White LED color balance method?

I am trying to replicate some LED white balance hardware like this:


There are white LED strips containing alternating temperatures of LED light (such as 2500 kelvin and 6500 kelvin). By adjusting the brightness of each, you can achieve a range of white levels.

I have not had success finding information on this, and wondered if someone here already did this.

Some of these LED strips come with a sample reference chart showing the mix, so it may not be possible via a formula due to the dimming curve that LEDs have.

Any LED tinkerers out there even understand what I am talking about?


Same think could be done by mounting two LED strips parallel to each other. One warm white, and one cool white. Cross-fading between the two should be easy.

RGBW LED strips (with a cool white LED) could be another option. https://www.adafruit.com/product/2440 Leo..

It looks like that company is using RGB LEDs to produce white light in various color temperature. Normally white leds are sold by different color temperature (warm white/cool white). White LEDs produce white light using a specific white phosphor that is stimulated/energized by an ultra-violet LED emitter. To provide a spectrum of white light, you would need RGB LEDS.

If you want to use RGB LEDs to produce white lights of varying brightness, you will need to use gamma correction. You can mathematically calculate an appropriate PWM value once you determine the gamma correction value for each set of RGB values that produce white light of prescribed color temperature and similar brightness. Adafruit has a web page that explains the gamma correction (see page "Digging Deeper" and provides formula (in sample code) for gamma correction. ...



The program memory table example is just to speed up processing. In your case, calculating gamma correction by formula should work fast enough.