CREE Xlamp XR7090WH K2?

I cant beleive it. This morning without warning I recieved 3 of these LEDs from CREE sans any type of payment. So what should I do with them before I burn them up? I need some advice a tutilage from an experinced modder.

send them to me for a trilux build!!!!!

Josh

!! I wish cree or other powerled makers would just send me free stuff!

I'm not familair with the cree part numbers, but they should be great performers. I wouldn't try to burn them up!

If anything you could build some sort of area lighting or portable flood lantern type thing with them... There are cree optics out there, but I forget who/where.

:wow: How do I get my name on that surprise mailing list?

1W cree white, 57 lumens at 350ma 4V typical.

http://www.cree.com/products/pdf/XLamp7090XR.pdf

Thurmond

LumenHound said:

:wow: How do I get my name on that surprise mailing list?

Click to expand...

Link for free samples:

http://www.cree.com/xlamp/Sample.aspx

Thurmond

:thumbsup: Thanks Thurmond.

I predict Cree will be getting a sudden increase in sample requests.

LED Crazy Overdrive.

Put LED in Freezer on Copper plate heatsink-cup for water
(which will be frozen)

Leave in freezer overnight.

Then put 200% the recommended amperage thru it and see what happens.

Bond wires will melt likely. Blow open like a fuse.

I noticed that they still have a rediculously high Vf. Even higher than a K2, and everyone is compaining about that. 4V@700mA is a little excessive.

evan9162 said:

I noticed that they still have a rediculously high Vf. Even higher than a K2, and everyone is compaining about that. 4V@700mA is a little excessive.

Click to expand...

If the LED is running on 4V and 350mA then it is NOT a 1W LED it is a 1.4W LED and that is a different thing.

4V x 0,350mA = 1.4W

What's your point? What people call 1W Luxeons typically dissipate 1.25W - why do you bother to bring it up?

The point is that a typical luxeon has a Vf of 3.6V at 700mA, and a typical Cree has a Vf of 4V at 700mA. This increases the power requirements of the Cree, and makes powering them more difficult than powering a luxeon.

evan9162 said:

I noticed that they still have a rediculously high Vf. Even higher than a K2, and everyone is compaining about that. 4V@700mA is a little excessive.

Click to expand...

evan9162 said:

What's your point? What people call 1W Luxeons typically dissipate 1.25W - why do you bother to bring it up?

The point is that a typical luxeon has a Vf of 3.6V at 700mA, and a typical Cree has a Vf of 4V at 700mA. This increases the power requirements of the Cree, and makes powering them more difficult than powering a luxeon.

Click to expand...

Actually, I have K2 production parts here which have 3.8V to 4.2V at 700mA.

Yes, I know they will slowly drop over the next 2,000 hours, with alot of it occuring in the first 60 hours. By 2,000 hours, it looks like you see the majority of the shift, but testing is still in progress...and they do continue to shift even after 2,000 hours, just not as much.

An example of a K2 burn-in, is found here:

Yeah, I'm supposed to get a few K2s this week, and I'm quite interested in learning seeing how high the Vf is and how much it drops.

What current did you burn the K2 in at?

1.5 Amps, reflow soldered directly (slug directly to copper plate) to a ~5" by 12" 1/4" thick plate of solid copper with a fan blowing over the plate, ~30 cfm, and the temperature of the plate was nearly room temp (doesn't feel warm at all).

All measurements are after the reflow soldering.

evan9162 said:

What's your point? What people call 1W Luxeons typically dissipate 1.25W - why do you bother to bring it up?

Click to expand...

Calling a Luxeon I a 1 watt is incorrect as well.

A typical Luxeon I with a Vf of H and driven at spec (350mA) is indeed very close to 1 watt (1.1 average), while a Luxeon III with a Vf of J driven at spec (700mA) is actually more like 2.4 watts average rather than the "3 watts" people have been calling them.

The more the voltage drops the less the "wattage" of the LED, but the higher the efficiency.

NewBie said:

1.5 Amps, reflow soldered directly (slug directly to copper plate) to a ~5" by 12" 1/4" thick plate of solid copper with a fan blowing over the plate, ~30 cfm, and the temperature of the plate was nearly room temp (doesn't feel warm at all).

All measurements are after the reflow soldering.

Click to expand...

Ah, darn. I was hoping it was at 1A or something, so we could eek out a little more by burning in at 1.5A. Maybe I'll burn 2 of these in at 1.5A with a fan cooled heat sink, then turn the fan off for the third and see what happens.

Melchior said:

LED Crazy Overdrive.

Put LED in Freezer on Copper plate heatsink-cup for water
(which will be frozen)

Leave in freezer overnight.

Then put 200% the recommended amperage thru it and see what happens.

Click to expand...

We hit them harder than that all the time and they don't need to be frozen. Running at 730 ma on open air aluminum heatsinks, no problems. Cree makes a good chip.