Luxeon III

From the recent posts I've read, nobody is terribly impressed with the 3W Luxeons. Are they just relabeled 1W LS's with a little better thermal management? Has anyone had really good results with one? Do they really put out the specified Lumens when driven to 1A?
Thanks,
Rob

Rob,

As far as I am concerned, the III's are everything the 1W is with the unproven but suspected as well as purported ability to take higher levels of current and make photons instead of phonons.

Do they "really" put out the lumens? Well, got an integrating sphere we can use to see? /ubbthreads/images/graemlins/tongue.gif /ubbthreads/images/graemlins/grin.gif

- Don

We use them in the TriLight-III, and internally, they look different than the 1w parts - the phosphor seems to only coat the die, and not everywhere

Light output is very impressive, and color also

the 1w hd and se luxeons have the phosphor coated only on the die also, whereas the 1w ld's are the only leds that are using the old process of filling the entire cup.

This is what happens when I direct-drive a Luxeon III (in royal blue) off two 123s and aim a camera at it.

The camera flash, which was set to high, DID fire. (Forced the camera to ISO 200, F2.8, high flash for this pic.)




I like the Lux 3s, as they're more safely overdriven IMO than the 1-watters were. They appear to be built to deal with overdrive conditions better. And the output is, to the eye at least, commensurate with rated specs.

oO

Here is a picture of the TriLight-III, 3x3w Luxeons

http://www.inretech.com/pictures/TriLight-III.jpg

How much current went through that RB led, OddOne?

Just put a SYOLW 3W in a Blaster III, direct-driven without any restistors.

Had two Blaster III's that were pretty much the same (both Q2KW). Both are direct-drive. Having just finished comparing the two in the dark backyard, I have to conclude that the throw and overall amount of light appears to be pretty much the same.

I MUST say that I had always thought that these two Blaster III's seemed to be very white. Compared to the 3W, however, the 1W now appears almost YELLOW. When used independently, however, either one is still one heck of a light.

In conclusion, based upon my statistically insignificant sample of ONE, the 3W appears to be nothing more than a very decent binned 1W. This, by itself, though, is probably worth the $$.

Maybe I'm a little slow, but how come no one is comparing the 1 watt Luxeon at it's rated current (~350ma) to the Lux III at its rated current (~700-1000ma). That would be comparing apples to apples don't you think? Then you could say the new L-III is brighter when driven at spec.

Hunterson,

We know it's a given that a LED driven harder *WILL* be brighter. That is less of an apples to apples comparison. The big reason comparisons are being made is that people have been driving 1W parts at 700+ mA for a while now. The question is, what benefit is realized when driving the Lux III's at 700+ mA compared to the 1W parts. We're slowly seeing very little increase, if any, in the brightness department. The bottom line is that a good 1W (Q or R flux) driven to the same level as the 3W ratings will yield similar results. On my sample of one, I couldn't tell the difference between an SYOLW 3W to a Q 1W driven close to 700mA. If I can get Q or R's cheaper than the S or T 3W parts, I'll take the money to the bank. As we see more and more 3W parts being used, we'll have a better picture of what truly the differences are.

CM

I still don't remember any official claims that the high binned 1 watt emitters should be any brighter than the L-III's when driven at the same high currents. The L-III's are just rated to survive at these currents for a specified time while, all other variables being equal the 1 watt units probably won't last as long.

Now the difference in a led lasting 10000 hours or 50000 hours is nothing to the people on this forum as our obsession with new advances will surely make the lights obsolete long before they fail.

However if the part is going in a car's tail light or a traffic light then the robustness (is that a word?) of the emitter plays an important part.

Since the 1 watt emitters have been driven at 2 and 3 times their rated current and survive with proper hear management, can the L-III's survive at higher the rated current, say 1500ma to 2000ma? Or will they be limited to the same ceiling as the 1 watt emitters and start producing more heat and less photons past 1000ma?

Please take my speculation with a grain of salt as I am still relatively new to all of this and have only the information available from previose posts I have read.

Dave

CM, upon reading some more posts I have repeated alot of things you and others have said, sorry about that.
Some times it is best for me to dummy up and read before offering an opinion. Carry on as if I weren't here.

From what I understand of the manufacturer's notes, the major difference would not be in the resultant brightness when comparing the LS1 and LS3 both being driven to the same level (700mA or 1A). The LS3 has a few tweaks which make it better able to withstand the high current without popping, so perhaps the benefits maybe that there is less heat being generated? Or that it can handle bad heatsinking better?

I believe the area that have not been checked, and which should be, to be able to properly comment on the benefits of using a LS3 over a LS1, is thermal management. Given a LS1 and LS3 driven to the same levels, how much heat is produced? How hot can the LED get before it pops? I believe that this is where we will really see the LS3 performing better than the LS1.

Afterall, the phosphor can only be energised to a certain level. After that, it is diminishing returns. So the little bit of extra energy that is not wasted as heat and is therefore available to create more phonons, doesn't really make much difference as the phosphor is already pretty much energised to the max. Perhaps that is why most people say the LS3 exhibits a whiter shade of white /ubbthreads/images/graemlins/wink.gif ?

Hunterson,

No apologies needed at all. There's a LOT of posts and sometimes wading through them can be frustrating. Keep asking, and we'll keep (or try to) answering /ubbthreads/images/graemlins/smile.gif

CM

In my light, the RB Luxeon III is taking 1.36-1.38 amps of current at 6VDC. So, it's pushing up into the 8-watt area when you factor the junction resistance into the equation. After about 5 minutes of operation the flashlight body is detectably warm, and at 10 minutes it's very warm but not offensively so.

I think that the L3s are going to handle the kind of overdriving that would instantly damage a 1-watter. If not for that, they wouldn't be anything spectactular compared to the first generation.

oO