LED (Light Emitting Diodes) are inexpensive semiconductor devices that convert electrical energy directly into light . The heart of the LED is a semiconductor chip , one side of which is bonded to the top of the reflector cap , often called anvil . Anvil carries a negative current. The other side is connected to the semiconductor microwires often called hair / Fousek , which supplies current positive. This assembly is encapsulated in the same manner as the upper half of the encapsulating epoxy resin which is precisely shaped and acts as a lens which changes the angle of the beam or scattering .

A semiconductor chip consists of two parts, one is the P type semiconductor dominated region of the hole , and the second part is the so-called N -type semiconductor , which is controlled by the electrons. When they are joined together , is formed between the P and N junction. It is - when an electric current is applied to the chip via conduction, electrons are pushed through the intersection in P - area. There the electrons and holes meet and merge and release energy in the form of photons of light. That is why LED can shine . The wavelength (color ) of the light depends on the materials that form the PN junction , which are useful materials in the production of LED chip.

Led development can be roughly divided into three stages. First was the arrival of the red and green LED , and then came the blue LED , and then the white LED . Red and green LED , there was a few decades , but they all are monochrome , monochromatic ( single wavelength ) in nature. When used as a light source illuminated objects were all colored by a single wavelength and led away by the attention or they were often in conflict with natural lit.

It was a long, hard journey of discovery and development than Shuji Nakamura , a Japanese scientist , was able to achieve a light blue gallium nitride LED in 1993. This proved to be a decisive breakthrough in the development of LED . With the advent of the blue LED , RGB LED combinations enable new applications of LED technology means combining RGB is based on it and white lighting. Along with advanced control effort management to achieve full spectrum RGB LED projection . The advent of blue LED technology allow the use of different phosphors to produce white LEDs in 1997. The ultimate goal is the development of LED super - bright white LED light that can actually replace conventional light sources .

Small size - Led diode is essentially a microscopic chip zapoudzdřený in epoxy resin and as such is very small and light .

Lower power consumption - LED consumes very little power , much smaller quantities than standard light bulbs , leading to greatly reduced energy costs and extremely enhanced global savings Energy. LEDs also require far less energy to produce longer , leading to an even greater reduction in the impact of artificial lighting on the environment. In general, LEDs are designed to operate at 2 to 3 6V , 002- 003A current which means that the LEDs usually, does not need to function more than 0.1 W.

LEDs are rugged - LEDs are durable, strong and devices are not susceptible to vibration as classic incandescent lamps .

Long life - when operating on a specific voltage , current, and provided environmental conditions may LEDs have a long life of up to 100,000 hours . LM standards for LEDs are usually designed for L50/L70 , which means the life of 50 000 to 70 000 hours. This is the point at which the average person would consider light output as incomplete and considerably less than when it was originally installed . LM79 and LM80 -08 -08 standards are applied to the LED photometric testing to ensure proper electrical functions , to control the color temperature , thermal stability, and lumen depreciation over time , which falls within certain parameters.

High luminous efficiency and low heat output - Due to the special materials that are used to make the transition of electrons LED , LED emit mainly electromagnetic energy , especially in the visible part of the spectrum . This differs from conventional fibers that are heated and emit large amounts of electromagnetic energy in the infrared spectrum , which is invisible and can be felt as heat. This means that LED can convert much more energy transformed into light , and therefore are also higher LED luminous efficiency with substantially lower amounts of heat. It also gives the possibility of ice to a large extent influence the energy demand for cooling air in buildings and add a secondary benefit from energy savings .

Environmental protection - LEDs are made from non-toxic materials , unlike fluorescent lamps that contain mercury , which poses a danger to the environment and human health. LEDs are recyclable.

Unbreakable - Semiconductor LED chips are completely encapsulated in epoxy resin enclosed area , often in ceramic containers and encapsulated with an organic phosphorus , which are much more robust than traditional glass bulbs and fluorescent lamps. This is a semiconductor technology so that no loosening of moving parts, which makes the LEDs are virtually indestructible .