suggestions for higher power white LEDs to testing?

[George Herold]

On Aug 27, 1:40 pm, Jon Kirwan <j...@infinitefactors.org> wrote:

On Fri, 27 Aug 2010 07:44:33 -0700 (PDT), George Herold





ggher...@gmail.com> wrote:
On Aug 26, 2:43 pm, Jon Kirwan <j...@infinitefactors.org> wrote:
On Thu, 26 Aug 2010 09:24:05 -0700 (PDT), George Herold

ggher...@gmail.com> wrote:
A colleague used a white LED to replace a flash lamp in a product.
Part number
LXML-PWN1-100.  We are obviously just flashing it, but when he ran it
CW it hurt to look at it.

~$2.50 each in quantities of 100’s  from Future Electronics.

I think we drive it with only 0.3 to 0.5 amps it claims to be able to
handle 0.7 A.

I will take a look.  [Though I'm honestly not looking (yet)
to buy 100 of a single part.]

Jon

Oh, If these might work for you, I could slip you a few in an
envelope.  I've got some other white LED's kicking around from a
previous project, but mostly through hole, lower current ones.

Well, if you feel that is okay.  I had no problem at $2.50
ea, just the "100's" part of it.  If you are willing to sell
a few of them, I'm fine with that.

There's a slush fund here where I put money for the parts/ supplies
that I steal from work, so I can add a few bucks to help out the
education effort.

Or I can send it.

I just sent $50 to the OSA for a Galileoscope project.  Students get
to make their own telescope.  The $50 covers parts, one is sent to a
school and I got one for myself (and my kids)

Hehe.  Is this something akin to the "one laptop per child"
thing, where you buy two and get one?

Jon- Hide quoted text -

- Show quoted text -

No problem if they fit your bill.

I found some other white LEDs from digikey, the package claims 1W part
# 365-1351-1. These were bought a year(?) ago and don't seem to be in
stock anymore... So next to worthless as far as I'm concerned.

You can send me your mail address via email. I'll drop them in the
mail on Monday.

The Galileo scope thing was in an email from the OSA. It sounded
nice. Give students something to get their hands on. When I clicked
on the link I found I could order one for myself and donate one to a
school. That was a big selling point. I'm not sure if I would have
donated one if I couldn't get one for myself. (Ohh and my kids.)

George H.

 

[Don Klipstein]

In article <rt8e76d990eqk3lk0tsigh8doc6kddsr0c@4ax.com>, Jon Kirwan wrote:

On Fri, 27 Aug 2010 02:47:48 +0100, Eeyore
rabbitsfriendsandrelations@removethishotmail.com> wrote:

Jon Kirwan wrote:

I've often wondered about aging issues.

Most higher power LED manufacturers quote lifetime at 70% of initial
luminosity.

Which provides a definition for one point. It doesn't say
much about the different causes and the general picture or
what one might expect in some specific situation.

As it turns out, Lumileds quotes a projected lifetime until fading to
70% of initial luminosity at a specific current and a specific junction
temperature.

For example:

http://www.philipslumileds.com/uploads/17/DS61-pdf

That one claims average of 70% of initial output at 50,000 hours at 1
amp and junction temperature not exceeding 135 degrees C.

I believe this is only a projection, since I doubt many of these have
been made 50,000 or more hours ago as of 8/27/2010.
--
- Don Klipstein (don@misty.com)

 

[Ecnerwal]

Which provides a definition for one point. It doesn't say
much about the different causes and the general picture or
what one might expect in some specific situation.

Well, as to specific causes, cooking is a big one. Pay a lot of
attention to cooling, and/or don't run at peak power. While it's nice to
get everything it's got to give, getting the heat out is a big issue
with the high power LEDs, and not getting the heat out is a major cause
of degradation at higher than expected rates.

--
Cats, coffee, chocolate...vices to live by

 

[Jon Kirwan]

On Sat, 28 Aug 2010 08:12:25 -0400, Ecnerwal
<MyNameForward@ReplaceWithMyVices.Com.invalid> wrote:

Which provides a definition for one point. It doesn't say
much about the different causes and the general picture or
what one might expect in some specific situation.

Well, as to specific causes, cooking is a big one. Pay a lot of
attention to cooling, and/or don't run at peak power. While it's nice to
get everything it's got to give, getting the heat out is a big issue
with the high power LEDs, and not getting the heat out is a major cause
of degradation at higher than expected rates.

That seems very good advice to remember. I'll keep it very
much in mind.

