LEDs are light-emitting diodes, which have the characteristics of ordinary diodes, and can also convert electrical energy into light energy, which can emit visible light when excited by direct current with a certain voltage value.
Compared with traditional lamps such as incandescent lamps and fluorescent lamps, this kind of lighting source has lower energy consumption, no harmful radiation, and longer use time. It is an energy-saving, environmentally friendly and economical lighting energy source.
However, due to the influence and restriction of many factors, the detection and evaluation of LED lamps are still in a relatively lagging state, which limits the large-scale use of LED lamps.
Strengthen the in-depth research on the detection standards, evaluation methods and detection technologies of LED lamps, aiming to promote the wider application of this new type of lighting energy.
Basic composition of LED lamps
LED lamps are mainly composed of 5 materials, which are bracket, chip, silver glue, gold wire, epoxy resin.
The core component of the LED is a semiconductor chip, one end of which is fixed on the bracket, and the other two ends are respectively fixed on the positive and negative pins, and the chip is encapsulated by epoxy resin. LEDs are made of I-IV compound semiconductor materials such as gallium phosphide and gallium arsenide.
The choice of semiconductor material has a direct impact on the color of light emission. Different materials have different light emission colors, and the forbidden band width of PN junction is also different, so that the wavelength of light is also different. different colors of light.
Common such as high-brightness monochromatic LED, ordinary monochromatic LED, super-brightness monochromatic LED, etc., the semiconductor materials are gallium arsenide aluminum arsenide, gallium phosphide, phosphor indium gallium arsenide.
LED lighting principle
LEDs have general PN junction electrical characteristics related to reverse cutoff, forward conduction, and breakdown. At the same time, under certain specific conditions, it can make it emit light. Therefore, it also has the light-emitting characteristics that the general PN junction does not have. In light-emitting diodes, the most important component is a semiconductor chip. The semiconductor chip is mainly composed of an n-type semiconductor and a p-type semiconductor.
The transition layer existing between the two is the PN structure. Based on the relevant knowledge of the semiconductor physical energy band theory, when the forward operating voltage of the LED is added, the majority carrier and the minority carrier combine with each other. emitted, which in turn produces light. On the contrary, when the negative voltage of the LED is applied, the minority carriers cannot be injected, and they cannot combine with the majority carriers, so they cannot emit light.
LED lighting testing standards
IEC 6203 1:2008 is the first LED safety testing standard in the industry. The standard was published in IECTC34/SC34A in 2008. After that, many LED lighting standards were published one after another.
LED lamps have semiconductor characteristics, which are quite different from traditional light sources in terms of color and luminous flux. Therefore, at present, there is no unified classification standard for LED lamps.
The lack of corresponding standards to regulate the detection of LED lamps will lead to confusion in the development of the industry, and the promotion and popularization of products will be seriously affected. At present, the implementation of LED lamp inspection is mainly based on “GB700.12002 General Safety Requirements and Tests for Lamps”, “Enclosure Protection Level (IP Code) GB4028-93” and “Measurement Method for Integral LED Street Lamps” as a reference; the inspection items are mainly: Electrical performance parameters, optical parameters, structure and appearance, reliability test.