Color Characteristics of LEDS

There’s an array of different LEDs that are available in the lighting market today. The diverse LED characteristics comprise of light color or radiation wavelength and light intensity among other features. 

These color characteristics are as a result of an assortment of factors during the manufacturing process. Factors such as semiconductor make-up, fabrication technology used, and encapsulation are also important in determining the LED color appearances.

Understanding LED colors

Color is a fundamental feature of light emitting diodes (LEDs). Initially, there were a limited number of colors available for these fixtures. You could only find red LEDs.
However, as technology advanced, there have been significant improvements in LED materials and colors.

Color Characteristics of LEDs: Color Temperature

One important aspect of color appearance is color temperature, which exemplifies how cool/bluish or how warm/yellowish technically white light appears. CCT Correlated Color Temperature (abbreviated as CCT), is actually a metric correlating the source of light appearance to a pre-heated theoretic dark/black body appearance. As a black-hued body gets hotter, it becomes red, orange, white, and ultimately blue. The CCT value of a light source, provided in Kelvin (K), represents the temperature at which a hot black body closely matches the light source color under investigation. It symbolizes the color of emitted light and not that of illuminated objects.

What is Color Rendering Index (CRI)?

Metrics Color representation has numerous distinct forms, including reference based systems, gamut based systems, and systems which are built upon sophisticated color appearance models.
CRI refers to a measure of fidelity (that’s how ‘true’ a certain light source is when related to a reference source), but it doesn’t address the issue of color appeal and discrimination.

Chromaticity and LED Colors

Chromaticity refers to an objective interpretation of the quality of color irrespective of its luminance. It consists of two distinct parameters, often described as colorfulness (s) and hue (h). For a specified CCT, a light source with a positive Duv value has a chromaticity which falls above the locus of the blackbody (appearing slightly greenish), while a source featuring a negative Duv value has a chromaticity which falls below the locus the blackbody (appearing slightly pinkish).

The Influence of LED voltage drops

The LED voltage drop often lies between 2 and 4 volts. The actual voltage that occurs across the two terminals is highly dependent on the type of LED/materials used and influences the color of LED in question.

As expected, the voltage curve of an LED broadly resembles that of a forward diode characteristic. But once the diode is switched on, the voltage becomes relatively flat for various forward current levels.

LED Characteristics: The Summary

The following table gives a summarized insight concerning LED color characteristics.

Wavelength Range In NM	Color Of the LED	Voltage(V) at 20MA	The Type of Material
Blow 400	UV(Ultraviolent)	3.1 to 4.4	AIN, AlGaN, AlGalnP
400 to 450	Violet	2.8 to 4.0	GaP,AlGalnP
450 to 500	Blue	2.5 to 3.7	lnGaN
500 to 570	Green	1.9 to 4.0	GaP, AlGalnP
570 to 590	Yellow	2.1 to 2.2	GaAsP, AlGalnP
590 to 610	Orange or Amber	2.0 to 2.1	GaAsP, AlGalnP
610 to 760	Red	1.6 to 2.0	AlGaAs, GaAsP, AlGalnP

Below 760

Infrared

Below 1.9

GaAs, AlGaAs

Besides LED color, the following are other major LED specifications:

• Light intensity value( denoted as Iv)

• Current vs. voltage specification

• Reverse voltage

• Angle of view

LED Specifications for Operational Life

LED’s light intensity doesn’t diminish with time. What this implies is that LEDs have a specific operational life. This specification helps determine the application of different kinds of LEDs. LED specifications are determined by the following formulas.

L70% = The time taken for a 70 percent illumination (this is also known as lumen maintenance)

L50% = The time taken for a 50 percent illumination (also known as lumen maintenance)

Note: According to LED standards, your LEDs shouldn’t exhibit any major shift in chromaticity.
These figures’ rationale is that 70 percent lumen maintenance is equated to a 30 percent light output reduction. This’s an approximate threshold figure required to detect to gradual light output reductions.

LED CEILING LIGHTS: THEY WILL REDEFINE YOUR LIVING ROOM

LED lighting is one of today’s most efficient and rapidly-developing technologies. They last longer, offer better light quality and are more durable. Like any other diodes, they consist of a semiconductor material doped with certain impurities to create a p-n junction. Current flows smoothly from the anode (p-side) to the cathode (n-side) not in the opposite direction. When an electron collides with a hole, it automatically falls into the lower energy level and generates photon energy.

