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The Lighting Handbook
Functions and types LEDs
An LED (light-emitting diode) electronic
semiconductor component that emits light
when current flows through it.
LED features
– High efficiency high luminous efficacy
(lumen/watt)
– Long service life
– Broad spectrum white light
(warm white daylight white)
– infrared radiation
– Compact size
– Good excellent colour rendering
index (Ra)
– Luminous flux and service life highly
temperature-sensitive
– environmentally harmful materials
(e. 100% luminous flux
after switching on
– ignition, boosting cooling time
– High-precision digital dimming
– shifting colour locations during
dimming
– Luminous flux and service life greatly
dependent temperature (increase at
lower temperatures)
LED technology
. This allows dense arrangement of
chips close each other.
Basically, there are three types LED:
– Standard through-hole LED: often used as
indicator light source, although with low
light output.g. The wave-
length the light depends the semicon-
ductor material and its doping. mercury)
– Resistant vibrations and impact
– Saturated colours
– Immediate start, i. Due their shorter service
life, higher probability failure and sensi-
tivity radiation, they are not used in
lighting technology.
Basically, consists LED chip pro-
tected silicon coating mounted on
a housing ceramic plate with contacts. The spectrum
of LEDs offers major benefit: only light
(electromagnetic radiation the visible
range) and ultraviolet infrared radiation
is emitted.
– CoB (chip board) LED: the LED chip is
mounted directly the printed circuit
board.
– SMD (surface mounted device) LED: LED
that reflow-soldered the surface a
printed circuit board (using reflow oven).e
