Smart Shopping for LED Surgical Headlights

LEDs are rapidly becoming the most valued light source in medical illumination today, and surgical headlights are certainly no exception. Surgeons choose LED-based headlights for numerous reasons including their long lifespan, energy efficiency, ruggedness and the low-maintenance requirements. LED Technology has also opened many innovative pathways with its dynamic color mixing and color sequencing capabilities.

 

Daniel Cook, author of the “Surgeon’s Advice” column in Outpatient Surgery Magazine (October 2012,) interviewed Mark Drzala, M.D. and Assistant Professor at New Jersey’s University of Medicine and Dentistry. Dr. Drzala is a big fan of LED headlights and uses them often in his work. The following are a list of reasons for Mark’s Dr. Drzala’s affinity for LED-based headlights, along with the features consumers should consider when purchasing the portable headlights for their specific medical application.

• Freedom of movement. Most LED headlights are battery-operated — as opposed to xenon headlights that connect to light sources through fiber-optic cables — so you can work untethered around the surgical field, says an orthopedic spine surgeon with New Jersey Spine Specialists in Summit, N.J. "Surgeons like to move freely around the OR," he says. "They don't want to waste time asking someone to constantly disconnect and reconnect the headlight. That's a real nuisance.
• Battery life and weight. Consider the size and weight of a headlight's battery pack, suggests Dr. Drzala, because some physicians with back issues might find it difficult to operate with packs belted around their waists. "At the same time, some of the battery pack belts are robust and might actually provide some back support," he points out.
  
  LED headlights are powered by rechargeable batteries ensuring considerable duration on a single charge. Some LED headlights boast lifespans of 50,000 hours as well.
• Bright illumination. Can you narrow the headlight's aperture? And if so, does the illumination diminish when you do? Also look for uniform illumination, suggests Dr. Drzala, meaning hot spots don't appear in the center of the surgical field along with dimming along its perimeter.
  
  Some yellow-based lights sources have an incandescent look to them, while others have a cooler, higher Kelvin rating, which renders tissue with better coloration. "Surgeons must conduct their own head-to-head trials and see which ones they like best, because no 2 LED headlights are alike," says Dr. Drzala.
• Comfort. Look for lightweight, comfortable headsets, although comfort is very much subjective. Surgeons might take time to adjust to the feel of a headlight, and initially think the device puts them off-balance as they lean into the surgical field. "The weight of a headset can take some getting used to," says Dr. Drzala. "But with time, you get a sense of how you have to move your head in order to effectively shine the light source onto the field."
• Longevity. The lifespan of a xenon headlight is impacted by dimming bulbs and delicate fiber-optic cables that connect to light sources. "Every time a fiber-optic strand breaks through normal wear and tear, you lose a little bit of illumination," says Dr. Drzala. So, he says, xenon bulbs dim over time, while LEDs remain as bright as new even after repeated use. “A new xenon headlight and a new, high-quality LED model are equivalent," says Dr. Drzala. "But as time passes, LED headlights will better maintain their illumination and brightness."

Contact Norlux today for a consultation on your next LED lighting project for medical applications. We’re fast, highly automated, and we manufacture entirely in the U.S.A. 

 

Sources:  “Smart Shopping for Surgical Headlights” by Daniel Cook

Outpatient Surgery Magazine; “Surgeon’s Advice” column. October 2012.

http://www.outpatientsurgery.net/issues/2012/10/who-doesnt-like-leds&pg=3

LEDs Illuminate San Antonio’s River Walk for the Holidays

For the second consecutive year, San Antonio's River Walk will be aglow this holiday season with more than 1.76 million multi-colored light-emitting diode (LED) lights wrapping the trees and lining the street bridges along its banks. The new energy efficient lighting not only enhances the experience to all who visit the River Walk, but it also adds 20 times more lights, utilizes less than half the energy of traditional incandescent lighting and supports long-term sustainability efforts.

Earlier this year, the City of San Antonio converted 85,000 incandescent lights to 100 percent LED lights for this year’s River Walk Holiday Lights experience. Using more than 1.76 million LED mini-bulbs will save the equivalent of approximately 33,000 kilowatt-hours of energy. The LED lighting is durable and is expected to last 10 years in comparison to incandescent bulbs, which were replaced annually.

Local lighting consultant and renowned artist Bill FitzGibbons, who has created LED lighting displays across the world, developed the LED lighting plan for the City of San Antonio. In addition to the minibulbs, the eco-friendly lights incorporate the addition of multi-color programmable holiday accent lighting on all 22 street bridges at the River Walk. The lights will be wrapped on 170 trees lining the river, as high as 60 feet. To further enhance the Holiday experience, 26 heritage or iconic trees will feature up-lighting.

The enhanced LED lighting plan compliments Mayor Julián Castro’s inaugural Light Up Downtown Holiday Lighting Contest, which showcases creative holiday LED lighting displays at participating businesses on the street level. Both initiatives aim to bring visitors to downtown San Antonio this Holiday season while encouraging sustainability and energy conservation.

Norlux's team of engineers understand LEDs and related technologies like no other manufacturer in the world today. Contact us today to discuss your LED based lighting projects.

Source:
http://www.sanantonio.gov/riverwalklights.aspx

Intelligent Outlets Ensure Safer Skies

At Norlux, our goal is to innovate and update current product generations to ensure the best customized solution for your needs- both now and into the future. So when we partnered with an aviation company to make an intelligent outlet for aircrafts, utilizing GFI and over-current detection was simply not good enough. Our customer wanted us to add more protection to create the safest product in the air.

An FAA memorandum on power systems in airplanes, PS-ANM-01-111-165, requires that “…the design does not introduce a source of injury due to electrical shock…” While electrical shock can be guarded against with the use of a plug cover and still meet the requirements, it can be easily circumvented in real world applications. We wanted added protection for when the cover is removed and the outlet is exposed. The memorandum offers an optional example of such protection, suggesting “a design where output power is present at the PSS [power supply system] socket only when the PED [portable electronic device] connector is correctly mated with the socket.” Our design does just that; only a proper insertion of a plug activates power to the socket.

