作者：Blade

LED road lighting companies return to the senses

 

LED road lighting companies return to the senses

 

Led road lighting should continue to engage, LED road lighting applications in the Chinese market a few years, has a certain basis, should be concerned about product development in the promotion at the same time, improve product cost-effective to solve the problem of cooling and other applications based on truly meet the lighting needs of the users. “a veteran in the industry would look at the LED lighting market and development priorities. November 9, 2011 Summit, one of the 8th China International Semiconductor Lighting Forum LED road lighting market and technology application be held as scheduled from the domestic and foreign experts, academics, entrepreneurs, etc. LED high bay lighting development status, technology and the industrial development trend, the need to focus on the problem, how to play to the advantages of the LED road lighting source through a more scientific and rational design, in interaction with the environment to achieve a more secure, comfortable road lights have become the key topic of the meeting.

 

Speakers of this conference Geng Bo, Deputy Secretary-General of the National Semiconductor Lighting Project R & D and Industry Alliance, Taiwan’s Industrial Technology Research Institute of the electro-optical components and systems applications department at Zhu catechumens, Germany University School of Architecture of the University of British Xie Erfei lighting and visual perception Professor Steve Fotios, Philips LED road lighting Company in Asia Marketing Director Zhou Xuejun, Philips Lighting Asia, senior research fellow, Zhu Xiaoyan, Guangdong Long traffic Technology Co., Ltd., chairman of Chen Bin, Fudan University, the light source and lighting engineering associate professor Lin Yandan, etc., made ​​a keynote report. From a different point of view of the road lighting market and technical issues of road lighting applications.

 

LED highbay technology and product status

LED highbay technology and product status

LED lighting technology and product status
High Power LED luminous efficiency of R & D indicators have reached 161lm / W, and production of LED luminous efficiency most of the range of 80-120lm. Lighting products, including not only the LED’s, led highbay drivers and lamp parts. The current high price of LED lights, a three-watt LED cup light of the market on the most common “CPL light Cup as an example, the luminous flux in the 120-from 200lm to the price of nearly $ 30-60. Halogen Cup 20W of the luminous flux 320lm, led highbay while the price of around $ 2-10.
LED light source and light contrast
LED as lighting products, one of the biggest weaknesses of the luminous flux and cost almost a linear relationship. This makes the LED light source in the high cost of high luminous flux range, the cost is very low. Therefore, we should first consider the low luminous flux of the application market, led high bay such as 200-800lm application requirements. The scope of the luminous flux LED light effect in the current level corresponds to about 3-15W of power.
How the LED light source to enter the general lighting market
Applications for traditional lighting market, LED light can not escape from the existing sales channels. So to replace the LED light source are bound to go through the existing sales channels. The sale of the driving force of these channels depends on price, led highbay reputation and service. Market channels for a variety of lighting may be different Take the indoor lighting product sales, the daily loss categories of products, such as energy saving lamps, lamp cups, light bulbs, flashlight, its dominant channels include professional lighting market, building materials supermarkets, consumer, supermarkets, convenience stores, hardware stores, led highbay direct marketing network, etc., and hidden channels is a property management company (home class and business class), municipal companies; for home lighting products, ceiling lamps, wall,lamps, floor lamps, kitchen lamps, children’s lamps, mirror lights, low-power local lighting (down lights, spotlights, lighting grid), the dominant channel, including the professional market, led highbay building materials supermarket, the supermarket of home appliances, furniture stores direct marketing network, and hidden channels is a home improvement company, to buy (on-site promotion, buy the network), electrician (installation companies and the renovation team), etc.

LED landscape lighting fiscal subsidy program will be announced in April

 

LED landscape lighting fiscal subsidy program will be announced in April

 

Has learned from the person concerned, the fastest drafted jointly by the NDRC and the Ministry of Finance of LED lighting products, financial subsidy programs may be announced before the end of the year.

 

The sources, led lighting products, financial subsidies, energy-saving lamps will be modeled on the form of subsidies, the tender selected manufacturer and supplier prices. Only the successful LED landscape lighting manufacturers, are eligible to enjoy a certain degree of financial subsidy on the successful agreement price basis. Target subsidies may still be divided into two types of bulk users and urban and rural users. Among them, the urban and rural residents are subsidizing the efforts will be more than large users.

Announced in 2008, the promotion of efficient lighting products, financial subsidy funds for Interim Measures for the Administration of the provisions of efficient lighting products to promote enterprise and supply agreement price through bidding. The national unified tender, and in accordance with the tender results, publicity of successful enterprises, energy efficient lighting products and its successful agreement supply prices.

 

Among them, the bulk of users of each energy efficient lighting products, the central government 30% of the successful agreement supplier price subsidies; urban and rural users, each of efficient lighting products, the central government, 50% of the successful agreement supplier price subsidies.

 

To the source comments to the manufacturer of led high bay lighting products, LED landscape lighting products, financial subsidy program starting in July-August. Domestic LED lighting market downturn, the industry’s subsidy policy introduced in the first quarter of next year before the advent of the industry off-season to boost the market.

