Pretty Lights Gets Even Prettier with New LED Stage Show

We’ve already covered the basics in another blog, but here’s a quick recap for you: Pretty Lights is the moniker of electronic musician Derek Vincent Smith. His hugely popular performances utilize major RGB LED lighting installations that are programmed to respond to and synchronize with his bombastic, dub step-and-sample-based songs. No matter what you think of the music, his show is a highly entertaining visual treat, to say the least. And now, it’s gotten even better, thanks to a new color-changing LED lights display, which includes illustrative design and brighter lights with even more highly-saturated colors and depth.  From Hey Reverb,  “As his stage name suggests, Pretty Lights’ music is as much about the visual experience as it is about the auditory one. His incredibly syncopated lighting production spared no expense and was customized in an entirely new way for every track he played. Included were multidirectional lasers pouring into clouds of fog, flurries of strobes, a tiered throne for Smith and a city of LED towers spanning the length of the stage.” Pretty Lights is touring now throughout the United States—check the tour dates, and cap off your summer with some LED light-fueled music!

Photos by Ryan Dearth, heyreverb.com.

Pretty Lights Gets Even Prettier with New LED Stage Show

We’ve already covered the basics in another blog, but here’s a quick recap for you: Pretty Lights is the moniker of electronic musician Derek Vincent Smith. His hugely popular performances utilize major RGB LED lighting installations that are programmed to respond to and synchronize with his bombastic, dub step-and-sample-based songs. No matter what you think of the music, his show is a highly entertaining visual treat, to say the least. And now, it’s gotten even better, thanks to a new color-changing LED lights display, which includes illustrative design and brighter lights with even more highly-saturated colors and depth.  From Hey Reverb,  “As his stage name suggests, Pretty Lights’ music is as much about the visual experience as it is about the auditory one. His incredibly syncopated lighting production spared no expense and was customized in an entirely new way for every track he played. Included were multidirectional lasers pouring into clouds of fog, flurries of strobes, a tiered throne for Smith and a city of LED towers spanning the length of the stage.” Pretty Lights is touring now throughout the United States—check the tour dates, and cap off your summer with some LED light-fueled music!

Photos by Ryan Dearth, heyreverb.com.

Color-Changing LED Dome Lights

Our Customer Service Representative Michael installed color-changing LED strip in the dome light of his car as his July Employee DIY Project and it’s pretty stunning! Using our High Power RF Controller, Michael now has remote-controlled automotive LED lights. It just took a few components from elementalled.

Building blocks of intelligent lighting design help create successful LED products (MAGAZINE)

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This article was published in the July/August 2011 issue of LEDs Magazine.

View the Table of Contents and download the PDF file of the complete July/August 2011 issue.

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The long-awaited hockey-stick expansion of the LED-based lighting marketplace is beginning to take shape as more replacement fixtures are entering the consumer and industrial landscape. The market potential is leading more product-development teams to attempt their own solid-state-lighting (SSL) designs, whether the product is a small MR16 or a larger PAR lamp. Yet herein lies the issue. LEDs are powerful semiconductor devices, and so allow product developers to deliver a whole new world of differentiation with their designs, such as intelligent lights with sensors and dimming capabilities. Lamp and luminaire designers are no longer defining LED fixtures only in terms of basic lux and color requirements.

In this still-maturing technology segment, many product designers are still coming up to speed on the language necessary to understand how to build any of this potential intelligence into their lighting system. This puts them at a disadvantage when it comes to discussions with potential vendors and partners. The developers, trying to grasp a changing and maturing technology landscape, need an understanding of the basics – the building blocks of intelligent lighting design.

These essential questions can help a developer understand not only how to correctly define a project, but also how to choose appropriate partners, design-service providers and vendors.

Building Block #1:
Do you require dimming?

The dimming question is tougher than it appears at face value. A “yes” answer sets off a daisy chain of follow-up questions including three major issues: input voltage, the dimming scheme, and dimming quality/performance.

Let’s first consider the input voltage. Low-voltage fixtures such as MR16 lamps that have inputs of 12 VAC or 24 VAC make it more difficult to develop a driver that can operate with the majority of the TRIAC dimmers installed in the existing infrastructure. Companies such as Cypress and Zetex are creating such drivers at this time. For standard line-voltage applications, there are many more available drivers that support TRIAC dimming. At the high end, there are a small number of 277V dimmers that are available for high-bay lighting, although the requirement for this feature is trending upward.

