Trends | LpR Article

LEDs are Revolutionizing Light – The Past and Future of Lighting

Light is a basic part of life as such and modern living relies on artificial light. Lighting is a constantly developing, even accelerating technology, with LEDs representing the current zenith. On the occasion of the beginning of the IYL 2015, Stephan Wegstein representing VESTEL, a leading contract manufacturer in Turkey, has been asked to explain the challenges this poses and how suitable strategies and technologies can assist in staying on top of developments.

Today’s modern world is unthinkable without light and without artificial sources of light. Thomas Edison’s invention of the light bulb in 1880 and its introduction onto the market changed society radically. We are now due for a drastic change once again: not only is the LED a lamp, it also has a huge impact on our planet’s natural resources.

The development of LEDs to replace classical incandescent bulbs may be compared to the evolution of automobiles. Gottlieb Daimler and Carl Benz invented the “car” as a motorized carriage in 1886. This vehicle actually had nothing in common with the vehicles we are familiar with today. One hundred and twenty-eight years ago, the two inventors simply started off from what they were familiar with: horse-drawn carriages. They did away with horses and shafts, mounted an engine on the remaining body and replaced the reins with a steering wheel. But neither Benz nor Daimler had the faintest idea of what was to come; today’s cars crammed with driver assistance systems, comfort and electronics. Body, steering wheel and engine are the only items our vehicles still have in common with their ancestor.

Thomas Edison and Heinrich Goebel invented their light bulbs virtually at the same time the car was developed. In 1889, the chemist, Carl Auer von Welsbach, replaced the original carbon filament in light bulbs with a metal filament made of Osmium. A drawn tantalum wire made its debut in 1903 and after about 1910, tungsten became the metal of choice. Up to now, the bulbs of incandescent lights contained a vacuum, but in 1910 the American, Irving Langmuir, started filling these bulbs with a neutral gas and also spiraled the wire.

Incandescent lamps matured to the standard lighting solution in many areas of our lives for the next century. Poor efficiency and more innovative solutions were catalysts to the ban of some incandescent light bulbs in the European Union after September 1, 2012. They are being replaced by energy saving or LED lamps and the ban of most halogen lamps is now imminent.

But now, however, even energy saving lamps are on the retreat. Most consumers consider the risk posed by mercury, should a light bulb break, too high. Not to mention the energy balance when including the energy consumed in their production. LED lamps and lights are catching up across-the-board and in many fields. The step from incandescent light to LED needed 100 years. And even though engineers are producing innovations virtually every six months, we are just on the brink of developments. The potential is phenomenal here and the growth rates enormous. The market prospects are outstanding and investments are pouring in. Fading into obscurity all too often, however, are many aspects important to the structured development of this market.

Electronic Controllers - a Basic Requirement

Electronic controllers are the heart of every LED lighting solution. Simply switching LEDs on and off is still conventional practice today. The DALI bus system (digital addressable lighting interface) is often used to network individual lamps, especially in simple installations. Up to 64 devices may, in this way, be operated on one bus. Communication is via two conductors of the power cable, with all DALI components connected to this conductor pair.

Modern life evolves around artificial lighting

Figures 1 & 2: Modern life evolves around artificial lighting

KNX and also DMX systems are used for larger installations with more complex demands. Main areas of application include show stages, music clubs, theatre stages, museums and architectural lighting. DMX systems are the ideal partner to lighting using color and effects, with fluorescent lamps and LED deployed where control must happen in real time. DMX is capable of controlling up to 512 lighting channels simultaneously, with 250 kbit/s data rates. This allows excellent illumination of lighting settings demanding large numbers of RGB light pixels and fast, dynamic color change.

Wireless solutions also support the development of new lighting scenarios without major efforts of installation, especially in the consumer industry. Bluetooth and ZigBee are two well-known approaches here. Many major companies have formed alliances for the uniform development of the two standards in order to ensure the compatibility of their products. One fly in the ointment: for reasons of cost, the drivers for these products are generally based on analogue technology and are not the cheapest solution. Because these lights were designed for mostly smaller control applications such as dimming or bus connections, microcontrollers remain the exception here.

