Creation of LED luminaires: from Concept to off-the-shelf Product
Today in lighting technology revolutionary changes are taking place - LEDs are replacing traditional light sources. And, of course, the emergence of technological innovations creates an almost childlike curiosity: how is it all created? It is obvious that LED luminaires are made in some other way than conventional lighting devices, but how? The answer to this and many other questions can be found in this article.
For many decades luminaires were manufactured separately, light sources for them were also produced separately. Sometimes a bulb would go with the luminaire, but it was not mandatory, more often such set was made for the convenience of customers. Luminaires were manufactured by the companies which had a high level of expertise in the design, optics, metal processing, ceramics and so on. Electronic "filling" of the luminaire was reduced to a cartridge, cable, switch and socket. In the case of fluorescent or other gas-discharge lamps, electronic control gear was added to complete a set, and this was obtained by luminaire manufacturers as a ready unit. Very rarely a dimmer was included in the luminaire, as mainly it was an external device.
LEDs have changed everything. Firstly, the lifespan of the light source is comparable with (and in some cases exceeds) the lifetime of other elements of the luminaire. This led to the fact that LEDs are usually made non-replaceable (or there is possibility to replace the unit with LEDs, but as a repair and not as a regular maintenance procedure). Secondly, the parameters of the luminaire, the lifespan, for example, now depend not only and not so much on the light source, but also on other electronic components. Thirdly, LEDs can perform many more functions, so the LED luminaires have a more complex structure in comparison with their "colleagues" with traditional light sources.
Vadim Dadyka, Director General, AtomSvet LLC
"It is already clear that there is no alternative to LEDs, and in 10 years’ time few people will remember the fluorescent lamps, including CFLs, not to mention the incandescent lamps. The demand for high-quality LED products is gradually increasing, especially in industrial enterprises, large companies and government organizations. They are beginning to understand that they need to purchase light sources and LED luminaires from Russian or well-known global manufacturers. The only problem so far is in the relatively high prices of these products in comparison with the Chinese ones. But the Russian market is beginning to make more stringent demands of manufacturers, suppliers of components, as well as of the final product".
Idea and design
Sometimes luminaires are made to order. The customer brings the technical specifications to the manufacturer, who produces the necessary luminaires for him. But manufacturing of bespoke luminaires is very expensive, it is practised only for large projects, and in Russia it is still rare.
So at first the manufacturer develops a model line, which he judges will be in demand in the market. This is usually preceded by a study of the market and the needs of the potential range of customers. But it also happens that the designers or engineers invent something that is absent in the market, and the company's management believes that this new product is sure to be successful. Of course, for such breakthroughs the company needs to have highly skilled and, most importantly, creative professionals. But there is another way - to establish contacts with "unheralded" designers, who have interesting ideas. They are willing to sell them at quite moderate prices, and your engineers will bring the idea to a real project. Finally, the most expensive way, which, however, guarantees success in most cases, is to use the services of some eminent design studio.
Of course, there are manufacturers of luminaires that do not bother with design, but just take one of the commonly used options (such as the ubiquitous typical "Armstrong" luminaires for ceilings) or even buy ready-made housings. If the main task of the manufacturer is to keep the prices as low as possible, then such an approach is justified. Unfortunately, the Russian manufacturers of LED luminaires are forced to use standard housings often originally designed for fluorescent lamps, not only because of greed or lack of understanding of the market, but also for objective reasons. Tender conditions and lack of a coherent strategy of state support make the manufacturers produce the most inexpensive models with low performance. We hope that newly adopted state policy of supporting local manufacturers will improve the situation on the market of LED luminaires.
Yevgeniy Dolin, Director General, Board Member
Nonprofit partnership of LEDs and LED-based systems manufacturers (NPLM): "Now the decision has been made to start large scale construction of sports facilities. As a rule, they are administered by municipalities, so they are built and financed by budget money. Here it is necessary to introduce protectionist measures for Russian manufacturers and thus not just give them a chance to make a profit, but also to manufacture products with a better performance. That is not just stipulating the purchase of a certain quantity of domestic products, but also requiring the supplier to offer products with the best features".
