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LED illumination

Regardless of the area of application, whether in offices, living rooms, stores, congress halls, halls or outdoors, light-emitting d iodes(LEDs) cannot directly replace existing means of lighting such as incandescent lamps, fluorescent lamps, energy-saving lamps or gas discharge lamps. Photometric, electrical, mechanical and thermal properties of light-emitting diodes speak against this.

Criterion for the feel-good atmosphere

On the one hand, there is the feel-good atmosphere emanating from incandescent lamps. This feel-good atmosphere depends in part on the color rendering fidelity and naturalness with which colors are presented. The color rendering index(Ra), which characterizes the color rendering of illuminated objects, serves as a comparative value. Color rendering is in turn related to the broad wave spectrum emitted by incandescent lamps, which provides a warm white.

Luxeon white binning classification, diagram:

Luxeon white binning classification, diagram:

However, because light-emitting diodes emit monochromatic light, various techniques must be applied to turn monochromatic-emitting color light-emitting diodes into ones that produce white light. The emission spectrum of white LEDs(WLED) is classified using binning and correlated color temperature( CCT). These methods can be used to develop LEDs that match the feel-good atmosphere produced by incandescent lamps, which would be one of several prerequisites for LED lighting in homes, offices, retail stores and department stores.

The light emission of LED luminaires

Another aspect ofLED luminaires that needs to be taken into consideration is the radiation and the beam angle, or the radiation range of light-emitting diodes. Light-emitting diodes are point sources whose light emission is concentrated on an area of only one square millimeter. The beam angle of LEDs is limited, unlike the incandescent lamp, which has an isotropic light emission. Therefore, an LED lamp illuminates only a partial area, not the entire area. Only with technical measures such as diffusion lenses can the beam angle be widened. Several LED spotlights arranged as an LED array become an LED floodlight.

LED lamps in bulb form and as spotlights with E27 and G4 bases, photos:

LED lamps in bulb form and as spotlights with E27 and G4 bases, photos:

For the use of light-emitting diodes for lighting purposes, their brightness and lighting efficiency, Luminous Efficacy, are decisive. In terms of brightness and luminous efficacy, power LEDs have shown tremendous performance improvements in terms of brightness, which is quite comparable to the light output of incandescent lamps. Power LEDs achieve and exceed luminous fluxes of 1,000 lumens( lm), and their luminous efficacy is more than 250 lm/W, twenty times higher than that of incandescent bulbs.

To reduce the already low energy consumption of LED lighting systems, they can be equipped with intelligent control. With the Intelligent Lighting Platform( ILP), there is an entry- level platform for lighting designers.

Englisch: LED illumination
Updated at: 11.10.2017
#Words: 433
Links: area, application (app), light, color, rendering
Translations: DE

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