Designing LED Grow Lights with a microcontroller

A recent article from Embedded.com may help walk DIY LED Grow Light builders through a simple application and design process when using a Microcontroller as a Switch-Mode Power Supply (SMPS). Though not quite as easy as some other LED Grow Light build ups on the internet, this design can be useful for both boost operation or buck-boost operation depending on the LED Grow Light application and LED voltages required.

Light-emitting diodes (LEDs) have emerged in recent years as viable sources of light and are no longer used solely as status-light indicators for electronic equipment. Advances in technology have provided LEDs that are typically three times more efficient than incandescent bulbs. LEDs are also extremely durable and have lifetimes exceeding tens of thousands of hours. Power LEDs for lighting applications are designed to be driven with a constant current source. It is common to see standard current drive levels of 350mA and 700mA among different LED manufacturers.

The forward voltage across the LED can, however, vary depending on the type and number of junctions connected in series. Many manufacturers of power LEDs will provide multiple junctions, integrated into a single module.

One simple method that can be used to drive an LED is to install a resistor, in series, to limit the current. A linear voltage regulator or operational-amplifier (op-amp) circuit can also be connected in a constant-current configuration. However, these linear methods will not have enough efficiency at the required power levels.

A Switch-Mode Power Supply (SMPS) provides a much more efficient solution for driving the LED. An SMPS can buck or boost the input voltage to the correct level, to provide the desired LED current. The system input-voltage range and the required LED forward voltage will determine the SMPS topology that is selected. Buck-boost converter
The buck-boost converter topology is used when the supply voltage may be above or below the required output voltage and is especially useful for battery applications. This topology is also known as a fly-back or inverting regulator. A buck-boost converter can be implemented as shown in Figure 1 above.

This implementation has the advantage that a simple, low-side MOSFET driver circuit can be used. The topology shown in Figure 1 will generate a positive voltage, referenced to the input-voltage rail. The downside of this buck- boost implementation is that the load is not referenced to the circuit ground.

A simplified circuit design for an LED driver is shown in Figure 2 below, using a mixed signal, high voltage 8bit microcontroller, such as Microchip Technology's PIC16HV785. The output of the circuit is referenced to the battery voltage, not to ground. The output of the inverter is connected to the LED anode and produces a voltage that is greater than the input voltage.
The PIC16HV785 mixed signal microcontroller combines an 8bit microcontroller core with several on-chip analogue peripherals. These include a high speed, two-phase PWM circuit, ideal for current-mode control of switch-mode power supplies, and two on-chip op-amps that can be used to amplify the voltage across the current-sensing resistors.

This allows the use of very small sensing resistors, which reduces circuit losses and increases overall efficiency. The on-chip high voltage shunt regulator eliminates the need for an external 5V regulator when operating from higher supply voltages.

The PIC16HV785 also integrates a digital Capture, Compare and PWM (CCP) module, two analogue comparators, a 10bit A/D converter, an 8MHz internal clock circuit, internal precision voltage reference, and a programmable Brown-Out Reset (BOR) circuit. All of the pins of the op amps and comparators are externally accessible, so that any circuit configuration can be implemented.

The current-sensing op amp is connected as a differential amplifier, to obtain an accurate measurement of the voltage across the current- sense resistor. The current is measured in the return of the power source, to simplify the requirements of the circuit. R1, R2 and C1 form a low-pass filter to reduce any switching noise that may be present. The cut-off frequency of this filter must be chosen above the converter switching frequency, to avoid limiting the control loop response.

Analogue Style Module
The two-phase PWM module, an internal comparator and a voltage reference form the circuit that regulates the amount of LED current. The two-phase PWM is an analogue-style module that works on the set/reset principle.

First, a clock signal, derived from the system clock, is used to periodically turn on the PWM output. The PWM clock signal sets the fundamental PWM frequency. Then, a reset signal from one of the on-chip comparators turns off the PWM output, when a specified reference level has been reached.

The amplified current signal is internally routed to the positive input of Comparator 1 on the PIC16HV785. The Capture-Compare Peripheral (CCP1) on the PIC16HV785 is used in the PWM mode to generate the voltage reference for the comparator. Using the PWM allows fine control of the comparator reference voltage. The PWM signal is filtered with an RC filter to produce an analogue voltage and is connected to the negative comparator input pin.

The software for this application is very simple, since the LED current-control function is accomplished in the analogue domain. After all peripherals have been enabled and a current-reference level has been set, the LED will continue to illuminate without software intervention.

However, the application code can use the on-chip 10bit A/D converter to measure the supply voltage, which then drives the LED in a constant-power mode. As the battery input voltage changes, a new voltage-reference value is produced by the D/A circuit (implemented with the CCP peripheral) to provide the required compensation.

Setting LED brightness
Since the microcontroller core is only spending a small portion of time in the power-regulation process, more time can be dedicated to the user interface and to provide additional features, such as battery status monitoring and bright- ness level control. There are two ways that the LED light level can be adjusted using this circuit and software.

The first technique relies on the principle that the brightness of the LED will change with the drive current. In fact, an approximate linear control of the LED brightness can be accomplished using this method. However, variable current dimming is not the most efficient way to set the LED brightness level. The LED achieves its best efficiency at the maximum drive-current level specified by the manufacturer.

A low-frequency PWM signal of between 60Hz and 1kHz can be used to modulate the LED drive current. Instead of reducing the current drive level, the LED is always driven at maximum current during the on-time. The duty cycle of the PWM signal sets the average amount of time that the LED is energised.

