Using Cree at 1A without destroying Them ?

Hello,
Is somebody know if it's possible to use cree at 1A for long time without destroying them ?
Thank you

Cree LEDs are actually rated to handle up to 1A continually, provided you have adequate heatsinking (if you don't have adequate heatsinking, pretty much any current for a prolonged period can destroy them).

I am using a P4 Cree in my MrBulk Chameleon at 1 amp and 1.2 amps to the led, and it is holding up. Not running it for long at 1.2 amps to led, but that is my caution, it may not be yours.

Bill

Good heatsinking is the key to running them at >700mA.

CM, you did a good job re heatsinking my Chameleon. At 1 amp to led the overall light output is very stable.

Bill

perhaps a good real world test would be to get the U2 style Cree running at 1.2A from DX and try running it on high mode for a couple of battery cycles back to back.

I have run one at just over an Amp, it was mounted to a Computer Cpu heatsink,
keeping it cool is the key

Bullzeyebill said:

CM, you did a good job re heatsinking my Chameleon. At 1 amp to led the overall light output is very stable.

Bill

Click to expand...

It does help to have a LED with very low thermal resistance. The Cree's thermal characteristics make the Lumiled K2 look like a failure. Wait...the K2 IS a failure

The bigger question, and one I've yet to see answered, is: Is it worth it? That is to say: Will a CREE emitter produce enough more light at 1A than at 700mA or so to make the additional heat issues and reduced runtime worth it? I've seen two people suggest it wouldn't (in the LumaPower M1 sales thread). And it looks like maybe LP revised their plans to bump the M1 up to 1A directly after the Chinese Lunar New Year, suggesting perhaps they thought (more) testing was in order to determine that?

How hard would it be to strap a CREE emitter to a big heat sink and a variable power supply, set up measurement for temperature, current, voltage and total light output, and actually find out? Wouldn't this be the logical thing to do, rather than throwing darts with a blindfold on?

Certainly somebody here on CPF has the tools to do that, no?

SEMIJim said:

The bigger question, and one I've yet to see answered, is: Is it worth it? That is to say: Will a CREE emitter produce enough more light at 1A than at 700mA or so to make the additional heat issues and reduced runtime worth it? ...

Click to expand...

If you've seen Bullzeyebill's setup, especially the BBH on the VIP (sorry for the acronyms) the answer would be a definitive yes. The associated drawbacks of driving at 1A or more must be weighed by each individual user. No one else can make that judgement. Multiple level lights like the VIP or Chameleon or HDS lend themselves to driving the LED hard since you can always back off the level for typical usage. For those few times when you do need the output (for a particular task, or for the occassional wow factor to remind yourself that yes, there is a Santa Claus) the higher drive level is there just a click or two away.

SEMIJim said:

...How hard would it be to strap a CREE emitter to a big heat sink and a variable power supply, set up measurement for temperature, current, voltage and total light output, and actually find out? Wouldn't this be the logical thing to do, rather than throwing darts with a blindfold on?

Certainly somebody here on CPF has the tools to do that, no?

Click to expand...

Good question. Check Newbie's numerous posts. He has done a lot of characterizations of various LED's. He has driven LED's to 2A. Long term effects are difficult to quantify, Lumiled's has characterized their Luxeons and there's lots of data on lumen maintenance. The latest generation LED's have much better thermal characteristics than what's been characterized in the past so I only see things getting better.

hehe, liquid nitrogen to 5amp

of course, i didn't do it but hey, some one must be thinking the same as me, right?