Luxeon K2 in place of Luxeon 3?

[Chrontius]

I've got a rather underwhelming purple-tinted Pelican M3 LED with a Luxeon star in there which is probably glued down tight.

For a first LED mod, I want to swap out the emitter for something else. I understand SSC is a better drop-in replacement for Luxeon than Cree due to beam profile, but what about a Luxeon K2 TFFC? With the same driver as the Lux3, what sort of percentage increase can I expect? If the current one is being driven around three watts, what will the K2 do for me?

 

[tebore]

The K2 won't physically fit where the Luxeon 3 was, however if the area isn't specially shaped for the luxeon 3 that's not a worry. The K2 doesn't need isolation for the slug like the P4. The K2 has a slightly wider beam, so the reflector doesn't need to be changed much. I believe the K2 TFFC's die is slightly lower than the old Lux 3 so you might need to shim it.

The K2 TFFC is about 2x as bright as a lux 3. I believe the Efficiency of the K2 is around that of a U-bin P4. It's not the most efficient LED that's a given but it's tougher than a P4 that's for sure. Compared to Cree I'm not sure. The K2 can take a lot of current and was designed that way. The P4 not so much current, it's pretty much comfortable at 700mAh, it's boundaries are pushed when you push 1amp.

The K2TFFC also has better color/tint than a P4. The P4 especially the U2 bin has a mean corona of yellow around the hotspot. The K2 has a uniform tint.

 

[Chrontius]

The area is a roughly circular area designed for a generic black-box LED with the reflector designed for a certain height. All I need is two little indents (any star will provide) for wires.

Hm. Luxeon datasheets give a typical height of Luxeon 3 stars at 7.36 mm and Luxeon K2 TFFC stars as 7.7.

 

[tebore]

The area is a roughly circular area designed for a generic black-box LED with the reflector designed for a certain height. All I need is two little indents (any star will provide) for wires.

Hm. Luxeon datasheets give a typical height of Luxeon 3 stars at 7.36 mm and Luxeon K2 TFFC stars as 7.7.

The physical body package sits higher but the where the die sits is what's going to decide the beam. I know the die in the TFFC sits lower in the body than the plain K2. Hopefully someone with experience replacing Lux 3s with K2 TFFCs will chime in.

 

[darkzero]

The P4 especially the U2 bin has a mean corona of yellow around the hotspot.

I hate that with the U2s. I rather use the U1s.

 

[Chrontius]

I was afraid of that... I'm pretty sure it'll still fit, shim and all, but I am a little bit worried. Is a K2 a better idea than a SSC? And is a Rebel entirely out of the question?