enough model airplanes when I was a kid to get such
> things out of my system.

In theory, it's my day job to occassionally construct small electronic
devices, so I guess that could cut either way, but in practice I could
use the practice, and I like messing with fussy projects.

Also, I'm really cheap.

This looks interesting. Since I have multiple light housings, 3 separate
units isn't impossible.

--
Ryan Cousineau rcousine@gmail.com http://www.wiredcola.com/
"In other newsgroups, they killfile trolls."
"In rec.bicycles.racing, we coach them."

[Kevin McMurtrie]

In article
<rcousine-1EEBED.23114905022008@[74.223.185.199.nw.nuvox.net]>,
Ryan Cousineau <rcousine@gmail.com> wrote:

> In article
> <195e56b1-d12f-4c61-b239-9fa3417d1e76@e4g2000hsg.googlegroups.com>,
> Chalo <chalo.colina@gmail.com> wrote:
>
> > Ryan Cousineau wrote:
> > >
> > > These wild and crazy kids seem to offer a not-quite drop-in kit for MR11
> > > conversion:
> > >
> > > http://www.cutter.com.au/products.php?cat=41
> > >
> > > US$30, a pretty good deal if it works. Since I have a bottle-sized NiMH
> > > battery, my goal would be to get something like 4 hours of
> > > super-lighting, enough for any night ride I'm likely to undertake.
> >
> > I like the 3- and 4-emitter packaging. Even when overdriven at
> > 1000mA, meaning almost 4W per LED, single emitters are going to have a
> > tough time meeting expectations established by halogen and xenon
> > lights operating at much higher per-unit wattages. Stuffing a few
> > LEDs together in the same volume should accomplish a couple of
> > things-- getting the total lumens output up to a satisfying amount,
> > and running each individual emitter at a lower, more efficient power
> > level. (Although incandescent bulbs become more efficient with
> > escalating power, LEDs make more light per watt when underdriven.)
>
> Looking down below, I see the parts you've suggested are for a
> single-LED reflector/module, though the power board can handle multiple
> LEDs.
>
> Since I already have some nice MR-11-sized housings (two BLTs, one
> Sigma), I'd like to make use of them. It looks like the current
> available LED mounts for the Cree/Seoul/Luxeon super-LEDs all feature
> sufficiently large bases (for cooling) that it's strictly a case of
> one-per-housing. Do you know otherwise? Similarly, it looks like the
> replacement reflector kits shown there are designed for only one LED,
> too.
>
> I guess the solutions is to abandon my current housings, and fill
> something like this with LEDs:
>
> http://www.dealextreme.com/details.dx/sku.1915
>
> And make the emitter of the gods! It would work with the controller
> board below. This housing seems to be intended to fit inside a
> C-cell-sized Maglite head.
>
> > I don't know if you are into rolling your own, but there are places
> > where you can get the subcomponents for a song. They're in Hong Kong,
> > which spooked me at first-- but after a couple of satisfactory
> > transactions with them, I've decided they are a good resource:
> >
> > http://www.kaidomain.com/WEBUI/ProductDetail.aspx?TranID=2982
> > http://www.dealextreme.com/details.dx/sku.3417
> > http://www.dealextreme.com/details.dx/sku.3257
>
> Oooh er. Such pretty prices!

Stretching the specs? Kaidomain says the inverter is up to 94%
efficient but the chip manufacturer says 86%. Kaidomain's example for
driving one CREE shows 109% efficiency. Hmmm...

Beating 90% efficiency requires more exotic components. Buck inverters
with synchronous rectification can hit 95% at moderate currents but the
circuit overhead hurts low current efficiency. Low loss capacitors and
coils get very expensive too. You could easily hit $50 on a small
inverter. Outside of bicycle riders, not many would pay so much.

I was using an LM2679 simple switcher. It's not supper efficient but,
like the title implies, it's super simple. Now if I could only find a
precision current amplifier that wasn't the size of a grain of sand.


> > If you're not entertained by the idea of puzzling out and fussily
> > constructing small electronic devices, then by all means you should
> > pay a little more and get something closer to a plug-and-play
> > solution. But I have really been enjoying this stuff. I guess I
> > didn't build enough model airplanes when I was a kid to get such
> > things out of my system.
>
> In theory, it's my day job to occassionally construct small electronic
> devices, so I guess that could cut either way, but in practice I could
> use the practice, and I like messing with fussy projects.
>
> Also, I'm really cheap.
>
> This looks interesting. Since I have multiple light housings, 3 separate
> units isn't impossible.

Sounds like a fun job.

--
I don't read Google's spam. Reply with another service.