The chosen PWM frequency should be sufficiently high so that the LED current is turned on and off at a rate that will not cause the human eye to detect flickering. The PWM frequency must also be low enough so that the current-regulation circuit has enough time to stabilise during the PWM on-time. If these conditions are met, the human eye will average the light output from the LED over time.

The PIC16HV785 contains all the required components to implement an efficient high power LED drive circuit. It can be easily configured for boost operation or buck-boost operation, depending on the input voltage range.

The application uses only a small portion of the microcontroller's RAM and Flash memory, leaving plenty of room for additional application code. With enough unused peripherals on the PIC16HV785 microcontroller, a second LED driver, battery charger, or other switch-mode circuit can also be implemented.


If one of the hobbyist readers chooses to build a LED Grow Light using a microcontroller please share your project with the rest of the LED grow light readers here, using your link or comment below.

Future LED Grow Lights use Nanophosphors as Quantum Wells


DIY LED Grow Lights of the future may include this new full spectrum technology. Quantum dots are nanoscale semiconductor particles that possess unique optical properties - their emission color can be tuned throughout the visible and infrared spectrum. This means the quantum dot enabled LEDs can emit at almost any color. This provides more color options and better quality white LEDs.

Evident Technologies, Inc. of Troy, New York USA, has licensed nanocrystal patents from Philips Electronics. According to Philips, the nanoncrystal technology could pave the way for commercialization of nanocrystal-based LEDs. Evident says that it will use the nanocrystals as a phosphor for its LEDs in a product line that it will launch immediately. The company plans to make LEDs in additional colors that were not previously available. White LEDs use phosphors to convert blue LEDs into white or other colors, Philips says that while the underlying phosphor technology can limit the range of colors that are attainable. According to Philips, the semiconductor nanocrystals do not have these color limitations. Evident actually uses nanocrystal phosphors as quantom wells. These can be tuned to any wavelength of light emission.

Will LED Light Bulbs beat Solid State Lighting Advances?


Seems Matsushita Electric Works Panasonic announced details of a new solid state lighting product line and the research that surrounds it to the general public during the 21st International Vacuum Nanoelectronics Conference held in Poland last month.

Though the company claims their new silicon light bulb technology might one day be as important as LED and OLED lighting, it appears unlikely as Panasonic's BSD(Ballistic electron Surface-emitting Device)lighting technology doesn't currently have the potential to upset the lead that LED Lighting has, given the usable life (10,000 hours) and lumens per watt (100 lumens per Watt) that the data claims, not to mention the price point for LED Light Bulbs has been falling very fast.

This was developed in cooperation with the Graduate School of Engineering at the Tokyo University of Agriculture and Technology, and most likely uses licensed technology from Group IV Semiconductor (in Canada)- which has developed a silicon chip that excites Xenon gas to emit UV light from within the vacuum bulb which in turn causes the phosphor to fluoresce.

Any Solid State Lighting technology, Silicon based or otherwise that can push forward Solid State Grow Lights is always a positive.

LED Grow Lights sprout with Lamina


Is it Lamina Solutions Center (LSC) or the Lamina Resource Center?

Sure I am a little dazed and confused by the press release from Lamina, either way I felt this was a worthy post for anyone interested in LED Grow Lights.

Lamina Resource Center Offers Advanced Tools, Unique Expertise For Customer Product Development Needs

Center Offers Advice, Equipment, Design Software, Simulation and Testing of Concepts That Can Flourish with Inclusion of Lamina’s Solid-State LED Technology

WESTAMPTON, N.J.--(BUSINESS WIRE)--Lamina Lighting Incorporated (Lamina), an innovator of LED lighting systems and technologies, today announced it has launched the Lamina Resource Center, a unique service that allows customers and potential customers to utilize the company’s specialized expertise and equipment for their own product development purposes. The Center also gives customers the ability to “test-drive” the integration of Lamina’s unique solid-state LED lighting technology into their designs and concepts, giving them a true indication of the product’s enhanced potential through the use of LEDs.

“Lamina’s Resource Center is a great way for lighting professionals to see exactly what our innovative technology can do when integrated into their designs,” said Frank M. Shinneman, President and CEO of Lamina. “We have made our specialized equipment and technical expertise available to our customers for use in their concept and product development.”

Services offered by the Lamina Resource Center include Proof of Concept Development and Optical Measurement Services. Through the company’s Proof of Concept services, customers can validate the use of Lamina’s LED technology in their applications, either through demos or by actually integrating the technology into existing fixtures to the point of electronics circuit design. This gives customers the resources and confidence to ascertain the appropriateness of solid-state lighting for their application, and take the first step in development to showcase the result of integrating LED technology.

Through Lamina’s Optical Measurement Services, customers can take advantage of Lamina’s design and measuring equipment -- some of the most sophisticated in the industry. These devices include high-precision illuminance (lux) meters, LightTools, Zemax and ASAP optical design software, integrating spheres, spectoradiometers, goniometers, luminance meters, and more.

Other services offered by Lamina’s Resource Center may include the development of complex custom electronics applications where Lamina’s experienced electronic engineers will utilize the company’s design and simulation tools to assist customers in the development of applications that require in-depth knowledge of communication protocols, microcontrollers, analog power management circuits, and other technologies. Optical Design services would involve implementing a custom optical design then simulating it in order to demonstrate expected results, and then assistance in implementing a final optical solution. Evaluating secondary optics would utilize Lamina’s measurement expertise to assess and characterize the ever-increasing variety of standard optics available, allowing the customer to identify which optic is suitable for their specific application. And finally, the characterization of high-power LEDs can help customers save money by using Lamina’s dedicated light measurement equipment to provide a ample variety of accurate LED measurements, rather than outsourcing the acquisition of this data to a third party.

