5W White Lamina BL4000

[georges80]

Well, after getting a sample of the BL4000 and testing it with my various drivers it was time to put it into something.

Using a FlexiLED head and machining up a longer body with some ridges to increase cooling area I dropped the BL4000 into it. Adjusted the height of the 'pedestal' to put it into the reflector's sweet spot and thermally epoxied it all up.

I then used an nFlex (configured to 700mA) in a small case at the end of the locline. Added in a 12V jack so I can plug it into any 8 - 24V DC source and it was ready to go.

Excellent artifact free beam due to the way Lamina makes their 'dome' and with the FlexiLED head I get a nice 60 degree spread. Perfect for use as a tasklight and with nFlex I can adjust the output level as required.

Here's some pics.

The idea is with ~ 12" of locline I can just 'wind' it around any handy object and adjust the head to where I want it to point. Next camping trip I'll 'test' it out in real use. It is BRIGHT /ubbthreads/images/graemlins/grin.gif

george.

 

[evan9162]

Got a shot of the BL4000 bare? Is it an array like the BL2000 and BL3000, or is it a single large power LED ala Luxeon?

 

[MR Bulk]

Hmmm, now what new project could I use a few hundred BL4000s in?

 

[IsaacHayes]

Yeah I'm confused as to how the led is made too...

 

[georges80]

lamina ceramics bl4000 will reveal all. It's basically similar to a Star in concept - so you just thermal epoxy it down and wire it up.

Lamina doesn't do 'bare emitters', after all their technology is the metal/ceramic packaging.

george.

 

[jtice]

hmmm, the BL4000 is a small emitter huh?

odd how the BL2000 is fairly large, then the BL3000 is huge, then this BL4000 is even smaller than the BL2000 /ubbthreads/images/graemlins/banghead.gif

 

[evan9162]

Yeah, I should have looked at the Lamina website first.

The best thing about this guy is the thermal resistance: 2.5-3.2C/W J-Hs. At 700mA with a good heat sink, Tj is in the 40-50C range.

Compare that to 8C/W for a Luxeon V. It looks like a series/parallel, or at least series arrangement since the Vf is in the 6-8V range, but typical Vf values are higher than with a Luxeon V.

Lamina's datasheets are a double-edged sword. For one, they don't give you an absolute maximum current (so you don't get a good idea of what's bad for these) - the only guideline is that you keep Tj below 125C - if that statement holds true, then it's good news for those of us that like to push the envelope driving these to their ragged edge.

Best case, heat sink held at 25C, and with typical thermal resistance of 2.5C/W, Tj Max = 125C, then we could push 40W through one of these! /ubbthreads/images/graemlins/eek.gif

The Vf/If curve looks strange, it usually changes very little with high currents, but here it's quite linear. If that trend holds, the last place on the graph is 1200mA, 9V for 10.8W.

At 10.8W, we're at about 52C Tj, light output is reduced to 90%, non-temp corrected output would be about 190 lm. Temp corrected output around 170 lm. This with the heat sink held at 25C.

So, back to the 40W thing.
Big assumptions ahead!

Assuming the Vf/If curve holds true, maximum junction temperature will be reached at 2.8A, Vf=13.8V. The graph doesn't go anywhere near that current level. Anyone with a light meter feeling adventurous???

 

[IsaacHayes]

So this looks small enough to fit into a mag reflector perhaps and might just get a tight beam?

To me this is just a better version of the 2000, since it puts out a little more lumens in a smaller package. Perhaps they'll have a BL6000 smaller version of the 3000 with as many lumens?

 

[OddOne]

Based on their typical numbers, it's about as efficient as your typical first-gen white LED - 22lm/W. With Lumileds coming out with their second-gen in a month or two (maybe) and Cree already selling theirs, Lamina needs to get some much more efficient LED dice into their packages. Or, better, Lamina needs to license their C.O.M. tech to Cree, etc. and let them make 60lm/W LED plates. /ubbthreads/images/graemlins/grin.gif

This may be the year of the LED if these manufacturers can pull it together...

oO