Cree XR-E vs Luxeon K2 in USA?

FWIR the K2's aren't super efficient anyways, but yes, the efficiengy WILL go up as the current is droped.
Jeff

WildRice said:

FWIR the K2's aren't super efficient anyways, but yes, the efficiengy WILL go up as the current is droped.
Jeff

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I was looking at the data sheet and it should be ~ 50Lumen/Watt is that right @ 350ma?

Yeah if you look at the data sheet, it shows the efficiency curve. Not cooincidentally, both the suggested nominal drive level and the most efficient drive level are both 350mA.

The American Cree dealers can be found on the Cree website.

the cree shown in the link above shows that you can have it mounter to a Star MCPCB would it then be the same form factor as a Luxeon Star as far as all the height, length and depth measurements? In other words if I boagt a 700Mah driver and hooked it up to what I current ly have a Luxeon Star in should it fit. And the Crees are not suposed to be driven at over 700Mah right. its 70-80 lumens at 350Mah and suggested 140-160 at 700Mah right?

thefish said:

Where can I get my hands on a Cree XR-E and an optic for it? I know http://www.cutter.com.au/proddetail.php?prod=cut651 has them but I would rather order it from the USA and not have to pay exchange fees to my credit card. Also what is the efficiency of a 120 Lumen rated (1000ma) K2 if it is run at 350ma?

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Its my understanding that the K2 needs 1500ma to get the 120 lumens, if it is fed 1000ma(like most Luxeon 3) it is a tad more effecent than a Luxeon 3 but also only puts out Luxeon 3 lumens ie 80-90 at best. As the K2 uses less and less ma's it becomes pretty good at lumens efficentcy at least against the lumileds line of leds, but if you want those 120 lumens it needs 1500ma, and I'm not sure that there are drivers for it so direct drive like in the Mags is the only way to feed it, but I'm a nuby so forgive all this if its horse pucky. I have ordered 2 K2 Stars but now I think my Flash Light is only going to drive them a 1000ma because it has a regulator in it, there are a ton of 700ma regulators that would push the Cree to its 140-160 lumens max as long as it can be made to fit the Luxeon Star Form Factor at least for my light

thefish said:

Where can I get my hands on a Cree XR-E and an optic for it? I know http://www.cutter.com.au/proddetail.php?prod=cut651 has them but I would rather order it from the USA and not have to pay exchange fees to my credit card. Also what is the efficiency of a 120 Lumen rated (1000ma) K2 if it is run at 350ma?

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Led lighting supply is the exclusive distributor for eastern USA and Canada : http://ledlightingsupply.com/ledlightingsupply/index.htm

For the west coast the distributor is : ETG Corp.
http://www.etgtech.com/

SuperTorch said:

Its my understanding that the K2 needs 1500ma to get the 120 lumens,

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Are you sure that 1500mA can make the K2 get the 120 lumens
What's the forwarding voltage for it
I have K2 with Vf 4.2V
and not sure if I put 1500mA current on it will K2 be burnt down.

SuperTorch said:

Its my understanding that the K2 needs 1500ma to get the 120 lumens, if it is fed 1000ma(like most Luxeon 3) it is a tad more effecent than a Luxeon 3 but also only puts out Luxeon 3 lumens ie 80-90 at best. As the K2 uses less and less ma's it becomes pretty good at lumens efficentcy at least against the lumileds line of leds, but if you want those 120 lumens it needs 1500ma, and I'm not sure that there are drivers for it so direct drive like in the Mags is the only way to feed it, but I'm a nuby so forgive all this if its horse pucky. I have ordered 2 K2 Stars but now I think my Flash Light is only going to drive them a 1000ma because it has a regulator in it, there are a ton of 700ma regulators that would push the Cree to its 140-160 lumens max as long as it can be made to fit the Luxeon Star Form Factor at least for my light

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Hello SuperTorch

A K2 will ermit about 100 Lumens at 1000mA.
A LuxIII U-bin about 100 Lumens at 700mA. So it's not right to say, that the K2 is more efficient.

Best regards

____
Tom

I based it off of these numbers from this K2 Star

http://www.luxeonstar.com/item.php?id=2213&link_str=&link_catg=&partno=05027-PW14

but my caculations are never very reliable so take it for what its worth.

I thought the Luxeon III at 1000ma and the K2 got about 90 lumen at 1000ma and that the K2 is actualy overdriven Luxeon III's. The Luxeon V can get about 120L out of 700ma and it shows the Luxeon III emitters at 1000ma at 80 Lumens.

SuperTorch said:

I thought the Luxeon III at 1000ma and the K2 got about 90 lumen at 1000ma and that the K2 is actualy overdriven Luxeon III's. The Luxeon V can get about 120L out of 700ma and it shows the Luxeon III emitters at 1000ma at 80 Lumens.

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SuperTorch, the K2's and the Luxeon's are different products.
A LuxIII U-bin is rated at 700mA and the output is 87,4-113,6 lumens.
A LuxV W-bin puts out 147,7-192 lumens at 700mA.

Bin Codes Explained

I prefer anytime a U-bin LuxIII against a K2. Besides the better efficiency you can be more sure about the tint of the beam.
In the past, the luxeon-lottery was a big game but in meantime the development progressed.

Also the costs dropped down for premium leds, unless the K2's are still cheaper.

Best regards

____
Tom

Where can I buy a Lux V W bin Star?

Here.
Lux V