The second issue is the type of dimming-control required (see page 49 for more information on dimming-control scenarios). TRIACs were not designed to interface with LED systems but are broadly installed. Your new favorite dimmable AC/DC LED driver may only work with half the TRIAC dimmers installed in typical application scenarios. A driver also may be unable to correctly read the low and high end of the TRIAC and so will only offer about a 20-40% dimming range without introducing flicker, especially on the low-voltage side of the range.

If the dimming control comes from a microcontroller, the power from the AC line needs to be appropriately managed. Standard AC/DC drivers from companies such as Advanced Transformer are not made to power a microcontroller that has a 5V input rail. The microcontroller will also require an input signal to control the modification of the output dimming waveform, which can even introduce the complexity of supporting a communication network to carry the dimming information.

The final issue is the quality of the dimming waveform itself, because all dimming circuits are not equal. Dimming is nominally done via a pulse-width modulation (PWM) signal, a digital waveform used to control power (usually current) to the load based on the PWM duty cycle (from 0-100%). But the PWM signal can introduce complications via EMI noise that can result in LED flicker and create obstacles in the regulatory approval process.

The details of PWM signal control are beyond our scope here, but product designers should look for low-noise implementations. Some drivers use pseudo-random control of the PWM signal to greatly reduce noise.

Dimming performance can also suffer in terms of how smoothly a light dims if the control comes from a digital output. An 8-bit PWM waveform only has 256 possible steps that can dim a string of white LEDs. Especially at the low-end of the dimming range, those individual step changes become visible to the user. However, a 16-bit PWM has over 65,000 steps, allowing for a much smoother dimming curve.

Building Block #2:
Do you require feedback?

The notion of actually being able to adjust the operation of a light engine on the fly, based on input from sensors and operating characteristics such as temperature, is an advantage that LEDs afford. Yet the concept is new both to product developers working on lighting and to lighting designers.

In the case of LED lighting, sensing and control can yield more robust products from a lifetime standpoint. In part this is due to proactively preventing potentially-damaging operating conditions. Any LED system should be able to appropriately track different conditions such as overvoltage, undervoltage, short circuit, open circuit, and thermal runaway. Let’s consider how monitoring these conditions can be leveraged using Fig. 1. While this is an example using a Cypress Semiconductor driver, other IC vendors support similar sensing in simple white-light applications.

FIG. 1.

The circuit relies on a transformer (in dotted lines) to create an isolated topology, which makes it easier to pass UL certification. However, the circuit itself is able to sense what is happening at the load through the tertiary winding of the transformer (at the bottom of the transformer), and as such is able to recreate the waveform internally and adjust how it drives the LEDs.

The circuit also includes a temperature sensor and will shut down if the temperature rises above a set threshold. Temperature is the bane of the existence of LED lighting design engineers, since LEDs conduct all their heat through the base. This puts the engineers into an uncomfortable position of having to work as much on thermal design as on electrical design. This ensures that temperatures do not rise beyond datasheet junction temperatures of the components on the PCB board and cause a failure. Also, it’s widely known that temperature dramatically affects the flux and color output of the LEDs themselves, which can make the visual appearance of a row of fixtures appear to be different in color or brightness.

A system with added intelligence and driven by a microcontroller can implement an improved temperature-compensation algorithm using a simple and cheap thermistor placed near the LEDs themselves. After reading the board temperature, a well-known equation is used to calculate the junction temperature of the LEDs. Junction temperature is equal to the temperature measured on the board plus the product of the thermal resistance of the board, the constant current of the LEDs, and the forward voltage of the LEDs. These are all easily-discoverable values. The calculated temperature can then be used to derive any adjustments to the drive current or voltage in order to keep the flux output (or the color output of an RGB series of LEDs) inside the visible limit.

Building Block #3:
How do you want to drive the LEDs?

This is another simple question that becomes more complex the moment you bring a power engineer to the table. When faced with the omnipresent cost question, most engineers will quickly turn to a linear implementation, which can cost half of the switching alternative. Unfortunately, the tradeoff for using a linear drive system is about a 50% hit in the overall system efficiency, and that tends to counteract the green energy-efficiency advantage of LED lighting.

Switching implementations typically use either a step-down buck or step-up boost topology. There is a wide range of suitable driver ICs on the market that support such topologies. But product developers should keep a critical eye on a few operational features that can crucially impact performance.

