How to improve the reliability of LED intelligent lighting system

 

How to improve the reliability of LED intelligent lighting system

 

LED drive power of the low life expectancy is an important reason is the lack of the life of the drive power required for aluminum electrolytic capacitors, mainly due to working long hours and led lights inside the ambient temperature is high, resulting in aluminum electrolytic capacitors quickly consumptiondry, life is much shorter, generally only work about 5,000 hours. The LED light source life is 50,000 hours, the working life of aluminum electrolytic capacitors has become a life short rib led drive power of LED intelligent lighting system.

 

Now some vendors in order to solve this problem, the invention of aluminum electrolytic capacitors, LED drive power program. But not all of the LED drive power suppliers are in favor of this approach. Chen Rong said: “At present, the LED drive power production, there is no a is a non-electrolytic capacitor driven program, because without it, then a lot of test criteria to pass EMI testing and flicker-free test.”

 

While the aluminum electrolytic capacitors, LED driver power of led high bay lighting system is usually more of these tests, if you replaced the film capacitors and ceramic capacitors or tantalum capacitors, the situation how? Film capacitors to achieve the same capacitance (typically 100-220uF), the volume will be enormous, and the cost is too high, the general capacity of the ceramic capacitor is too small, such as multiple ceramic capacitors to achieve such a large capacity, footprint and cost too much, and tantalum capacitors to have such a large-capacity.

 

Many suppliers claim that the non-electrolytic capacitors LED intelligent lighting system program, it may just get rid of the aluminum electrolytic capacitor of the AC input, constant current output of aluminum electrolytic capacitors should be difficult to remove or replace.

PESD for LED outdoor led spotlights

 

outdoor led spotlights

 

LEDs are semiconductor devices, are more sensitive to static electricity to prevent static electricity and eliminate static electricity work to do, especially for white, green, blue, purple outdoor led spotlights.

 

1. Generation of static electricity:

 

① friction: in everyday life, any two objects of different materials contact after separation, you can generate static electricity, while the most common way to generate static electricity, friction power. The better the insulation of the material, the more likely friction call. In addition, any two different substances, objects in contact after separation, can also generate static electricity.

 

② induction: a conductive material, due to the electron energy in the surface of the free flow, if placed in an electric field, due to same-sex repulsion, opposites attract, the positive and negative ions will be transferred on its surface will produce charge .

 

③ conduction: for electronic contact with the electrically charged objects in its surface free flow of conductive material, the charge transfer.

 

2. The hazards of static outdoor led spotlights:

 

① heat generated due to the instantaneous electric field or current, the LED local injury, the performance of the rapid increase in leakage current can still work, but the decrease in brightness, life impaired.

 

② electric field or current destruction of the insulation layer of the LED, the device does not work (completely destroyed), dead lights.

 

3 ESD and the elimination of measures:

 

All employees have direct contact with the led high bay lights for the entire process do to prevent and eliminate static electricity measures, mainly

 

①, workshop laying anti-static floor and good grounding.

 

②, the table to prevent static table, the production machine well grounded.

 

③, the operator to wear anti-static clothing, with anti-static

The application range of high power led technology

 

The application range of high power led technology

 

High power led technology in the oil field, petrochemical, railway, mining, military and other special industry, stage decoration, urban landscape lighting, display and sports stadiums and other special lamps have a wide application prospect.

How it works:

 

Light-emitting diode (LED) is a solid device for a can convert electrical energy into light energy, its structure is mainly composed of chips of the PN junction electrode and optical systems. The basic working principle of the high power led technology is an electro-optical conversion process, when a forward bias is applied to both ends in the PN junction, PN junction barrier to reduce the spread of P region of positive charge will be N region, the N-zone electronic the proliferation of P region, the formation of non-equilibrium charge accumulation in the two regions. PN junction due to the relative instability of minority carriers generated by current injection, injected into the non-equilibrium holes in the valence band to the conduction band electron recombination in which the excess energy will be in the form of light radiate outward. electrons and holes, the greater the energy difference between the photon energy is higher. Energy steps of different sizes, frequency and wavelength of light is different, the corresponding color of the light will be different.

 

High power led technology is a phase for low-power LED lamp (compare high power led high bay lights and low power led bulbs), the higher the power of high-power LED lamp, the brightness is brighter, higher prices. Small power LED lamp rated current is 20mA, rated current higher than 20mA of almost all can be regarded as high.

The third-party testing for high power uv led suppliers

 

The third-party testing for high power uv led suppliers

 

In order to eliminate the injustice of the test, many companies are entrusted to a third party to test the LED assembly and circuit structure. LED devices may be tested in the harsh environment, or use a few weeks. During the test, at the same time the pressure, temperature cycling, fixed voltage / change current fixed / change test, test to determine whether the high power uv led suppliers to meet the application requirements in other harsh environmental conditions.

