Making Your Own RGBW LED From Individual LEDs

[itsdonny]

I can't find a bright enough RGBW LED for a project I'm working on, aside from the fact that they're expensive, so I was thinking to use 3 Cree XB-D Red, Green and Blue LEDs and then either a white XB-D LED or something brighter for the white. (I'm open to suggestions). If I put the 4 LEDs adjacent to each other will this work well? Has anyone tried it? My main concern is good color blending and keeping the heat down. All of this needs to shine through a 30mm lens. I'm pretty sure i would have to have a custom designed optic here. Does anyone have any connections with someone who designs optics for LEDs? I don't know that I have the funds at the moment to hire a firm. Thanks for any advice.

Don

 

[MikeAusC]

Why do you need a custom optic ? I've tested many standard lenses that work well with LEDs.

Do you want all 4 LEDs to shine through the one lens ? Unless you want a very wide beam, there's no lens can be made to do that.

4 lenses would work to produce a narrower beam.

 

[SemiMan]

I can't find a bright enough RGBW LED for a project I'm working on, aside from the fact that they're expensive, so I was thinking to use 3 Cree XB-D Red, Green and Blue LEDs and then either a white XB-D LED or something brighter for the white. (I'm open to suggestions). If I put the 4 LEDs adjacent to each other will this work well? Has anyone tried it? My main concern is good color blending and keeping the heat down. All of this needs to shine through a 30mm lens. I'm pretty sure i would have to have a custom designed optic here. Does anyone have any connections with someone who designs optics for LEDs? I don't know that I have the funds at the moment to hire a firm. Thanks for any advice.

Don

I am going off memory, but I think it was Polymer optics that has a special 4 - LED mixing assembly designed to perfectly mix four colors into a single beam. If you can't find it PM me and I will contact a colleague who will know. It was designed to use 4 Luxeon Rebels which in themselves are designed to but together in groups of 4 closely.

Optic design is expensive ... as is manufacturing. Mixing colors such that you have no color shadowing is very difficult as well. $10,000 for a design is not a lot, prototypes at hundreds "each", and $10K for a single cavity precision mold. Color mixing requires precision, it is not a casual optic design/manufacture.

Semiman

 

[anuragwap]

I've read horror stories about Polymer 230 optics at aquariumreefledlighting.com (unfortunately its down now). Apart from flimsy construction, the user reported poor color mixing and poor light transmission, as significant angle of view of the LEDs was obstructed by the surrounding plastic. So he had to file it off to fit to the quad rebel pcb, the end result was still horrible in terms of mixing. (I remember his layout was slightly different from the Polymer recommended one, but that shouldn't have created the problem as the spacing among the LED domes was right)

An old CPF thread describes poor experience with another optic from this company. If you are still brave enough to experiment (and design your own MCPCB as recommended in the polymer 230 datasheet), you can get it from here (watch the high price!).

Khatod too had introduced their rebel line of color mixing optics (KEPL1241xxA) sometimes around 2009, nowhere to be found now. I've written to them requesting samples, but didn't get any reply.

 

[itsdonny]

Thanks guys for the input and links! I did find the polymer optic: http://www.polymer-optics.co.uk/Luxeon Colour Mixer Range.pdf

By their photos it seems to do a pretty decent job. It may be worth experimenting with if I go that path.

I found the khatod color mixing optics too. Here is one example for those interested: http://www.khatod.com/Khatod/view_p...6W183JE,_NCSW119_LEDs_with_Black_Holder,461,1

Thanks again!

 

[SemiMan]

I've read horror stories about Polymer 230 optics at aquariumreefledlighting.com (unfortunately its down now). Apart from flimsy construction, the user reported poor color mixing and poor light transmission, as significant angle of view of the LEDs was obstructed by the surrounding plastic. So he had to file it off to fit to the quad rebel pcb, the end result was still horrible in terms of mixing. (I remember his layout was slightly different from the Polymer recommended one, but that shouldn't have created the problem as the spacing among the LED domes was right)

An old CPF thread describes poor experience with another optic from this company. If you are still brave enough to experiment (and design your own MCPCB as recommended in the polymer 230 datasheet), you can get it from here (watch the high price!).

Khatod too had introduced their rebel line of color mixing optics (KEPL1241xxA) sometimes around 2009, nowhere to be found now. I've written to them requesting samples, but didn't get any reply.

It was the 230 that I was thinking of. I did not realize it was such a tight beam (5 degree half width I think).

I have a polymer optics demo in my hand and found the color mixing to be quite good. The efficiency is low, mid 60's percent if I remember.

Like any optic, if you do not have exact optical placement, you will run into issues. That includes x, y, and z axis. Narrow beam optics tend to be even finickier.

I am not remembering the Khatod equivalent to this. I will be at Lightfair. They normally have a booth I can stop by and ask.

Semiman

 

[itsdonny]

Strange, I replied to this thread and it didn't go through.

Anyhow, I didn't realize the efficiency was so low when you mix colors with an optic. Perhaps the XM-L would be a better choice even though it costs more.

 

[idleprocess]

Does Cree still make the RGBW MC-E? I would think that might produce somewhat tolerable results through a single optic.

 

[uk_caver]

Cutter still seem to list it as available.

Regarding optics in general, I'm sure there's a good perspective to think about them from, but I'm not entirely sure what it is.
Possibly I should start a thread with a few questions I have?

 

[Illum]

Does Cree still make the RGBW MC-E? I would think that might produce somewhat tolerable results through a single optic.

this? http://www.ledsupply.com/creemce-rgbw.php

Not very bright compared to todays standards