A Question about Cree LEDs

curious boy · Dec 6, 2006

Last week,I got a CREE-P4. I run it at the current of 700am.
But now, I want to make it brighter.
So I want to know if CREE-P4 can be run at the current of 1000am safely.

TigerhawkT3 · Dec 6, 2006

I believe NewBie has posted a graph that shows current vs. voltage/output/something for currents of up to 2A. Also, UnknownVT's recent review thread indicates that the P1D-CE uses 1.46A on high, so even with a mere 65% converter efficiency (hypothetical!), that would be an amp through the LED.

McGizmo · Dec 6, 2006

The die is rated at 2 amps according to fellow at Cree. The reasonable limit on the package and lumen maintenance, beyond the 700 mA spec is not information shared by Cree to the public to my limited knowledge.

curious boy · Dec 6, 2006

I see. Thanks a lot!!

Pinter · Dec 6, 2006

I'm just testing my Cree XR-E P4 at 1000mA.
On my bike light the heatsink remains cold so heat is not an issue, outside temperature is 10 degrees Celsius, cold but not frosty.
So far, after nearly 9 hours of operation there is no measurable light degradation.

IsaacHayes · Dec 6, 2006

1amp should be safe. As long as heatsinking is good. You may shorten the life some, but it's still gonna be tons of hours...

curious boy · Dec 6, 2006

OK!
Tonight I will increase the current to 1 amp.
Thanks!!!

FirstDsent · Dec 6, 2006

Originally Posted by IsaacHayes
As long as heatsinking is good.

That is the only phrase you need from this thread. 1A will get hot. If you hold the Cree in the air and hit it with 1A it will smoke in seconds. Pull the heat from it effectively and it will be fine. Use some thermal paste. You can get it from the Sandwitch Shoppe, or Lighthound if you don't have some already.

Bernie

IsaacHayes · Dec 6, 2006

Or thermal epoxy. Keep it thin as possible.

I snipped the corners to break electrical contact from the bottom of one of mine, and used AA epoxy and pressed and slid it a bit to get it really thin on a pentium heatsink. It's not a huge heatsink, but has lots of fins. 1.3amp it only gets barely luke warm. Disconnect power and in seconds the heatsink feels ice cold again.

This is being built into a spotlight. I hope to have some time to day to work more on it.

Martini · Dec 6, 2006

curious boy said:
Last week,I got a CREE-P4. I run it at the current of 700am.
But now, I want to make it brighter.
So I want to know if CREE-P4 can be run at the current of 1000am safely.

I don't think it matters what time you use it; the results should be the same. :laughing:

I'm sorry, I couldn't help myself...

A Question about Cree LEDs

curious boy

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TigerhawkT3

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McGizmo

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curious boy

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Pinter

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IsaacHayes

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curious boy

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FirstDsent

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IsaacHayes

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Martini

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