This extra level of protection was accomplished by adding plug presence detection (PPD) to the outlet. With PPD, the intelligent outlet does not supply power to the receptacle unless a plug is detected in the outlet. This prevents an individual from an electrical shocked caused by inserting a foreign object- a paperclip, a child’s toy, a piece of food- into the outlet. The PPD detection uses infrared emitters/receivers embedded into the side of the outlet to detect when a plug is in the outlet. Unlike some designs that only have one sensor in the outlet, our design uses two separate emitters/receivers as a redundancy check. With one sensor for each prong, the dual sensor design ensures that it is in fact a plug that is inserted into the outlet, and not a conductive object inserted into only one side. The sensor system can also be calibrated once the outlet is installed so that any ambient inferred light will be compensated for, preventing any false detections. The PPD also correctly detects all plugs styles that can fit into the universal outlet faceplate.

On top of the strict guidelines required to make the outlet safe for aviation use, we have gone above and beyond to ensure a high-quality product for our customer and the safest device for the end user. Contact Norlux today for a consultation on your LED lighting project.

Reference:
http://rgl.faa.gov/Regulatory_and_Guidance_Library/rgPolicy.nsf/0/6283af43db9a694486256fd30077ca7d/$FILE/PSSforPED.pdf

Combining Surface Mount Technology (SMT) & Microelectronics Assembly

Throughout the history of electronics manufacturing, there have been distinct boundaries between those that assemble SMT components and those that assemble microelectronics. In today’s market, it is difficult to identify a U.S. source for low-volume prototype services that offers both disciplines.

SMT and microelectronics die and wire bond services are not usually found in one contract assembly location. In the past, organizations had to deal with two different companies to fulfill build requirements. For example, hybrids or chip on board (COB) integrate wire bonding directly on the board.


The specific application, process requirements, thermal considerations and printed circuit board characteristics all must be accounted for when determining how and when to involve the precise sequence of SMT and microelectronics assembly.  With proper planning, manufacturers can take a product from design to volume-production at a lower cost, in a shorter time and with less risk than a company not specialized in these technologies trying to do the prototyping, manufacturing and test on its own.

Although these SMT and microelectronics assembly have been--traditionally--separate, more manufacturers are faced with both SMT and microelectronics build requests since many boards and assemblies are requiring mixed technologies.  Microelectronics assemblies require a class 100,000 cleanroom for most operations with some of the sub-processes requiring class 10,000. Expertise is expected in process engineering, die attach, wire bonding, and custom deliverable parts. Most companies looking to outsource these processes want someone with 15-to-20 years of experience in building microelectronics parts.

Taking into account and planning of SMT and microelectronics assembly simultaneously has many advantages. Simultaneous production planning enables process engineers to look at the total product rather than at one board or view it in isolation. Temperature plays a large part in determining the order of assembly; maximum temperature requirements for wire bonding can be different than for other components. Working together enables an evaluation of which part needs which processes and at what temperature profile so as not to destroy other elements of the component or adjacent wire bonds.

Norlux's team of engineers understand SMT and micreoelectronic assembly like no other manufacturer in the world today. Contact us today to discuss your LED based lighting projects.

Blog re-published with permission.  Authored originally by Jessica Sylvester on Oct 09, 2012
http://www.palomartechnologies.com/blog/bid/109934/Combining-Surface-Mount-Technology-SMT-Microelectronics-Assembly

Prototype Fabrication: Bringing Vision to Fruition

With great advances in LED (Light Emitting Diode) technology over the years, the opportunities are increasing for companies to design and implement LED-based lighting products. These products utilize the inherent energy savings and environmentally friendly characteristics of LEDs. The common business goal is to develop LED lighting products that fit specific market applications and can compete favorably with the competition in appearance, efficacy (lumen per watt,) as well as price. Product design and development begins with the collective input of Marketing, R&D and Engineering, with the eventual aim of creating a fully functional and testable prototype.
 

Prototyping is always a critical phase in product development. It amounts to taking your best theoretical concepts and engineering them into existence, with the help of a quality manufacturer. A company that excels at providing timely and accurate LED light engine prototypes must shine in the following areas:

• Understand the customer requirements and needs, even before they do
• Create multiple, innovative solutions to achieve the desired results
• Master capabilities in all aspects of LED lighting
• Thermal management
• Optics
• Controls
• Drivers
• Chip-on-Board (COB)
• Gold wire bonding
• Surface-mount technology (SMT)
• Printed circuit board (PCB) layout
• Screen/stencil printing
• Exhibit flexibility with design changes
• Demonstrate quick-turn capabilities
• Produce high-quality, accurate first yield assemblies
• Maintain close communications between the customer and the prototyping engineering group
• Facilitate seamless transitions between manual and automated processes
• Sustain electrostatic discharge (ESD) control

The ultimate goal is to get the prototype back to the customer quickly for evaluation. Customers take this opportunity to align initial calculations/expectations with real-world results. This is the time to verify form, fit and function of the finished product, or suggest a possible change moving forward.
 

With an ever-evolving technology like LEDs, it is business critical that companies get their LED lighting designs developed, built, tested, refined and launched in a timely manner. Product lifecycles are short with LED-based lighting fixtures, and the competition will take your share of the market if you’re not nimble. Fast and accurate prototyping is a critical phase your company needs to master to beat your competition to the punch.

 

Contact Norlux today for a consultation on your next LED lighting project, and we’ll start bringing your unique vision to fruition today.

Industrial Applications Embrace LED Technology

The usage of energy efficient LEDs in large-scale industrial lighting applications is becoming more critical than ever. Factories, warehouses, manufacturing plants and workshops all require a very large volume of light to properly illuminate operations, and as a result have created huge costs for businesses utilizing outdated lighting technologies of the past. Commercial grade LED industrial lighting is designed to replace existing mercury, sodium and metal halide lamp fixtures of much higher wattages, and therefore save money, energy and by extension: the environment. Thanks to advancements in semiconductors, optics and materials, LED lighting has excellent applications in industrial environments.

Below, Steve Henry (greenmanufacturer.net; 11/2011) gives us an overview of features that illustrate why LED technology is suitable for nearly any industrial lighting application. 

