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Kind of. The really high efficiency LEDs are blue. The problem is with the efficiency of green LEDs. I suppose you could just use red and yellow LEDs and compl
by upofadown 11y ago
Kind of. The really high efficiency LEDs are blue. The problem is with the efficiency of green LEDs.
I suppose you could just use red and yellow LEDs and completely solve the circadian light problem. I think that such streetlights would be hard to sell.
- sp332 11y agoYou can cover the blue LEDs with yellow phosphor and get a subjectively "white" light, such as the Amazon Kindles. You could even cover that in a blue-reducing filter to make it much more yellow, but I don't know how bad the efficiency would be after all that.
- ars 11y ago> Kind of. The really high efficiency LEDs are blue. The problem is with the efficiency of green LEDs. Hu? That's not true. Blue is less efficient, not more. The lower the wavelength the more efficient (toward the red side of the rainbow). Also mono-color LEDs are MUCH more efficient than the ultraviolet ones with a phosphor (AKA white) ones. If you wanted efficiency then have red and green in an LED, and that's it. You don't really need full color at night.
- upofadown 11y agoEach LED technology has an optimal wavelength. The current tendency is to use blue LEDs and then make white light with phosphors so the development is mostly on the blue LED technologies. The green problem is caused by the lack of a technology. So you end up with bluish/green coming down from the blue side and yellowish/green when going up from the red side. That prevents really efficient RGB LEDs and makes the inefficient phosphor based white LEDs competitive. If you ever see a RGB LCD backlight you will see that there are more green LEDs than red or blue LEDs.