作者：Blade

United States indicate: led lightings can inhibit urban crime

Criminal psychology–the general term for the influence and domination of crime perpetrators from various mental activities or psychological factors. The criminal mind is the intrinsic motivation of the crime and the dominant power。 It is the crime Criminal Minds external performance. The movie “Criminal Minds” (Criminal Minds) is a psychological suspense thriller drama, a group of elite pooled analysis of the country’s most intractable the comic crime cases criminals psychology and predict their next step before they once again have violence action.

led lightings, United States indicate: led lightings can inhibit urban crime

The American Austin City Police Department and Austin Energy Energy Board cooperation protect the residents of the city.Since a significant increase in violent crime rate in mid-2011, the two institutions plan fitted with led lightings, the prevention of crime in the U.S. city of Austin, the three most dangerous locations.

Austin Energy spokesman Carlos Cordova, announced that a well-lit place is usually not an offense where there has been committed, because when you want to do bad things and nobody seen.

In accordance with the requirements of the city’s Police Department, Austin Energy erected 25 LED lights. The new LED bulb and high quality LED Flood Lights illumination is brighter than the old bulbs. Cordova said under good lighting environment, people can be assured of recreational activities, and no need to worry about security issues.

Austin, 8th and 9th of the street lighting test results are very successful, this lighting project is one of a series of policies against urban crime. The growth of violent crime by 15 percent from 2011 to January 2012. But until July, violent crime only grow by 7.8% next city a larger project, 70,000 lamps will be updated by Austin Energy budget expenditures.

It is reported that this new led lightings products can reduce the crime rate. Among each countries, the earlier start to use is Japan, called LED guard against light, which has been gradually applied in street alleys to replace fluorescent lamps mainly traditional street lights.

In addition, studies have pointed out that the blue light can make people more calm, and some of the LED light will also guard against taking blue, white separate configuration.

The semiconductor future lighting ferret saving potential

The semiconductor lighting ferret saving potential

According to the U.S. Department of Energy’s Sandia National Laboratory, lighting energy consumption dataccounting for 8.9% of global energy consumption, accounting for 19% of the total electrical energy consumption contribution to GDP was only 0.63%. If general future lighting use semiconductor lighting products, the 2050 lighting electricity consumption is expected to maintain the 2005 level, and contribution to GDP ratio will rise to 1.63%. Semiconductor lighting industry as the new industry, it not only led lights to the development of related industries, creating new market demand, but also its wider application will greatly reduce the total electrical energy consumption to achieve energy savings.

future lighting, The semiconductor future lighting ferret saving potential

China’s annual lighting electricity consumption is about 500 billion kwh, accounting for 13% of the total electricity consumption, accounting for 6% of the energy consumption and the annual growth rate of 5% -10% of the total electricity consumption of the whole year than the United Kingdom. LED light efficiency is much higher than traditional lighting and display light source, which showing good energy saving effect, such as 70% energy saving landscape lighting, backlight energy by 50%, 50% energy saving road lighting.

Experts predict that China’s semiconductor future lighting market share accounted for 30% of the general lighting market in 2015, the annual energy saving of about 100 billion kwh, reduce carbon emissions by 98.99 million tons, about one percentage point contribution to reducing energy consumption per unit of GDP; to market share, it can account for 50% of the general lighting market in 2020, the annual saving of about 340 billion kwh, equivalent to four total annual generating capacity of the Three Gorges Project.

The highest technical content epitaxy, chip development mainly in Europe and the United States, Japan and other developed countries, packaging applications are mainly distributed in Korea, China Taiwan and mainland China. With the accumulation of technical and financial aspects of LED manufacturers in Korea, Taiwan, and are actively to the upstream chips, epitaxial materials development in mainland China, due to the huge market prospects, and has become the hot spots of the global industrial transfer.

As technology continues to evolve at the same time, the continuous improvement of the luminous efficiency, the gradual expansion of the market, the price of LED lighting is also declining, the LED devices price of 50-60 $ /klm 2015 may be down to 1 /5. Semiconductor future lighting technology and its products forward higher luminous efficiency, lower cost, more reliable, more diversified field of development and wider application of direction.