• Energy-efficient. The main driver for LED adoption is energy efficiency. Achieving the lighting levels required for a particular application at the lowest possible energy input becomes critical as energy costs rise and as government regulations clamp down on wasteful energy sources.
• Long-living. Correctly designed, LED fixtures offer up to 60,000 hours of illumination, with no "droop," or color shifts, and no penalty for frequent on/off cycles.  LEDs' longer lifespan than most other lighting sources' means less material is disposed over time.
• Low-maintenance. Because it is rugged and long-running, LED lighting requires very little maintenance. When LED lighting is used in a fixture with an intelligent modular design, even end-of-life replacement of components becomes quick and simple.
• Resistant to Shock, Vibration, Corrosion. LEDs can be used in environments where other technologies fail—prematurely or catastrophically.
• Cold Start-Capable. LEDs provide instant on and instant restrike capabilities to -40 degrees C, with no warm-up time required to achieve full brightness.
• Non-damaging. LEDs do not produce ultraviolet or infrared radiation often emitted by other lighting sources. This lowers cooling costs, simplifies maintenance, prolongs product life, protects eyes and sensitive equipment, and provides a margin of safety in hazardous environments.
• Safe for Hazardous Locations. Available LED luminaires are rated for use in areas where flammable gases and vapors are present under conditions defined by NEC Class I, Division 2 and IEC Zone 2.
• Easily Positionable. LED lighting often is the best choice for areas with low clearance, severe weather conditions, excessive moisture or dust, corrosive atmospheres, and high ambient temperatures.
• Nontoxic. LED lighting is also the only non-incandescent lighting source that contains no mercury. This eliminates any chance for mercury to escape into the environment either in operation or after disposal, therefore special handling is not required. Lights with lead-free solder ensure no toxins leak out when components finally reach end-of-life.
• White and Bright. Today's industrial LED luminaires provide high-quality white light that eases eye strain.
• Highly Directional. LED luminaires can be configured to produce nearly any horizontal and vertical distribution of light—from illuminating a tall, narrow fence line for security purposes to area lighting that allows production crews to work efficiently and safely.

LED industrial lighting is here today, and it's here to stay. The benefits it provides simply cannot be ignored. Even local and national governments are taking notice of LEDs as they focus on the problems of energy consumption, greenhouse gases, pollutants, and toxic waste.  LEDs are Green, and most important green feature of LEDs are their energy efficiency. LEDs have the smallest environmental footprint of any manufactured source. Because a large percentage of electricity in the U.S. is produced by burning fossil fuels, switching to LED lighting also is likely to cut emissions of greenhouse gases and toxic pollutants. In addition, LEDs are mercury-free.

 

For all of the advantages of LED based illumination, it's easy to see why the industrial market space is embracing LED technology now and will continue to switch-over well into the future.  Contact Norlux today for a consultation on your LED lighting project.

Reference: 

"Shedding light on LED for industry: LED primed to replace metal halide, mercury vapor".By Steve Henry; October 12, 2011; Green Manufacturer http://www.greenmanufacturer.net/article/facilities/shedding-light-on-led-for-industry

Norlux: Perfecting LED Logistics

In the world of LEDs, you’re going to find a lot of logistical details. These can range from choosing among a variety of LED package types, to managing lead times on shipments from overseas, choosing the right correlated color temperature (CCT) variation for your application, dealing with revision changes on LEDs as your product matures, and many more.

At Norlux, we are experts in all of these areas. We can help you manage all of these details so that you can keep your focus on your own business needs and trust the logistics to us.

Norlux has a build-to-order manufacturing model. This philosophy combined with our high capacity gives us the ability to be very nimble in meeting our customer’s demand. Norlux works with our trading partners to find the optimal balance between shipment and replenishment cycles, which, in turn, will reduce transportation expenses. Also, our central location in the suburban Chicago area makes us an optimal distribution point for North American customers.

Our volume and scale bring value to you. Norlux purchases millions of LEDs per year, so we have gained significant buying power and strong supplier relationships with all major LED manufacturers. This ultimately gives our customers access to more competitive pricing and in many cases, shorter lead times than would be otherwise achievable. Norlux also has a world class material tracking system, complete with lot number traceability.

Product lifecycle management is another area we excel in. With rapid improvements in performance and falling prices seen in the LED industry, you need an expert in managing your product lifecycle. At Norlux, we have a system in place for dealing with this. We coordinate the changes for you every step of the way. If the market price of your LED platform falls, you will benefit from the positive impact shortly thereafter. By minimizing inventory on hand and knowing precisely what exists in the supply chain, we can help you make an optimal business decision on how and when to evolve your design.

You should be free to keep your attention on your own business’ growth rather than managing these kinds of details. At Norlux, we want to partner with you and allow our expertise to fill this role, so that you can move forward with confidence and assurance in the LED lighting world. Contact us today to discuss your LED logistical needs!

Rating Systems for Outdoor Lighting Applications

Outdoor lighting applications are subject to two very important rating systems that serve to define the fixture's level of protection from the elements (IP Rating) and the projection of stray and unwanted lighting from a luminaire (BUG Rating).

IP Rating:
IP or “Ingress Protection” ratings are crucial to outdoor lighting applications because they represent a more accurate means of classifying a fixtures ability to stop the ingress of solid particles (dust and dirt) and water in the form of rain, a hose (cleaning or watering foliage) or total submersion.  The first digit in an IP rating refers to how dust proof a fixture is and the second digit refers to how waterproof a fixture is. The two numbers combined will depict the likelihood of foreign objects getting into the light fitting and possibly damaging the sensitive electronics inside. The higher the protection numbers in the chart (see example below), the greater the protection from ingress. Lower numbered fixtures are typically better suited for inside, carpeted areas like offices, waiting rooms or schools.

 

BUG Rating:
BUG stands for “Backlight”, “Uplight” and “Glare.” The acronym describes the types of stray light escaping from an outdoor lighting luminaire. Backlight is the light directed in back of the mounting pole, uplight is the light directed above the horizontal plane of the luminaire, and glare is the amount of light emitted from the luminaire at angles known to cause glare. It is expected that BUG values will be published by luminaire manufacturers so lighting specifiers, designers or purchasers can tell at a glance how well a certain luminaire controls stray light or compares with other luminaires under consideration for an installation. The BUG system was developed by the Illuminating Engineering Society (IES) to make comparing and evaluating outdoor luminaires fast, easy and more comprehensive, than older systems.