About Lamina

Founded in 2001 as a spin-off from the Sarnoff Corporation, Lamina Lighting is at the forefront of global LED research and product development. With its Atlas(tm), Titan(tm) and SoL(tm) Series LED product lines, Lamina provides ultra-high brightness white LED lighting products that satisfy the growing global need to replace conventional lighting with LED technology for general illumination. Among its other benefits, Lamina's environmentally responsive LED technology and programs aid in lowering CO2 emissions-the dominant GHG contributor to global warming. Headquartered in Westampton, New Jersey, Lamina Lighting is funded by five premier technology venture funds. For more, visit www.laminalighting.com .

©2008 Lamina Lighting Incorporated. Lamina is a registered trademark and the Lamina logo, Atlas, Titan, TitanTurbo, TruColor, EZ-Connect and SōL are trademarks of Lamina Lighting Incorporated. All other trademarks mentioned are the property of their respective owners.

SSPR
Belinda Banks, 609-750-9110
Belinda@sspr.com
or
Lamina Lighting Incorporated
Dan Polito, Vice President of Marketing
609-265-6802
dpolito@laminalighting.com


and for the LED Grow Light reader that wants it straight and pure:

Lamina Solutions Center (LSC)

Lamina has developed a solution resource center where our customers receive a high level of technical support with the primary focus being to assist them in developing Lamina-based LED applications.

Our LSC is made up of both proof of concept and optical development services. With our proof of concept services customers can now confirm the viability of Lamina technology in their applications. This is typically facilitated via application demos, or by incorporating Lamina LED technology into their electronic circuit designs which can also include their current lighting fixtures. With Lamina’s comprehensive optical services we also offer our customers LED and LED lighting system assessment capabilities. Customers with qualified Lamina LED lighting opportunities can now utilize the knowledge and experience of our SSL engineers, verify designs with our specialized measurement and simulation equipment thereby reducing application development time.

Lamina offers qualified customers some of the most specialized measurement, simulation and design equipment available, including:

• High precision illuminance (lux) and luminance (nit) meters
• Spectroradiometers
• Goniometers
• Integrating spheres
• Zemax™, LightTools™ and ASAP™ optical simulation and design software

The breakdown of services that the Lamina Solutions Center offers includes:

Lamina Proof of Concept Development Services
Our proof of concept services enables qualified customers the opportunity to incorporate Lamina LED technology in their new product designs or by retrofitting their existing lighting fixtures. The confidence gained by this exercise helps to alleviate the uncertainties about the suitability of SSL for their lighting applications. Our LSC can quickly evolve your idea from concept to final product through the use of Lamina LED technology.

Specialized Electronics Application Development Services
Our team of experienced electronic engineers utilize the most sophisticated design and simulation tools available. Armed with this state-of-the-art equipment and proficiency in electronics, our application engineers counsel our customers in the development of multifaceted and specialized applications – many involving a through understanding of micro-controllers, communication protocols, analog power management circuits, and a host of other technologies.

Optical Evaluation, Characterization, Design and Simulation
Our optical evaluation service allows accurate characterization and assessment of the ever-growing range of market-available optics thereby enabling our customers to identify which optics are appropriate for their project. Typically our LSC team often performs an optical design and simulation early in the process in order to display probable results. We then corroborate with the customer to execute the final optical solution. This process is best-suited for those customers that have projects which require specific optical design, or those that may not have their own optical engineers or optical design software.

Ultra-Bright LED Classification
Obviously, LED data is critical when making important design decisions. That said, many customers do not have specialized light measurement equipment internally so they must farm this process out to a coslty third party. Our in-house optics assessment capabilities provides myriad of accurate LED measurements such as CRI, flux, chromaticity, lumen output, radiation patterns, spectral distribution and intensity.

Let us help you take the first step to develop a proof of concept to showcase what can be achieved with Lamina-based LED technology. Please contact the Lamina Solutions Center via email at customerservice@laminalighting.com or call us at +1 800-808-5822 (US Toll Free) or +1 609-265-1401 (outside the US).


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Would love to hear from anyone in the LED Grow Light community who has used or is using the above solid state lighting resources or solutions.

LED Lighting Replacement For Conventional HPS/HID Lights

LED Street Light
Though far from an LED Grow Light and not fine tuned for the wavelengths required by plants, this could be a direct solid state lighting replacement for Indoor Gardeners that currently use HID or HPS bulbs.

After four years of extensive Research & Development, Remco Solid State Lighting Inc., a Toronto, Canada-based SSL Solutions Company, has broken through the barrier to replace conventional street lighting with its recently patented SSL technology and LED-based street light.

Its disruptive SSL technology utilizes the dynamic resistance of LEDs providing a LED light engine that is up to 98% power efficient – only a 2% power loss that enables optimal power and LED lighting efficiencies. IES certified photometric lab results and successful pilot field-testing conducted at Camp Borden military base have verified these industry-leading levels of performance.

A number of companies have ventured into the LED street lighting market with varying degrees of success. Now, Remco Solid State Lighting has delved into this market utilizing its recently patented power efficient light engine and prototyped an LED Street Light for a truly equivalent LED replacement of the conventional cobra head street light.

“Real LED-based lighting application replacements for existing light sources must be direct lighting replacement solutions - lumen for lumen and LUX for LUX, plus offer the benefits of energy savings and reduced maintenance cost," stated Ron Russell, Remco’s CTO and inventor of Remco’s patented LED light engine. Not only is it scaleable to all lighting applications but it also offers a significant competitive advantage in high power LED lighting applications.

