Tunable led lights have emerged as an interesting alternative for building owners and facility managers seeking to reduce energy usage while simultaneously optimizing the use of their lighting systems. This adaptable approach to lighting results in an amenity that may significantly improve the visual perception of people, objects, finishes, and places.

So, what exactly is adjustable white lighting? Simply described, it is the white light output that can be modified in terms of both strength (light output) and color appearance (think warm morning to chilly afternoon). This allows for manual or dynamic changes in light brightness and white light shade for function, mood, or choice. Circadian-friendly lighting, activity signaling in schools, adjusting lighting to accurately visually represent a new interior design, calibrating color across areas, mixing electric light with daylighting, and more applications are possible.

Let’s start with some context: colors, or rather wavelengths associated with colors, make up light. A rainbow, which is white light refracted into its component hues, is a typical example of this notion. Red, green, and blue are the main hues. They combine to generate white light, which serves as the foundation for color perception. The hue or shade of white light output by a light source is defined by the relative concentration of wavelengths.

Color perception in white light is often stated in terms of correlated color temperature (cct), which specifies the hue of a light source and its emission in comparison to an idealized blackbody radiator. Light sources may be classified as optically warm (less than 3000k cct, peach-white) to neutral (3500k to 4000k, white) to cool. A standard incandescent bulb is regarded as warm in conventional lighting, but most linear fluorescents are considered cool. These white tones highlight certain colors in the area and define the color appearance of the light, which we identify with various emotions warm for closeness and relaxation, colder for work and learning.

Color options in conventional lighting were fixed dependent on the bulbs bought, unless they were altered to a new cct value or a color filter was applied. We get the very simple capacity of dynamically manufacturing practically any hue, including any shade of white light, using LEDs. CCT is modified by the interplay of LEDs and dimming controls, which result in tunable-white illumination.

Led color adjustment

There are three basic color-tunable led product options:

1. Full-color-tunable: These led solutions provide a wide range of rich hues, making them perfect for architecture and other comparable applications. Despite the fact that they can produce white light, their use in general illumination has been restricted.
2. Dim-to-warm: During dimming, these items automatically lower white-light cct to a visually warm color look, akin to an incandescent bulb. When a led bulb is chosen for its energy savings and efficiency, yet incandescent-like dimming is needed, this gives a fast and straightforward solution.

3. Variable white: These devices provide manual or automated cct modification throughout a predetermined temperature range from warm to chilly. This option is prevalent in general lighting and accent lighting, and is often applied using luminaires (light fixtures).

In theory, the technique for cct modulation in tunable white lighting is quite straightforward. On the board, two or more groups of warm- and cool-white phosphor-coated LEDs are used to create controllable arrays. The luminaire’s cct may be altered anywhere between the lowest and maximum led values by dimming each group relative to the other. Meanwhile, the intensity may be adjusted. To improve the colour range and assist colour rendering, more primaries (colour LEDs) may be added. As an added bonus, the product can dim to warm.

There are two methods for producing variable white operation. The most basic is to employ a warm-cool gamut. The relative dimming of warm- and cool-white LEDs results in a cct range that might be broad or limited. A more advanced technique employs a triangular/area gamut, in which the warm and cool primaries are augmented by one or more colors regulated by response algorithms. Instead of a straight line, a more triangular range is achieved, allowing the luminaire to better follow the curvature of white light along the blackbody curve and so obtain a greater degree of color control precision, as well as the capacity to generate new hues.

Tunable white lighting is often placed with a driver (which acts similarly to a fluorescent ballast in a led luminaire) that may include a color-mixing lighting controller, allowing for color and light output adjustment. Color and light output are controlled by input devices through an analog 0-10v signal, a digital wired interface, or a digital wireless protocol. A broad range of interfaces are available, comparable to those used in fixed-output lighting control. These include manual sliders and pushbuttons, touchscreens, and mobile applications, as well as programmed software control profiles in an intelligent networked control system.

What are the advantages of variable white lighting?

You may wish to adjust the lighting in your house, workplace, or business site for a variety of reasons. With the proliferation of lighting control options, many people have grown to anticipate the ability to modify illumination to some level. This is not only convenient, but it is also useful in many ways:

• Circadian rhythm & lighting your health
• Increased productivity 
• Better design

Light manipulation to control circadian rhythm

Circadian rhythm is the internal clock of your body. Our bodies are designed to recognize when to get up and when to sleep. Bodies are believed to have a natural rhythm that governs attention, sleeping, and eating routines throughout the day. Light intensity, timing, duration, and wavelength have all been demonstrated in studies to alter the biological clock of people.

Because so many objects around us now have lights, this routine may be easily disrupted. Have you heard about all the research that shows that staring at your phone before bed is detrimental to your sleep? That is about circadian rhythm. The bright chilly white on your face shortly before the night is bad for your circadian rhythm. Disruptions in this cycle may lead to a variety of health problems including sleep disturbances.