As for the strategy of price reduction at all costs - it leads nowhere. As practice shows, there is always a manufacturer who makes it cheaper, even in the short run at a loss to himself. The lamp in the typical faceless housing is easy to fake, causing damage to your reputation. That is why the world's leading manufacturers of lighting equipment always use an individual design for their luminaires. At the same time luminaires with an original design, if properly developed, can be installed without problems in standard suspended ceilings or other building structures in the same way as products with the "typical" appearance. Among Russian manufacturers of luminaires AtomSvet products have an individual design, for example. Even luminaires intended for use on the factory floors have an original design. Incidentally, some design decisions for LED luminaires are aimed at the quite practical function of improving performance. For example, the rounded shape of the housing does not allow dirt to gather, which is important for use in industrial facilities with difficult operating conditions.
Based on the general concept the technical specification for the luminaire development is written, and the maximum cost of components and production procedures are determined to achieve the planned payback period of the luminaire.
Engineers who design the luminaire should have an education in lighting engineering or some discipline which is close to it. It is also desirable to attract designers, specialists in thermal engineering and work with metals to the team. In cases where the luminaire is designed for special applications, expert advice on chemistry and mechanics may be required.
At this stage the selection of the optical system and the LEDs are selected to obtain the desired light intensity distribution curve (LIDC).
One should not think that the optical system is necessarily just lenses and reflectors. The glass that covers the LEDs is also the part of optical system which determines the LIDC. A diffuser is also part of the optical system. Here there can be no details.
The optical system embedded into the LEDs is called the primary optics. Other optical system elements placed outside the LED are called the secondary optics. In some cases, the primary optics already provide the necessary LIDC, but as a rule, in luminaires designed for rooms with high ceilings, as well as for spotlights the secondary optics are essential, as it is necessary to provide a small (about 15 - 30 degrees) angle of light distribution.
The choice of the optical system determines largely the extent to which luminaire is resistant to a hostile environment. For example, for luminaires installed on the factory floors with high concentrations of aggressive substances the luminaires with optical systems, based on Macrolon LED polycarbonate made by the German company Bayer, can be recommended. This is the polycarbonate used in the optical system of its luminaires, for example, by the Russian company, AtomSvet.
The choice of LEDs is an important issue in the luminaire design. In the mass consciousness of the consumer there is an idea that if Cree LEDs are installed in the luminaire, it automatically guarantees the quality. Of course, Cree is one of the leading companies that manufacture LEDs. But, unfortunately, if you look at the volume of lamps with allegedly Cree LEDs offered on the market, we find that this company is simply not producing so many LEDs. That is, either some reject LEDs of eminent manufacturer are used, or simply something else is substituted under a popular brand name. The Japanese company Nichia is also one of the world's leading LED manufacturers; moreover, the first white LEDs were created in its laboratories.
But just to have a "loud" brand is not enough. The same manufacturers produce LEDs with different sets of parameters, the so-called bins. The choice of the right bins among the variety of LEDs offered by the manufacturer is a real art, and the extent to which the designers are good at it will determine whether luminaire delights the consumer with pleasant white colour or there are some shades present which are unpleasant to the eye. Energy efficiency of the luminaire also depends on the selected bins.
It should be noted that the factories producing luminaires more often receive not individual LEDs but ready-made LED matrixes. The LEDs in them have already been selected by bins for a particular purpose.
Selection of electronics
The most important element of the LED luminaire is power supply unit (driver). As practice for LED luminaires operation shows, the power supply unit usually fails earlier than the LEDs. And whereas for household luminaires this means taking the unit to a repair shop, failure of luminaires installed in manufacturing facilities mean stopping the conveyor, disassembling the unit, and mounting a new one. During downtime there is a significant loss of income. That is why the electronic components used in power supply units and other luminaire units should have an Industrial reliability level.
