RGB = W - sort of

[sharpstick]

Considering that white LEDs are not very efficient at converting to white light, I am thinking of using separate R G and B LEDs to make a more efficient light source. I understand that it will have a somewhat spiky spectrum, but I've put RG & B together before and they make a reasonably good whitish light. The hardest part was balancing the light. I used a set of pots to balance the 3 colors. Using pots to adjust current regulators seems like it would be the best way.
I've searched the forum but haven't found this discussed before.

 

[2xTrinity]

Considering that white LEDs are not very efficient at converting to white light, I am thinking of using separate R G and B LEDs to make a more efficient light source. I understand that it will have a somewhat spiky spectrum, but I've put RG & B together before and they make a reasonably good whitish light. The hardest part was balancing the light. I used a set of pots to balance the 3 colors. Using pots to adjust current regulators seems like it would be the best way.
I've searched the forum but haven't found this discussed before.

Blue + phosphor white is presently significantly more efficient than RGB white in lumens/watt. Cree Q5 bins, and Luxeon Rebel-100 for example, are over 100 lumens/watt. Even with top binned red, green, and blue colored LEDs, I think you'd be hard-pressed to break 50 lm/W.

RGB may be a better way to go if you want adjustable color temperature, or the ability to switch to single colors by the end-user, but otherwise I wouldn't bother. If what you're after is a warmer color temperature (and better color rendition) than what you can get with phoshpor LEDs, I'd suggest getting white LEDs with a greenish tint to them, then adding a small red component to the mix.