suggestions for higher power white LEDs to testing?

[default]

On Thu, 26 Aug 2010 09:46:34 +1000, David Eather <eather@tpg.com.au>
wrote:

On 26/08/2010 5:47 AM, Ecnerwal wrote:
In article<ovna7651f35uq5j3k9dmcdtlih9ckgt11a@4ax.com>,
Jon Kirwan<jonk@infinitefactors.org> wrote:

I've stayed completely away from driving the higher powered
white LEDs, so far. But I'm interested in playing with some
various boost driver designs of mine made from spare parts I
make out of dead CFL lamps (it's fun to do) and I'd like to
buy an "interesting" collection of roughly-1W category white
LEDs for testing purposes. Right now, I don't have a single
LED that requires more than about 100mW to drive.

Well, I haven't played with them yet, but in skimming the pond scum for
interesting parts to add to an order since I was already paying
shipping, I got a few of optek's mini-half-watt series in warm white, as
seeming not too bad on bang/buck and light/watt. I am sort of amused (or
bemused) that their data sheet does not actually connect the cut corner
of the SMD package to polarity...

Those run 180 mA continuous or 350 mA pulsed (10%).

my fav company www.dealextreme.com also carry a wide range of good
quality (and some more typical quality) high power leds.

I wasn't thrilled with them. I ordered some calipers from them.
Backordered of course. Three months later I finally get them, and in
that time Harbor Freight had them for a few dollars less.
--

 

[default]

On Wed, 25 Aug 2010 11:40:24 -0700, Jon Kirwan
<jonk@infinitefactors.org> wrote:

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.

I've had good results with:
http://stores.ebay.com/Shop4leds

I got some piranha style RGB leds and some "straw hat" style 100 ma
white leds - the straw hat ones are at their limit with 100 ma going
through them - one set lasted for a few months (dawn to dusk - fine in
winter dead or dying in summer. Reduced the current to 50 ma and they
are good year round.
--

 

[Jon Kirwan]

On Thu, 26 Aug 2010 15:57:28 -0400, default
<default@defaulter.net> wrote:

On Thu, 26 Aug 2010 09:46:34 +1000, David Eather <eather@tpg.com.au
wrote:

On 26/08/2010 5:47 AM, Ecnerwal wrote:
In article<ovna7651f35uq5j3k9dmcdtlih9ckgt11a@4ax.com>,
Jon Kirwan<jonk@infinitefactors.org> wrote:

I've stayed completely away from driving the higher powered
white LEDs, so far. But I'm interested in playing with some
various boost driver designs of mine made from spare parts I
make out of dead CFL lamps (it's fun to do) and I'd like to
buy an "interesting" collection of roughly-1W category white
LEDs for testing purposes. Right now, I don't have a single
LED that requires more than about 100mW to drive.

Well, I haven't played with them yet, but in skimming the pond scum for
interesting parts to add to an order since I was already paying
shipping, I got a few of optek's mini-half-watt series in warm white, as
seeming not too bad on bang/buck and light/watt. I am sort of amused (or
bemused) that their data sheet does not actually connect the cut corner
of the SMD package to polarity...

Those run 180 mA continuous or 350 mA pulsed (10%).

my fav company www.dealextreme.com also carry a wide range of good
quality (and some more typical quality) high power leds.

I wasn't thrilled with them. I ordered some calipers from them.
Backordered of course. Three months later I finally get them, and in
that time Harbor Freight had them for a few dollars less.

That was _almost_ my case. My products were backordered for
some time and eventually I decided to send a message asking
what is going on and when the backorder would be released.
More time goes by (month more? that, after a previous 6
weeks of delay) and I get a message about "would you like to
get something else?" Dialog is very slow (language?) and it
took still more time to begin to understand that they
intended to keep the money no matter what and not make it
easy, either, to put it onto some other order. I still don't
know how that gets done.

And, I suppose, I've become less interested in finding out.

Jon

 

[Jon Kirwan]

On Thu, 26 Aug 2010 16:01:15 -0400, default
<default@defaulter.net> wrote:

On Wed, 25 Aug 2010 11:40:24 -0700, Jon Kirwan
jonk@infinitefactors.org> wrote:

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.

I've had good results with:
http://stores.ebay.com/Shop4leds

I got some piranha style RGB leds and some "straw hat" style 100 ma
white leds - the straw hat ones are at their limit with 100 ma going
through them - one set lasted for a few months (dawn to dusk - fine in
winter dead or dying in summer. Reduced the current to 50 ma and they
are good year round.

Okay. I've often wondered about aging issues. So that's
good to know.

When high power is the primary goal of a product, often other
goals are sacrificed on its alter.

