L.E.D. LIGHTING PRINCIPLES
L.E.D. LIGHTING PRINCIPLES
THE LED DIODE
- Page 1 LED (Light Emitting Diode) General Information
- Page 1 Main Features
- Page 2 LED main types
LED ILLUMINATING FEATURES
- Page 3 Lux and Lumen in the lighting systems.
- Page 4 Narrow emission spectrum.
- Page 5 CIE Colour diagram
- Page 6 Correlated Colour Temperature (CCT)
- Page 7 Choice of Colour Temperature and of BIN
- Page 8 Colour Rendering Index (Ra o CRI)
- Page 9 Colour mixing systems.
- Page 9 Referential rules
L.E.D. LIGHTING DEVICES
- Page 10 LED lighting types
- Page 10 LED choice
- Page 12 Structure of LED lighting outfits
- Page 12 Power Supply circuits
- Page 12 Heat sinks
- Page 12 Optical devices
- Page 13 Materials and Shapes
- Page 13 Dimmer
- Page 13 Varilight
- Page 14 The advantages of using LED technology
- Page 15 Choice of a LED fixture (Comparison with competitors)
LED (Light Emitting Diode) General Information:
LEDs are more and more used in lighting engineering, especially to replace traditional light sources and thanks to their features they can be considered the light generating system that will develop the most in the next future.
LEDs exploit the characteristics of a particular material (semiconductor) that, if conveniently treated, can transmit light when it’s passed through by an electrical current (electronic light). For their structure they belong to the SSL family (Solid State Lighting), that means they work with no need for “cruets” containing gas mixtures, which are required by most traditional light sources (filament bulbs, fluorescent and discharge lamps, etc.).
The main advantages of using LED lighting compared with the use of traditional light sources are:
- Longer life-time (up to 60,000 hours)
- No need for maintenance
- High lighting efficiency (up to 100 Lumen generated with just 1 Watt).
- Reduced size: the LED is at present the smallest lighting source in the market.
- Low electric consumptions (¼ compared to halogen bulbs).
- Immediate lighting even at very low temperatures.
- Availability of colourful lighting sources (the emission on a narrow frequency band of colour allows the creation of “pure” and very “full” colours even at low powers).
- Emission of UV-free and IR-free light that prevent an early aging of the illuminated objects.
- Higher mechanical reliability due to the SS (Solid State) structure LED are made of. Which means higher resistance to shocks, vibrations, etc.
- Wide range of choice for the white light “colour temperature” that can vary from the warm white of a candle (1000°K) to the cold white of a cloudless day (10000°K).
- Eco-friendliness: all L.E.D. components are built with limited environmental impact materials and recyclable ones and thanks to the easy orientation of its light beam L.E.D. contribute to a decrease in light pollution.
- Low operating-temperature: Reduced risks of fire because of L.E.D.s’ limited heat production
- Electric Safety: The voltage of a single Power LED reaches just 3,3Volt.
Main types of LED:
LED production ranges from microLEDs of a few millimetres size which reach voltages of a few mWatt up to large PowerLED multichips that can reach and absorb hundreds of Watts. We can single out two main categories of LEDs according to the absorbed electric power and light delivered:
- Low/Medium power LEDs: generally guided by currents that do not exceed 150 mA. They are mostly used to obtain light signals or decoration.
 Strip led Pixel |
 Polaris LED |
- Power LEDs : used to illuminate surfaces and whole environments.
- There are single chip Power LEDs that are currently the outmost technical expression as for light performance (up to 130 lm/W), pilot currents (up to 1000 mA) and mechanical structure (they are equipped with primary lens).
- Multichip Power LEDs. Made of different chips in order to supply many lumens from a single case
 Titan LED |
 Quadro CLL |
LEDs have particular lighting engineering features that open the door to new possibilities in the world of planning and design for lighting devices.
Lumen and Lux in the Lighting Systems
Lumen
It indicates the light flux and represents the quantity of light per second given out by a light source. In short it is the light power that a LED can supply.
