Luxeon 5W

[PeLu]

Dear lightlovers,

you probably made all your own measurements already .-)

First sample gave the following results:

All measured with a photogoniometer.

At 6.15 V and 700mA (=4.3W) 130lm
nice lampertian light distribution and light colour of 5500 K (less bluish than most of the Nichia with the usual B colour code)

without optics ~40cd peak intensity.
'Old' optics fit (sample has no optics), giving a 2 by 6 degree 'flat' beam.

At 100 uA it is still possible to read with it.

At 50mA efficiency seems to be at 45lm/W (compared to 27lm/W at 700mA).

At 30mA it gives much more light as 3 white Nichia at 20mA (should be about the same power, maybe a little less for the Luxeon).

My opinion is, that it is a good LED even when there is no need for 130lm (or too less power).

P.S.: I will have no time for CPF as I had the last half year and will probably not read any messages. I spent much much more time using LED lights than debating about them .-)

 

[Klaus]

Thank you so much Peter for the first report on the 5W LS !

Klaus

 

[hotfoot]

Yes, Peter - Thanks!

Did the rest of you see his numbers - 130 lumens @ 4.3W! Wow!

I'm really now just wondering what 5 watts of heat really feels like when its dissipating to your hand via a 2CR123 flashlight the size of an X5....

 

[Chris M.]

I'm really now just wondering what 5 watts of heat really feels like when its dissipating to your hand via a 2CR123 flashlight the size of an X5....

Ever experienced the SureFire E2 / E2e? This is a 5 watt light too, and gets rather warm after a few minutes "on", and downright hot after 20 minutes or so. About the smallest size you could accomodate a Luxeon LED and batteries too. I think it should work with adequate heatsinking arrangements, even if only restricted to short bursts of under 3 minutes in the case of homebrew lights. Whether SureFire themselves can pull it off as a commercial product remains to be seen.

I heard rumors that SureFire, who were exhibiting at a trade show in Germany recently, had a prototype torch on show using the 5 watt Luxeon, but it was described as being "maglite sized" and getting rather hot and dim after only a short time. If this was true, I`d guess it was a crude proto thrown together to show off the LED and not yet a viable torch design. PK never responded to an email I sent asking about this (he is a busy guy I suppose), so I can comment no further.....


By the way- Nice to hear from you again Peter, hopefully you`ll get the chance to drop by now and then in the future to share your wisdom among us.

 

[hotfoot]

<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Originally posted by Chris M.:
Ever experienced the SureFire E2 / E2e? [/QB]<HR></BLOCKQUOTE>

No...

I *have*, however, just had the privelege of trying out the 18-LED Luxeon flood unit, though. The one I tried was mounted on a heatsink the size of a diesel-truck piston and didn't even get warm - I figure the that's because the heatsinking was excellent and that the unit was under-driven (or "merely" driven to spec - it's just that a lot of us are now used to overdriven LSs).

The flood didn't seem all that bright either - maybe 2-3 times as bright as a 4W fluorescent tube. The color reminded me of those mercury street lamps.

I might try to mildly overdrive it to see how much this guy can pump out...

I'd really still prefer the 5-watters, though - the smaller footprint alone would be worth the price. Don't think the 18-up will be around much longer as a Lumileds product now that big brother's here