For more detailed information on the BUG rating, please visit this guide from the International Dark-Sky Association.  See also the chart below that defines the various light angles of acceptable and stray light.

 

Our team of engineers at Norlux are experts in LED lighting for outdoor applications.  Please contact us to discuss your LED based outdoor projects today.

 

Reference:

International Dark-Sky Association: volume 2: issue 1 : 2009: (BUG Illustration and Information)

http://www.aal.net/content/resources/files/BUG_rating.pdf

The Benefits of LED Based Surgical Lighting

LED lighting units are becoming more and more prominent in all segments of lighting, and surgical lighting is certainly no exception. LEDs are proving to be perfectly suited for examination and surgical illumination applications, and the switch in lighting technology from halogen to LEDs is widespread. Hospitals are always interested in finding more effective ways to run their operations at an optimum level and LEDs fit the bill not only economically, but also in terms of comfort for both surgeon (who endure hours under these lights) and patients alike.

Light emitting diode surgical lights, first introduced in the United States in July 2006, were initially met with a healthy mix of interest and skepticism. Why use LEDs in the operating room (OR)? Were the proposed benefits real? Did those benefits justify turning away from proven technologies, such as halogen, especially with lives on the line in the OR?  In the relatively short period since their introduction, these questions have been answered and the validity of LED surgical lights has been confirmed by a variety of factors. 

Low heat
Reducing heat, particularly in the area of the surgeon’s head, provides a more comfortable environment with the potential to improve surgical team performance, OR efficiency, which also would improve patient outcomes. While traditional surgical light manufacturers have made continual progress to reduce the heat produced by their lights, LED technology essentially ends this battle. In fact, the heat output of LEDs is better described as “no heat” rather than “low heat,” with temperature increases in the area of surgeon’s head measured at less than 1 degree Celsius by one manufacturer.

Extended Lifespan

LED based lights offer dramatically longer life cycles over conventional halogen based lights. The expected service life for the light source used in traditional lights is upwards of 2,000 hours. Various LED surgical light manufacturers talk about dramatically different numbers. The diodes used in LED lights are manufactured to last 50,000 hours on average. LED surgical light manufacturers will either use that 50,000-hour figure or a more conservative guarantee of 20,000 hours referring to the whole light and all its components.

Quality of Light

Beyond the benefits of long life and low/no heat, which seem to dominate most conversations on LED technology, it is important from a surgical team’s viewpoint to pose more basic questions regarding the quality of the light output. Some things to consider are:

• A homogeneous light field: The quality of light is a subjective issue, with surgeon preference coming into play to explain why some lights get approval over others. Among the factors that are at work here is whether the light field is homogeneous. Surgeons are looking for consistency of the light across its focused area with no hot spots or drop-offs.
  The quality of the field is certainly affected by the configuration of LEDs in the light head, with more LEDs providing greater coverage and a better pattern. The critical assessment of the quality of the light field is best left to the surgeon’s discerning eye during a light trial.
• Focusing ability: Another basic question is how the light is focused. Some LED lights offer a manual focus but a few can be focused electronically. What is the size of the spot and quality of the focus? Again, these functions are best judged by clinical staff during a light trial.
• Intensity: The maximum allowable intensity of a surgical light is 160,000 Lux. The best traditional lights provide this level of intensity. The best LED surgical lights also meet this standard and provide dimming capabilities so a surgical team can adjust to the demands of each procedure.

Advanced Features

Depending on the manufacturer, LED surgical lights also offer various advanced features that can contribute significantly to a surgical team’s ability to deal with common problems, as well as provide them with new capabilities.

• Shadow correction: Shadows during surgery are created by surgeon positioning, surgical team movement, equipment or the depth of a wound. The key is to minimize shadows so a surgeon always has the clearest possible view of the surgical site. In a typical LED surgical light, each LED generates the entire spot. These individual spots are then precisely overlapped, so no matter how many LEDs are blocked, the spot remains round and consistent. As obstructions move inside the light field, the pattern does not change.
• Adjustable color temperature: An option currently offered by two LED light manufacturers is the ability to adjust color temperature. Color temperature is measured in Kelvin (K) with a lower number indicating a warmer, more orange light and a higher number representing a cooler, neutral, white light. The ability to adjust color temperature, not possible prior to the introduction of LED lights, allows a surgical team to improve contrast and tissue differentiation, based on factors such as the type and depth of the surgery, blood flow and a surgeon’s preference.

It comes down to a better view for a surgeon, and that can only help to benefit the patient. OR managers benefit by having one light that can address varied surgeon preferences, so staff satisfaction is increased and room scheduling is easier. The hospital benefits by being better positioned to recruit and retain qualified surgical talent. Factor in the economic advantages of consuming less electricity to power LED lights, and it’s easy to see why LEDs are the driving force in surgical lighting.

The team at Norlux will help design and manufacture your LED based examination, procedure and surgical lighting systems; call Norlux today!

Reference:

"The future of LED lighting and why surgeons prefer it: Benefits start to push new technology ahead of traditional products"

By Dave Rector, Jan 2008

http://www.matmanmag.com/matmanmag_app/jsp/articledisplay.jsp?dcrpath=MATMANMAG/Article/data/01JAN2008/0801MMH_FEA_OR_Technology&domain=MATMANMAG

Wireless Controls in LED Applications

With the advent of solid state lighting, we are now able to add intelligent controls to the lighting solutions. Already existing circuitry designed to control and dim the LEDs can easily be added on to include wireless control; a microcontroller can use its dormant Rx/Tx pins and connect to a wireless transceiver, instantly creating a wireless solution.

Wireless controls range from intelligent home automation to whole factory control. The fact that no control wires are required allows the customer to place the lighting controller wherever deemed most convenient. This means that adding a wireless switch at home would not require the costly addition of a junction box and wiring it directly to the light source. Wireless controls also allow for mobile control; from a laptop on the manufacturing floor to an iPad on your living room couch. Wireless solutions with a gateway to the internet can even be monitored and controlled from a remote location via the internet connection.