Conventional street lights typically use a high-pressure sodium bulb. Even non-technical people can see the difference in the picture. The CTO also conveyed that, despite having retrofitted a cobra head street light fixture with Remco’s proprietary thermal management and LED light engine using a stock HPS cobra head lens, Remco’s LED Street Light was able to outperform and produce more light at a greater efficiency than the conventional high-pressure sodium street light.

Mark Matthews, Remco's President and CEO stated, “What we strive to achieve with our SSL technology and LED lighting applications is equivalent useable lumens utilizing LEDs to replace conventional lighting with significant energy savings. Our Light engine is up to 98% power efficient and this technology is the key, especially in high power lighting applications."

According to Alex Savu, Energy Manager at Camp Borden military base in Canada (where the LED street light pilot test was performed), conventional HPS street lights consume 138 watts (100 watt HPS bulb plus the ballast which consumes an additional 38 watts) and the Remco prototype (a light engine and LED fixture within a cobra head fixture) consumed only 111 watts to generate 4770 useable lumens – a direct lighting replacement.

Matthews explained that, “While the test confirms only a 20% energy savings at 40.1 lumens per watt, these results are excellent considering that we have incorporated our LED fixture within a cobra head fixture and lost 20% of the lumens output absorbed by the standard HPS cobra head lens; whereas, we could have generated approximately 5300 useable lumens without the HPS lens.”

“When we complete our commercial product to replace all models of 100 watt HPS street lights (Note: the ballast also consumes 38 watts) with our patented LED light engine, proprietary thermal management and optics, utilizing 100 lumens/watt white LEDs, the commercial Remco LED street light luminaire will achieve approximately a 50% energy savings at 72 watts.”

It is estimated that there are 50 million 100 watt conventional street lights in North America, and we would like to replace all conventional street lights worldwide with Remco’s energy efficient LED Street Light as a contribution to help reduce Global Warming.

Alex Savu reported that since performing the tests, he has seen the superior performance of Remco's LED Street Light. He said, "The light is phenomenal. Basically, it is superior. It looks good!" He explained, "We would have to change our current units ten times before changing one of their units. The way we operate our lights, their units will last 27.4 years." (10 hours per day, seven days per week.)

Savu added, "Once we put theirs up, there were no complaints whatsoever." “However,” he said, "most of the other street lights we tested received complaints; either they were not bright enough or there was something wrong with the light."

In addition to its power efficient light engine for street lights, the company has developed a fully integrated pendant linear SSL luminaire prototype to replace fluorescent lighting capable of 66% energy savings as well fabricating prototypes of Edison-based LED bulbs with brightness levels equivalent to the incandescent bulbs they replace at energy savings of 85% to 95%!

Remco’s new LED light engine technology and SSL luminaires are gaining attention. In 2008 the company was selected as one of Canada’s Top Ten Cleantech technology companies by the Ottawa Centre for Research and Innovation.

Remco is on the verge of setting new standards in the Solid State Lighting industry and is currently seeking capital and licensing to major global lighting/fixture organizations and/or international distributors to collectively take a commanding lead in high power LED lighting applications.

Photo cutline: Remco’s Bright LED Street Light is in the foreground and conventional HPS street lights in the background.

GaN Stacked Carbon Film LED Grow Light

GaN on Carbon LED
Leave it to the Empire of the Sun to conquer Solid State Lighting, if this ever makes it into the LED Grow Light market the rays of the rising sun will be upon us all.

A joint research group announced that they developed a new technique to form gallium nitride (GaN) based LED on a flexible substrate.

The group was led by Hiroshi Fujioka a professor at Institute of Industrial Science at the University of Tokyo and the Kanagawa Academy of Science and Technology (KAST). The technique employs a kind of physical vapor deposition (PVD) process, which is suitable for the production of large size LEDs in large quantities.

"With this technique, it is highly possible to form, for example, a 1m square GaN LED that emits light from the entire surface at a low cost," Fujioka said.

The group has only confirmed emission by "photoexcitation" with the irradiation of UV light on a 2cm square so far, but it is planning to conduct the experiment of emission by electrical excitation, as in the ordinary LEDs, in a few months.

Fujioka and others used an "organic polymer sintered graphite sheet (PGS)" for the substrate, instead of a sapphire substrate, which is commonly used in GaN LEDs. PGS is a thin graphite sheet obtained by sintering a sheet of plastic film in an anoxic environment at a high temperature of 3,000°C.

The C atoms are bonded together in a hexagonal shape in a planar manner, and this planar structure is vertically stacked to form layers. The graphite sheet is 25-100μm thick. "The surface is flat at the atomic level," Fujioka said.

The group formed crystals of GaN and aluminum nitride (AlN) on PGS by using a proprietary PVD process developed by Fujioka and others and found that the crystals thus grown have a superior quality free from defects.

"We conducted X-ray analysis and examined the photoexcitation emission spectrum," Fujioka said. "The crystal quality was on par with or even higher than that of commercially available GaN LEDs."

The wavelength corresponding to the emission inherent to GaN (3.3eV) is approximately 365nm. But an ordinary GaN has some emission peaks at wavelengths longer than that due to the crystal defects. GaN crystals formed by the latest technology do not have such undesired emission peaks.

The PVD process used in the formation of GaN film is called "pulse excitation deposition." It is Fujioka's proprietary technique developed based on a sputtering method used in the production of LCD panels, etc. According to this technique, metal Ga is sublimed by pulse plasma and then subjected to a reaction with nitrogen. The process temperature is reportedly 600-800°C when forming a GaN film.