The first is switching frequency. For example, if a driver is able to switch at 1.5 MHz rather than 1.0 MHz it will reduce the size of the inductor needed for the circuit, which in turn helps solve the inevitable board-space crunch in most retrofit applications.

A second key specification is a resistance value called RDSon, which is associated with the high-voltage MOSFET that switches the output and in some cases is integrated in the driver IC. If that RDSon value is too high, over 1 ohm for example, then the power dissipation will suffer, again killing the efficiency of the system.
The final key concern is the driver efficiency specification. A decent switching regulator can get up to 95% efficiency, which can differentiate a lighting system effectively in this competitive marketplace.

Building Block #4:
What’s going to set your product apart from the competition?

To be frank, this final question is about the sum of the parts of a lighting-system design that truly differentiate a product – or the lack of differentiating features. There is a veritable crush of companies seeking to carve out a space in this burgeoning LED retrofit market. Many will simply decide to create a non-dimmable or TRIAC-dimmable LED fixture or lamp and try to win in the market based on low cost. These companies will rise and fall based on the commodity pricing of basic components, not on the quality of their overall system.

Companies who instead desire to push forward with a combination of simple differentiating techniques will carve out unique and stand-alone spaces for themselves. Many lighting engineers simply don’t know enough of what’s available in the semiconductor market to take advantage of simple solutions. These techniques include some features in LED retrofit bulbs and fixtures, and other features in complete lighting system designs. Fig. 2 depicts some examples.

FIG. 2.

The block diagram shows a potential retrofit bulb. It takes the AC/DC line voltage such as 120 VAC, and then drops the voltage to drive a microcontroller which handles the TRIAC dimming of the LEDs. This is a similar approach to creating the PWM signal that we discussed earlier. However, this example also interfaces with a motion sensor that is a relatively low-cost external device that might be implemented in a lighting system. The sensor detects the presence of an individual in a room, causing the intelligent light to turn on automatically. A sensor that can be in the sub-$0.10 range can result in a product that is easily differentiated from the competition.

Consider as a second example a table lamp. In the simplest fashion it takes an offline signal and drives a set of white LEDs with no dimming. Again, there are multiple vendors in the market designing this lamp. However, the development team can differentiate the product with the addition of a capacitive touch-sensitive slider on the lamp to both turn the light on and off and to adjust the dimming level. Adding a capacitive slider to a design that already includes a microcontroller can cost as little as a line of copper on a circuit board. In other words, it is not expensive but yet again provides a unique advantage.

As a final example, consider outdoor backlights, such as those used behind restaurant signs. To save energy, the restaurant will want to drive the sign at different levels in the day or at night. But the simplest version of an SSL design will not allow such control.

There are driver ICs that allow software control of the constant current used to drive the LEDs. For example, the level might be software-adjustable from 350 mA to 700 mA – significantly changing the brightness. Such an LED backlight design can offer even more energy savings to the potential customer, maximizing efficiency during the entire day.

There are far more examples of features the lighting-product developer will encounter as LED technology continues to mature. Examples include additional communication interfaces, control mechanisms or thermal platforms. Differentiating a product in this market is not an onerous process, does not have to be costly, and can ultimately help a company position itself effectively. The building blocks discussed here are obviously not the only questions necessary to create an intelligent lighting fixture, but they offer an excellent starting point to successful products.

About the Author

LED lighting and control systems evolve for optimal efficacy (MAGAZINE)

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This article was published in the July/August 2011 issue of LEDs Magazine.

View the Table of Contents and download the PDF file of the complete July/August 2011 issue.

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For multiple fiscal and environmental reasons, lighting efficacy – defined loosely as light only when, where, and how it is needed – should be given the utmost consideration when we deploy lighting systems. From an energy-consumption standpoint, LED-based lighting represents the most important advancement in lighting in decades. LEDs as light sources are inherently efficient and LEDs can be configured in systems that are much more intelligent in terms of both controllability and adaptability than traditional fluorescent and HID technologies. Indeed LED-based solid-state lighting (SSL) can provide an advantage in efficacy from many angles, but luminaire and control-system architectures must evolve to deliver truly optimal efficacy.

From a system perspective, lighting efficacy is comprised of several elements, all of which are of first-order importance. Several are outlined in Table 1. Light source efficacy is not enough. Truly efficient lighting also requires efficient electronics, fixtures that don’t waste light, and control systems that further reduce wasted light.