Some of the networks implemented by wireless control are mesh networks and point-to-point networks. Mesh networks occur when each light acts as an individual node, passing controlling data through the network. This allows for a larger range of communication from the initial command point as the signal gets passed from node to node until it reaches its final destination. Conversely, a point-to-point network occurs when a single remote manipulates a single light source. 

There are many different solutions to wireless control in LED applications. Some of the leading communication protocols are IR (infrared), Zigbee and Wi-Fi. IR controls, while a tried-and-true communication path, has become antiquated because its range and light of sight disadvantages have been overcome by other advances in wireless communication. Zigbee and Wi-Fi, on the other hand, take advantage of radio waves to extend the range and remove the line-of-sight requirement. 

Zigbee is IEEE 802.15.4 compliant and uses a mesh network and low data rates to connect many nodes to each other. Because Zigbee is a standard, it allows for interoperation with existing zigbee products that include many other controls then just lighting. Communication directly between a zigbee light source and a zigbee sensor can be achieved without the need for human control. The zigbee alliance boasts 64,000 individual nodes on a single network; however an extra gateway device is required to interface the zigbee communication to the internet. This means that a gateway is required if you want your PC or IPhone to communicate to a zigbee network.

Another popular communication protocol is Wi-Fi. While Wi-Fi is limited to only 255 nodes per access point (although it is often recommended that the number be less than 30), it can handle large amounts of data and is already connected to the internet via a router. This makes Wi-Fi a good choice for advanced lights that a consumer may only need a handful of.

When choosing a wireless solution for your lighting needs, it is important to consider the quantity of nodes per network as well as the need for internet connectivity. For example, many LED lights in a manufacturing warehouse can easily take advantage of a large mesh network solution that the zigbee affords. However, controlling a single strip of colored LEDs from your IPhone lends itself to Wi-Fi connectivity because it could connect directly to your router.

Here at Norlux we are committed to explore and understand all developments in wireless control of LED lighting. If you are interested in a wireless LED solution, please contact the engineers at Norlux.

Utilizing UV LEDs in Manufacturing

The UV-LED market is a relatively small segment of the overall LED market. It is estimated roughly to be $30 million annually, whereas, the overall LED market is already in the multibillion dollar range. The UV-LED market is expected to grow by 30% annually to about $100 million in 2016.  This late surge is due to breakthroughs in radiant power and intensity of UV-LED that will enable the displacement of mercury-vapor lamps altogether in the future. This could be due in part to recent achievements in product flux density of UV-LED chips beyond the flux density of 4W/cm2 at different wavelengths.

In manufacturing applications, the spectral ranges that are often used reside in the UV-A (315-400nm) and UV-B (280-315nm) range. Actually, 90% of the UV LED applications are based on these two ranges. The UV-A range is used in applications such as curing of adhesives, coatings and inks. Meanwhile, the UV-B range is often used for applications such as visual inspection systems on machine vision, and detecting. And, at the lower end, the UV-C spectral range (100-280nm) is  primarily used for air and water sterilization.

Since the curing process for manufacturing applications requires large and high-powered LEDs, it is often optimal to use LEDs in the range of 385, 395 and 405 nm. These ranges are preferred due to the ability to drive the LEDs at higher power with better efficiency.

Key UV LED Features & Benefits:

• Longer Life, >50,000 hours
• Stable power output throughout the life of the LED
• Instant on/off
• Emits no heat, able to cure heat-sensitive substrates
• Non-hazardous, contains no mercury
• Consumes less power
• Slower degradation when compared to conventional arc lamps
• No shutters needed
• No costly replacement parts required, greatly limits machine downtime
• Cost savings over product lifetime

To date, the migration from vapor lamps to UV LED is somewhat slow. Some contributing factors are life expectancy and efficiency. Typical UV LED life expectancy is about 2,000 hours to 5,000 hours compared to vapor lamps at 8,000 hours to 12,000 hours. But, recent advancement in the next generations of UV-LED has a life expectancy of 50,000 hours or 10 times that of the average UV LEDs. Meanwhile, the typical efficiency of UV LED is about 5% to 8%, which requires further development enhancements. Regardless, the UV LED adoption will grow as the gap narrows between UV-LEDs and vapor lamps. This will translate into a faster growing market in the future.

Reference:
http://www.ecnmag.com/articles/2010/04/key-benefits-next-gen-uv-led-tech

UV Light Applications for Manufacturers

Below the visible spectrum lies a band of wavelengths called ultraviolet (UV). Ranging from 100 to 400 nm, the radiation can effectively be used to sterilize cosmetics, perform forensic analysis, disinfect water and cure materials. More specific to manufacturing, UV rays take on roles designed to speed up the entire fabrication process.

Uses in Manufacturing
Ultraviolet curing is a process in which UV energy produced by a mercury discharge lamp is absorbed by a sensitizer, causing a reaction in the monomer which makes it hard and dry. This UV “curable” monomer includes a sensitizer which absorbs UV energy and initiates a polymerizing reaction. Manufacturers use this process to instantly cure or “dry” inks, coatings or adhesives throughout the engineering process.

At Norlux, for example, UV acrylate encapsulating resins are employed for achieving brighter chip-on-board (COB) LED assemblies. When cured with a DYMAX 2000-EC moderate intensity flood curing system, the Light-Cap family of encapsulates offer superior optical transmission during the life of the LED assembly. Their resistance to elevated operating temperatures results in reduced yellowing (a common phenomenon in brighter COB applications) compared to traditional encapsulating resins. UV/visible light curing coatings offer a wide range of high performance properties including lower stress and more durable wire bonds, superior adhesion, multiple viscosities, minimal shrinkage and low outgassing. Other characteristics described include good moisture resistance, optical clarity and excellent environmental resistance.

UV cured materials are widely used in circuit protection and electronic assembly applications, where products are electrically insulated and designed for various operations including: conformal coating, encapsulation, bonding, keypad coatings, thermal management, and masking. These materials are IPC approved, MIL-I-46058C and UL listed self-extinguishing graded, and are available in multiple viscosity grades depending on application method.