I'll take a look on Shop4leds on ebay, too, then.

thanks,
Jon

 

[Eeyore]

Jon Kirwan wrote:

On Thu, 26 Aug 2010 16:51:06 +0100, Eeyore
rabbitsfriendsandrelations@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

 

[Eeyore]

Jon Kirwan wrote:

On Thu, 26 Aug 2010 16:51:06 +0100, Eeyore
rabbitsfriendsandrelations@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.

This coming from someone who thought I needed a capacitor,
didn't notice I needed a resistor, and wasn't sure about
mosfet vs bjt (which is a difference in complexity) for a
project that uses just three parts?

WTF are you talking about ?

Graham

 

[Jon Kirwan]

On Thu, 26 Aug 2010 22:14:20 +0100, Eeyore
<rabbitsfriendsandrelations@removethishotmail.com> wrote:

Jon Kirwan wrote:
On Thu, 26 Aug 2010 16:51:06 +0100, Eeyore
rabbitsfriendsandrelations@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.

Besides the fact that these are kids, Graham, it is exciting
for them to do something useful and fun with parts their
parents throw away. Kind of a segue to more. And it often
impresses their parents, which may for some excite them
towards further effort. And I can always help them at that
point, if they are interested in doing more.

I am on the ground, spending _my_ time in the trenches with
kids, Graham. I am dealing with what I have to work with. If
you'd like to come on over and help out, I'm all for it. And
I'd value your opinion on this more, then, because of your
direct experience with my situation.

What are _you_ doing, Graham, to pass on your knowledge and
interests to children?

Jon

 

[Jon Kirwan]

On Thu, 26 Aug 2010 22:15:51 +0100, Eeyore
<rabbitsfriendsandrelations@removethishotmail.com> wrote:

Jon Kirwan wrote:
On Thu, 26 Aug 2010 16:51:06 +0100, Eeyore
rabbitsfriendsandrelations@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.

This coming from someone who thought I needed a capacitor,
didn't notice I needed a resistor, and wasn't sure about
mosfet vs bjt (which is a difference in complexity) for a
project that uses just three parts?

WTF are you talking about ?

Without the battery or LED, three parts. You didn't follow
and I guess we can leave it there, then.

Jon

 

[John Fields]

On Thu, 26 Aug 2010 22:14:20 +0100, Eeyore
<rabbitsfriendsandrelations@removethishotmail.com> wrote:

Jon Kirwan wrote:
On Thu, 26 Aug 2010 16:51:06 +0100, Eeyore
rabbitsfriendsandrelations@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.

---
Don't you mean: "of using"?

But, in that vein, why would an Allen-Bradley carbon comp resistor
made in 1945 not work now, and perform to spec.?

Or, for that matter, a 2N2222 made a dozen years ago?
---

I bought new parts for the vast majority of my hobby projects.

---
Bullshit.

You bought what you could get, and whether they were "new" parts was
the least of your concern.

---
JF

 

[Jon Kirwan]

On Thu, 26 Aug 2010 16:51:35 -0500, John Fields
<jfields@austininstruments.com> wrote:

On Thu, 26 Aug 2010 22:14:20 +0100, Eeyore
rabbitsfriendsandrelations@removethishotmail.com> wrote:

Jon Kirwan wrote:
On Thu, 26 Aug 2010 16:51:06 +0100, Eeyore
rabbitsfriendsandrelations@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.

---
Don't you mean: "of using"?

But, in that vein, why would an Allen-Bradley carbon comp resistor
made in 1945 not work now, and perform to spec.?

Or, for that matter, a 2N2222 made a dozen years ago?
---

I bought new parts for the vast majority of my hobby projects.

---
Bullshit.

You bought what you could get, and whether they were "new" parts was
the least of your concern.

---
JF

Maybe Graham is just saying he was born with a silver spoon
in his mouth. But I really think it is his failure to
actually remember what it is like as a kid looking in, from
the outside.

I didn't do much as a kid -- instead spending far more time
on optics, explosives, rocketry and the like. Some others
did and they eventually made career decisions and left me far
behind in this regard. But I've always had a kids interest
in electronics, as a hobby. Never had a single hour of
formal training in it, though.

But I remember vividly building my first radio out of galena
and molten lead, with a sewing needle, to make the diode. And
all the rest involved, too. And making a jacob's ladder from
a TV flyback supply. And calling up a bowling alley owner
for permission to scavenge what I could from his building
after it was hit by a tornado the day before, for parts. And
tearing apart phone company throw-aways I'd get out of a
dumpster behind their building. Etc.

I had no money, lived in a home without walls at the time,
and had to get by without a lot that some living in better
circumstances had access to.