Thanks,
Jon

 

[John O'Flaherty]

On Sat, 28 Aug 2010 08:12:25 -0400, Ecnerwal
<MyNameForward@ReplaceWithMyVices.Com.invalid> wrote:

Which provides a definition for one point. It doesn't say
much about the different causes and the general picture or
what one might expect in some specific situation.

Well, as to specific causes, cooking is a big one.

.... not cooking?

Pay a lot of
attention to cooling, and/or don't run at peak power. While it's nice to
get everything it's got to give, getting the heat out is a big issue
with the high power LEDs, and not getting the heat out is a major cause
of degradation at higher than expected rates.

--
John

 

[Jon Kirwan]

On Wed, 1 Sep 2010 12:05:16 -0700 (PDT), Nunya
<jack_shephard@cox.net> wrote:

On Aug 25, 11:40 am, Jon Kirwan <j...@infinitefactors.org> wrote:

snip

Anyway, open to good experiences.  Suppliers you've liked, as
well.  My temptation is to just buy only what I can find at
Digikey and do the order, that way.  But I know that may be
too limiting and so I'm pretty sure I will need to pick these
up from a variety of suppliers.

Thanks very much in advance,
Jon

Google up the youtube videos and sites and links
surrounding modding the Logitech G15 and G19
keyboards. They use an open source stage lighting
management program to individually address every
key's LED color and brightness.

Pretty cool keyboards too.
http://www.youtube.com/watch?v=5Wy5YKdbjZQ

They have a hardware page at:
http://www.g15-mod.com/e_hardw.htm

But it really looks to me like this is a special keyboard
with all the LEDs and drive circuitry already included when
you buy it. I'm not sure what is being modded, except
perhaps some software? I certainly do not see any schematics
there and the web site is ... well, terse.

Jon

 

[Nunya]

On Aug 25, 11:40 am, Jon Kirwan <j...@infinitefactors.org> wrote:

snip

Anyway, open to good experiences.  Suppliers you've liked, as
well.  My temptation is to just buy only what I can find at
Digikey and do the order, that way.  But I know that may be
too limiting and so I'm pretty sure I will need to pick these
up from a variety of suppliers.

Thanks very much in advance,
Jon

Google up the youtube videos and sites and links
surrounding modding the Logitech G15 and G19
keyboards. They use an open source stage lighting
management program to individually address every
key's LED color and brightness.

Pretty cool keyboards too.
http://www.youtube.com/watch?v=5Wy5YKdbjZQ

 

[Nunya]

On Aug 26, 2:14 pm, Eeyore
<rabbitsfriendsandrelati...@removethishotmail.com> wrote:

Jon Kirwan wrote:
On Thu, 26 Aug 2010 16:51:06 +0100, Eeyore
rabbitsfriendsandrelati...@removethishotmail.com> wrote:

Jon Kirwan wrote:
This is a game I play with students to show them what they
can do with junk and a little effort and knowledge.
Might be more useful to show them what they can do *without* using JUNK
! They might learn some REAL design skills.

I see you've never been a child.

I see you don't realise the disadvantages of use life-expired
components. I bought new parts for the vast majority of my hobby projects..

Graham

You're an idiot, again, as usual.

Of course new is better. Unless you are bulding a race engine.
Give me a "seasoned block" any day.

I do not expect you to understand which and when.

 

[Nunya]

On Sep 1, 12:38 pm, Jon Kirwan <j...@infinitefactors.org> wrote:

On Wed, 1 Sep 2010 12:05:16 -0700 (PDT), Nunya



jack_sheph...@cox.net> wrote:
On Aug 25, 11:40 am, Jon Kirwan <j...@infinitefactors.org> wrote:

snip

Anyway, open to good experiences.  Suppliers you've liked, as
well.  My temptation is to just buy only what I can find at
Digikey and do the order, that way.  But I know that may be
too limiting and so I'm pretty sure I will need to pick these
up from a variety of suppliers.

Thanks very much in advance,
Jon

 Google up the youtube videos and sites and links
surrounding modding the Logitech G15 and G19
keyboards.  They use an open source stage lighting
management program to individually address every
key's LED color and brightness.

 Pretty cool keyboards too.
http://www.youtube.com/watch?v=5Wy5YKdbjZQ

They have a hardware page at:
 http://www.g15-mod.com/e_hardw.htm

But it really looks to me like this is a special keyboard
with all the LEDs and drive circuitry already included when
you buy it.  I'm not sure what is being modded, except
perhaps some software?  I certainly do not see any schematics
there and the web site is ... well, terse.

