visual difference between lumiled 1 vs. 3

[photorob]

So I have a pile of leds laying around and over time with all these soel and cree modding they have piled up. I've come into a dilemma now though. How can you tell the diffence between the lux 1 vs. the lux 3's.

 

[evan9162]

For red/red-orange/amber: The Lux III has a visibly larger die (the chip inside)

For all others:

Batwing (low dome) emitters are only Lux I

Lambertian (high dome) and side emitters: For emitters made as emitters (not freed from a star board), there is absolutely no way whatsoever to differentiate a Lux I from a Lux III emitter. Niether physically or electrically. A lux I and lux III emitter are physically identical, and you can't discern them through any electrical test either.


If an emitter has fat power leads, then it is a Lux III that has been freed from a star board.

 

[chesterqw]

well, run 1.5amp at 3.5v on all the luxeons.

those who survive are luxIII and those who didn't are luxI.

am i smart or what

 

[photorob]

I did notice that the bottom of the leds did have a noticeable difference. Some of them have oval bottoms, some have round. I just don't know what that means.

 

[ginaz]

are we talking stars or emitters? i seem to recall lux 3 stars being somewhat thicker than lux 1's.

 

[evan9162]

I did notice that the bottom of the leds did have a noticeable difference. Some of them have oval bottoms, some have round. I just don't know what that means.

The round slugs are a new design elment - they are appearing across all luxeon I/III/V products. There's no distinction there

 

[skalomax]

well, run 1.5amp at 3.5v on all the luxeons.

those who survive are luxIII and those who didn't are luxI.

am i smart or what

Somewhat

 

[wasBlinded]

well, run 1.5amp at 3.5v on all the luxeons.

those who survive are luxIII and those who didn't are luxI.

am i smart or what

Unfortunately, that won't work either. LuxI and LuxIII emitters are probably exactly the same. Some are binned and sold as LuxI and some are binned and sold as LuxIII.

There was a time in the past that the LuxI had an aluminum slug while the LuxIII had a copper one. That gave a heat dissipation advantage to the LuxIII. Today the emitters sold as LuxI also have copper slugs, so no difference.

Lux1 stars do have a thinner MCPCB than LuxIII stars, but still the emitters themselves are essentialy the same.