 

 

Taiwan fourth street lights will change to be solar powered led street light

Taiwan fourth street lights will change to be solar powered led street light

According to Taiwan media, Taiwan Ministry of Economic Affairs Bureau of Energy said yesterday that Taiwan has a total of nearly one million mercury lamps before mid-nextyear will have a fourth replaced by energy-saving LED street lamp can save 24 billion a year (NT, the same below) electricity, solar powered led street light, nearly 24 million of maintenance costs.

According to reports, the Energy Board officials pointed out that the mercury street lampsevery six months on the need to change a light bulb, LED street lamp life of up to five years, compared to the 100 watts LED street lamp with the traditional 250-watt mercurystreet lamps, solar powered led street light, energy saving and high rate of Liu Cheng. In addition to energy-savingadvantages of LED road lighting quality is better, no mercury. The officials said that the Taiwan authorities have been locked in Keelung City, Hsinchu City, Chiayi City, three provinces and cities as LED street light “model city”, led high bay, is expected to be completed withinthree years.

It is understood that the “Executive Yuan” before the approved 20 billion in government tax revenues, 16 county and city governments to apply for a set of LED lights, the number assigned in accordance with the percentage of mercury street lamps, a huge number, donot rule out the performance assurance model that the authorities only grant a partial amount, solar powered led street light, the local government to the provincial under the electricity to make up theinstallation costs.

In addition, the remote outlying islands, including Kinmen, Penghu and Lienchiang,”Energy Board” will also be the annual budget are set out costs hypallage.

The relationship between current and PWM duty cycle in LED gu10 downlight

 

The relationship between current and PWM duty cycle in LED gu10 downlight

 

Imax is the maximum current of the circuit in the DC case. Located in the PWM duty cycle for the m circuit current values ​​fluctuate around the current value at the time t1, the charging curve should meet the following criteria: the point t charge curve slope, k1, a point discharge curve is k2, should k1mT = | k2 | (1-m) T, the current drive circuit of LED gu10 downlight to maintain a tiny fluctuations in the vicinity of a constant value.

 

The use of computer online through RS-485 control the PWM duty cycle changes needed in the 256 stalls, each with a computer to the RS-485 sends two-byte hex commands, thus changing the C8051 produce the duty cycle to change the brightness of LED gu10 downlight.

 

The main function of the RS-485 interface circuit is: will send a signal from the microprocessor, TX through the “transmitter” to convert the differential signal in the communication network of led high bay light, can also communication network in the differential signal through the receiver to convert microprocessor to receive the RX signal. Any one time, one RS-485 transceiver can only work in two modes “receive” or “Send”. Therefore, the circuit shown in Figure 6, the R / D signal output by the microprocessor directly control SN75LBC184 chip transmitter / receiver enable: R / D signal to “1”, the SN75LBC184 chip transmitter. The receiver is disabled, the microprocessor can SN75LBC184. Range of high duty cycle segment, due to the charging curve slope approaching the same, the current value tends to be the maximum in the low-range segment, shorter charging time, circuit loss, the inductor current value close to zero.

PWM LED street lighting dimming method by inductor

 

PWM LED street lighting dimming method by inductor

 

Circuit, when the inductor through current, the inductor will produce a magnetic field that is part of the current way to convert magnetic energy “stored in the inductor; when no longer current to the inductor, inductors the magnetic energy by the current in the released from the loop. This current mutation is the inductor, the inductance of this charge and discharge “principle, which is used to average the PWM LED street lighting dimming discontinuous current.

 

To ensure that the PWM cycle is less than the inductance of τ time, because if the PWM cycle is greater than τ, then there is likely to appear in the case of the PWM duty cycle changes, the current in a circuit to achieve a DC current of the inductor saturation, affecting LED street lighting current regulation. When C8051330 clock frequency is 25 MHz, the choice of PWM cycle current change stalls. If the cycle is the greater, the stalls of the PWM duty cycle is more, on the contrary, the less. Intended duty cycle of 256 stalls, the frequency of the PWM wave should choose below 100kHz, the cycle of more than 10 μs, DC sense of 10Ω, the inductance value should be selected greater than 0.1 mH to Figure 2, the PWM frequency of 100kHz, duty cycle 90%, the inductance of 0.1 mH to 1 mH to 40 mH, the simulation results of the circuit current.

 

This voltage is the voltage on a 20-Ω resistor in series circuit for led high bay light, stable voltage of 340 mV, the circuit current is 17 mA, because the actual circuit current loss, so the actual current value is smaller than the analog current value. But the current trend and simulation.

PWM LED dimming method for LED high power light

 

PWM LED dimming method for LED high power light

 

Analog dimming by changing the LED high power light circuit current size of the dimming, the power supply voltage constant by changing the resistance value of R to change the current in the loop, so as to achieve the effect of changing the LED brightness. Many other analog dimming are using an extension of this method, its advantage is that the current can be continuous, but adjustable current range is often limited by the hardware few adjust stalls, for the light sensor sensitive high-precision lighting equipment. this method is not ideal.