The benefits

LED ceiling lights exist in different sizes and shapes, with excellent fittings available for any room. Whether your home is stately or terraced, you can utilize these lamps to positive effect. The type of illumination you’ll get not only looks attractive, but it’s economical. They last much longer than traditional bulbs and consumes up to 90 percent less energy. The possibilities of LED ceiling lights are endless. It doesn’t matter how small or big your house is you’ll always find something that perfectly matches your needs.

Why You Should Consider Them

LED ceiling lights are ideally suitable for applications which are subject to recurrent on-off cycling, unlike traditional lamps that quickly burn out when cycled frequently.
• They can easily be turned down or dimmed
• Installation is quick and very simple. A common indicator will attain full brightness in microseconds.
• They don’t contain mercury, unlike fluorescent lamps
• They are relatively small in size and are easily fixed onto printed circuit boards.
• Being solid state devices, they are difficult to get damaged with external shock, unlike incandescent and fluorescent bulbs which are fragile.

Light emitting diodes are the latest and most sensational technological developments in the lighting industry. They are small, compact light bulbs which are exceptionally energy efficient and durable.

Amazingly Efficient and Energy-Saving

Additionally, LED lighting offers several other advantages, including longer life (60,000 hours), reduced maintenance cost, lower energy consumption, and increased safety. Currently, they are being used for numerous applications- automotive, residential lighting, broadcasting, industrial automation, aerospace, entertainment, and electronic instrumentation.

Also, they are extremely energy efficient and use only a small fraction of the energy consumed by fluorescent lamps; there’s dramatic reduction in power costs. Since they don’t incorporate delicate components like glass and filaments, they’re able to withstand vibrations, shock, and extreme temperature.

Safety and Color

LED ceiling lights produce virtually no heat hence they can be left on for several hours without harmful effect if touched. They generate 3.4 BTU’s/Hour and reduce the potential risks of burns and fires.Moreover, they are fabricated with non-toxic materials, unlike conventional lighting options that use mercury which may cause danger to the environment. Also, they are recyclable and earth friendly.

LED ceiling lights are available in a wide range of colors- red, blue, amber, and green. Since incandescent bulbs use filters to generate colors, they’re extremely inefficient. Note that they can be combined to create millions of colors that can bring more elegance to your kitchen, bedroom, or even bathroom.

Check Out Lumens Not Just Watts

Image Courtesy - Luxtg.com

One of the biggest mistakes so many people make when they buy light bulbs is that they focus on the watts. We all know that the less watts, the more efficient the bulb will be, which will save money in the long run.

When it comes to buying LED bulbs, you should also focus on the lumens. The lumens relate to the amount of light and brightness the bulb produces. In most instances you will buy a light bulb based on the amount of energy it will consume, which is why LED bulbs have become a popular choice throughout the world.

We are now advising you that the watts isn't the only deciding factor you need to consider when buying energy efficient light bulbs which are going to provide you with years of illumination and use.

Understanding Lumens

In order to understand lumens, you need to get a good understanding of what they are. Lumens measure the amount of light you will get from the light bulb. Remember LED light bulbs give you a focused light and you want to be careful that you don't overdo the amount of lumens, which is going to give you a much brighter light than you may have been anticipating.

The best rule of thumb is the more lumens a bulb has, the brighter it is going to be. If you want a lower light and more ambiance, then you choose a bulb with less lumens.

Rule of thumb

When it comes to lumens, you get to buy the amount of light you want.

Example:

• 60W bulb = 800 lumens
• 40W bulb = 450 lumens

Comparisons

Now if you want a lighter and softer light and you usually use 40W bulbs in your bedrooms and living areas, then you know you need to look for a bulb offering 450 lumens, but still most people will also want to focus on the watts, which is completely understandable.

Watts determines how much energy you use and we all now know that LED bulbs are more economical than the traditional bulbs on the market. At the same time when buying LED bulbs, you can focus on lumens and watts and will find that you can buy a 450 lumen bulb in a number of different watt strengths.

A 5W bulb is guaranteed to save you more money in the long run than a 7W bulb, if they are both 450 lumens, they will provide the same amount of light, just at a different energy rate.

Knowing how to calculate the LUX level for any Room can come very handy while choosing any LED lighting systems; therefore learn How to calculate the LUX level in a Room.