Advantages
UV curable materials provide manufacturers of electronics ease and flexibility in their conformal coating process. Because UV curable materials can be applied in a variety of ways including manual and automatic spray and dispensing, manufacturers are provided with different processing options while allowing them to meet cycle time and product specification requirements. For example, some Printed Circuit Board Assemblies (PCBAs) require environmental or dielectric protection or both. A PCBA manufacturer may set up a conformal coating line that has an automated spray/dispense system and a UV curing chamber. This curing methodology allows manufactures to eliminate thermal and room temperature curing methods, and also ensures that the material has reached full cure upon exit from the UV curing chamber. Other coating materials do not reach full cure for 48–72 hours.

LEDs as Alternatives to mercury arc lamps
UV LED technology is rapidly replacing traditional mercury or arc-based lights. In production curing operations, mercury-vapor lamps are hindered by short lifetime (2000-10,000 hrs.), slow warm-up and cool-down times, and wide spectral power distribution. The UV output of a mercury vapor lamp drops off rapidly over its operational life because some of its electrode material vaporizes, depositing a film on the inside of the quartz tube, which the UV cannot penetrate. This results in an unpredictable amount of UV output over time, which is a critical process parameter.

The mercury lamp has a main peak at 365 nm but several smaller peaks in the visible and infrared regions. The results are peaks in heat output, making working with plastics and other heat-sensitive materials a challenge. Due to the high voltage heat and environmental issues surrounding disposal of mercury bulbs, manufacturers now consider LED based UV curing. There seem to be too many variables to consider when dealing with traditional mercury or arc-based lights in standard curing processes.

UV LEDs bring such benefits as knowing precisely what power level is being delivered to the curing medium, as well as the other advantages LEDs are known for, such as the ability to pulse-width-modulate the output. The change from conventional curing technologies to UV LED allows system manufacturers to offer their users lower operating costs and higher quality products while enabling new capabilities and even reduced shipping and inventory storage due to the ability to print on thinner, heat-sensitive substrates.

Source: (http://ledsmagazine.com/features/9/2/5), (http://ledsmagazine.com/press/8554)

Integrating Touch User Interfaces with LED Lighting

Touch based user interfaces controls have become common for controlling consumer electronic, commercial, and industrial systems. Most recently, the architectural marketplace has been quick to incorporate touch controls with LED technology.  At the May 2012 Lightfair convention in Las Vegas, dozens of touch based light control systems were showcased.  In fact, the Illumination Engineering Society (IES) has an excellent overview topology (publication TM-23-11) on the structure of an LED control system that could feature a touch based interface.

Reprinted with permission from Lighting Control Protocols (TM-23-11) by the Illuminating Engineering Society of North America.

For this discussion, we’ll focus on the “front-end” of the diagram. The most common way to detect a touch is by indirectly sensing the conductive mass of the human finger. Sometimes referred to as “capacitive” touch, this technology relies on detecting an electric field disruption of an approaching finger with a sensing electrode below a dielectric decorative substrate like glass or plastic.  Successful specification, design, and implementation of a touch-based user interface require a basic understanding of the active elements that comprise the system.

The dielectric decorative substrate is best described as the surface that a user touches when interacting with the interface. Typically constructed of glass or plastic, it serves as the primary aesthetic element in the product’s user interface design. In the case of touchscreens, the decorative substrate is usually planer and constructed of glass. In the case of discrete touch points, the geometry is almost unlimited with touch points integrated into many surfaces (commonly injection molded decorated plastic). The decorative substrate can also be backlit for aesthetic or functional purposes.

The electronic carrier is the element containing the sensing electrode structure and interconnects for the touch user interface. Discrete touch points (fixed touch points behind decorative icons) frequently use rigid FR4 printed circuit boards and touch screen use transparent conductive electrodes. Electronic carriers can be in the form of an external circuit or integrated with the LED driver. When designing touch solutions, thinner is better. A thinner decorative substrate and a thinner electronic carrier result in better signal to noise ratios resulting in a more robust touch solution.

LED drivers that are microprocessor based become excellent candidates for an integrated touch control, particularly if the driver circuit is co-located with the user interface. Since many microprocessors can be configured as touch controllers, cost is reduced with a simple solution. Several manufacturers offer low-power touch controllers that are suitable for battery operated “touch” remote controls which can connect to the LED driver using a wireless protocol such as ZigBee.

Norlux has extensive experience in the design of LED Drivers and has developed touch controls for the Architectural market. From simple on-off switching to full wireless intensity, color, and saturation control, Norlux is your one-stop partner for LED lighting and control solutions.

References
IES (Illumination Engineering Society) publication TM-23-11 (http://www.ies.org/PDF/Store/TM-23-11_FINAL.pdf)

LED Downlights – A Hot Trend in Architectural Lighting

With advancements in lighting technology, LED downlighting is an exciting option for architects and builders today. More people are becoming aware of the numerous benefits of choosing LED downlighting, and how it brings a modern dimension to home and office lighting. There is no doubt that a well-placed LED downlight can create a sophisticated, elegant and highly customized look in commercial or residential buildings. They excel at highlighting architectural features of interest, while drawing attention away from less exciting elements. LED downlights are widely used in bedrooms, sitting rooms, reception areas, display cases, cabinets, offices, art displays, bars, hotels and lobbies.

So why are LEDs becoming so popular in architectural lighting applications? With near perfect lighting effects, LED downlights depict an atmosphere of comfort and warmth. Add a dimmable function, and they not only adjust light output to fit any desired mood, but also conserve energy and lengthen the LED lifespan in the process. Beyond mere aesthetics, the inherent attributes of LEDs and their resultant benefits make them an ideal candidate for downlighting. 

• Lifespan: LED downlights are ultra-durable with a lifetime of over 35,000 hours (average), which is roughly equivalent to a lifespan of 20-25 years with normal usage.
  
• Temperature: LED downlights produce less heat than traditional lights, increasing safety by minimizing fire risk.
• Energy Efficiency: With high efficacy of LEDs and a long lifetime, LED downlights can save 70% on energy bills when replacing conventional recessed lights and incandescent lights.
• Maintenance: LEDs do not require much maintenance inherent with frequent lamp replacements. The low operating temperature of LEDs helps reduce air conditioning and maintenance costs as well, saving money long term.
• Color: LEDs for lighting applications have been designed to achieve a warm, white light that ranges > 90 on the color rendering index (CRI), and are described as “eye comfortable”. This light brings out the details of the decor, subtly improving aesthetics and mood.
• Safety and health: LEDs emit no ultraviolet rays or toxic substances (mercury). There are no environmental hazards to be concerned with when disposing LEDs either; heightening the overall “green” aspect of any space. Moreover, the lack of Infra-Red and Ultra-Violet rays emitted by LEDs means the light is healthier and less harsh, putting inhabitants at ease.