Jon

The G19 is fully addressable. The G15 required hacking to get
to run under Linux, and modding to get to run in banks of colors,
and some haked down to individual key level, which is a
hardware level hack.

For me, simply changing the current limit resistors on the
LED boards would have been enough to make both 'brightness'
settings a bit brighter.

http://www.mediafire.com/imgbnc.php/3c169272b92c0d85e2a677b0a85f33b16g.jpg

 

[Eeyore]

Ecnerwal wrote:

Which provides a definition for one point. It doesn't say
much about the different causes and the general picture or
what one might expect in some specific situation.

Well, as to specific causes, cooking is a big one. Pay a lot of
attention to cooling, and/or don't run at peak power. While it's nice to
get everything it's got to give, getting the heat out is a big issue
with the high power LEDs, and not getting the heat out is a major cause
of degradation at higher than expected rates.

Absolutely right. As with any semiconductor device, operation at higher
temperatures reduces device life.

These big LEDs cost a lot, so it makes sense to run them as 'hard' as
you can to get value for money. This not only reduces lifetime but
degrades efficiency too.

Graham

 

[Eeyore]

Jon Kirwan wrote:

On Sat, 28 Aug 2010 08:12:25 -0400, Ecnerwal
MyNameForward@ReplaceWithMyVices.Com.invalid> wrote:

Which provides a definition for one point. It doesn't say
much about the different causes and the general picture or
what one might expect in some specific situation.
Well, as to specific causes, cooking is a big one. Pay a lot of
attention to cooling, and/or don't run at peak power. While it's nice to
get everything it's got to give, getting the heat out is a big issue
with the high power LEDs, and not getting the heat out is a major cause
of degradation at higher than expected rates.

That seems very good advice to remember. I'll keep it very
much in mind.

Check Ebay for LED heatsinks.

Graham

 

[Michael A. Terrell]

Eeyore wrote:

Ecnerwal wrote:
Which provides a definition for one point. It doesn't say
much about the different causes and the general picture or
what one might expect in some specific situation.

Well, as to specific causes, cooking is a big one. Pay a lot of
attention to cooling, and/or don't run at peak power. While it's nice to
get everything it's got to give, getting the heat out is a big issue
with the high power LEDs, and not getting the heat out is a major cause
of degradation at higher than expected rates.

Absolutely right. As with any semiconductor device, operation at higher
temperatures reduces device life.

Higher than what? Talk about a overly broad, vague statement.


--
Politicians should only get paid if the budget is balanced, and there is
enough left over to pay them.

 

[Grant]

On Mon, 06 Sep 2010 12:51:38 -0400, "Michael A. Terrell" <mike.terrell@earthlink.net> wrote:

Eeyore wrote:

Ecnerwal wrote:
Which provides a definition for one point. It doesn't say
much about the different causes and the general picture or
what one might expect in some specific situation.

Well, as to specific causes, cooking is a big one. Pay a lot of
attention to cooling, and/or don't run at peak power. While it's nice to
get everything it's got to give, getting the heat out is a big issue
with the high power LEDs, and not getting the heat out is a major cause
of degradation at higher than expected rates.

Absolutely right. As with any semiconductor device, operation at higher
temperatures reduces device life.


Higher than what? Talk about a overly broad, vague statement.

You could fall back on life halved for each 10'C temp rise? Vague, but
I've seen the idea expressed many times over the years.

Besides, we work with stuff that goes pop sometimes for no apparent reason.

Murphy lives! And that magic smoke is difficult to keep in place

Grant.

 

[Grant]

On Mon, 06 Sep 2010 23:20:24 -0400, "Michael A. Terrell" <mike.terrell@earthlink.net> wrote:

Grant wrote:

On Mon, 06 Sep 2010 12:51:38 -0400, "Michael A. Terrell" <mike.terrell@earthlink.net> wrote:


Eeyore wrote:

Ecnerwal wrote:
Which provides a definition for one point. It doesn't say
much about the different causes and the general picture or
what one might expect in some specific situation.

Well, as to specific causes, cooking is a big one. Pay a lot of
attention to cooling, and/or don't run at peak power. While it's nice to
get everything it's got to give, getting the heat out is a big issue
with the high power LEDs, and not getting the heat out is a major cause
of degradation at higher than expected rates.

Absolutely right. As with any semiconductor device, operation at higher
temperatures reduces device life.


Higher than what? Talk about a overly broad, vague statement.