"The technique is applicable to the formation of large films," Fujioka said. "It doesn't take a long time for a manufacturer to make large LEDs."

N atoms in GaN bonded to C atoms in PGS

According to the group, the key factor that made the formation of high quality GaN crystals on PGS is that the lattice constant of carbon (C) atoms constituting PGS and that of the hexagonal nitrogen (N) atoms in the nitride coincide with each other. Moreover, the C-C bonding in PGS tends to attract and bond N atoms.

"First, N atoms are fixed on PGS and then GaN crystals are formed on it," Fujioka said.

PGS is "widely used in heat radiation sheets of personal computers, etc because it has a thermal conductivity four times as high as that of copper (Cu) and they are much cheaper than sapphire substrates" (Fujioka). Because it is flexible and thin and has a high heat resistance, large bendable emission sheets as thin as cloth can be produced at a low cost, he said.

Gallium (Ga), known as an expensive material, "may only be required in a small amount even for a large film if the sheet is less than 1μm thick," he added.

The details of the latest technology will be presented by Fujioka and others at 55th Spring Meeting 2008 sponsored by the Japan Society of Applied Physics, which runs from March 27-30, 2008.

Innovative Ultra-Efficient Polarized LED Wins $30K Prize


Martin Schubert’s polarized LED could improve LCD displays, save energy

Troy, N.Y. — In recent years, light emitting diodes (LEDs) have begun to change the way we see the world. Now, a Rensselaer Polytechnic Institute student has developed a new type of LED that could allow for their widespread use as light sources for liquid crystal displays (LCDs) on everything from televisions and computers to cell phones and cameras.

Martin Schubert, a doctoral student in electrical, computer, and systems engineering, has developed the first polarized LED, an innovation that could vastly improve LCD screens, conserve energy, and usher in the next generation of ultra-efficient LEDs. Schubert’s innovation has earned him the $30,000 Lemelson-Rensselaer Student Prize.

“In our community of innovators, the Lemelson-Rensselaer Student Prize recognizes our most inspired and dedicated students for their ingenuity and deep understanding of the greater global implications of their innovations,” said Rensselaer President Shirley Ann Jackson. “Martin Schubert is both a talented engineer and inspired entrepreneur. He launched his innovation not only because he had the engineering prowess, but because he also has a remarkable understanding of the technological, environmental, and energy saving outcomes his enlightened innovation will bring. Today we applaud him and the other finalists for their dedication and excellence, and we encourage them to continue to spark informed innovation around the world.”

Schubert is the second recipient of the $30,000 Lemelson-Rensselaer Student prize. The prize, which was first given in 2007, is awarded to a Rensselaer senior or graduate student who has created or improved a product or process, applied a technology in a new way, or otherwise demonstrated remarkable inventiveness.

For photos and video of the winner and award finalists, as well as a Webcast of the announcement ceremony, please visit: www.rpi.edu/lemelson.

The Next Generation of LEDs
Schubert’s polarized LED advances current LED technology in its ability to better control the direction and polarization of the light being emitted. With better control over the light, less energy is wasted producing scattered light, allowing more light to reach its desired location. This makes the polarized LED perfectly suited as a backlighting unit for any kind of LCD, according to Schubert. Its focused light will produce images on the display that are more colorful, vibrant, and lifelike, with no motion artifacts.

Schubert first discovered that traditional LEDs actually produce polarized light, but existing LEDs did not capitalize on the light’s polarization. Armed with this information, he devised an optics setup around the LED chip to enhance the polarization, creating the first polarized LED.

The invention could advance the effort to combine the power and environmental soundness of LEDs with the beauty and clarity of LCDs. Schubert expects that his polarized LED could quickly become commonplace in televisions and monitors around the world, replacing widely used fluorescent lights that are less efficient and laden with mercury. His innovation also could be used for street lighting, high-contrast imaging, sensing, and free-space optics, he said.

The Next Generation of Lighting Researcher
Schubert is the son of renowned lighting research expert and senior chair of the Rensselaer Future Chips Constellation, E. Fred Schubert. The younger Schubert, who received his bachelor’s and master’s degrees from Cornell University in electrical engineering, was set to pursue a career in computer chip development. But his father quickly identified his skills and ideas for the advancement of lighting technology and recruited him to join the large lighting research effort at Rensselaer.

“Martin Schubert has had the opportunity to work in one of the most advanced and well-known lighting research teams in the world,” said Rensselaer Dean of Engineering Alan Cramb. “And Schubert has shown that not only can he keep up in the lab, but he can also independently excel and innovate. His discovery of the first polarized LED marks an important advance in photonics technology that I am sure will resonate in photonics laboratories and companies around the world. Schubert is absolutely a young engineer to watch.”

Under the tutelage of his adviser, Michael Shur, the Patricia W. and C. Sheldon Roberts ’48 Professor of Solid State Electronics and director of the Rensselaer/IBM Center for Broadband Data Transfer Science and Technology, Schubert quickly excelled in the field. As soon as he arrived at Rensselaer, he began working nearly independently on his research, using some of the top research equipment available to the constellation, including a cutting-edge clean room laboratory.

During his time with Rensselaer Schubert has published three peer-reviewed, archival papers and filed for several patent applications on his polarized LEDs. In addition, Schubert is co-author of 15 other papers on related research, including a paper in one of the top journals in his field, Nature Photonics. The Nature research on the world’s first ideal anti-reflective coating was featured in media outlets around the world, from NPR’s “Morning Edition” to the London Daily Telegraph and Scientific American magazine.