[Chalo]

Kevin McMurtrie wrote:
>
> Chalo wrote:
> >
> > Kevin McMurtrie wrote:
> > >
> > > This might cause shortages of high-end LED lights. (It's keeping me
> > > from building my home-made light.)
> >
> > What do you have in mind for your own light?
>
> I built a prototype using an array of 12 LXML-PWC1-0090 Rebels and 18mm
> lenses. A switching power supply adjusted the power smoothly from about
> 0.1mA to 950mA per LED. It electrically worked perfectly. At 5W, it
> totally blew away a 5W CCFL headlight I had built before. It could
> momentarily be cranked up brighter than a car high-beam.

That's a big array. 950mA x 4V x 12 is about 45W. You must have a
pretty manly battery for that.

> I had mounted the
> LEDs on the edge of a copper plate that was formed into a chassis. It
> was heavy and weak. I tried to trade a bit of copper for carbon fiber
> then things really got ugly.

That sounds like a job for a piece of aluminum channel. the sides of
the channel would provide structural rigidity, a place to attach
mounts, heat rejection area, and protection for the optics.

> My next attempt will probably use Rebels on a thin film PCB over an
> aluminum heatsink. I see that the Xlamp XR-E matches the specs and
> price of the TFFC Rebels and K2s. How is the color uniformity?

It's OK. The overall color on Xlamps I have used is slightly better
than the overall color on Rebels I have used, especially at low drive
currents where the Rebel turns distinctly purple. Since the Cree
gives off light from a "pool" of phosphor atop the die, any optic that
in effect gives you a magnified image of the emitter will also give
you a yellow ring around the hotspot. Textured optics or focusing
reflectors won't do that.

The Cree Xlamp XR-E has a different shape dome and illuminated area
than any of the Luxeon LEDs. As a result, some optics that work well
for one don't do so well for the other. The appeal of Seoul
Semiconductor Z-Power emitters is largely in their form and light
pattern being identical to Luxeon I and Luxeon III emitters, while
their color and lumens-per-watt characteristics are more like Cree
emitters. Many flashlight geeks are using them as drop-in upgrades
for devices that they built with Luxeons over the past few years. I
have not used any Seoul LEDs in my projects yet.

Seoul Z-Power stars and bare emitters with a U bin rating (nominal 100
lm @ 350mA) are selling at dealextreme.com for less than $6.

Chalo

[Chalo]

Kevin McMurtrie wrote:
>
> Ryan Cousineau wrote:
> >
> > Chalo wrote:
> > >
> > > I don't know if you are into rolling your own, but there are places
> > > where you can get the subcomponents for a song. They're in Hong Kong,
> > > which spooked me at first-- but after a couple of satisfactory
> > > transactions with them, I've decided they are a good resource:
> > >
> > > http://www.kaidomain.com/WEBUI/ProductDetail.aspx?TranID=2982
> > >http://www.dealextreme.com/details.dx/sku.3417
> > >http://www.dealextreme.com/details.dx/sku.3257
> >
> > Oooh er. Such pretty prices!
>
> Stretching the specs? Kaidomain says the inverter is up to 94%
> efficient but the chip manufacturer says 86%. Kaidomain's example for
> driving one CREE shows 109% efficiency. Hmmm...
>
> Beating 90% efficiency requires more exotic components. Buck inverters
> with synchronous rectification can hit 95% at moderate currents but the
> circuit overhead hurts low current efficiency. Low loss capacitors and
> coils get very expensive too. You could easily hit $50 on a small
> inverter. Outside of bicycle riders, not many would pay so much.

Flashlight geeks probably would, but they would not look to places
like kaidomain.com and dealextreme.com for devices at that end of the
price and performance spectrum.

Having dealt with these Hong Kong suppliers, I'll say this much:
Don't trust their numbers-- trust the manufacturers' numbers or those
provided by other users who made their own measurements.
Candlepowerforums.com is a good place to find such postings. The user
postings at the retail websites in question should be viewed
critically, but so far I have not observed signs of shilling or
knowingly inaccurate claims there.

I don't even bother with expecting certain performance numbers from
regulators I buy out of Hong Kong. If they appear to work and only
cost $3, I'm satisfied with that. If they beat 60% efficiency, to me
it's just a bonus. I assume up front that the regulator will need its
own heat evacuation.

I have bought regulators from dealextreme.com that needed a solder
joint repaired, but I have not bought any that didn't work and didn't
respond to rudimentary troubleshooting.

Chalo

[russellseaton1@yahoo.com]

You could easily hit $50 on a small
> > inverter. *Outside of bicycle riders, not many would pay so much.
>
> Flashlight geeks probably would,


Its comforting to know there are subsets of the population that are
far, far, far crazier than the nuttiest bicyclist.