Lighting Systems based on LEDs Systems conception

The arrival of efficient light sources is undoubtedly the right response to ecological issues and the desire to reduce carbon footprint. This new industry also benefits large industrial groups, most of them Asian. However, given the high manufacturing costs of LED lamps compared with incandescent lamps, its long-term viability can only be envisaged with the promise of high reliability and long life. Rudimentary lighting sources (oil lamps, incandescent bulbs, etc.) can easily be designed as a single element, since they do not require a peripheral element to operate. The same is not true of LED lighting systems (such as fluorescent lamps), since they feature numerous sub-systems (light source, power supply, optics, heatsink, etc.) which, in turn, can be further broken down into sub-parts (substrate, chip, phosphor, etc.).

An LED lighting system can therefore be approached in a modular fashion, with each sub-assembly being of vital importance. The electronic ballast is often a critical point, as its components (and in particular the electrochemical capacitors) have much shorter lifetimes than the light source itself. In a world of fierce competition, the electronic part of the ballast offers the most obvious room for manoeuvre, with considerable product differences in ballast topologies as well as in build quality. This, of course, has direct consequences on functionality (dimmable or not), service life and quality of light output. In fact, light stability is just as important as ballast output current stability: poor filtering induces flickering, which is not without consequences for comfort, and can even lead to headaches and nausea in some people. Similarly, poor thermal management will have consequences for chip life and efficiency...

As complexity increases, so do the risk factors for failure, which can occur at any level and on any scale, from the electronic ballast to the interfaces between epitaxial layers on an atomic scale.

The economic world has become aware of the industrial and commercial potential of lighting, and the renewal of the billions of light sources in operation on Earth offers unprecedented financial prospects, stimulating development and innovation in this field. Increased performance, innovations or evolutions such as filament LEDs, as well as the integration of lasers for lighting or Lifi are all expected developments in the lighting sector. In conjunction with laser technology, the automotive industry is developing the next generation of car headlights: more directional, more intense, with greater range, while incorporating dynamic control of the illuminated zone to avoid dazzling the driver of an oncoming vehicle. Urban lighting is not to be outdone either: color temperature and dynamic intensity according to time...