LED all lighting of heaven : Rio de Janeiro

Rio de Janeiro (which means “January River “), sometimes referred to as the inside about Rio.

LED Lighting CoastLED Lighting Coast

Located in southeastern Brazil. In 1960, as the Brazilian capital, Is the second largest city in Brazil, Second only to Sao Paulo. Southeast Atlantic. 636 km long coastline.

 

is it paradise?is it paradise?

 

Christ the Redeemer watching over Rio de JaneiroChrist the Redeemer watching over Rio de Janeiro

 

the hazy Rio de janeirothe hazy Rio de janeiro

 

Rio de Janeiro nightRio de Janeiro night

Rio de Janeiro is tropical wet and dry season climate, year-round high temperatures, dry season and the rainy season of the year. City in the port of Rio de Janeiro is one of the three major natural harbor in the world, Christ in Rio de Janeiro, such as the city’s logo, is also the world’s new seven wonders of the world.

Rio de Janeiro on October 2, 2009, to obtain the right to host the 31 session of the Summer Olympic Games in 2016.

As we all know, Rio de Janeiro, has been disabled all incandescent.
The use of low power consumption, long life, high brightness, low-calorie, environmentally friendly LED lights.

The inherent characteristics of the LED it is the ideal light source to replace the traditional light source, it has a wide range of uses.
LED is basically a small chip is encapsulated in epoxy resin inside, so it’s very small, very light.
LED power consumption is very low, in general, LED’s operating voltage is 2-3.6V. The operating current is 0.02-0.03A. That is to say: the power consumption is not more than 0.1W.
Proper current and voltage, LED life of up to 100,000 hours.
LED is made ​​from non-toxic materials, unlike fluorescent lamps containing mercury can cause pollution, while LED can also be recycled.

The paradise city because LED lights: Rio de Janeiro.

 

LED technology matures gradually, 500 billion market needed R and D to support

In 1879, Thomas Edison invented the incandescent lamp, which marks the human into the era of electric lighting fire lighting. From the incandescent generation, it has been lasted more than 130 years, with the advancement of technology, the illumination light source keep the direction of more energy efficient development. In the 1930s, the Dutch scientists developed the first branch fluorescent lamps, on this basis, to the 1980s, he also has developed a compact fluorescent lamp, and quickly occupied the market with energy saving, long life and other advantages than incandescent, incandescent light has now entered the phase-out period. Since the 1940s, scientists have since developed high-pressure sodium lamps, metal halide lamps, high-intensity gas discharge lamp. Due to its high efficiency, high power density, etc., it is widely used in outdoor lighting, road lighting and commercial lighting and other fields.

In the 1960s, the U.S. Hewlett-Packard run mass production of the red LED production for the first time. After nearly half a century of development, the semiconductor light-emitting diode (LED lights)-based lighting, because of its low power consumption, long life, fast response, small size, rich colors dynamically control advantages, more and more widely used in indoor and outdoor lighting, large-size LCD backlight display, medical, transportation and other fields. After following incandescent, the fluorescent lighting technology revolution open a new era of lighting.

LED technology matures gradually, 500 billion market needed R and D to support

LED technology matures gradually

Currently, developed countries, the lighting power consumption accounts for about 20% of the total electricity consumption, energy-saving potential is considerable. In the context of today’s world energy crisis, the growing pressure on energy saving, the world’s major developed countries have to increase from the National Strategic support and attention of the semiconductor lighting to give strong support in terms of policy, such as the development of semiconductor LED technology and industrial development planning, accelerated incandescent high energy-consuming lighting source phase-out plan, the introduction of demonstration applications and promotion policy, attaches importance to and actively promote the testing and standardization process, to seize the industry dominance.

2010 METI “bulb-type LED technology included in the eco-point system to support and clearly indicate LED lighting products market share of 50% in 2015, and LED lighting products 100% market share by 2020. The South Korean government regard solar, semiconductor lighting, hybrid cars as three green growth engines, proposed to the government office lighting LED product replacement rate in 2012 that reached 30%, and to 2015 reached into the world top three semiconductor lighting industry.