Schubert is expected to complete his doctorate in electrical engineering this fall. After graduation he plans to pursue a career in semiconductor devices and photonics.

Schubert was born in Germany and grew up in New Jersey and later the Boston area.

The Lemelson Program
Schubert joins last year’s winner of the Lemelson-Rensselaer student prize, doctoral student Brian Schulkin. Schulkin, who invented the first portable terahertz sensing device, the “Mini-Z”, is currently working on an even smaller device and was recently named to the 2007 Scientific American 50 — the magazine’s prestigious annual list recognizing leadership in science and technology.

The $30,000 Lemelson-Rensselaer Student Prize is funded through a partnership with the Lemelson-MIT Program, which has awarded the $30,000 Lemelson-MIT Student Prize to outstanding student inventors at MIT since 1995. More information can be found at http://web.mit.edu/invent/.

Timothy Lu, a graduate student in the Harvard-MIT Division of Health Sciences and Technology, is the 2008 winner for the $30,000 Lemelson-MIT Student Prize. Lu has invented processes that promise to enhance the effectiveness of antibiotics and help eradicate layers of bacteria known as biofilms, in order to combat bacterial infections, such as those caused by Escherichia coli biofilms and MRSA (methicillin-resistant Staphylococcus aureus). More information is available on http://web.mit.edu/invent/n-pressreleases/n-press-08SP.html.

The University of Illinois at Urbana-Champaign also joined Rensselaer as a new partner institution last year with the announcement of the $30,000 Lemelson-Illinois Student Prize. The winner of the 2008 Lemelson-Illinois Student Prize will be announced during a formal award ceremony on Feb. 28, 2008.

On May 26, the winners of all three student prizes will join together at MIT for a discussion and ceremony to honor all of the winners. In June, the winners will take part in the Lemelson-MIT Program’s second annual EurekaFest, a multiday event to celebrate the inventive spirit in Boston and Cambridge, Mass.

About the Lemelson-MIT Program
The Lemelson-MIT Program recognizes outstanding inventors, encourages sustainable new solutions to real-world problems, and enables and inspires young people to pursue creative lives and careers through invention. Jerome H. Lemelson, one of the world’s most prolific inventors, and his wife, Dorothy, founded the nonprofit Lemelson-MIT Program at the Massachusetts Institute of Technology in 1994. More information is online at http://web.mit.edu/invent/.

About Rensselaer
Rensselaer Polytechnic Institute, founded in 1824, is the nation’s oldest technological university. The university offers bachelor’s, master’s, and doctoral degrees in engineering, the sciences, information technology, architecture, management, and the humanities and social sciences. Institute programs serve undergraduates, graduate students, and working professionals around the world. Rensselaer faculty are known for pre-eminence in research conducted in a wide range of fields, with particular emphasis in biotechnology, nanotechnology, information technology, and the media arts and technology. The Institute is well known for its success in the transfer of technology from the laboratory to the marketplace so that new discoveries and inventions benefit human life, protect the environment, and strengthen economic development.

Naturally I don't want to downplay the achievements or hard work of Mr. Martin's in any way, but looking over the finalists and entries while the watching the webcast of the award ceremony I personally think this prize may have been awarded improperly due to his fathers position at the institute. Though I may be biased in who should have won this award (as with the 2007 finalists; Eben Bayer and Greg Ten Eyck should have split last years prize), it seems many can innovate or build smaller widgets (and help pollute the planet), but few can truly help create a better world in which all species may live sustainably. Sure the work is great no doubt, but given the speed at which innovation(and the destruction of the planet) is progressing it may be a little late when one looks deeply at the bigger picture that is unfolding for all.

DIY High Performance LED Lighting System

Looks like the toadheads have done it again, this time a three (3) part series on on how to build your own DIY LED Lighting System the right way with off the shelf components! - these folks never cease to amaze me with the quality of technical articles published (especially if your an automotive gear head or overall geek like myself).

Turn on your LED Night Light and take a peek below!

Oh, and if the Jaycar Electronics link within the DIY LED Lighting article doesn't work don't fret it will be live again soon enough. Remember your exchange rate when calculating the actual cost for this project.

Part 1 : http://www.autospeed.com/A_109714/cms/article.html

Part 2 : http://www.autospeed.com/A_109715/cms/article.html

Part 3 : http://autospeed.com/cms/A_109716/article.html


Can't wait until these guys find the 15W HB LEDS to play around with.

LED 'Lighting for Tomorrow' Competition 2008

Solid State LED Lighting for TomorrowIts that time of year again for all of the DIY LED Grow Light Hobbyists to show some Lux, the official LED Lighting for Tomorrow Competition 2008 kicks off and plans on being the biggest yet, last years event attracted over 40 entries in the LED lighting category. If you fancy yourself a budding LED Grow Light specialist this could be your calling, and don't forget the fame and fortune if you win. Realize that the LED Lighting contest is mostly for general illumination which use Ultra-High Brightness (UHB) LEDs, but with a twist as this year a new "Future LED" Showcase category has been added and if an innovative technology entry for an indoor solid state LED plant light were to be received the judging panel wouldn't turn it away and your entry may even help create a new separate category for Solid State Plant Lighting in future LED Lighting Competitions.

This years Solid State Lighting (SSL) competition is organized by the U.S. Department of Energy, the American Lighting Association, and the Consortium for Energy Efficiency.