 

Digital dimming, also known as PWM dimming by PWM wave to turn the LED high power light on and off to change the forward current conduction time in order to achieve the effect of brightness adjustment. The method is based on the human eye perceives brightness flicker less sensitive to the characteristics of the load led high bay light when dark. Bright and dark frequency of 100 Hz, the average brightness of the human eye can see, rather than the LED high power light flashes. PWM to adjust the brightness by adjusting the proportion of bright and dark time in a PWM cycle, because the human eye, flashes of light greater than 100 Hz, the perceived brightness is a cumulative process, ie, the brightest time in the share of the entire cycle The greater the proportion of, the human eye more bright. However, for high frequency sampling equipment, such as high-frequency sampling camera, sampling may be just taken to the LED is dark image. This article analog and digital combination of the design of the LED driver circuit.

How to select a suitable LED street light bulb

 

How to select a suitable LED street light bulb

 

For local lighting, not only need to compare the luminous flux and power, more needs to focus on measuring the light distribution characteristics. The use of the Bonneville Power headquarters hall projection lamp, compared to the PAR38 halogen lamps, fluorescent lamps greatly reduces the power loss, but not meeting the target light distribution effect. LED street light bulb is very good solution to this problem, because of its small light divergence angle, making the art lighting effects than the surrounding wall is much better. Considering the selection of lamps, such as launch angle and center emission optical density and other factors, should be luminous flux and power together as examine the indicators.

 

LED replacement lamps for efficient lighting (CFL) phase, may not really reflect its value faster lamps, but this is not a replacement key. The economic rate of return is only partially depends on the difference between the current system and replacement system power. Although fluorescent energy saving, but the LED street light bulb needs more time to reflect its economic value. CFL can not focus light in the art, it is not suitable for this application.

 

Compared to fluorescent lamps, LED lights can improve the color quality and power efficiency. Purchase products, check the technical specifications of the led high bay products (such as CCT, CRI, etc.) to ensure that the product is suitable for the application of the basic requirements. However, the color index is sometimes the human eye to see the same information and can not effectively convey the quality of color illuminate. Hence the need for an entity model to the specific analysis and evaluation.

The lumens depreciation of LED studio lighting

 

The lumens depreciation of LED studio lighting

 

As for the LED studio lighting products enter the EU must be certified by CE, while taking into account the electromagnetic radiation on the human body may cause harm to the EU also announced in 2013, to enforce the standards of the human body electromagnetic radiation safety norms.

 

With the U.S. Environmental Protection Agency announced in October 2011, the new version of the solid-state lighting and light products listed on the specification, the industry pointed out that the recent concern of the LM-80 light decay test, expected to be enforced from April 2012 onwards, in the new specification on the road, the future North American market, lighting manufacturers will give priority to buy validated by the LM-80 LED products into the U.S. market in the future, for non-validation of the Taiwan LED studio lighting packaging and grain plants, terrorism will be subjected to hinder.

 

Subject to the LM-80 light fades verify 6,000 hours of testing, time-consuming as long as six to eight months, part of the LED industry is of the view that the LED product specifications and technology with each passing day, after as long as several months, led high bay lighting verification standards may turn to change, therefore this certification still hold doubts, but the Taiwan Industrial Technology Research Institute, said that the lM-80 is considered the ticket to enter the U.S. market, manufacturers must report certificate issued by the LM-80 (LED lumen maintenance) trials in order to achieve the energy Star label, North America Illuminating Engineering Society (IES) has also set out the LM-80 light attenuation testing standards, not only for the LED application products provide measurement standards, to provide consumers with quality assurance, will become common testing standards in the world.

The future development of LED intelligent street lights

 

The future development of LED intelligent street lights

 

Continuous development and progress of today’s society, many household items and appliances are beginning to want more and more artificial intelligence to improve the humane operation of the product, the leader in the electrical products on the market which is to touch cell phones, laptops, etc. LED products for the emerging industries of course, is not far behind, using a variety of humane intelligent design used the inside of the power LED intelligent street lights, electronic ballasts, tunnel lamp driver-related products.

 

LED intelligent street lights control system for centralized monitoring and control. Depending on demand, time-sharing dimming LED lights, garden lights, saving 20% to 30% and extend lamp life. The advantage is an independent store preset information for the control of each phase, when a line failure can be immediately detected and the point of failure and fault sacrifice quality to save, troubleshooting, save resources and time.

 

In order to bridge in the river, with a more striking light and shadow performances and landmark results, a complete set of high-tech bridge design intelligent control systems and lighting change programs, bridges or lively or brilliant or exciting or quiet rich the scene changes effect the bridge to better interact and blend with the Cosmos waterscape person to write a gorgeous CLS movement.

 

Bridge LED lighting control system using the TCP / IP protocol, and after optimized signal transmission, so that the connected device in the led high bay lighting system consisting of more and longer distance connections, the transmission control protocol control the quality and reliability of the LED lighting system higher, two-way communication enables remote monitoring and control equipment more effectively, so that the LED landscape lighting control system is more stable.