While some might balk at the slightly higher price of LED downlights, such amounts can be recovered relatively quickly since consumers are assured of significant energy saving over the lifespan of the product. LED users will enjoy excellent quality of light for their home or building, at a more affordable monthly power rate.

Increasingly, more professional manufacturers and suppliers of LED down lights have emerged. Now one can choose the right LED downlights with affordable prices and guaranteed quality for not only commercial applications but residential lighting as well. Contact Norlux today for a consultation on your LED lighting project.

LEDs and Aviation Illumination, Ascending to New Heights

The Aviation industry and airfield signage specifically, utilize LED lighting technology more than most other applications today, both in the military and commercial sectors. “Their attributes are well-known – crisp lighting, energy efficiency, long lifetimes, low voltage requirements, compact size, fast on/off time, shock resistance and no color filter requirements. Applications for LED illumination in aviation range from wing-tip lights to indicator lights on flight decks to pilot guidance lights on airfields to mood lighting in aircraft cabins” (Les, 2009). Here at Norlux, we develop light engines, drivers, and power supplies for both air and ground based aviation applications; and business we do with companies within the aviation realm is certainly thriving. It seems LEDs found a perfect application fit to showcase their many well-known attributes.

Upgrading old or obsolete lighting technologies pose challenges within the aviation industry, and inching towards the future is never as easy as it seems. “Work is progressing to leverage the advantages of LED lighting in the aviation industry and to overcome challenges presented by the technology, such as in the areas of thermal management and in retrofitting the technology into existing lighting systems” (Les, 2009). Raleigh-Durham International Airport offers a great example of the costs in time and money to overhaul their entire runway lighting system in order to take advantage of what LED technology provides. “Officials at Raleigh-Durham International Airport (RDU) in North Carolina realized they were spending a lot of money maintaining an antiquated airfield lighting system. The lighting fixtures were subpar. The cable was old and cracking and meg-ohm readings for many of the circuits were at zero, which meant the airport had to keep pumping up the power to feed the lights. Signage was also a problem. Some were very bright; others rather dim. Some signs were even bright and dim within the same unit” (Nordstro, 2010). "The FAA wasn't very happy with us," recalls Steve Pittman, deputy airport director of Facilities, Engineering and Maintenance. "They didn't demand that we upgrade our lighting system, but they did suggest we do something about our signage lighting" (Nordstro, 2010). “RDU took the hint and initiated a $20 million project to convert its incandescent airfield lighting system to LED technology. Over the last two+ years, roughly 230 signs and 3,200 bulbs were changed - everything from taxiway edge and centerline lighting to runway centerline lights, obstruction lights, touchdown zone lights, runway end identifier lights, and elevated and in-pavement guard lights” (Nordstro, 2010). The makeover, as it turns out, was nothing short of spectacular. “Everything that can be LED is LED. It's an amazing look at night" (Nordstro, 2010).

So why make the change to LED lights? Costs in terms of man-hours as well as dollars are a driving force. “A primary benefit of LED lights is the lack of maintenance required once they are installed” (Airport Technology.com, 2008). “LEDs are a very efficient light source [for aircraft] and can significantly reduce seat-mile costs and schedule upsets because of their dramatically increased reliability over filament lights” (Les, 2009). Cost savings and energy efficiency always lead the list of attributes associated with LEDs. “With the former incandescent lighting system, RDU maintenance crews were replacing bulbs twice a year per fixture. Operations crews were constantly checking the airfield for burned out lights. There were operational consequences as well. Airfield pavement sections had to be closed when bulbs were replaced. Electrical circuits were tied together in haphazard and confusing ways, which made maintenance time-consuming and costly” (Nordstro, 2010). “Replacing every bulb in every light at least twice a year was not only a safety issue, it was quite costly in parts and labor. Subsequent analysis showed that moving from incandescent lighting to LEDs would save approximately $400,000 per year in energy and maintenance costs including labor and parts” (Nordstro, 2010).

Energy efficiency and the “green” aspects of LEDs are always attractive elements to any application, and aviation lighting is no different. “LEDs are the hot item in lighting these days, both due to their energy saving properties and also the expected long life of the light source” (Airport Technology.com, 2008). Solar-powered LEDs are also a viable option, especially for some smaller airfields. As a versatile lighting alternative for “temporary runways, remote airfields without grid access, or as an emergency-response application, solar-powered LED lights offer distinct advantages. Self-contained, portable and wireless solar LED lights can be installed and operational in a matter of hours to provide bright and reliable lighting” (Airport Technology.com, 2008). "With a quick set-up, no scheduled maintenance and complete freedom from the costs and logistical restrictions associated with installing and operating a grid or generator-powered system, solar LED lights offer a versatile and cost-effective alternative for a variety of applications” (Airport Technology.com, 2008).

With the ten- to twelve-year lifespan of LEDs (on average), users employing LED lighting technologies can reallocate manpower and funds away from expensive and time-consuming maintenance duties onto more customer-centric tasks. It goes without saying that in the transportation/aviation industry “organizations that are responsible for large assets, the move to green technology is important” to keep business competitive, solvent and on the cutting edge of technology (Airport Technology.com, 2008).

Sources:
http://www.photonics.com/Article.aspx?AID=37892 
Caren B. Les, Photonics.com – June 2009

http://airportimprovement.com/content/story.php?article=00203http://airportimprovement.com/content/story.php?article=00203
Robert Nordstro, Airport Improvement Magazine - September 2010

http://www.airport-technology.com/features/feature46764/
Author Unknown, Airport Technology.com – December 2008

LED Thermal Management

It can be a huge challenge to keep electronic products running cool, and LED lighting products are no exception.  An LED’s light output is determined by the amount of current applied to the LED and the subsequent management of the heat emitting from the LED.  The higher the electrical current, the more heat generated at the LED junction.  This heat can lead to output deterioration, which limits the amount of light that can be generated by an LED, reducing the life of the LED over time.