Important Dates to remember if you plan on entering:

January 17-21, 2008 - Lighting for Tomorrow 2008 Competition Launched at the Dallas Lighting Market

February 29, 2008 - Online Intent-to-submit form is due. (I recommend using the PDF version which is more complete, they ask that you only use one form of submission and both are due by the above date)

April 30, 2008 - All entries due

September 14-16, 2008 - Lighting for Tomorrow 2008 Competition Winners Announced at the American Lighting Association Annual Conference

Rules and Entrant Guides: For complete information on the LED Lighting design contest including applications, competition rules, guidelines, and sponsors visit: 2008 Lighting for Tomorrow Competition

Don't forget to take a look at the some of the photos from last years winners in the LED Lighting Fixtures (LLF) division for ideas on what the competition is doing with LEDs and Solid State Lighting.

This year the LED Lighting Fixtures (LLF) division has three (3) categories: 1) fixtures meeting the ENERGY STAR for solid-state lighting (SSL) requirements, 2) other decorative entries such as chandeliers, sconces, table lamps and portables using LEDs with device efficacy of at least 50 lm/W, and 3) the new "Future LED" category which invites luminaires using the world's highest efficiency LEDs; The “Future LED” category will require a minimum LED device efficacy of 90 lm/W, which would fit the bill nicely for an LED Grow Light entry.

LED lighting applications in the 'near term' and 'other lighting' categories include:

􀂉 Under-cabinet lighting for kitchens
􀂉 Portable desk/task light
􀂉 Recessed downlight rated for residential use
􀂉 Outdoor porch light
􀂉 Outdoor step light
􀂉 Outdoor pathway light
􀂉 Wall sconce
􀂉 Table or floor lamp
􀂉 Pendant
􀂉 Chandelier
􀂉 Vanity light
􀂉 Ceiling fan w/ light kit

But the 'Future LED Showcase' is wide open with a write-in of your choice, so what will you build next? A rotating LED grow light with LED light arms that track or sweep around for greater coverage could be one idea :)

Start up your wire-wrapping grow light engines and lets get this showcase shining!

For more information or to ask questions contact: Ruth Taylor, Pacific Northwest National Laboratory - 509-375-2389, ruth.taylor@pnl.gov

Strategies in Light Kicks Off 2008 Conference

When it comes to USA-based conferences serving the global LED industry, Strategies in Light defines the space. The consensus here is that by attending the US-based "Strategies" and the Taiwan-based Blue 2008 conference (BlueTaiwan.com) you'll have captured the business heart of the global solid state lighting, LED-lighting and LED industries. There are several good market, business, and technical conferences in the various LED producing countries and regions, including Korea, Japan, China and Europe, and any conference will draw primarily from the country where it is held, but Strategies and Blue do something different, making those two unique.

Strategies in Light
Now in its 9th year, Strategies is by far the largest LED conference, and successfully covers the breadth of the market. Established by Strategies Unlimited, which along with LEDs Magazine is part of PennWell publishing, the conference has kept pace with the growing market, both in its content and attendance. This year is projected to be another record-breaker, with up to 800 attendees and a still larger exhibition compared to last year. Strategies has grown so well and consistently primarily because it has made a quality agenda that matches the needs of today's market the priority. It's easy to throw out the buzz words and fill slots with "somebody", but there is truly an art to creating a neatly segmented, logically flowing 2-day conference that presents the most qualified speakers on the topics at hand. Strategies Unlimited's Dr. Robert Steele, a long time friend of our team, has been the guiding force in defining that agenda each year.

Bob is probably the most unassuming industry expert you will ever meet. He has a passion for the industry, and wants it to succeed for all the right reasons. Far from simply being a cheerleader, he brings an intimate knowledge of the overall LED marketplace and is willing to share what he knows, both in the form of his keynote talks, as well as any time you're fortunate enough to be able to engage him in a one-on-one conversation. His experience has been driven as a long-time analyst for the opto-electronic industry, which brought him to the compound semi materials, and subsequently into the application areas they serve. In the late 1990s, as the opto-communications technology was becoming ubiquitous, the LED technologies began to separate themselves as a market in their own right, with the timing of their potential for adoption in general purpose lighting starting to become evident to those that were participating. That opportunity wasn't lost on the team at Strategies Unlimited, and they began to add some additional focus into the LED arena. Interestingly, Jo Ann McDonald, our founding editor at CompoundSemi Online (which later added its Solid State Lighting Net/LIGHTimes arm), was enlisted for her conference and marketing expertise to help implement that new event, suggesting the name "Strategies in Light" in the process. Jo Ann and Bob's collaboration worked, and Strategies set off towards the success that you see today.

Perhaps the coolest thing about Strategies is that it has evolved in lock-step with the interests and opportunities of the industry as a whole. Always a west-coast US event, it is located almost exactly mid-way between Asia and Europe, much as the US LED-related market is. Asia has been the historic epi-center in chips, and strong in packaged LED lamps and the earliest mainstream applications, including keypads, handhelds, and display backlighting. Europe has been an hotbed of forward thinking lighting design, laid a lot of the groundwork for automotive applications and was the early champion of OLED technologies. In between are the US and Canada, where you find major chip, lamp and lighting companies, as well as a lot of the IP that makes up today's light engines and control systems. From an original focus on the materials and chips, Strategies has moved up the chain to a focus today on the breadth of applications and industry issues as a whole, with only a few talks on underlying componentry or technology. This is about "the markets" in which high brightness LEDs have and will find their homes.

Keynoters this year include Bas van de Kieft, Executive VP of Phillips lighting, who will share his thoughts on some scenarios regarding the penetration of the general lighting market by solid state lighting, and of course, Bob Steele who will be sharing the latest global market report and forecast. Featured speakers from luminaire manufacturers include Bob Smith, Director of Innovation and Advanced Engineering at Cooper Lighting (whose enthusiasm for SSL is extremely contagious) and Liam Kelly, who is managing director at Nualight. At the technology level, we'll be hearing from Bernhard Stapp, VP and GM of SSL at OSRAM Opto Semiconductors on the target markets and status of OLEDs. It's simple... don't miss Strategies.

