作者：Blade

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will produce a magnetic field that is part of the current way to convert magnetic energy “stored in the inductor; when no longer current to the inductor, inductors the magnetic energy by the current in the released from the loop.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.

The “olive branch” threw to the LED outdoor landscape lighting business

 

The “olive branch” threw to the LED outdoor landscape lighting business

 

Yesterday, Nanhai District, special SMEs service Nisshin light industry in rout held on-site banking institutions with the new light source enterprises have signed a credit ceremony, held in the processing trade business seminars. In the meantime, the rout 63 municipal streetlight EMC information is officially released, more than 80 companies to the scene.

 

In the backdrop of the energy saving, power consumption high-pressure street lamps became “big.” For this rout street plan to the area of municipal management of street lights by “EMC” model into the energy-saving and environmentally friendly LED outdoor landscape lighting, while the rout municipal jurisdiction of street light maintenance pipe raising projects bundled contract of urban road lighting system upgrade.

 

The successful companies provide free led high bay lights, the electricity savings, we returned to the enterprise. “The rout Municipal Office of the relevant responsible person said, 2010 63 sections, regional, for example, sets of 63 meter electricity is 1.385 million yuan , assuming that the replacement LED outdoor landscape lighting electricity decreased $ 500,000, then freed up 88.5 million as compensation for corporate. It is reported that relates to the 1749 traditional high-pressure bulb needs to be replaced, a preliminary decision that the entire cooperation period of 7 years.

 

“In fact, from imported materials processing and then export is tax free, but there are policy due to ignorance, to pay more taxes.” Foshan Customs South China Sea Office of the processing trade, regulatory chief of Zhou Bin said, began to think that know for sure, but in communication with the enterprise, many companies still are not familiar with the policies and regulations.

The comparison of lighting effects between mains led lights and CFL

 

The comparison of lighting effects between mains led lights and CFL

 

Two different types of CFL lamps were installed in different locations of the hall. The divergence angle of the two fluorescent lamps are more than 110 °, while the Cree mains led lights is only 18 °. The optical density of the center beam of LED products is significantly larger than the fluorescent lamps is much higher, fluorescent 300, while the led high bay light to the 4465, which makes the LED lamps can be more light is concentrated in the local area.

 

Three lamp power and luminous efficiency are relatively similar, so the highlights of the Cree LED application is not on the energy-saving and high brightness. In fact, the Cree mains led lights lumen output is only a little more than half of 23W compact fluorescent lamps. It has the advantage that the beam in a small conical body, especially for local lighting. Cree LED lights will emit less light in the wide-angle region.

 

In short, the Cree mains led lights can increase the contrast of art and the surrounding wall, the color of the art look more distinctive. Table II a brief description of the different lamps caused by different light conditions. Art in the top of the wall, as opposed to 23W fluorescent lamps, Cree LED, the average vertical illumination reduces, it will be more light is concentrated in the surface of the artwork. Able to analyze the contrast on the CFL is only 0.5, while the LED lights to contrast 1.9, which greatly enhanced the art lighting effects.

The long cycle of growth case of mr16 light fittings meet the bottleneck

The long cycle of growth case of mr16 light fittings meet the bottleneck

From global population growth, electricity demand, energy-saving trends in three aspects, analysis of the growth trend of the global LED lighting market in the next decade, the Topology pointed out that the Asian region will become the greatest grow thin demand for LED lighting. LED high bay. The Japanese market, for example, the 311 earthquake caused the power shortage crisis, it makes the LED lighting market in Japan early in2014 matured. In addition, Central and South American countries including Mexico, Cuba, Brazil, Venezuela to ban incandescent, mr16 light fittings, and power supply are insufficient toenhance the demand for energy-efficient lighting products, coupled with a lower requirement for LED lighting product specifications, is expected to become the future ofthe various LED lighting manufacturers one of the main area of the layout.