Something you should know about LED dimming technology

Under such circumstances, you may probably choose to use step-down (wide voltage) constant-current sources, like using 10V-30V constant-current power suppliers to realize the LED dimming technology. However, this kind of step-down constant-current source still has defects. When the forward input voltage has been adjusted into a certain low level, the load current of LEDs will be forced down to a very low level. This would dramatically increase the entire potential (voltage) of load (LED lights), even exceeding the normal working range of this step-down constant-current source (causing flicker). Working in the low brightness conditions for a long time will decline the efficiency of step-down constant-current sources and increase the working temperature in the mean time. Since the efficiency of step-down constant-current sources has directly relations with the potential drop ratio. The larger the potential drop ratio, the lower the efficiency, and more power will be consumed, causing obvious damages to power suppliers and the service life of lighting sources.

Under such circumstances, you may probably choose to use step-down (wide voltage) constant-current sources, like using 10V-30V constant-current power suppliers to realize the LED dimming technology.

  Commonly used incandescent lamps and halogen lamps usually used SCR dimming technology. Since all of them are purely resistive devices, the input signal of these lamps are not necessarily sine waves like LED lighting devices required. The waveform of current will be indentified with the waveform of voltage forever. Thus regardless of the distortion of the input voltage waveform to a sine wave, changing the effective value of input voltage can realize the dimming effect.   However, the SCR will bring unexpected problems to LED dimming technology: LC filters in the input side will bring vibrations to SCR. This vibration has no effects on incandescent lamps, since the thermal inertia them hardly can be captured by human eyes. But this vibration will exert very obvious influences on LED power suppliers, causing audio noise and flickers. Besides, SCR dimming will also destroy the waveform of sine waves, reducing the power factor (normally less than 0.5). In order words, SCR dimming dramatically decline the lighting efficiency of LED lighting systems. Sometimes, SCR dimming technology will increase harmonic coefficients, generating non-sinusoidal waveforms, which will be a serious interference to single (EM), polluting the power grid. In serious conditions, the entire power grid will be failed.   Either step-down constant-current sources or SCR dimming sources are suitable for LED dimming technology. Some people may ask: what on earth type of dimming method is the most appropriate for this new lighting technology?

Some knowledge that you must know about LED dimming technology

How to comprehend LED dimming technology? How to know it well and master it? In order to answer these questions, we need first understand the voltage-current characteristic of LEDs.

 

Some knowledge that you must know about LED dimming technology

 

What is the voltage-current characteristic of LEDs? It is known by all that when voltage worked on PN junctions (typical construction of semiconductors), internal current will be varied with the vibration of input voltage. The characteristic curve can be cleared display on oscilloscope. A complete voltage-current curve includes the forward characteristic curve and the reverse characteristic curve. Typically, the reverse characteristic curve will be much steeper than the forward one. When input voltage surpassed a certain threshold value, the corresponding internal current will increase exponentially, and consequently, breakdown the entire LED PN junction. While the forward internal voltage is also determined by its forward internal current.

 

According to the voltage-current characteristic, we could conclude that LED dimming technology definitely cannot be realized through simply reducing input current or input voltage. In addition, LEDs’ sinusoidal waveform is different from the waveform of incandescent lamps, thus it is also impossible to vary the lighting effects (dimming effects) by changing their conduction angles.

 

For example, a LED lamp with an input voltage of 24VDC, with 8 pieces high-powered LED chips (1W/each) in series. Given that the forward current is about 350mA and the forward internal voltage for each LED chips supposed to be 3.3V, thus the total input voltage for the entire lighting sources (8 pieces LEDs connected in series) should be 26.4V. It is cleared that the load voltage (26.4V) is much higher than the input voltage (24V), thus here constant-current power suppliers should be applied. In order to realize the dimming effect, engineers have to reduce the internal current from 350mA to 100mA, causing the forward voltage in each LED chip reduced to only 2.8V. Then the total input voltage of the entire system is 22.4V (now the load voltage is smaller than the input voltage). So the constant-current is incompetent. That is the reason why many terminal users or buyers saw flickers of their LED lights. Theoretically, according to the working principles of LEDs, LED lighting applications will be free from flickers in ideal conditions.