Designers need to account for temperature factors in the early stages of the design process to mitigate heat’s potential adverse effects.  Thankfully, the effects of heat in an LED system can be understood through calculation and simulation.  A model that is used frequently is the thermal circuit model.  These thermal circuit models are similar to resistor circuits using Ohm’s law.  An LED’s power dissipation is modeled as a current source, thermal resistances are modeled as resistors, and the ambient temperature is modeled as a voltage source.  The thermal resistance must be minimized to increase an LED’s light output or its useful ambient temperature range for a given power dissipation.

Minimizing the thermal resistance can be done in a number of ways.  Conduction, convection, and radiation are the three means of heat transfer.  Conduction and convection are typically used to transfer heat from LEDs to ambient temperature.  Convection requires the movement of air, which in many instances requires a mechanical means of moving air, such as a fan.  In many cases, fans are not an acceptable way of cooling LEDs in light fixtures due to noise and reliability concerns.  Conduction, however, is the transfer of heat from one solid to another, and is typically the way LED systems are cooled.  Conduction requires the accurate design of heat sinks to properly cool an LED system in its intended environment.  This is where the thermal circuit model is valuable.  The thermal resistance value of a heat sink can be calculated for the specific LED system and its temperature environment.  This information allows for the proper selection criteria for a standard heat sink or provides the information needed to design an effective thermal management system.

Designers at Norlux are experienced in LED thermal management and the design of thermal systems.  If you are facing challenges regarding LED performance and LED heat dissipation, contact Norlux for a solution that’s ahead of the curve.

Undercabinet Lighting: A Great Application for LEDs

Incumbent technologies such as halogen and fluorescent lighting have dominated the undercabinet fixture market for years. Of course, both of these light sources are known to have some significant deficiencies. Halogen lighting is an energy hog, gets extremely hot, and has a short lamp life. Fluorescent tubes have poor dimming capability (if any at all), contain harmful mercury, and are available in a limited number of lengths. LEDs, on the other hand, are more than just a buzzword in the lighting industry nowadays. The attributes of LEDs and the corresponding benefits they provide make them an ideal candidate for undercabinet applications.
 

Heat:

Typical halogen undercabinet fixtures will run between 70°C – 90°C. This adds heat to an already hot cooking area, can cause cabinet discoloration and delaminating, and can dry-out or melt perishables stored on the shelving above. By comparison, LED fixtures will typically run at less than 40°C and are safe to touch.

Size:

LEDs are extremely small and low profile. This characteristic allows lighting designers to create lower profile fixtures, which are easier to conceal. In addition, LEDs can be arranged to create a fixture of any length.

Life and Power:

When utilized 4 hours per day, the average life of a halogen bulb is approximately 4 years. By comparison, LEDs in the same application will typically maintain more than 70% of their initial intensity after 34 years of use. Also, at the same 4 hours per day, consuming power at $0.10 per KWH, a single 22˝ LED undercabinet fixture will save its owner $7.68 per year in energy costs.

Optical:

In an undercabinet application, light is required everywhere from the front edge of the counter top to where the wall meets the cabinet. This is typically a 130° range when viewed from the light source. All light falling outside this range is undesirable and wasted. Due to the fact that LEDs are directional in nature, a fixture designer can better focus the light where it is needed using asymmetric engineered diffusers or any number of optic techniques.

Dimming:

Most people consider dimming an absolute must for kitchen applications. Electronically speaking, LEDs are extremely versatile and can be designed into circuits utilizing diverse dimming methods. One can even design an undercabinet system that can be dimmed using common off-the-shelf dimmers.

Environment:

LEDs do not contain harmful elements such as mercury or lead. This provides environmentally responsible designers and manufacturers the opportunity to produce a "green" product, which can even meet strict RoHS standards.

For more information, please contact Norlux at 630-784-7500 or visit us at www.norluxcorp.com.

LEDs & Machine Vision Systems: A Perfect Match

Machine vision systems often require bright and consistent lighting, so features of interest are easier to identify and process. Barcode scanners are the most common example of machine vision, and many more affordable scanners employ red LEDs instead of lasers. Computer optical mice offer another example of LEDs usage in machine vision, as they are used to provide a surface-level light source for the miniature camera within the mouse. LEDs work extremely well considering the unique illumination demands of machine vision systems, and their employment within will likely remain one of LEDs chief applications.

LEDs emit a nearly ideal light source for machine vision systems for several reasons:

• The illuminated field requirements for machine vision systems are typically smaller and often quite expensive, so the cost of the light source is a minor concern comparatively. Conversely, the ease and frequency in which a broken light source is replaced is a major concern, when located within complex machinery. LED’s long life (50,000 hours or better on average) and efficiency are certainly beneficial in this case.
• LED elements tend to be small (some as minute as a pepper flake) and can be placed in high density over flat or shaped substrates (PCBs etc.), so that bright and homogeneous sources can direct light from tightly controlled directions onto inspected parts. This effect can often be attained with small, low-cost lenses and diffusers, helping to achieve high light densities with a high level of control. LED sources can also be shaped into several formations (spot lights for reflective illumination; ring lights for coaxial illumination; back lights for contour illumination; linear assemblies; flat, large format panels; dome sources for diffused, omni-directional illumination).
• High-powered LEDs are available that can easily produce a strobe effect (in the microsecond range and below), which make for well-lit images even with very short light pulses. When synchronized perfectly with imaging, LEDs can generate crisp and sharp "still" images, despite quickly moving parts.
• LEDs come in several different colors and wavelengths, which allow one to pick-and-chose which LED best fits their application. When a machine works to identify features of interest on a label or product, different colors may provide better results than others, separating informative bandwidth from disturbing effects of ambient light.
• LEDs typically function at comparatively low working temperatures, simplifying heat management and dissipation. This allows for the use of plastic lenses, filters, and diffusers. Waterproof units can also easily be designed, allowing use in harsh or wet environments (food, beverage, oil industries).

For more information, please contact Norlux at 630-784-7500 or visit us at www.norluxcorp.com.