Table 1. Elements of lighting efficacy

Based on efficacy advantages, LED-based fixtures appear to be either in the lead or quickly approaching the lead in many applications such as high-bay lighting, street lighting, indoor downlighting and even fluorescent troffer replacement. Still, we need to rethink proper light levels, focus on lighting only where it is required, and push deployment of control schemes to maximize energy savings and eliminate light pollution in the environment.

The lighting industry still has work to do in determining proper light levels. For example, regulatory bodies in North America do not currently take into consideration the differences between photopic (day), mesopic (dusk), and scotopic (night) human visual systems. Our visual system has evolved to account for the differences in lighting between day and night. During bright sunlit days, our eyes are more excited by warmer CCTs (correlated color temperatures) than during dim nights when our eye sensitivity shifts toward the colder, more-bluish moonlight. Mesopic lumen output describes a situation in between photopic and scotopic and is generally considered the most appropriate measure for street lighting.

Efficacy and eye sensitivity

The differences in efficacy can be dramatic when considered relative to photopic, mesopic, and scotopic sensitivity. This is shown in Table 2, which compares a low-CCT high-pressure-sodium (HPS) source to a much-higher -CCT, metal-halide (MH) source. High-CCT sources such as MH and LED are not necessarily given proper credit for exciting the eye in an optimal way for given environmental conditions. Given the data in the table, it’s no surprise that many people involved with case studies report that LED street lights with a lower total lumen output appear brighter than higher-total-lumen HPS street lights. Note that this statement refers to the brightness of the target area and not the fixture itself which may (falsely) appear brighter due to glare effects. We need standards that ensure safety without wasting light and energy.

Table 2. Comparison of high-pressure sodium (HPS) and metal-halide (MH) source efficacies.

Likewise, some regulations and guidelines don’t consider the CRI (color rendering index) of a light source even though it has recently been proven to have an effect in some applications (again, like street lighting) where small-target visibility is critical. Both CCT and CRI are critical because the required lumen output of a lamp varies greatly based on these factors. That said, their importance is still being debated and as recently as 2007, CIE’s stated position in CIE 180:2007 is that, “Colour rendering is not highly important for roadway lighting, except in sensitive urban centres and/or areas with large numbers of pedestrians.”

Utilization factor

Now let’s discuss utilization factor. The first three efficacy elements in Table 1 are static, at least within a relatively short timeframe of days or weeks. This is not the case with the fourth element that addresses the difference between the light supplied relative to the light needed. Utilization factor is a combination of the percentage of time that the lights are on and, when lights are on, the intensity of the light compared to what’s required or being utilized. Optimized lighting controls are essential to improving utilization factor and thereby reducing energy costs. LED lights present a new opportunity for controls as they are easy to regulate using various dimming methods, sensor interfaces, and communication infrastructures that allow the light to be modulated based on environmental conditions.

Lighting systems can perform occupancy detection to control on and off states. Several technologies can detect occupancy including passive infrared (PIR) or ultrasonic motion sensors, capacitive- or MEMS-based microphones, and digital cameras that perform image processing. Motion sensors are relatively inexpensive and are used most often although a combination of a motion sensor and another occupancy-detection method can yield superior performance. Multi-technology sensors decrease the likelihood of erroneous behavior, thus maximizing precision and decreasing energy usage.

Controlling fixtures and dimming lights to produce the appropriate amount of artificial light based on ambient light conditions is critical to both energy efficiency and user experience. Dual-loop sensors are now able to differentiate between light provided by the sun and artificial lighting systems so that fixtures can maintain a consistent light level on a target area. LED-based lamps have the advantage that deep dimming is easy to do and actually increases lamp life, in contrast with competing technologies.

Leveraging lumen depreciation

SSL also affords the potential of further energy savings in luminaire designs that accurately account for lumen depreciation in regulating light output. Light-output regulation is very important to LED-based lighting because of the technology’s extremely long lifetime. If properly protected and driven, LEDs shouldn’t burn out. Instead, the LED light output decreases over time based on a phenomenon called lumen depreciation. L70 is a parameter that describes the point in time at which the light output has decreased 30% from its initial value, and is typically on the order of 35,000 to 100,000 hours for LED lamps, as shown in Fig. 1.

FIG. 1.

