Knowledge base

Lyon 2014, Fête des Lumières (Festival of Lights)


To avoid ESD damage when mounting LED Stripes, the installer should be earthed with anti-static tapes. Use appropriate clothing to avoid static electricity.


In the production of modern LEDs, manufacturing tolerances are inevitable even with the smallest parameter fluctuations. These semiconductors are therefore sorted and classified according to their color values ​​and efficiencies after production. All LEDs that have the same or similar values ​​fall into the same bin. The closer the tolerances are determined, the higher the quality of systems consisting of multiple LEDs.

Decisive selection criteria are:

Luminous flux, measured in lumens (lm)

• Color temperature, measured in Kelvin (K)

Forward voltage, measured in volts (V)

COB (= Chip on Board)

These are used for particularly powerful, densely packed LED modules. Non-encapsulated LED chips are glued directly onto a printed circuit board and connected via so-called "bond wires". A glued Epoxy lens, called Bubble, generates the beam angle, which can be broad or narrow beam.

CRI (Color Rendering Index)

Indicates the quality of the color rendering of artificial light sources. In english CRI is translated with color rendering index and abbreviated Ra. The maximum value of the index is 100 and means no distortion of the colors by the light source. Incandescent lamps could reach this value. LED lamps are typically at a Ra 80, but can also reach values ​​around Ra 90 and more.


LEDs are basically dimmable, in the professional LED range the pulse width modulation (PWM) has established. There are dimming modules for 1-10 V and DALI lighting controllers commonly used in electrical engineering, which convert the signal accordingly. Similarly, there are interfaces for DMX controllers to accommodate more complex requirements e.g. to allow for RGB or white controls. Many manufacturers offer dimmable LED lamps (retrofits). The standard dimmers (phase dimmer) have been developed for incandescent lamps and are therefore designed for higher minimum loads (W). This could result in reduced function.

Electromagnetic compatibility?

The LED has a high EMC (electromagnetic compatibility). It generates no electromagnetic interference fields and can hardly be influenced by such interference fields.


The efficiency of the LED power supplies is given in %, which should always be taken into account when planning the LED power supplies. Example: Power supply unit 12 VDC 300 W Efficiency 80% in continuous operation max. 240 W available.

Colour variations

The LEDs we use come from well-known manufacturers such as Cree, Bridgelux, Epistar, Samsung, etc. We endeavor to deliver all orders with the same color selection, but exact color reproduction can not be guaranteed for different production batches.

Color rendering

The color spectrum is a part of the electromagnetic spectrum that can be perceived by the human eye without technical aids (about 380 to 750 nm). The color temperature is a measure of the color impression of a light source measured in Kelvin (K). For LED lamps, the color temperature typically ranges between 2700 K and 6500 K.

Heat Sink

Is the housing, which serves for heat dissipation of the LED. Thermally highly conductive materials are used here, which release heat generated inside the lamp to the environment ➜ Passive cooling.

High power LEDs / Power LEDs

High-power LEDs produce the most light. Initially, they came on the market as an efficient 1 watt version operated at 350 mA constant current. This was followed by high-power LEDs in 3 Watt version, operated with 700 mA constant current. At the same time, the LEDs could be further miniaturized. The smallest high-power LED is hardly larger than a match head and already reaches 170 lumens per watt.

Infrared radiation (IR)

LEDs do not emit IR radiation. The heat generated during light generation is generated directly in the crystal and has to be dissipated ➜Thermal management. LED light is therefore ideally suited for the illumination of heat-sensitive exhibits but also for food.

Junction temperature

The degradation (lessening) of the LED luminous flux essentially depends on the temperature of the light-emitting layer (junction) in the semiconductor crystal during operation.

Decisive for the junction temperature is the temperature balance of a LED ➜Thermomanagement.

Constant current

A constant current source realizes within very small deviations the ideal power source, which feeds a constant electric current into a circuit, independent of the electrical voltage at its connection points or from the execution of the further circuit. The output current is also referred to as impressed current.


