Color Changing LEDs provide stunning effects in lobbies, collaborative spaces, museums, or other common areas and enhance the experiences of employees or visitors. This article addresses the mechanics behind color changing LEDs and elaborates on some of the options and benefits of using color changing LEDs for desired outcomes such as the lighting we provided for the lion sign at the entrance of the San Diego Zoo.
Before choosing a specific color changing LED, it’s important to understand how they work. Let’s take a colorful walk down memory lane. You might remember from school that mixing blue and yellow color pencils on paper made green. And that primary colors are red, blue, and yellow, and you mix them to make secondary colors. A standard RGB color changing LED uses a very similar model of mixing primary colors. An LED is comprised of red, green, and blue colored diodes that are controlled by a microcontroller.
The color that lights up is dependent on which color the microcontroller turns on or off. For instance, when the blue diode is turned on, the light is blue. If both the blue and red diodes are turned on, the light appears as a shade of purple known as magenta. Furthermore, the combination of green and red yields a yellow color, the combination of blue and green produces cyan, and the combination of all three colors produce white.
Color shifts can be created by setting the percentage of brightness to gradually increase or decrease over time with the microcontroller. For example, if the red is on at full brightness, and the brightness of the blue is set to slowly increase from 0% to 100%, you will see a gradual color shift from red to magenta.
The brightness of an LED is dependent on how long it is turned on. For instance, if the amount of time the LED is on is the same as the time it is off, it will be on for 50% of the time and shall thus appear at 50% of its full brightness.
Likewise, a gradual color shift from red to yellow can be created, by starting with the red turned on and the green mainly turned off. When you gradually increase the percentage of the green turning on and off until it is mainly turned on, the red will appear to gradually shift to yellow.
All that being said, we chose to use an RGBW LED that uses four-color diodes (red, green blue and white) for the lighting in the San Diego Zoo lion in the picture shown above. We opted for the RGBW over the standard RGB LED for a couple of reasons. First, the white light emitted from the white diode in the RGBW is of much better quality. It shows as pure white whereas the white light created from combining all three colors from a standard RGB LED is a slightly bluish-white. Additionally, RGBW LEDs have the ability to produce soft pastel colors and temperature changes by mixing color into the white.
We opted to use a standalone 8-channel microcontroller with an RF remote. This enables the client to stand in front of the sign and fine tune precise shades of color for each portion of the sign. Each section of the sign can also be set independently, or all together if desired. Additionally, colors can be set to cycle and fade automatically. All these features not only allow a user to have the flexibility of setting specific colors, but also change color themes based on seasons and/or holidays such as pink for Breast Cancer Awareness Month or red and green for Christmas, etc…
While this 8-channel controller works very well for this situation, it’s important to note that there are other controllers that will work best for different scenarios. A DMX system, for example, can control many different light sources, all from one central host (usually a PC). Data is sent across a network to multiple controllers that will then decode the data and act according to the instructions from the PC. This is particularly useful for controlling lights to follow a programmed “scene”, usually for the purpose of syncing with music for a live event, concert or theme park setting.
In summary, it’s no wonder why color changing LEDs are becoming increasingly popular and are gradually being integrated into a whole array of modalities. Even though the technology behind color-changing LEDs is surprisingly straightforward, there are a few things to consider when choosing which type of color-changing LED and microcontroller will work best for your situation. For more information about incorporating color changing LED lighting into your next signage project or installation, contact us today.
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