Principles of LED technology
- Principles of LED technology
- Benefits of LED technology
- Features of LED technology
- LED Application Guide
The basis for light generation inside a Light Emitting Diode (LED), a solid-state semiconductor, is the conversion of electrical energy directly into light.A light-emitting diode (LED) is a two-lead semiconductor light source. It is a basic p n-junction diode, which emits light when activated. When a fitting voltage is applied to the leads, electrons are able to recombine with electron holes within the device, releasing energy in the form of photons. This effect is called electroluminescence, and the colour of the light (corresponding to the energy of the photon) is determined by the energy band gap of the semiconductor.
Benefits of LED technology
On this page you will find an overview of the characteristics and benefits of LEDs. In the various indoor and outdoor applications different advantages will be important.
In general :
- More energy-efficient than incandescent and halogen lamps
- Much longer life, up to 50,000 hours
- Reduced maintenance cost
- No unwanted IR or UV radiation in the beam of light
Unique LED advantages :
- Design flexibility, hidden compact light sources
- Directed light for increased system efficacy
- Robust, vibration-proof, solid-state lighting
- Less light pollution due to precise optical control
- Dynamic colour control
- Fully dimmable without colour variation
- Instant switch-on at full colour and full lighting level
- Install and forget for a long time
High luminous efficiency
- No hazardous metals e.g. mercury in the light source
- Safety and low temperature:
- Low voltage DC operation
- Highly efficient in cold environment
- Cold start capability down to -40°C
- Sealed for life waterproof luminaires
LED light source is a unidirectional lamp - house, whose light is very concentrated, and it can be utilized by 77% in the case of the actual utilization of photo synthetic efficiency without any mirrors and can be further improved with lens (For example, the utilization efficiency of LED light source street light overpasses conventional light source lamp at least an increase of about 15 - 30 percentage. Only this is quite saving electricity (about 15 - 30 percentage).
Long life is another important advantage of LED light source, when 70% of the LED light output in 50kh. It has 1.5 times long life than that of the traditional long life metal halide lamp light source. If lighting for 12 hours per day, LED can be continuously used for about 1 1.5 years. When there is 50% of the LED Light output in 100 kh, so LED cab be made with virtually no need for changing the light source lamp all the life.
Traditional light sources burn all the way to a sudden end of life, and the life of LED is no obvious point. It can always go bright, but as times goes by, the brightness will be of an extremely slow decline.
LED light source emitting in the startup process is only electronic transitions causing electro luminescence with no change in material or physical state, so the time from the power to the light - emitting can be to nanosecond (6 - 10 seconds), and it is free to frequently switch, mean while switch frequently will not affect the light source life.
Conventional gas sources usually have a longer start - up time (typically minutes or seconds class), and because of the traditional light sources emitting light in the process accompanied by material’s physical changes, frequent switching the light source would have a significant impact on life expectancy of light source.
There is low - temperature startup difficult problem with the ordinary gas discharge lamp or the start will be a longer warm - stage because gas is not easy to be ionized under low temperatures. LED is a light - emitting device and completely ignore the existence of such problems. Under low temperature LEDs start - up times has no difference from that under the normal temperature. What's more, the temperature will decrease the junction temperature of LED and its brightness is going to rise. Under low temperatures, the brightness will increase by about 10%.
Because of DC power of LED and the brightness changes with the supply current, it can be achieved to change the LED brightness adjustment as long as to change the supply current. For DC power supply, it is very easy to adjust the output current, so it can be very convenient to the realization of LED dimming with the ratio from 0% - 100%. And you can save at least 30% of the electricity at the different time settings for different light level.
Maintenance - free
As the LED light source has a super long life, lamps made with LED light source do not have to replace light source within 10years, which eliminate the periodic maintenance of light work. We can see LED lights and high - pressure discharge lamp cumulative cost comparison during 10 years. Although the initial cost of LED light is 2.5 or 3 times than the traditional light source light, with time lasts, the traditional light source need to be replaced frequently, and the cumulative costs become step - like increase. Three years later LED light on the advantages of low maintenance costs began to be obvious, and ten years later the cumulative use of LED lights costs are only about half of the traditional lamp.
LED light source does not contain Hg, Pb, or any other heavy metals, so it will cause no environmental pollution; and because of long life of LED light source, lamps in use within the framework of life - cycle do not have to replace the light source, and it will not produce the same cyclical trash as that of a traditional light sources. It will achieve a truly comprehensive environmental protection.
High Color Rendering: More natural colors
The color rendering index (CRI) is a quantitative unit of measure that defines how well a light source reproduces the colors of various objects faithfully in comparison with an ideal or natural light source. The CRI is based on a 0-100 scale. A high CRI is crucial in surroundings where natural colors are required. The higher the color index, the better colors appear. Although an EN standard lays down certain legal requirements for CRI, it is generally the application that determines the required CRI value. Ultimately, however, it is the user who decides what CRI is most suitable for the application in question.
Light sources with a high CRI of at least 85 are desirable in applications such as :
- Shops and Malls
- Food Lighting
- Operating Rooms and Surgery Lamps
- Direct or Indirect Lighting for Advertising Purpose
- Underwater Lighting (e.g. for Filming or Diving)
The European standard ENI 2464-I, which lays down the lighting requirements for offices and indoor workplaces, prescribes a CRI of at least 80. Since these LEDs have a CRI of up to 94, they are well suited to offices, indoor workplaces and environments where natural colors are desirable. Moreover, our LED portfolio displays high CRIs throughout the color temperature range and color spectrum.