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Technische Hinweise /
Technical Specifications
Conseils techniques
What is an LED?
LED stands for Light Emitting Diode, short luminous diode. In contrast to
conventional lamps like incandescent, halogen or discharge lamps, the light
of LEDs is generated in tiny electronic chips. These chips are made of se-
miconductor crystals embedded in a plastic case. This plastic case ensures
protection fromenvironmental influences aswell as improves thephotometric
properties. LEDs are regarded as extremely long-life and efficient, due to
many different Codes and light colours they are suitable for a great variety of
applications.
The light of an LED
In the p-n-junction or depletion layer (an area within the chip) the light is generated. The process is called electro-
luminescence. Depending on the semiconductor material the colour appears, there are LEDs in red, yellow, green,
orange and blue.
White light
For the generation of white light with LEDs, there are two different possibilities.
First, the blue light of an LED is transformed to white light by luminescence
conversion like in fluorescent lamps. For this process a very thin film of yellow
phosphor material is applied to a blue LED chip. The secondmethod, however,
generates white light by additive colour mixing. There, a minimum of three LED
chips is needed, at least red, green and blue (RGB).
Average life
Average lifeof LED lamps isdefinedas that point of time (no. of bur-
ning hours) when 50%of a big number of identical lamps (same
lamp Code) fall below 70%of their initial luminous flux (L70B50,
according to IEC60969). This operating life is determined at
room temperature (25°C), in open fixture, burning position base
up and at nominal voltage (rated value). Achievement of full
lamp life needs good heat exchange especially at the electronic
components.
Luminous Efficiency
How efficient a light source might be can be described by the luminous efficacy (lm/W). Highly efficient LEDs achieve
luminous efficacies of more than 130 lm/W even today and so belong to the most efficient light sources. Luminous
efficacy depends on many factors: design and generation of LED, optics (lens and reflector), ambient temperature,
ballast, driver and many more. The main focus must be put to the temperature of the chip. Similar to the span of
service life, luminous efficacy goes down with rising temperatures.
Thermo Management
For their efficiency and longevity LEDs need to get the generated heat out of the chip and release it to the environment.
How good this process works is determined by thermo management. The LED itself is referred to a cold light source.
This means, that there is no IR radiation in the light bundle. And not, like many people would think, that it would not
generate any heat, on the contrary. How much heat it produces depends on power and efficiency.
Light Distribution
LEDs originally offer directional light due to the casing design. This property makes luminous diodes
interesting products for all kinds of applications where things depend on precise illumination.
Information
All the technical parameters apply to the entire lamp. Due to the complex production process for light-
emitting diodes, the typical values shown for the technical LED parameters are purely statistical values
that do not necessarily match the actual technical parameters of each individual product, which can
vary from the typical value.
Dimming/ Controllability
LEDs are, in principle, suitable for control, but the operation of lamps/luminaires with LED technology in combination
with integrated electronic is not subject to an official technical standard. Due to different technological concepts the
dimming behaviour of lamps with integrated electronics distinguishes from conventional incandescent or halogen
lamps and thus, can be limited in certain cases. Under unfavourable conditions (many possible influences) the inte-
gral electronic components can lead to acoustic noise. As perfect dimming by conventional technology cannot be
guaranteed, LEDOTRON offers an interesting alternative with control unit and lamps that support this function.
Epoxy
Chip
Bond
Wire
Anode
Reflector
Cathode
Cooling surface
1
0.9
0.8
0.7
0.6
0.5
0.4
0.3
0.2
0.1
0
400 nm 450 nm 500 nm 550 nm 600 nm 650 nm 700 nm 750 nm
Spectrum LED (warmwhite/ 3 000K)
0
50 000
40%
50%
60%
70%
80%
90%
100%
hours of operation
rel. luminous flux
29