Thermal management solutions for high-brightness LED applications

With the increasingly serious in energy shortage and environmental pollution, LED lamps (especially for high-brightness LED applications) have become a hot topic among lighting applications providers and customers due to their energy-saving and environmental friendly characteristics. Normally, LED lamps are composed of LED modules, cooling sections, drivers, lens, and other optical/electrical components. It is the cooling section that the most important, since LED lamps with a poor heat dissipation effect will reduce their lifetime. According to the testing report of Cree XLamp XR-E, there is a closed relation between working temperatures and service life of LED lamps. Thus solving the problem of thermal management has become a key point to high-brightness LED applications.

 

Thermal management solutions for high-brightness LED applications

 

However, the heat generated by LED lighting sources is not the major factor for LED working conditions and service life. The accumulation of heat within chips (hot spots) is a more serious problem for LED lamps. For general standard LED devices, LED modules that have a power consumption of 1W will have a heat flux of 100W/cm2, 300W/ cm2 for 3W LED modules, while the average heat flux of CPU is only 60-130 W/cm2. A large amount of heat concentrated within the small-sized wafer, leading to the increase of temperature, the uneven distribution of thermal stress, and finally the reduction of wafer luminous efficiency and emission efficiency of the fluorescent powder. When the temperature exceeds a certain value (threshold), the failure rate of the device will increase exponentially. When multiple LED lights constitute the entire white light illumination system, the heat dissipation is even more serious.

 

Heat conduction and heat convection are two main path for heat dissipation of LED devices. Traditionally, the cooling structures of LED lamps include bases, heat sinks and radiators. Bases are directly connected with LED chips and typically used for conducting heat generated by chips, with thermal conductivity but not electrical conductivity. Heat sinks can spread the heat, used to avoid the heat accumulation on LED chips. They can also increase the efficiency of radiators. Heat radiator can effectively dissipate all heat outwards into the air. Among them, it is the base that needs to be taken careful consideration of. Bases made by materials with relatively large thermal conductivity will result in severe self heat effects, which is a devastating impact on the performance and reliability of LED devices.

High brightness LED emerged in the market

High brightness LED brought many compelling features to car manufacturers. In spite that most of these features were derived from the working principles and similar production process of LED indicators-products are much older than themselves and well-proved.

 

High brightness LED brought many compelling features to car manufacturers.

 

LED taillights, LED signal lamps, LED working lights, LED brake lights can overcome shortcomings that much common in incandescent lights. Usually, vehicles will meet with frequent moderate shocks and vibrations, which may probably cut down the service life of incandescent lamps. Besides, the instantaneous surge current caused by temperature coefficient of filament resistance will accelerate the destruction of bulbs. Thermal loop-an important feature of break lights will definitely shortened the service life of incandescent lamps.

 

The instantaneous surge current generated by incandescent bulbs made the circuit protection and fault detection be more complicated. Automobile manufacturers have to set the fuse rating and the fault detection threshold large enough, to adapt the inrush current magnitude and duration without causing fuse blows failures or detection failures.

 

In contrast, when cars in shocks and vibrations that in the normal range of amplitude and frequency, structures of high brightness LED would be much stronger than incandescent bulbs. LEDs have compact structures (small sized) and light weight, which can reduce the mechanical torque generated by shocks and vibrations. The compact construction of high brightness LED contributed to the flexibility in the design of vehicle lighting applications. Within such limited space, designers hope that each compartment can meet the requirements of the overall design of the car. For example, some small cars would not set the CHMSL (Center High Mounted Stop Lamp) module in the rear cover. Instead, manufacturers made use of the feature of compact construction of high brightness LED and embedded them into trunk lids.

 

Designers also found out several problems about automobile taillights and the control system. These problems were also emerged in other systems that control devices were far apart with devices that under control. LED is essentially a kind of current devices. The combination of electron-hole pairs can emit photons. When increasing the input current, the compound speed and output luminous flux will also be raised. Definitely, the efficiency of this process cannot reach up to 100%, thus the a certain proportion of electrical energy will convert into heat. Unless in very poor working conditions, LED Lights will not break down like incandescent lamps does. But working in a over-heated condition for a long time will also accelerate the light attenuation of LEDs and consequently the service life.