However, the global LED lighting market into maturity in 2016, will face a two-stagedevelopment bottleneck. First, mr16 light fittings, by the high price, the market is the lack of product awareness and other factors, market penetration is difficult to exceed 20% bottleneck,once across the threshold will enter the fast-growing outbreak. Second, subject to theLED product life of up to 20,000 hours, about eight to 10 years only to be replaced under the influence, when the market penetration to grow to 40%, may again be faced with thereplacement cycle is too long, mr16 light fittings, making the weak demand into growth the plight ofstagnation. Mainstream LED lamp cup in a market – the CPL light Cup over the useful life of 50,000 hours have been significantly more than ordinary LED lamp life.

In the long run, LED lighting products in the global government successively activated to ban incandescent policy, mr16 light fittings, coupled with new residential built-in LED lighting alterationslighting needs in emerging markets such as China and other rural and urbanization, the pace and promote LED advertising light boxes build driven by bullish factors, LED lighting era just around the corner!

The comparison analysis of LED street light costs

 

The comparison analysis of LED street light costs

 

The new LED street light costs have a higher purchase costs, but these excess costs in theory, with its lower power consumption and maintenance costs offset.

 

Lighting retrofit project, the LED replacement lamp all the work on the automatic control circuit, work 12 hours a day, five days a week, 52 weeks a year (3120 hours / year). LEDPAR38 announced the useful life is 50,000 hours, in accordance with the above use, equivalent to 16 years. The average life expectancy of two fluorescent lamps is 8000 hours, equivalent to two years and six months.

 

In the United States, different states or different geographical and commercial electricity price has a big gap. April 2011, the average retail electricity price given by the United States is about 0.1 $ / KWh tariff rate from Hawaii 0.284 $ / KWh to the Utah minimum .0695 $ / KWh. Generally speaking, LED street light costs, able to withstand the economic areas of high electricity bills, because they bring energy savings sufficient to compensate for their own high sales price.

 

CFL spectrum in the long-wavelength red range is weak, compared to halogen or LED lights, which appear to be biased in favor of the yellow-green. Cree led high bay light can provide better light quality, and the halogen incandescent lamp spectrum, with a high color rendering index. Color rendering index, two CFL’s index of 82, two Cree LED 93 Cree LED lights will be more in the red spectral region of the long-wavelength energy distribution.

 

The annual replacement cost of the Bonneville Power Authority CFLR30 lights about 424.69 $ 537.26 $ CFLPar38 including labor costs. In the same circumstances, the LED new lamp reset each year to spend about 275.56 $. LED lights in the 16-year life cycle will not damage or maintenance.

SMD high power led market calls for the LED engine

The rapid development of LED lighting Products, a mighty force competing to join the new company was born in the world almost every day, especially the interior lighting of the mass market, forcing traditional lighting companies to tap into joining. SMD high power led is an electronic product, it requires not only such traditional lamps that structure, the shell must also be given a variety of string, and parallel matrix LED lights source lamp board, AC / DC constant current drive power, aluminum or ceramic, etc. heat , SMD high power led manufacturers need to employ electronic, optical, structural design engineer; traditional lighting is only one electrical products, traditional lighting manufacturers design, structural modeling of the production of lamps, the light source —- bulb bought to the professional factory plug will be able to use universal.

SMD high power led market calls for the LED engine

LED lighting design variety prevails, the inconvenience to the production, use, and industrial management, in particular the transition from traditional lighting plant to the SMD high power led plant, or just entering the initial of the LED lighting industry, will feel overwhelmed, where to start as well? Just enter the led high bay lighting industry, in order to reduce the risk and cost, often only to buy off-the-shelf LED light source lamp board, AC / DC constant current drive power, aluminum or ceramic such as the radiator assembly. Traditional lighting plant owners as effort as well buy a light bulb, buy a ready-made “LED light AC / DC constant current drive power” module into its traditional lamp housing can be magnificent turn as a the new LED lighting. Dreams can come true!, LED lighting, LED light source and the AC / DC constant current drive power integration module.