Modern life evolves around artificial lighting

Figure 2

The Future Belongs to Even More Intelligent Systems

Innovative circuit designs, with the digital control concept already in place, will force the introduction of “intelligence” in LED drivers. Companies will then be able to use protected firmware to protect their IP from competitors and also to react flexibly to customer demands. The implementation of these intelligent drivers is inevitable, especially in view of new “tunable white” solutions. The advantage of tunable white LED modules is that they, in combination with light management systems, may be set up or programmed to produce dynamic light management scenarios such as automatic brightness control or different color temperatures continuously variable between 3000 and 6500 K. This range is typically between 2700 and 6500 K for spotlights and between 3000 and 6000 K for area lighting. This is the basic prerequisite for contemporary and biologically effective solutions to lighting designed to reproduce natural light conditions in a room. Well-being and productivity benefit by lighting that is close to daylight, especially for persons spending many hours in artificial lighting.

Sustainability Based on Standardization

Apart from new technology, one of the main objectives of large and responsible manufacturers is to deploy manufacturing processes to optimally preserve resources. Standardized interfaces and components are important steps to more efficient production.

The I2C bus used in automotive electronics demonstrates an approach to this. This is a synchronous two-wire bus with a wire each for data and clocking. It is an excellent solution to communication between ICs over short distances, developed in the early 80s by Philips. Transfer rates are between 100 kbit/s in standard mode and 3.4 Mbit/s in high-speed mode. Manufacturers of automotive ICs such as the American semiconductor manufacturer ISSI are using this system in their RGBW LED driver solutions. The I2C bus would also be very suitable as a standardized interface, but unfortunately no adequately standardized modules exist yet. This repeatedly renders the use of microcontrollers for lighting control a challenge to manufacturers, since the processors must, in each case, be programmed to suit the customer.

These street lights and high bay lights are an exampleof the beginningof component standardization.The optics usedcan be easily re- configured due to the standardized format. As demonstrated here, they can be used for different applications with similar requirements

Figure 3: These street lights and high bay lights are an example of the beginning of component standardization. The optics used can be easily re- configured due to the standardized format. As demonstrated here, they can be used for different applications with similar requirements

Customer requirements are wide ranging and many LEDs recurrently need special nozzles to enable automatic SMD manufacture. The high quality standard cannot be guaranteed unless tools are matched to suit the individual LEDs. Unsuitable tools may damage primary optical components or their fastening means when these are sent for automatic placement. This may lead to loss of performance or even complete failure. Standardization is inevitable here. Not only would this allow gripping different LED types with the same tool, thereby minimizing set-up times, but production could also switch to alternative LED brands. Approval and use of different suppliers of the same light would clearly reduce the delivery times of modules or luminous sources and also the production costs. This would be a logical step. LEDs, after all, are increasingly becoming commodities, i.e. components such as resistors or diodes that are interchangeable between manufacturers. A few manufacturers of secondary optics have already implemented such standardizations. Some module manufacturers and luminaire manufacturers make already use of this advantage, such as VESTEL with the latest streetlights, which are using configurable optics by a Finnish manufacturer. This enables flexible responses, such as offering customers the light distribution pattern they need. Corresponding simulation data, which should accompany the light just like its datasheet, may also be compiled fast and effectively. Fully equipped laboratories with photogoniometers allow fast verification of the theoretically calculated results.

Besides the certified test labs, it is mandatory to have an efficiently organized and structured manufacturing environment witha solid and clear manufacturing process

Figure 4: Besides the certified test labs, it is mandatory to have an efficiently organized and structured manufacturing environment with a solid and clear manufacturing process

The same LEDs and optical families are also deployed for industrial lighting in halls (high bay), again reducing the variety of components.

Companies are implementing this on a small scale already and the important step of optimizing all processes should logically follow.

