really cheap Cree XR-Es

scottv

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Feb 28, 2007
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I got some of these MR16 bulbs off of ebay
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=200084157834

unit comes apart into
1-1/4" diameter circuit board/aluminum plate with 3 Cree XR-Es
3 Lenses (~9 degree ?)
350mA constant current driver that'll take anything from .5 to at least 12V (didn't test it higher) Driver has the MR16 pins soldered directly to it and is buried in thermal grease (?)

plus the plastic base, aluminum shroud, front plate and screws

The price seems to vary alot and there is another Cree MR16 version on ebay that I haven't taken apart.

It was way less than the individual LEDs and a driver circuit from any of the electronic suppliers

I got this *after* I spent $75 on 4 XR-Es and two drivers

ScottV
 
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Monolith

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Be careful of the tints. Each of you are pointing to different tints. The 10 pack is for 3,000K (warm white) versus the single 6,000K (cool, cool white).
 

scottv

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I got a 5 pack and made an offer

Bulbs ended up being 30.56 each with shipping a month ago.
The seller indicated that the price would come down as the newness wore off and supply stabilized.
I've seen the other type go for $20 + shipping (the one I haven't disassembled)

I'm working on a bit of silliness for Burningman (portable streetlight) but figure the LEDs will eventually end up in a solar lighting system.
 
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vinsanity286

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any idea of what bin these lights are? And is the lumen rating really that different between cool and warm tints? It would be nice if it gave the leds around 750ma but it should still be nice and bright. Does anyone know how efficient the driver is at around 4.8 volts? I am thinking it would make a decent bike light. thanks!

Just found this one http://cgi.ebay.com/CREE-LED-Par30-Par38-lamps-Warm-White-Daylight_W0QQitemZ130083855684QQihZ003QQcategoryZ42225QQrdZ1QQcmdZViewItem

7 emitters claimed to be warm tint p4 bin for only $60 with free shipping. Sounds like a hell of a deal to me but there is not much info on the page.
 
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scottv

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Feb 28, 2007
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I goofed

I measured the voltage drop across the terminals after running the MR16 for 3 days on an 8D battery set and got .5V

uhm . . that was the wrong way to check it.

It's a 12V driver

I hooked the bulb up to a monster DC power supply.
At around 4.7 it starts up but dim
it gets brighter until around 9V where it seems to hold about the same brightness up to 12V
i didn't push it above 12, again
 

vinsanity286

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Thanks for setting things straight. I have wanted to use these crees as a primary or auxilary vehicle light ever since they came out and something like that 7 emitter setup like I posted looks perfect for it. Quick somebody buy it and tell me how it works:whistle:
 

WeLight

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Sep 28, 2005
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As Cree have not released the XR-E in warm white I would be very skeptical

Cheers
WL
 

scottv

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I would guess bottom of the bin.

There's no indication in the packaging or on the subassembly.

But I have some P2s that are a bit brighter using the same 350mA driver.

I think the bulb would make a great headlight
It's a strong spotlight - if a bit lumpy.

I really like it with the bare circuit board.
The illumination is really even and wide. They're so bright that it's a useful amount of light in nearly a 90 degree spread.

It does get hot at full brightness. After 24 hours on eveready Ds the brightness dropped off and the bulb was not even warm. Ran like that for another 48 hours.

I've got some 250mA drivers on the way. Guessing that It'll extend the battery life and also the LED lifetime through less heat. Am I the only one that thinks 50 lumens per LED is still a lot of light?
 

ksonger

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Dec 30, 2006
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i ordered one of these in a standard base and it is VERY bright. I used it to replace on of my track lights in the kitchen and the wife complained that it was blue and was too bright, hurt her eyes. I have one of the warm lights on order. this particular dealer is willing to sell wholesale and would, i am sure, agree to set up a group buy for some combination of warm/cool, standard base, mr16 etc.

amybe i should set up a beam shot comparing my jetbeam c-le! :)

ken
 

scottv

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Feb 28, 2007
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Another neat thing

The LEDs aren't surface mounted
they're just tacked on with solder on the top of opposite sides
thermal grease underneath
Makes it easier to "repurpose" them
 
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