There is a continuing debate among specialists, what is better – a power supply unit designed specifically for the luminaire produced at the same factory, or a ready-made module produced by the company, which is a recognized leader in the manufacture of drivers. In fact, both options have their own advantages. In the first case, the power supply unit can be more accurately adjusted to the luminaire parameters. In the second case, we have a proven technology. More important is that the luminaire manufacturer does not try to save on the power supply unit. And there is a temptation to do so - looking at the luminaire we can see just how the LEDs work, and only a specialist can appreciate the work of the power supply unit, and many buyers simply don’t pay any attention to this unit.
In addition to the power supply unit there are other electronic components installed in the luminaire: dimmers, wireless modules and so on. Typically, these units are installed as options, according to customer requirements.
Leading manufacturers of LED luminaires, including Russian companies such as AtomSvet, Light technologies, LEDEL and some others, pay a great deal of attention to this design stage. Small manufacturers make more simple thermal calculations or do not make them at all.
At this stage it is determined, in which temperature mode the LEDs and other electronics mounted in the housing must operate. Based on the values of the thermal energy released, thermal resistance of the housing and requirements of the heat sink are determined.
In the case of overheating the lifetime of LEDs and other electronic components is reduced. That is, if the temperature calculation has not been made or has been done incorrectly, the LED luminaire, costing more than luminaires with conventional light sources, will not provide any benefits in energy consumption nor longer life in comparison with them.
Based on the concept of the designer, the parameters of the optical system and electronic units, as well as the requirements resulting from the temperature calculation, the housing design is developed.
The material of which the luminaire will be made (plastic, metal), and the manufacturing technology (sheet assembly, moulding, extrusion) is selected according to the requirements.
The most complex and expensive procedure at this stage is development and manufacture of moulds for casting or extrusion. Hundreds of thousands or even millions of rubles have to be spent, and highly qualified workers employed to fulfill the order. Usually specialized firms make the moulds according to customer documentation. Often at this stage one has to turn to foreign companies, as there is a big problem with mould production specialists in our country.
Before mould production the electronics must be debugged, the necessary technical and economic calculations should be made. It is very expensive to remake the mould.
After the housing production and installation of the “filling” we get a prototype. It is desirable to test it in different conditions and then make the necessary adjustments. Even if you have designed and assembled the luminaire perfectly, some things can be corrected only following the results of testing. For example, the determination of which greenhouse luminaire spectrum is optimal for a particular plant species.
The assembly shop receives luminaire components in the form of finished units. Its assembly is not a big problem; in some cases it is possible to do it even without soldering. Naturally, the assembly shop must be equipped to comply with all the standards. Measures must be taken to protect against static electricity.
Typically, the sequence is as follows. First, the LED module is attached to the optics. Then, the assembly is attached to the heat sink using thermal grease. Then the power supply unit and (if necessary) the control electronics are installed. The housing is closed and screwed tight; the luminaire goes to final check and packaging.
There are not many requirements regarding the qualification of employees directly involved in luminaire assembly. It is sufficient for them to have secondary education, a desire to work, neatness and assiduity. They can be trained in other things directly in production. But employees of the technical control department are specialists with a higher technical education, as close as possible to the production profile.
The most important thing is the quality control. Have you ever thought about how the countries of Southeast Asia, in some of which the industrialization occurred only at the end of the 20th century, can manufacture products quite on the level of developed European countries? The secret is in the quality management procedures describing a set of measures and procedures for quality control of the product. These procedures are defined by the international standard ISO 9001: 2008. If the company has been certified according to this standard, then it can be argued with great certainty that it produces high quality products, wherever its location is. Let it be in Thailand, or in the Philippines. And in the country, which was the first to launch a man into space, the quality will be high all the more.
Can't decide?Contact our manager
or fill out the form on the web site
and we will try to help you out?