The comprehensive experience of a manufacturer is manifest in the production and development of LED products. Corresponding products are therefore 100 percent recyclable and free of Mercury, offering a long service life and the reduction of energy consumption by 80% compared to conventional lighting. Production sites must, to this end, be sure to deploy state of the art technology. Modern laboratories and quality standards are sine qua non. Therefore, laboratories need to be certified, for instance UL accredited like the Turkish Mega- factory in Manisa. Close cooperation with certification institutes of the different countries is a matter of course and also important in order to reduce the time-to-market. Experience gained in the production of, among other things, 50,000 TV sets with LED backlighting per day, is extremely useful since everyone is familiar with the concept of LED lighting.

Networking in Many Ways

Increased networking in all spheres of our lives will also affect the way in which we illuminate our environment. The trailblazer was Philips; they equipped their TVs with “Ambilight” years ago. Rows of LEDs on the back of the TV will illuminate the wall behind to match the current TV image, creating an aura surrounding the screen.

A lot of suppliers are now also offering a complete lighting system, i.e. the Hue system, based on the ZigBee standard and controllable via an app. A bridge, connected to the router and functioning as the link between the lighting system and lights, is required for control. The system is controlled via an
app on a smartphone or tablet PC.

Other manufacturers introduced Smart Bulb series comprising app-controlled LEDs, at the IFA 2014 in Berlin. Apart from the ZigBee version, a Bluetooth controlled series is also available.

These, however, are only the first and tender beginnings of “networked lighting”. Our home controller will in future recognize that the TV is in operation and change to a lighting scenario more suitable for this purpose than for reading, for instance. Since the Internet of things will manifest itself here as well, various apparatus and applications will be interlinked and lighting will be highly customizable.

Experts agree that intelligent lighting modules like this Xicato XIM module that offers additional features and which can be integrated in the IoT will soon be an integral part of our technical lives

Figure 5: Experts agree that intelligent lighting modules like this Xicato XIM module that offers additional features and which can be integrated in the IoT will soon be an integral part of our technical lives

Added Value through Integration

Key players in the market for brown and white goods will have important functions in future. New and innovative solutions are in the offing already and Özcan Karadogan, MD of VESTEL Germany announced: “We will be incorporating LED lights in TV controllers in time for the next IFA. We will soon introduce the first TVs onto the market, which, in addition to normal remote control, will also include a tablet PC. The tablet will then come with an app to control the lighting in the room as well. Why should we need to get up if the lighting can also be controlled via a tablet?” This concept appears reasonable, considering that about 13 million TVs are leaving only this factory in Turkey each year, heading for the European market. This corresponds to more than 50,000 potential customers per day who require lighting control. The introduction of tablets as remote controllers takes integration of lighting control in home automation to a new level in everyday life.

Whatever the operation, customer satisfaction is the key to success and should be top priority. Newcomers are in a position to bring their new ideas to bear in the lighting market, even coming from other fields of business. Survival in this new business and its enormous potential, however, requires the development of a wide and steadily growing range of products. Precisely this ongoing change and continuing development must lead to the introduction of standardized LED components and modern digital technology in order to ensure the required flexibility in the face of market demands. At the other side, lighting manufacturers nod not only to be fit in lighting technology, in this new era, they need to understand and implement new technologies for being competitive in this volatile market.

Waiting Will Not Pay

With technology developing at today’s breakneck pace, it will certainly not be 100 years to the major breakthrough, as with the automobile. The first automobiles with laser light are on the road already today. For this task, laser light is more efficient than LED light and will probably also find its way into applications demanding high intensity illumination such as aircraft landing lights and possibly lighting of aprons or sport stadiums. Even the upper efficiency limit of 276 lm/W for LEDs is a thing of the past. Waiting will not pay – we do not have the time! In many aspects of our environment it is evident already that we should take better care of our resources - saving more energy and reducing CO2 emission. Another aspect of this endeavor is moving our production facilities closer to the target markets - highly innovative manufacturers and premium industrial partners producing brown and white goods for Europe have for many years been minimizing transport costs and reducing the volumes of aircraft fuel and extremely toxic fuel oil for ships. These companies are prepared to invest millions and could also be reliable partners in Europe’s lighting industry.