Four key technologies of LED tube lights

Tube lights are widely used in our daily life, which is can be say one of the most commonly used lamps in the world, in supermarkets, in schools, in offices, in subways. In recent years, LED tube lights started to be used in these places due to their advantages in energy-saving and environmental protection. How to improve the lifetime and brightness of these lamps to make them meet the requirements of general lighting is a significant subject. In order to maintain a longer service life and higher brightness, problems waiting to be solved are: power suppliers, LED lighting sources, cooling sections and safety.

Tube lights are widely used in our daily life, which is can be say one of the most commonly used lamps in the world, in supermarkets, in schools, in offices, in subways.

 

The first and foremost requirement of power supplier is high efficiency. LED tube lights with high efficiency will generate less heat and have higher stability. Normally used power suppliers can be divided into two groups: isolated drivers and non-isolated drivers. Generally, isolated power suppliers are superior to non-isolated power suppliers in many aspects. They are smaller, having higher efficiency and easier in packaging and installation. Overall, isolated drivers have wider prospects in the market.

 

When making LED lighting sources, designers usually placed chips on pins. These silver pins can conduct heat generated by PN junctions during their works. Different from the traditional DIP products and patch products in the heat dissipation aspect, chips packaged in this way will not collect heat within them, having longer service life and less light attenuation. Traditional patch-packaged LEDs connected with positive and negative electrodes through gold wires, which will be weaker than silver pins in heat conduction.

 

Introducing infrared heat radiation into LED tube lights is a crucial approach to improve their service lives. Normally, designers would like to separate LED lighting sources and power suppliers in case that the cooling sections of these two parts have interference and guarantee an effective heat dissipation. There are three ways of heat dissipation: convection, conduction and radiation. In a closed environment, the heat dissipated by convection and conduction is very limited, while radiation is the mostly commonly used cooling method among LED tubes.

 

PC flame-proof plastic tubes used in LED tube lights can easily be penetrated by infrared heat. When we design LED lamps, we need to take safety into account. Using all-plastic insulation, even in the use of non-isolated power suppliers, safety still can be guaranteed.

Difficulties of LED lighting sources used in residential lighting applications

Currently, LED lighting applications have been researched, developed and produced by countless LED companies. LED technology has occupied a very important position in the project lighting market and the outdoor lighting market. But for residential lighting market, it is only to say that LED technology is still an emerging market full of potentials and opportunities. How to bring LED lighting sources into ordinary families?

 

Difficulties of LED lighting sources used in residential lighting applications

 

The distribution of domestic LED lighting industry is relatively concentrated: the Pearl River Delta, the Yangtze River Delta, the southeast region and Beijing area. Each area has basically formed a relatively complete industrial chain. Dalian, Shenzhen, Xiamen, Nanchang have large-scale production bases for LED.

 

Most people in this country are still lacking of necessary knowledge about LED lighting technology. Furthermore, prices of LED products are much higher than that of other traditional lamps. As a result, it is difficult for LED lamps have a deep penetration in residential lighting market. On 20th of March this year, the Ministry of Finance, the National Development of Reform Commission and the Ministry of Science and Technology launched a public tender named “2012 financial subsidies and projects for promotion of LED semiconductor lighting products”. Nearly 300 bidders from 110 LED companies all around the country participated in the tender. Many LED lamps have been listed as tender products, like LED down lights, reflective self-ballasted LED lights are classified as indoor lighting applications, and LED street lights, LED tunnel lights used for outdoor purposes. The National Development and Reform Commission declared that in 2012 the Chinese government will spend 40 billion yuan for LED lights procurement and provide 30% financial subsidy for users.

 

At present, LED lighting sources are still in the stage of immature, frequently encountering bottlenecks both in technologies and in equipment producing. In the field of substrate materials and wafer equipments, domestic LED lighting industry had obvious bottlenecks. The independent innovation and patents of our LED industry are mainly concentrated on the packaging area. Those core technologies, like White-ray LEDs, heat dissipation of high-powered LED lamps, durable and efficient phosphor technologies, patents in these fields are mostly under the control of giant manufacturers from Europe, America and Japan. Most crucial parameters of domestic LED products are still lagged far behind the international level, like brightness, heat dissipation, lighting efficiency, evenness of light distribution, antistatic abilities, anti-leakage abilities, etc.