 

Accelerated life cycle testing is a key test to avoid failure in special applications. The test helps to ensure that screen out those expectations at least for 100,000 hours, but only work 1000 hours in advance of LED failure. This situation may arise because of the low-quality LED will reduce the brightness after 1000 hours of work. In fact, if a lower-quality high power uv led suppliers have a higher drive current, at an early stage is high quality LED light, however, the excessive current causes the LED heat too fast, the end result is the brightness dimmed or burned.

 

In addition, the assembly technology to some extent on the LED performance than the chip itself is also a big example. The design engineer should ask for the reliability of the specifications of LED to LED suppliers, and the LED assembly and testing to ensure that the relatively high brightness is indeed better. Some excellent led high bay suppliers to ensure the reliability of the LED assembly technology for three years or longer, and can further provide the ultimate LED products, including the appropriate design with high quality LED and for special applications.

The products supporting capacity of household led lights

 

The products supporting capacity of household led lights

 

In addition to discrete LEDs, LED assembly and power supply for its performance, brightness and color index have a very significant impact. Due to ambient temperature, operating current, the circuit structure, voltage spikes and environmental factors and so can affect the LED performance indicators, the appropriate circuit design and assembly is critical to protect the LED and to ensure performance. Household led lights manufacturers use a variety of techniques and different materials to design the circuit structure and assembly, in most cases, the LED assembly on the experience level of the difference will cause the LED in the same application there are differences in overall performance and reliability.

 

With the rapid growth of the household led lights needs, serve the global market manufacturers and assembly plants also increasing rapidly. It is regrettable that the surge in the support of manufacturers is not only a large number of low-quality LED packaging and LED design engineers to experience a relative shortage of Therefore, in addition to the existing experience and accurate screening LED suppliers, OEMs must also examine their circuit design and assembly technology to ensure that it meets the design specifications, and design to provide sufficient cooling capacity, because the cause of led high bay lights failure and performance the inconsistency of the main factors is overheating.

 

Excellent household led lights manufacturers can not only create high-quality chips, but also has the ability, depending on the LED color, brightness, voltage drop and perspective of its classification packaging. The high quality LED suppliers to provide customers products with consistent operating characteristics, while lower-quality LED suppliers only provide LED similar to the “mixed”.

Lighting comparison between Fiber-optic lights and mains led lights

 

Lighting comparison between Fiber-optic lights and mains led lights

 

Excellent fiber-optic lighting, highly personalized color to meet the different needs of the people’s light environment. The great beauty of decorative effect, the twelve constellations. Fiber curtain swaying posture of Health, fresh and elegant, as if the people back to the mood of the curtain westerly. Star Gazing out the window, points of light flashes, your fingertips, it is very happy; a show of hands Reaching for the Stars, but it is the fiber pull network screen. Fiber optic lighting and people as well as the surrounding environment symbiosis, even up to the light one, the situation one of the realm. With the development and maturation of the various colors of mains led lights color-changing effects for recreational use of monochrome LED manufacturing technology is also increasingly mature.

 

Order to change the color, red, green and blue mains led lights (RGB) as a monochromatic light source, re-use technology to produce the final desired color is called “enriched”. Light performance practices of any other lighting and fiber optic lighting compared to prepared. Therefore, the development trend, fiber optic lighting is still accounting for a dominant position. , Fiber optic lighting and led high bay lighting market there are essential differences due to fiber-optic lighting and LED lighting, and performance results is different, and therefore also have their own emphasis in the sales market. Fiber optic lighting in the lighting industry to share some proportion of market share is not too much, but it is proportional to the acceleration of growth. The visitors continued to cause concern, especially in the usual light inconvenient places especially in the annual American Lighting Trade Fair.

Optimized design to improve the mains led lights’ life

 

Optimized design to improve the mains led lights’ life

 

The life of LED products including factors such as quality and reliability of the product, which product reliability is a key element affecting the life of the product. Reliability refers to the ability to complete the required functionality within the product specified conditions and the prescribed time. Result in poor product quality and reliability of the main reasons for the low level of design, lack of experience in hardware applications, the lack of electronic reliability of systems engineering methods and other factors. Practice has proved that the use of appropriate reliability engineering techniques to test the product.

 

At present, many companies in the face of intense domestic competition, but also expanding foreign markets to increase exports to European countries and the United States. The European Union and the United States introduced a number of directives and standards for mains led lights. For example, the U.S. Department of Energy and the EPA jointly issued the “Energy Star” Act, the overall LED bulb life to 25,000 hours of use but also to maintain at least 70% of the initial luminous flux. North American Lighting Association issued the LM-80-08 led high bay product standards to regulate the testing methods, how to test the product rated lumen maintenance of life “to be clearly defined. In Europe, specifically for the assessment standards for LED products are being developed, specific criteria are as follows: lighting performance requirements of standard IEC 62722-1 and IEC 62722-2-1 standard mains led lights module performance requirements of the IEC 62717, since the town stream LED bulbs performance requirements of standard IEC 62612, the LED drive performance requirements of the standard is IEC / EN 62384.