It's possible that Graham has no idea about any of this and
had everything pretty much handed to him.

Jon

 

[Eeyore]

Jon Kirwan wrote:

On Thu, 26 Aug 2010 22:15:51 +0100, Eeyore
rabbitsfriendsandrelations@removethishotmail.com> wrote:

Jon Kirwan wrote:
On Thu, 26 Aug 2010 16:51:06 +0100, Eeyore
rabbitsfriendsandrelations@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.
This coming from someone who thought I needed a capacitor,
didn't notice I needed a resistor, and wasn't sure about
mosfet vs bjt (which is a difference in complexity) for a
project that uses just three parts?
WTF are you talking about ?

Without the battery or LED, three parts. You didn't follow
and I guess we can leave it there, then.

You didn't answer my question.

 

[Eeyore]

Jon Kirwan wrote:

Besides the fact that these are kids, Graham

What makes you think kids read Usenet, let alone even know of its
existence ?

Graham

 

[Eeyore]

John Fields wrote:

Don't you mean: "of using"?

Yes

But, in that vein, why would an Allen-Bradley carbon comp resistor
made in 1945 not work now, and perform to spec.?

Or, for that matter, a 2N2222 made a dozen years ago?

If they haven't been stressed in a high temp environment designed for a
specific lifetime like a CFL they probably will be fine. By the way,
when did you find either in a CFL ?

I bought new parts for the vast majority of my hobby projects.

---
Bullshit.

Why is buying new parts bullshit ?

You bought what you could get, and whether they were "new" parts was
the least of your concern.

I was dealing with authorised distributors already at age 16 and buying
parts in quantity to get price breaks. My hobby had already moved to
small scale manufacture.

Graham

 

[Eeyore]

Jon Kirwan wrote:

I've often wondered about aging issues.

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

Graham

 

[Jon Kirwan]

On Fri, 27 Aug 2010 02:34:22 +0100, Eeyore
<rabbitsfriendsandrelations@removethishotmail.com> wrote:

On Thu, 26 Aug 2010 14:46:14 -0700, Jon Kirwan <jonk@infinitefactors.org> wrote:

On Thu, 26 Aug 2010 22:14:20 +0100, Eeyore
rabbitsfriendsandrelations@removethishotmail.com> wrote:

Jon Kirwan wrote:
On Thu, 26 Aug 2010 16:51:06 +0100, Eeyore
rabbitsfriendsandrelations@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.

Besides the fact that these are kids, Graham, it is exciting
for them to do something useful and fun with parts their
parents throw away. Kind of a segue to more. And it often
impresses their parents, which may for some excite them
towards further effort. And I can always help them at that
point, if they are interested in doing more.

I am on the ground, spending _my_ time in the trenches with
kids, Graham. I am dealing with what I have to work with. If
you'd like to come on over and help out, I'm all for it. And
I'd value your opinion on this more, then, because of your
direct experience with my situation.

What are _you_ doing, Graham, to pass on your knowledge and
interests to children?

Jon

What makes you think kids read Usenet, let alone even know of its
existence ?

Hmm?

I'm talking about _personal_ contact here in my local area
with real kids. I wasn't being serious about asking you to
fly out here and help me. My point there was that if you
were here, met the kids and saw the situation on the ground
here, I think you'd follow a lot better.

Jon

 

[Jon Kirwan]

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.

Jon

 

[Jon Kirwan]

On Fri, 27 Aug 2010 02:31:58 +0100, Eeyore
<rabbitsfriendsandrelations@removethishotmail.com> wrote:

Jon Kirwan wrote:
On Thu, 26 Aug 2010 22:15:51 +0100, Eeyore
rabbitsfriendsandrelations@removethishotmail.com> wrote:

Jon Kirwan wrote:
On Thu, 26 Aug 2010 16:51:06 +0100, Eeyore
rabbitsfriendsandrelations@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.
This coming from someone who thought I needed a capacitor,
didn't notice I needed a resistor, and wasn't sure about
mosfet vs bjt (which is a difference in complexity) for a
project that uses just three parts?

WTF are you talking about ?

Without the battery or LED, three parts. You didn't follow
and I guess we can leave it there, then.

You didn't answer my question.

Then you'll need to ask it better, I suppose.

Jon

 

[Jon Kirwan]

On Thu, 26 Aug 2010 20:26:35 +1000, David Eather
<eather@tpg.com.au> wrote:

snip
BTW do you
want to buy some LEDs - as long as your not fussy on the colour and buy
by the 1000's I know a guy ....
snip

If you are still interested in putting us in touch with each
other, feel free to contact me, directly.

Thanks,
Jon

 

[George Herold]

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.

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.

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)

George H.

 

[Jon Kirwan]

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