To maintain a minimum amount of light output over the lifetime of a fixture, say 750 lm for a 65W replacement lamp or 6,000 lm for a parking-lot light, many fixture designs initially output 30% more light than is required. This represents a significant waste of electricity in that the target area is being over-lit for virtually the entire lifetime of the fixture.

Intelligent fixtures can regulate the light output to a lower level initially and increase the output over the fixture life. Ancillary benefits include consistency of light intensity and color, lower overall energy expenditure, and lower total thermal load. Lowering the total thermal load is extremely beneficial as it leads to longer lifetimes for all electronic components, especially the LEDs and power electronics.

Though beneficial, light-output regulation provides a significant technical challenge. One could use a predictive algorithm that estimates LED efficacy or output based on hours of operation and temperature measurements. But LED performance over time and temperature may not be all that predictable. For several families of LEDs from various suppliers, the actual lumen-depreciation curves have been shown to be significantly shallower than those predicated by accelerated, high-temperature testing.

Alternatively, a fixture design could add a sensor to measure the lumen output during operation, but there are challenges here as well. First, achieving proper mechanical placement of the sensor to measure overall- or average-lumen output may be difficult or even impossible. Second, dirt can can prevent photons from getting out of the fixture and may even redirect them towards the sensor, thus corrupting the measurement. Third, sensor aging and temperature drift could complicate matters even further.

FIG. 2.

In lighting systems, external sensors could measure the light output and communicate the data to the fixture. Such a system could be cumbersome, costly, and have its own set of technical issues. The right answer is likely a combination of approaches, and light-output regulation appears to be one area that is ripe for innovation.

Microcontrollers and networks

Clearly the industry must move toward intelligent lighting platforms to maximize energy savings via sensors, programmatic controls, and communications links between fixtures. Such intelligent luminaires rely on driver modules that integrate a microcontroller for interfacing to sensors and for control of the dimming profile. The smart fixtures enable managed-lighting systems with wired- or wireless-communications capabilities.

The communications infrastructure allows lights to communicate with each other, with remote sensors, and with centralized control and data-collection points. Such control systems have existed for some time but have not been widely deployed, having an estimated market share at 2% to 4%. Cost and complexity have hampered deployments. Moreover, the lighting industry focused first on more efficient sources such as fluorescent and HID that weren’t inherently controllable.

With LED sources, it’s time for broader deployment of control networks although the technology landscape is fragmented. Wired communications options include 0-10V dimming, DALI (Digital Addressable Lighting Interface), DMX (Digital Multiplex) or power-line communications. Wireless personal area network (PAN) options include Zigbee, Z-Wave, 6LoWPAN, or even Google’s new Android lighting platform. All may find usage although the market will likely pick the winners.

New lighting system topology

The trend is clearly toward systems that integrate the control strategies and intelligence directly into the ballast or driver. But, the overall power-supply and control architectures of these systems will likely change to take full advantage of LED technology. For example, consider a space lit by four 25W downlights, as shown in Fig. 2.

The lamps are controlled by remote occupancy and ambient-light sensors over a wireless PAN. A wired configuration could just as easily have been shown. Regardless, each fixture operates from line voltage and includes significant intelligence and therefore requires:

• 25W AC/DC converter
• 25W DC/LED constant-current converter
• Radio for the wireless PAN
• A relatively expensive microcontroller including flash memory for the PAN protocol stack
• Energy meter
• Optional sensors (temperature, light output, or color).

FIG. 3.

As shown in Fig. 2, data gathered by the MCU could be backhauled to a central location that records energy usage. Such a system could also be under remote control in addition to being able to interface to local sensors. This system, while perfectly functional, is expensive to implement and does not take into account the simple but significant fact that we now have a light source that is easy to power remotely. An alternative approach is shown in Fig. 3.

In this case, the 100W power supply incorporates the room controller/coordinator and is therefore capable of communicating directly with the sensors and the remote-control/data-backhaul interface. In this case, each fixture contains:

• 25W DC/LED constant-current converter
• A relatively inexpensive microcontroller
• Optional sensors (temperature, light output, or color).

From a power-supply standpoint, one 100W AC/DC converter is both more electrically efficient and less expensive than four 25W AC/DC converters. Energy metering is performed at the centralized power supply instead of at each lamp. The lamps communicate with the 100W supply over an extremely simple and inexpensive wired interface and therefore contain a less-expensive microcontroller, lighter communications-protocol stack, and no radio. Finally, if the optional local sensors aren’t needed, then no electronics are required locally inside the lamp – the 100W power supply could send a constant current directly to the lamp.

