How Well Do You Know about Color Temperature?

Knowledge about color temperature

Color temperature is always mentioned in designing lighting devices, such as warm white, cool white, 3000K and etc. Therefore, two color temperature dimming is applied in the design of LED driver apart from simple brightness dimming. But for the following questions, can you give clear answers?

What does color temperature of 3000K mean?

What’s the difference between warm white and cool white?

How to apply different color temperature in different applications?

What determines the color temperature adjustment function of lights?

How does the two color temperature light adjust the color temperature?

Just 2 minutes, Lifud tells you the answers.

1. Definition of color temperature

Color temperature, a unit of measurement of the color components contained in light source, presents the color change of a black body being heated from absolute zero (- 273 ℃). When reaching a certain temperature, the spectrum of the black body is the color temperature of that temperature, conventionally expressed in Kelvins (symbol K).

Therefore, the color of the light with 3000K color temperature is the color of black body radiator at the temperature of 2727℃ (2727+273=3000). The color temperature of the light emitted by common white light is generally 2700K-6500K.  Theoretically, after being heated, the black body will gradually change from black to red, yellow, white, and finally emit blue light. Therefore, the lower the K value, the more yellow the color of the light presents, and the higher of K value, the closer the color of light is to blue.

2. How does color temperature influence your emotion?

Please look at the following picture.

Did you feel the magic of color temperature? For the same scene, different light can give you a completely different feeling. Generally, the closer the light color is to red (the lower the K value), people will feel much warmer and excited; more blue and white (the higher the K value), people will feel much colder and flat. That is the origin of warm white and cold white.

Meanwhile, according to the rhythm of the human body adapting to the natural light color temperature (as shown in the figure), warm light has a pleasant somnolent effect, while cold light will make people awake.

Therefore, color temperature can be used to create different atmosphere. For example, warm light used in home for a cozy environment, and the office should use cold white to improve work efficiency. This is the effect of lighting design combined with color temperature effect on human body rhythm.

3. What determines the color temperature?

Here comes the last questions: what determines the color temperature of LED light and why tunable white light can be called as two color temperature light?

Although the tunable white light is controlled by the LED driver, the color temperature of the lights is mainly determined by the lamp beads (LED light source). Generally, there are two output channels of warm white and cold white in the light, each of which is independent. By providing different proportion of current to each channel, the two channels can emit different brightness light inside the light to form different color temperature and achieve the effect of color temperature adjustment.

For example:

→Two groups of light source: color temperature of warm white is 3000K and cool white is 6000K. Maximum output current of the driver is 1000mA.

*When the driver provides current of 1000mA for the channel of warm light source and 0mA for the cool light source, then the color temperature that the light finally presents is 3000K.

*When the driver provides 500mA for both channels of warm and cool light source, then the color temperature that the light finally presents is around 3300K. (Lifud will share the calculation process in future article.)

*When the driver provides current of 0mA for the channel of warm light source and 1000mA for the cool light source, then the color temperature that the light finally presents is 6000K.

4. Type of color temperature adjustment

The color temperature adjustment includes segmented adjustment (such as three-stage and four-stage color temperature adjustment) and stepless dimming and tunable white. Both ways are realized by the driver. Taking Lifud LF-GIFxxxPA as an example, the driver has set three ratios of dual output current, and the color temperature of three gears can be changed by DIP switch (button). LF-GSDxxxYG is stepless dimming and tunnable white, which can realize the smooth change of color temperature in the range of 2000K-7000K (the maximum value of the actual color temperature variation range is determined by the LED light source of the light).

The above is all that Lifud wants to share with you today. Are you clear about color temperature now?

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