The temperature dependence of the LED lighting chips

 

The temperature dependence of the LED lighting chips

 

Like all semiconductors, the LED lighting chips maximum allowable junction temperature must not exceed, so as not to cause premature aging or complete failure. If the junction temperature is kept below the critical value, then the outside temperature rises, the maximum allowable forward current must be decreased. However, if the use of radiators, can increase the forward current in the specific temperature of the outside world. LED light output with the chip junction temperature rise and decline. The above situation occurs mainly in the red and yellow LED, white LED with a smaller temperature dependence. Light efficiency and the forward current to keep pace with growth, however, the LED lighting chips installed in the junction layer and the environment with high thermal resistivity can be reduced and even reversed this effect, it is because with the rise of the junction temperature, the emission will be reduced .

 

In addition, when the junction temperature rises and the LED forward voltage and temperature to keep pace with growth, the dominant wavelength of the emitted light to +0.1 nm / K typical rate of growth. A variety of white LED driver circuit features competitions in 1996, Nichia, Nakamura’s found a blue LED, white led chips used in led high bay arensidered the most development potential components of the illumination source, therefore, the white LED performance improvement and commercialization of application, it instantly became the focus of national research. The white LED used in the field of trail lights, automotive lighting, traffic signals, portable electronic products, LCD monitors and other public places. White LED lighting chips with rich primary colors color temperature and high luminous efficiency characteristics.

The advantages of aging test for led studio lighting

 

The advantages of aging test for led studio lighting

 

Automotive lighting, LED light source inside and outside of the building, as well as laptop computers or TV LCD screen backlight. The development of high-power led studio lighting technology to improve the design stage of the heat dissipation requirements. Like all other semiconductor, LED is not overheating, so as not to accelerate the weakening of output, or result in the worst situation: a total failure. Compared with incandescent lamps, high power LED with higher efficiency, but a considerable part of the input power is still turned into heat instead of light. Thus, the reliable operation of the need for good heat dissipation, and requirements in the design phase to consider the high temperature environment. Design led studio lighting driver circuit size, but also must take into account the temperature factor: must select the forward current to ensure that even if the ambient temperature reaches a maximum value, the LED chip will not overheat. With increasing temperature, by reducing the maximum allowable current, that is derated to achieve cooling.

 

The temperature dependence of the power supply to run led studio lighting disadvantages: the high temperature region, the LED is out of specification to run. In addition, when in the low temperature region, the lighting source powered by the significantly lower than the current maximum allowable current (see Figure 1 red curve). The green curve shown in Figure 1 (referred to as PTC thermistor) to control the led high bay lighting current through the LED driver circuit in the positive temperature coefficient thermistor is a major improvement.

Foxconn: to get rid of the LED “OEM” label

 

Foxconn: to get rid of the LED “OEM" label

 

In the aura of the Empire “on the world’s largest foundry, entered a 38 year Foxconn Technology Group (hereinafter referred to as: Foxconn) still look to the sun at high noon.

 

Built in the Pearl River Delta, Shenzhen, Foshan, Zhongshan, Dongguan Science and Technology Park, Shenzhen Longhua Science & Technology Park’s three companies year after year to enter the top ten corporate revenue in Shenzhen City, and tax top ten, and each year the Shenzhen tax contribution of over ten billion yuan . Park is transforming into a product R & D center, sales presentations and staff training center, mold manufacturing and technology research and development centers, new materials and new energy research and development centers, new equipment and automated manufacturing research and development center, a small amount of manufacturing base, and strive to become the construction of Shenzhen “National innovation-oriented city, “the main force pushing the hand.

 

Although Foxconn chairman Terry Gou is not satisfied with the title LED “OEM” factory, but in the field of consumer electronics, in order to create its own brand of Foxconn, almost impossible.

 

Now, Terry Gou eyes locked in the led high bay lighting industry is in a stage of rapid development.

 

Foxconn products, only LED products printed on ‘FOXCONN (Foxconn)’ brand label. “Recently, Foxconn LED lighting division who LED inside that, although the Group also international lighting giant Philips, GE and other OEM products, but the LED display, LED lighting products are now the only intra-group with their own brand products.

 

Foxconn expects the help of this emerging field of the LED “OEM” to achieve the transformation and upgrading, and thus out of its own brand breaking initiative. “The source said.

 

However, despite having others unmatched manufacturing cost advantages, but Foxconn’s Own Brand of LED is not all the way flat.