Our proposed system lies somewhere in the spectrum between 100% local power supplies and intelligence and 100% remote power supplies and intelligence (something akin to Redwood Systems’ technology). The market must decide on the best solution.

Finally, artificial-intelligence or fuzzy-logic technology will enable these systems to become more efficient by enabling active learning – prediction of occupancy and even a user’s desired light level. Such systems could also greatly simplify and possibly even eliminate the commissioning process. This is obviously yet another area begging for innovative solutions.
About the Author

LFI report, part 1: Linear LED lighting, OLED and planar lighting (MAGAZINE)

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This article was published in the July/August 2011 issue of LEDs Magazine.

View the Table of Contents and download the PDF file of the complete July/August 2011 issue.

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LFI report, part 2: Retrofit lamps, modular SSL

LFI report, part 3: LED technology, outdoor lighting

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LEDs again stole the show at the annual Lightfair International (LFI) tradeshow. While you could find plenty of conventional lighting on the exhibit floor, it was solid-state lighting (SSL) products that were prominent in most booths, ranging from A-lamp retrofits to decorative and architectural lighting. Purpose-built LED-based linear lighting that might replace fluorescent fixtures was arguably the biggest story. There was little new on the OLED lighting front at LFI, but other planar technologies are coming to market. There were both new players and new looks in outdoor SSL. And adaptive-control technology for sensing and controlling light levels is headed into the mainstream – despite the lack of broadly-accepted industry standards.

LFI continues to surge in popularity and surely LED lighting is partially responsible. Despite some concern in the industry about moving LFI to Philadelphia due to construction issues at the New York venue, registered attendance hit 23,709 – up slightly from last year’s Las Vegas show.

Again this year SSL dominated the LFI Innovation Awards. The Most Innovative Product of the Year award went to the Revel OLED luminaire from Acuity Brands. The Design Excellence Award went to Tech-Generation Brands for a low-voltage LED-based wall washer. Philips Lumileds took the Technical Innovation Award for its Luxeon A LED that the company is hot-testing at typical operating temperatures of 85°C. LED-based products also dominated the product-category awards, with winners including Cooper Lighting, Visa Lighting, and Lumenpulse.

Ironically, LEDs were an afterthought in the keynote presentations this year. But the conference sessions included plenty of LED-centric content.

In the following pages, we’ll present what we saw as the most-compelling product announcements and demonstrations in OLED and planar lighting, linear LED lighting, LED retrofit lamps, modular SSL products, LED technology, outdoor lighting, and other areas.

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Section 1: Linear LED lighting

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At LFI a year ago, LED-based lamps designed to replace T8 linear fluorescent tubes were in the headlines as many companies sought to deliver an SSL retrofit for what is the largest installed base of office and industrial lighting. But as we reported after the show, LED tubes haven’t delivered equitable performance.

This year the focus was more on purpose-designed LED-based fixtures that can serve in place of fluorescent troffers. That’s not to say there weren’t LED tubes on display. In fact, Cree showed a T8 tube reference design that product marketing manager Paul Scheidt said “addresses all of the shortcomings that the US Department of Energy (DOE) has documented about LED T8s.” Still, the bigger fluorescent-replacement news in the Cree booth was the CR fixture that the company launched prior to the show.

RTLED from Lithonia Lighting

Lithonia Lighting (an Acuity Brand) was out in front of the purpose-built, LED, linear-fixture trend by announcing the RTLED product at LFI last year, and showcasing the family in its 2011 LFI exhibit.

The product also integrates support for Acuity’s lighting-control technology that relies on wired links between fixtures using Cat-5 (computer-network) cables. Moreover the products implement what the company calls lumen management where the LED driver produces less output early in the fixture life and increases the output over time to combat lumen depreciation.

Lithonia also demonstrated square surface fixtures called TLED, and square recessed ACLED coffer fixtures, both of which use an array of LEDs and feature integrated controls.

LED Distributed Array from Osram

Osram Sylvania introduced an LED module for linear fixtures that it will both sell to others and use in its own luminaires. The LED Distributed Array integrates 48 LEDs on a 2×9-in circuit board. Luminaire designers can utilize multiple modules to create fixtures of almost any size. The company states that the module design produces uniform diffused light with no apparent bright or dark areas associated with LED location.

