LED modules
An LED module consists of the individual LEDs soldered onto a printed circuit board or PCB. ERCO sources the LEDs globally from reputable manufacturers, specifying the luminous flux, luminous efficacy, colour rendition, colour temperature (i.e. colour of light) and consistency in mass production. The choice of suitable LEDs and their arrangement on the PCB depends on the actual lighting task. To optimise the overall system, ERCO designs each PCB in-house. This involves using suitable layouts for each separate light distribution and precise mounting points for the secondary lens, while also considering optimum heat dissipation from the LED chips via the PCB to the housing.
PCB for optical projection system
The yellow surface coating of the LEDs emitting white light is a fluorescent material for luminescence conversion. Optimised spacing between the LEDs assists the heat management on the PCB. The round openings facilitate the precise and safe mounting of the collimating lens as part of the optical projection system.
PCB for optical reflection
Optical systems that direct the light via a light mixer improve efficiency if the PCB has a high reflectance. For this reason PCBs are painted white and the arrangement of LEDs on the PCB is designed to suit the optical system.
PCB for grazing light Grazing light requires a linear light source. The PCBs for facade washlighting are therefore arranged in a line.
Spectral distribution
Coloured light
The radiation spectrum of warm white LEDs is free of ultraviolet and infrared components and has a reduced blue component. Its relative damage factor for sensitive exhibits is less than for halogen lamps with UV filters, making warm white LEDs recommendable for museum lighting.
The saturated LED lighting colours enable a wide variety of mixed colours within the triangle of red, green and blue. LED modules with additional white LEDs, known as RGBW modules, improve the colour rendition for the colours of light with respect to the Planckian locus.
LED manufacture
Manufacture Modern production plants for compound semiconductor materials are geared to short throughput times and high production quantities. Hundreds of LED chips are produced from one wafer. (Photo: AIXTRON).
Construction of an LED The small, light-producing LED chip is fitted onto a large heat sink for good thermal management. The lens takes care of the primary light guidance.
Like microchips, LEDs consist of semiconductor crystals and are produced using similar methods. The production plants build up the semiconductor layer-by-layer on a wafer. The upper and lower layer of the LED chip features an anode or cathode and the light is produced from the zone in the centre. Despite the use of cutting-edge production plants, not all areas of the wafer have the same properties of luminous flux and colour location. The result is that "binning", i.e. the selection category after cutting the wafer into individual LED chips, becomes essential. ERCO only uses LEDs of the highest grade and with identical characteristics in its luminaires.
By using dedicated PCB layouts equipped with carefully selected LED binnings, ERCO ensures that optimum luminous flux and colour rendition is obtained for each specific lighting task.
The optical systems for LED lighting tools are vastly different from those of conventional luminaires. ERCO designs and builds these systems in-house to ensure a perfect match, thereby allowing their full potential to be exploited in terms of efficiency and lighting quality.
ERCO places particular importance on heat management. This ensures that LED modules operate within their safe temperature range, achieving rated life and output for the specified power throughout their operational life.
LEDs require perfectly matching electronic control gear. Only ERCO´s factory encoded DALI control gear offer plug and play connectivity, i.e. fully automatic recognition in the Light System DALI lighting system.
LEDs and digital lighting controls such as Light System DALI are truly made for each other. No other light source can be controlled as flexibly and efficiently as an LED. The user-friendly operation through lighting control allows great scope to design scenographic lighting in the sense of "tune the light", this enables the potential energy saving to be fully realised.
