Luxeon Q, observations and testing

I'm sorry, I keep being inaccurate ;-) , I did measure 260 lumens at 1A for the XP-E2 R3, like the graph said. But mind that these measurements are done with my other power supply (a Kert, which I think is an ok one) that is difficult to set to the desired current, so a 1A reading could have been anywhere between 0.97 and 1.03A, this also creates some (minor, but everything adds up) noise in the numbers.

In theory, there are reasons enough to think of to distrust every bit of my amateurish set-up, but on the other side, the fair amount of measurements on various leds I have done using this set-up do produce numbers, trends and graphs that do make enough sense to suspect that it is not working that bad overall. For instance, if the currents that I read out would be off from a certain value on, I would see that reflected in a bump in the output-graph and the voltage-graph. But I don't see any of that. So apart from everything not calibrated well, and all numbers surely being off by a few percent I think that I sort of trust what I am measuring.

But it may be time to buy a very decent multimeter (instead of the ok multimeter that I have, it is not the worst of the worst, i paid 60 euro's for it at the time) for current measurements, so that I do not have to rely on whatever the power supply in use tells me. It is asked before on BLF, but does anyone have a suggestion for one that is not a 200+ dollar Fluke or Agilent (I can afford up to maybe 60 dollars), and does measure up to 10A accurately without introducing too much resistance? (I can make some monster-size leads myself :-) )

You have 60€ multimeter and you don’t trust it?
I have UT-71C and it was best price/performance at the time (maybe it still is,don’t know what’s popular these days). For <60$
this one looks good:
http://www.ebay.com/itm/UNI-T-UT-61E-Modern-Digital-Multimeters-UT61E-/300672753978?pt=LH_DefaultDomain_0&hash=item46017e213a
Good precision+true RMS.

hi, i currently work on…let’s say “dedoming device” so i’m in for giveaway, it will be interesting to try and slice something other than xml… :stuck_out_tongue:

Thank you for your research! I like to read about different LEDs; datasheets are boring. :bigsmile: I would like to try one of these Luxeon Q LEDs.

the giveaway, it just ended , and there's winners. 10 people showed interest, and I added Comfy because I guessed he would not mind one either :

random.coffeefilterholder.org did its magic on these names:

And the winners are:

I think that it would be neat if texaspyro puts one in his sphere as well, so I will send a sixth one to him as well . Winners, please PM me an address, I will send the leds on monday or tuesday.

[quote=djozz]

removing the phosfor at the sides of the die will produce a narrower beam, but the illuminance of the die (and thus throw) I expect not to increase. If you remove the surrounding phosfor straight up to the die there will be blue light leaking from the sides (should be cool looking in a reflector light )

[/qoute]

A hobby is there to try it all, and theory is not always what happens in reality, so here I went :

The result in stereo (@ Hbomb: the way I make these stereo pairs is just taking cell phone pictures through the left and right eyepiece of my stereo microscope):

I put the trimmed led in my Uniquefire UF-T20, and throw did improve, but just a bit: 73 klux@1 meter now, still way less than a dedomed xpg2 or xpe2. The hotspot was indeed much nicer without the yellow around it:

Last thing was to put the pill into a Convoy C8 host with a (Fasttech) smooth reflector that I have waiting for a friend's project. And the pill does not fit, wrong threading! A Fasttech C8 pill does not fit a Fasttech Convoy C8! (you C8-addicts thread boys already knew this of course). But with some fiddling and the bezel not quite screwed down I got it working for the test, I got 66 klux at 1 meter throw, with a OTF output of 376 lumen. (the C8 addicts I believe got around 100klux at 3A from a dedomed xpg2 or xpe2, up to 125klux with a xpg2 at higher amps) :

Nice hotspot though :

Well, it was nice messing about again with the led, but still no shock and awe compared to what is already there I'm afraid.

So it's not enough that you torture and kill emitters with current? You have to also slice and dice them? You, are a very very bad man.

Great work and pictures. Thank you for this excellent exploration into the Luxeon Q. I wonder if the manufacture will take note of your work. I hope so.

Thanks for the give away. PM will be incoming.

Oh, and very cool using a paperclip as a cutting guide. I think I'll be stealing that one... :D

for the giveaway.

I'm very happy to have the opportunity to measure a few things on the Luxeon Q (output and Vf @ 350mA, Tint color coordinates xc,yc and the final OTF output at perhaps 1.75A). I have an Integrating Sphere and a Color Analyzer to my disposal. I will post the results here when done.

Thanks djozz. I stand by my original post. Amazing dissecting on the led. There is not a hope in this world it would work again if I went near it with a scalpel.

Sure there is… just practice on yourself first… J)

Excellent slicing & dicing!
You had fabulous pictures already & now an animated gif?
The forum doesn’t accept animated avatars, right? :smiley:

thanks for the answer djozz. The images work perfectly with my semi-crossed vision :slight_smile:

I have.

Ugggh, I hate it when that happens… there goes half your love life for a while… J)

Ouch! That happened not long ago

In fact, I believe it does, Johnnymac had one, and a few others.

MRsDNF, buddy, I think you need leather work gloves. Don’t want to ever cut a tendon. :ghost:

That cut was pretty deep, yes?

Djozz: Yea, Johnnymac’s shinning eyes!

Yay I won!! :party: Thank you for the giveaway!

Nice LED surgery too! :bigsmile:

Ouch!! :_( Can you get some kevlar gloves? I want a pair now I know they exist, for my knive sharpening. I don’t think even level 5 can protect from cutting machinery though.