Just after LFI, Sylvania’s sister business unit Osram Opto Semiconductors announced the Duris E3 LED designed with a wide beam angle to produce uniform light in linear fixtures.

ALM LED module from Cooper

Cooper Lighting launched an LED module called the ALM that the company will use as a technology base for linear lighting, and also unveiled 32 luminaires across Cooper brands that will utilize the new module.

The module design is based on a dense array of relatively low-power (0.25W) LEDs, and the design only drives the LEDs at half the rated power. The scheme optimizes efficacy, according to Cooper, and will yield products that last 50,000 hours. The company asserts that its linear products will match or exceed fluorescent systems in optical performance with a 15-20% reduction in power density.

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Section 2: OLED and planar lighting

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Acuity Brands took the top LFI Innovation Award with its Revel OLED luminaire, and actually announced two OLED products at LFI. The ceiling-mounted Revel (pictured) is more decorative in nature although the individual OLED modules can be positioned to direct light where it is needed. The Kindred is a stylish ambient light designed to be suspended from the ceiling. The Kindred integrates more OLED panels and produces more than 3000 lm in aggregate. Acuity termed the LFI announcement a commercial launch, but the products will not be available until the first quarter of 2012.

Oree’s LightCell planar LED-based technology

Oree and Future Lighting Solutions have partnered hoping to commercialize Oree’s LightCell planar LED-based technology. At LFI, the partners conducted private demonstrations of tunable white panels whereas much of Oree’s earlier efforts have been focused on color panels.

As shown in the picture, the panels are relatively small, but Oree believes they can be combined to construct much larger fixtures. Each small panel includes built-in LED emitters. Future plans to have a demonstration platform available for sale by the end of the summer, allowing product designers to experiment with the technology and start luminaire designs. Separately, Future announced an intelligent lighting platform based on a partnership with Synapse Wireless.

Rambus from GE Lighting

GE Lighting made LFI news with LED-based planar luminaires based on technology licensed from Rambus. Rambus’s edge-lit Pentelic technology relies on etching a substrate layer to control the ray angle of light to provide uniform distribution over a panel. The company has said that the technology delivers 92-95% optical efficiency. GE demonstrated the Pentelic-based Edge family of luminaires at LFI including a ceiling troffer, a circular suspended pendant and a suspended rectangular luminaire. GE plans to ship the troffer this year and the others in the first half of 2012. All of the products will support adaptive controls and dimming for maximum energy savings.

About the Author

Report estimates energy-saving potential of LED lamps in Japan (MAGAZINE)

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This article was published in the July/August 2011 issue of LEDs Magazine.

View the Table of Contents and download the PDF file of the complete July/August 2011 issue.

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The Institute of Energy Economics, Japan (http://eneken.ieej.or.jp/en) recently published a report on the electricity-saving potential of LED lighting and concluded that if all lighting in Japan was switched to LEDs, the total potential savings would amount to 92.2 TWh/year. This figure is equivalent to 9% of
Japan’s current total energy consumption. Fig. 1 (previous page) breaks down the savings by sector, and shows that the greatest potential exists in offices and commercial buildings.

Table 1. Cost and payback periods for replacing different lamp types with LED lamps. (*Includes possible infrastructure and labor costs required to make the changes.)

The report says that the switch would cost ¥15.7 trillion (around $197 billion), due to the current high cost of LED lamps compared with ¥100 for incandescent bulbs and ¥1000-1500 for CFLs. However the cost of replacing all the 340 million incandescent lamps would be ¥800 billion (around $9.9 billion). Such a move would lead to very significant savings of 27.3 TWh/year, as well as by far the shortest payback period.

The report also says that the cost of achieving the electricity savings (see Japan’s Eco-point Program transforms market for LED lamps) would be ¥1.3/kWh for incandescent lamps, based on a 40,000-hour lifetime. The figure is ¥14-17/kWh for replacing other technologies, and ¥9.2/kWh on average. In comparison, the cost of photovoltaic power generation is ¥40-50/kWh.

The report notes that households are highly sensitive to initial cost, so eco-point and other discounting measures are likely to be effective in promoting the spread of LED lamps. Meanwhile, businesses may require energy-conversation tax incentives and other subsidies to reduce the burden of up-front investment.

About the Author