The lifetime of an LED is basically extremely long, but this is also subject to a continuous decrease in luminous flux (degradation). The luminous flux decrease is directly temperature-dependent. (A lack of cooling makes LEDs in the luminous flux clear much faster) A once overheated LED is already irreparably damaged! It establishes the indication of an even economic light output of 70% (L70), or 80% (L80) of the initial luminous flux after an assumed operating time of e.g. 50,000 hrs. The LED is not yet defective on reaching this operating time and will continue to work for a long time. However, the required level of illumination will presumably be undercut thereafter, or other components such as e.g. electronics components may fail.

LED (Light Emitting Diode)

Is an electronic semiconductor device. If current flows through the diode, it emits light with a wavelength that depends on the nature of the semiconductor. Colored LEDs emit very color saturated monochrome light. There are no white LEDs ➜ white LED.

LED Power Supply

To operate all LEDs operating devices are required to generate a required supply voltage. Common voltages are 12 VDC, 24 VDC, and 350 mA and 700 mA constant current. The efficiency of the LED power supplies is given in %, which should always be taken into account when planning the LED power supplies. Example: Power supply unit 12 VDC 300 W Efficiency 80% permanently max. 240 W available.

Conductor cross section at constant current

The cable length and the cable cross-section are not critical factors as the current is constant and of low value (350 mA or 700 mA). Since the converter operates in stabilized constant current, there is no electromagnetic radiation on the cable. For this reason, the cables and lines can also have a length of 20 m to 30 m. Any losses on the line are automatically compensated by the LED power supply.

Cable cross-section on the secondary side at 12VDC and 24VDC

For constant voltage, the cable length and the cable cross-section must be taken into account. Ask us.

Luminous flux

Luminous flux of a complete luminaire, including operating device, housing and optics. The luminous flux of a light source with compact fluorescent lamp must be corrected by the luminaire efficiency. For example, a 1,200 lumen LED downlight could be equal to a compact fluorescent downlight with 1 x TC-D 26 W (1,800 lumens and an efficiency of 65%).

Light colour

White LEDs can now be easily manufactured from 2.300K to > 6.500K.


(Lat. Light, light) is the photometric unit of the luminous flux. The luminous flux is a measure of the total visible radiation emitted by a radiation source.

Ecological balance

In comparison to the overall energy balance, LED lamps are clearly superior to conventional incandescent and energy-saving lamps.


The organic light-emitting diode (OLED) is a thin-film luminous component made of organic semiconducting materials, which differs from the inorganic LED in that current density and luminance are lower and no single-crystalline materials are required.

Passive cooling

A passive heat sink works primarily by convection. The ambient air is heated, becomes specifically lighter and thus increases, whereby cooler air flows. The material most commonly used for passive heat sinks is aluminum ➜ Heat Sink.

Power LEDs

Power LEDs have much higher luminous flux than the standard types, eg. Currently this is over 120 lumens per watt.


LED lamps have a very long life and they do not contain mercury. But these are electronic components and they are therefore WEEE-liable. At the end of the day, LEDs have to be disposed of at the recycling center, just like electronic waste.


LEDs with the primary colors red, green, blue and the possibility to generate colored light or additive white light via special controls (DMX, DALI). Due to poor color rendering quality and a different aging of the colored LEDs, this application has not proven in practice in white light and is mainly used for colored applications. The advantage of high color saturation and the possibility to generate a high number of color tones is clearly given.


Like RGB, but with an additional white LED light source to achieve good results even in the white area. The white LED light source is available in both cold and warm white.


A LED replacement module variant with common bases E 14, E 27, GU10, GU 5,3 u.v.m. as a direct replacement for incandescent, halogen or energy-saving lamps. In various light colors, these retrofit lamps are suitable as energy-saving alternatives in the private or commercial sector. Retrofit LEDs, which are operated with 230V, have an integrated power supply unit. Retrofit LEDs, which are used as an alternative to low-voltage halogen lamps, can be operated on conventional transformers, electronic DC power supplies and to a limited extent on electronic transformers. They can usually be easily used in existing luminaires. However, they do not quite reach the full life of a complete LED luminaire. For example, a warm white LED bulb with 7 watts holds about 30,000 operating hours - that's four hours of burning per day, after all, over 20 years.