You could fall back on life halved for each 10'C temp rise? Vague, but
I've seen the idea expressed many times over the years.

Besides, we work with stuff that goes pop sometimes for no apparent reason.

Murphy lives! And that magic smoke is difficult to keep in place


Grant, I've worked in places that the equipment was operated well
below zero. A 10° C increase would have made the equipment perform
better and not affect it's life enough to notice. The record low at
that location was -69°F and on windy winter days it could be below
freezing inside the control room.

Fair enough I don't live where it snows

I've also used equipment that had strip heaters & a thermostat to
maintain a minimum temperature to prevent condensation. That's why i
said it was a vague statement.

Once I worked for AU agents for Tenney environmental test chambers,
had to fix one where Tenney forgot to put in stainless fixings to
survive their own environments. Customer certainly not impressed
with the rusting heater assembly mounts.

Closest I've been to extreme electronics locales, at least it was in
boxes and not the control room

Grant.

 

[Michael A. Terrell]

Grant wrote:

On Mon, 06 Sep 2010 23:20:24 -0400, "Michael A. Terrell" <mike.terrell@earthlink.net> wrote:


Grant wrote:

On Mon, 06 Sep 2010 12:51:38 -0400, "Michael A. Terrell" <mike.terrell@earthlink.net> wrote:


Eeyore wrote:

Ecnerwal wrote:
Which provides a definition for one point. It doesn't say
much about the different causes and the general picture or
what one might expect in some specific situation.

Well, as to specific causes, cooking is a big one. Pay a lot of
attention to cooling, and/or don't run at peak power. While it's nice to
get everything it's got to give, getting the heat out is a big issue
with the high power LEDs, and not getting the heat out is a major cause
of degradation at higher than expected rates.

Absolutely right. As with any semiconductor device, operation at higher
temperatures reduces device life.


Higher than what? Talk about a overly broad, vague statement.

You could fall back on life halved for each 10'C temp rise? Vague, but
I've seen the idea expressed many times over the years.

Besides, we work with stuff that goes pop sometimes for no apparent reason.

Murphy lives! And that magic smoke is difficult to keep in place


Grant, I've worked in places that the equipment was operated well
below zero. A 10° C increase would have made the equipment perform
better and not affect it's life enough to notice. The record low at
that location was -69°F and on windy winter days it could be below
freezing inside the control room.

Fair enough I don't live where it snows

I've also used equipment that had strip heaters & a thermostat to
maintain a minimum temperature to prevent condensation. That's why i
said it was a vague statement.

Once I worked for AU agents for Tenney environmental test chambers,
had to fix one where Tenney forgot to put in stainless fixings to
survive their own environments. Customer certainly not impressed
with the rusting heater assembly mounts.

Closest I've been to extreme electronics locales, at least it was in
boxes and not the control room

This was a military TV station in Alaska. The colder it was outside,
the less heat was availible for the station from the boiler plant at the
other end of the complex. At one time it heated the entire W.W.II base
of wood buildings, but that had been diverted to newer, larger concrete
buildings. There were days I couldn't get the test pattern anywhere
near linear, or the cameras to settle down. They were designed to
operate in the 60 to 80 F range.


--
Politicians should only get paid if the budget is balanced, and there is
enough left over to pay them.

 

[Eeyore]

Grant wrote:

On Mon, 06 Sep 2010 12:51:38 -0400, "Michael A. Terrell" <mike.terrell@earthlink.net> wrote:

Eeyore wrote:
Ecnerwal wrote:
Which provides a definition for one point. It doesn't say
much about the different causes and the general picture or
what one might expect in some specific situation.
Well, as to specific causes, cooking is a big one. Pay a lot of
attention to cooling, and/or don't run at peak power. While it's nice to
get everything it's got to give, getting the heat out is a big issue
with the high power LEDs, and not getting the heat out is a major cause
of degradation at higher than expected rates.
Absolutely right. As with any semiconductor device, operation at higher
temperatures reduces device life.

Higher than what? Talk about a overly broad, vague statement.

You could fall back on life halved for each 10'C temp rise? Vague, but
I've seen the idea expressed many times over the years.

Besides, we work with stuff that goes pop sometimes for no apparent reason.

Murphy lives! And that magic smoke is difficult to keep in place

Grant.

Respectable manufacturers will provide the relevant data. Junction
temperature will depend greatly on how good the heatsinking is too.

Graham

 

[Eeyore]

Nunya wrote:

You're an idiot, again, as usual.

You're a troll again as usual.