Blue 2008

The next "can't miss" on the industry calendar is the Blue 2008 event, returning this year to the attractive Ambassador Hotel in Hsinchu, Taiwan, on May 7-8. Work is underway now to finalize the agenda and speakers, so expect to hear more of those details here in 1-2 weeks. Blue was launched back in 2003, as a celebration of the commercial emergence of the nitride-based blue-spectrum devices, including blue and white LEDs, as well as the blue laser diodes that were to become the heart of the "high def" DVD revolution. When blue and white were added to the existing red and green LEDs, it marked the effective beginning of the LED lighting revolution. In 2004, Blue moved to Taiwan, establishing itself as a leading industry event, with its main focus on the chip and packaged "lamp" level of the LED supply chain. In 2006 and 2007, there was an agenda emphasis on "understanding and meeting the needs of the lighting industry" with the intention to better connect the chip and packaged device producers with the rapidly emerging general lighting markets. For the 2008, it's time for Blue to bring the spotlight back onto the core level of LED innovation at the materials, chip and packaged lamp level. We're pleased to be able to bring Bob Steele and his mid-year global market update to the Asian audience. He'll be joined by Asif Anwar of Strategy Analytics, who will be covering the GaN and materials market developments, along with some related updates including a bit on blue lasers. New with us this year will be Enboa Wu of Hong Kong's research lab, ASTRI for updates on mainland China's programs and progress, and we'll be rejoined by the good folks at Taiwan's Photonic Industry Development Association (PIDA) who will provide local market insights that you don't find anywhere else. Make your plans now.

When it comes to conferences, its all about who you'll meet and what nuggets you will carry away that make a difference in your business. Who you'll meet is almost entirely dependent on the quality of the agenda, which, in turn, is driven by the organizer's market knowledge and their integration with the industry (we call it having "skin in the game"). We'll be there, and we look forward to seeing you as well at Strategies and at Blue.

Germany Embraces LED Lighting for Carbon Credits

LEDs Integrated in European Energy Efficiency Program

Major German Utility Company Promotes Energy-Efficient, CO2 Offset-Certified Lamina LEDs to Consumers and Businesses as Replacements for Traditional Lighting Products

Lamina Lighting Incorporated (Lamina), an innovator of LED lighting systems and technologies, today announced that the company’s LED lamps will be utilized in an energy efficiency initiative launched by RWE Rhein-Ruhr, the major regional energy company of the RWE Group. RWE ranks among Europe’s leading integrated electricity and gas companies and is one of the largest electricity producers in Germany.

The program represents an effort by RWE Rhein-Ruhr to help commercial and residential customers conserve energy and reduce utility bills by replacing their current light sources with Lamina’s SōL™ MR16 LED product, the only LED in the world which carries a CO2 offset certification.

“We are very proud that our SōL MR16 LED has been chosen to play a relevant part in the RWE energy efficiency program in Germany,” said Frank M. Shinneman, President and CEO of Lamina. “Working together with RWE Rhein-Ruhr and our partner-distributor Richard Schahl GmbH in Germany, we are happy to help more people become familiar with Lamina’s unique product innovations and efficiencies, and how their use can have a positive effect on the environment in the long run.”

RWE is based in Essen, Germany, and through its various regional energy companies and subsidiaries supplies 20 million electricity customers and 10 million gas customers throughout Europe. The LED initiative involves public announcements in the company’s 38 showrooms across Germany, and the distribution of almost 3 million newsletters. The newsletters explain to residential customers the positive aspects of using LED replacements; 56,000 industrial customers will also receive special brochures. Plans are underway for RWE Rhein-Ruhr to work in partnership with Richard Schahl GmbH, the European distributor of Lamina products, to train RWE-certified electricians on the correct and professional installation of the Lamina LED lamps into businesses such as hotels and retail shops, as well as inform them about potential costs and energy savings. All major electrical wholesalers will carry stock for Lamina’s SōL MR16 throughout Germany.

Lamina’s SōL MR16 LED product uses less than 8 watts of energy and produces the same amount of light, for a much longer period of time, than a 20 watt halogen light bulb. Lamina labels its SōL product with a “green tag” which highlights the bulb’s energy consumption as compared to its equivalent in the form of carbon credits offset. For the SōL this amounts to approximately ½ of a carbon credit (a carbon credit is equal to the emission of one metric ton of carbon dioxide). SōL’s CO2 offset was certified by an independent third party: The Carbon Credit Company LLC – the U.S. subsidiary of Frankfurt-based 3C Group. Among other services, 3C helps companies like Lamina – and their customers – achieve “climate neutrality” with their products and operations. The concept of carbon neutrality dictates that organizations and/or individuals make a commitment to the option of compensating for unavoidable emissions by reducing or avoiding emissions elsewhere.

Certification of the SōL is just one aspect of Lamina’s Carbon Footprint Reduction Program™, a comprehensive, company-wide environmental initiative. Along with a growing list of partners, Lamina supports a web site, truthinlighting.org that provides a wealth of information about how companies and individuals can work toward achieving carbon neutrality. Interactive forums, blogs, and RSS feeds will establish the site as a source for concrete factual information in regard to lighting and energy consumption.

Lamina is also undertaking a plan that includes a carbon footprint reduction of its own with a goal of corporate carbon neutrality, also to be facilitated by 3C Group.