Switching frequency

LEDs are extremely switchable, with no switch-on delay the light is available with almost 100% luminous power. This makes the LED ideally suited for use with motion or presence detectors. High minus temperatures do not prevent the LED from starting immediately.

SMD (= Surface Mounted Devices)

SMD are extremely small standard products for industrial production. SMD LEDs are glued directly onto a printed circuit board and contacted in the solder bath. SMD LEDs are the type most commonly used in modules or lights. SMD designs are equipped with both low and power LEDs. They enable the automatic production of very powerful, extremely flat and narrow modules.

System performance

Indication of the power consumption of the light source (LED / illuminant) including control gear.

Temperature Management / Thermal Management

Even though the emitted light of an LED is not hot, it is not the case that LEDs do not give off heat. As with other lamps, only part of the energy is converted into light even with LEDs - heat is generated inside the semiconductor. This heat must be dissipated to ensure high efficiency and long life. Especially required for LEDs with high luminous flux. A one time overheated LED is already irreparably damaged! At low ambient temperatures, the LED is unbeatably superior to all other light sources.

UV radiation

Is an electromagnetic radiation, invisible to humans, which can lead to damage to health. LED luminaires do not generate any UV radiation and are therefore suitable for illuminating sensitive exhibits. In the field of outdoor lighting they attract less insects and are therefore more environmentally friendly.

Heat generation

LEDs transform more electricity into visible light than conventional bulbs. Nevertheless, even with today's LEDs, some of the energy intake still flows into the heat development. Where the LED technology has enough potential to further improve this value.

Maintenance factor (MF)

Describes the relationship between the luminous flux of a lighting system during commissioning and at the time of maintenance. It takes into account:

• Luminous flux decrease due to failure and aging of light sources

• the possible contamination of a luminaire over time

• the conditions that can contribute to pollution and aging.

What must be considered when wiring LEDs

Forward voltage and forward current are highly dependent on the semiconductor material. For LEDs that are operated in parallel, the limitation of the current is already realized by resistors. Application mainly for the operation of standard LEDs. But also power LEDs can be connected directly to a DC or AC voltage, provided that the upstream of corresponding resistors and rectifiers takes place. Application almost exclusively in power LED compact design or with RGB modules. Power LEDs with 350 mA or 700 mA must be connected in series. Failure to do so may in the worst case result in the destruction of the LEDs. For Power LED for 12V AC / DC (with integrated rectifier) ​​we recommend the use of 12V / DC power supplies. The LED can be safely operated over a further voltage range with a constant current. Optimally matched components are available in our product range (LED power supply, LED / LED lights) under consideration and compliance with the installation regulations.

White LED

White LED light can be generated by different manufacturing processes. The currently most common method uses the principle of "luminescence conversion" and is also used in fluorescent lamps. In this method, a wafer-thin phosphor luminescent layer is vapor-deposited above a blue LED chip. It converts a part of the blue light through the yellow phosphor into white light. The concentration and chemical composition of the phosphor must be controlled very precisely to achieve the desired light color. Thus, different shades of white are possible: from warm white (2700 - 3000 K) over neutral white (3500 - 4000 K) to cold white (5300 - 6500 K). Further advantages of this method are relatively high luminous fluxes and good color rendering of up to CRI / Ra> 90.


Indication of the ratio of the luminous efficacy to the power consumption Lumen / Watt, e.g. 2000 lumens / 26 W system power = 76.92 Lm / W.


LEDs are already much more efficient and economical with respect to many common light sources. Due to the long LED service life, longer service intervals are added and the associated savings potential for spare replacement, disposal and working hours. Reduced air conditioning costs due to lower heat development also contribute to economic efficiency.


LED is undoubtedly the lighting technology of the future and we are just at the beginning of a very interesting, new era. The rapid progress in the efficiency of the LEDs, the development of new, intelligent lighting solutions and the opportunity to develop a completely new lighting design is both a challenge and an opportunity. LEDs are already efficient, ecological and sustainable.