suggestions for higher power white LEDs to testing?

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.

I expect to buy perhaps a couple of dozen LEDs to make up a 'representative' variety that hobbyists are actually using in practice. But I'd like to add some interesting types, as well. For example, some with ball lenses in front. I only want to test with singles -- none of that 'tristar' stuff. (Probably, the 1W range limits that, anyway.) Operating currents in the 350mA to 500mA should be the bulk, but I also want to buy one or two 1A LEDs, just to play with. I also want to include a few at the extremities of color temperature, but the bulk should be in the 5500K-6000K range, I think. (I'm ignorant of what is going on in that area, so advice here is also good.) I'd like to get picks from various manufacturers, too. And based on various technologies and phosphors. I'd like to stay with ones that are known to last -- no point testing LEDs that rapidly age. And I'm concerned about overly complex heat sink situations, though I won't mind buying premade supplies for that if they are available, so some advice on this score for some LEDs that may be SMT and not so conducive to my jury-rigged setups may help in making selections where the LED is an SMT type may help me here, too.

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

Reply to
Jon Kirwan
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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%).

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Cats, coffee, chocolate...vices to live by
Reply to
Ecnerwal

lots of Chinese stuff - so just the thing hobbyists are playing with

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Reply to
David Eather

my fav company

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also carry a wide range of good quality (and some more typical quality) high power leds.

Reply to
David Eather

Any experiences with specific LEDs from there in the watt area I'm looking for?

Thanks, Jon

Reply to
Jon Kirwan

My only problem with dealextreme is that they owe me $60 still for product they never shipped, after more than a year. They told me, only about 60 days after they decided they couldn't ship, they couldn't refund the money to paypal (which I can't dispute, one way or another) and simply asked me to find something else to replace. However, there is no way to access that, anyway. No 'credit balance' I can include in a new order. I have to go through long, drawn out emails on the mere hope that somehow someone will maybe connect an old debt with some later purchase, if and when I decide to make one.

This isn't considered "okay" in my book. They could write me a check.

Jon

Reply to
Jon Kirwan

I had trouble with a refund too. A product missing one of the advertised features. I had to write it off and decided that I would deal with them as if they offered no warranty of any kind.

Reply to
David Eather

No. I used a few 1w amber LEDs for experiments into outdoor lighting - amber and red don't seem to attract many bugs. A friend bought 7000 standard amber LEDs to finish the experiments, duly delivered with no problems. I've also used a few 1w red LEDs for other things. They seemed to be a little static sensitive and sometimes the construction was not top notch (average soldering, a lens fell off, but at least they were correctly orientated on the heatsink)

Reply to
David Eather

That's an interesting experiment to try out. Did it work out the way you expected?

This was 7000 of the 1W ambers? I'm trying to imagine both powering as well as dissipating that and can't imagine this was a hobby... unless rich, time on hands, and a quirky idea in mind.

Hmm. Not exactly stellar. Were those also from that site?

Thanks, Jon

Reply to
Jon Kirwan

Okay. That's not quite the same thing as simply not refunding nor sending product. But I take the point.

Jon

Reply to
Jon Kirwan

Yeah only a few bugs - much better than an incandescent, very much better than a florescent. Amber is also much better than red for stuff like barbecues (food prep) and reading outdoors etc. But red does attract the fewest bugs.

7000 standard 5 mm (high intensity with a ridiculously highly focused beam) - I thought the 1w was the better approach. But yes he had too much time and a quirky idea in mind - nothing came of it. 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 ....

Yep. Average Chinese stuff. Hobbyist grade. I should clarify the soldering. It looked OK, I had no doubts it would work for the lifetime of any project, but I have seen better soldering. If it looked like it might have caused a failure or been faulty itself I would have called it bad soldering. Perhaps serviceable or workman-like is the better expression.

Reply to
David Eather

Makes sense.

I'm imagining an airport runway lighting....

I'm probably interested. Obviously, it'll be about reasonable value and I'd like to get at least _some_ whites in the roughly 1W power I mentioned if I go that route.

But yes, my LED supply is not very large and I'm interested in doing more, now.

Got it.

Thanks, Jon

Reply to
Jon Kirwan

Unlikely to be useful component values for the purpose. Plus components like electrolytic caps are likely to be end-of-lifed by the time a CFL fails. The mosfets and rectifiers might be OK but that's about it. Any inductor / transformer will be compromised by the fact you'll have no info on the material and value / ratios unless you measure it.

Suggest design from scratch.

Graham

Reply to
Eeyore

Um. I did design from scratch and I've already done all this.

I use the larger transformer for magnet wire. That's all. There is a tiny (usually yellow, or somewhat darker) toroid. That gets extracted and its wire is removed, also. The magnet wire I get from the larger transformer is then used (only a small part is needed) to wind the toroid.

The CFLs I have here use BJTs. They work fine on those units that are broken, with some rare exceptions. There are two of them and so far one has always worked. Even if it didn't, I'd grab one from another CFL. So it's not a problem.

I don't need the caps. They aren't required.

I do need a resistor. Sometimes, the ones inside are about the right value. Sometimes, I use one from my junkbox. But I can usually adapt the transformer design to cope with whatever I do find, if that were terribly important.

The LED I buy. Obviously. Since I posted about that.

This is a game I play with students to show them what they can do with junk and a little effort and knowledge.

Jon

Reply to
Jon Kirwan

Might be more useful to show them what they can do *without* using JUNK ! They might learn some REAL design skills.

Graham

Reply to
Eeyore

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=92s 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.

George H.

Reply to
George Herold

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Back again with your never-ending insipid shit, eh?

Just think about how easy it is to learn how to design with everything
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Reply to
John Fields

I see you've never been a child.

Jon

Reply to
Jon Kirwan

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

Jon

Reply to
Jon Kirwan

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?

Although I wouldn't imagine to know more than you do about audio amplifiers, Graham, I know more about this particular project than you do.

Care to be helpful, rather than critical? Can you offer some helpful suggestions about LEDs? Or would you prefer sharing in a little discussion with me about the REAL design skills involved, where it might help others to see your brilliance in action?

Jon

Reply to
Jon Kirwan

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