A very important information as for lumen is the efficiency indicating how many lumen are given out for each watt consumed.
The use of LEDs in lighting systems require a high light flux that, if not highly efficient, would cause electric energy and heat waste.
Light flux given out by a point source. The hydraulic equivalent of a light flux is given by the water amount issued by a sprinkler nozzle in the time unit and it is measured in litre per minute.
Lux
It indicates the illumination, that’s the light quantity or light flux, that falls back on a surface unit. In other words it is the light quantity that illuminates a specific area (table, sheet, floor, etc) and it is determined by the quantity of light sources that illuminate the area, by their light power and by their distance from the area.
Illumination level on a surface. The hydraulic equivalent is given by the water amount falling on a surface in the time unit.
For specific surfaces there are rigorous norms (EN12464) to set the minimum lighting degree.
Offices:
Type of interior, use and activity Em (lx) UGRL Ra Notes
Filing, copying, etc. 300 19 80
Writing, typing, reading and 500 19 80
Data treatment
Technical drawing 750 16 80
CAD working stations 500 19 80
Meeting and Conference rooms 500 19 80 Lighting must be adjustable
Reception area 300 22 80
Filing Area 200 25 80
Em (lx) =Lighting level on a surface.
URG = Dazzling coefficient.
Ra = Chromatic output coefficient
Exemples of some areas described in the Norm EN12464
In order to satisfy the different lighting demands devices must be accompanied by photometric curves obtained by tests highlighting the total power (Lumen) and the lighting level (Lux) from various distances and incidences. This is visualized by a photometric solid or by other graphic representations.
The accuracy by which the photometric tests are carried out is fundamental for a good data collection. On that purpose Cantalupi Lighting makes its tests on LED devices after 4 hours from their turn-on, that’s at the attainment of the product heat stability. Otherwise the data would be altered.
Narrow Emission Spectrum
When our eyes perceive a specific colour they are actually stimulated by an electromagnetic emission of a certain frequency and wavelength. Actually emissions often contain many frequencies with different wavelengths. Wavelengths and their powers, as a whole, are called Emission Spectrum and the colour we see is the result of the different frequencies perceived by our eyes and processed by our brain.
Colour perception will be stronger when the emitted frequencies are closer to the colour wavelengths.
L.E.D. is a controlled and narrow spectrum emission source. Thanks to a technological process it is possible to get the wavelengths of the emitted radiations concentrated in a spectrum only 50-80nm wide and placed inside a 380nm-780nm space, so to stimulate the eye/brain system to receive especially “pure” colours and, in the case of the three primary colours (Blue, Green, Red), to receive white light.
CIE (International Commission on Lighting) Chromatic Diagram
All colours are given chromatic references (x,y) placed on or inside the “hoof shaped” area called “Planckian locus”.
“Pure” colours are on the diagram edge and do not contain any white component. White colour co-ordinates are =0.333 y=0.333 and when colour temperature changes they also change, following a curve called Planckian curve sitting inside the Planckian locus.
Es:. A (impure) green colour can have co-ordinates x=0.070 y=0.800.
A (impure) blue colour can have co-ordinates x=0,150 y=0,200.
Plackian locus and curve (CCT)
Correlated Colour Temperature (CCT)
It’s one of the sizes allowing us to describe a lighting source characteristics and it’s a numerical measure of its chromatic appearance. It’s based on the principle that any object, if heated at a sufficiently high temperature, gives out light and the light colour will predictably vary as the temperature increases. The heated body will gradually turn from red to orange, yellow, white and finally to bluish white. The colour temperature of a lighting source is the temperature, expressed in Kelvin degrees (K), at which the heated body colour will exactly correspond to the lighting source one.
With the colour temperature variation from 1000°K to 20000°K also the emitted spectrum varies and therefore the corresponding chromatic co-ordinates x,y. as well.
This variation draws a curve on the chromatic diagram x,y called Planckian curve.
Lighting sources will therefore be classified in ranges ranking from warm (low colour temperature) to cold (high colour temperature) as indicated in the chart below:
Colour temperature in Kelvin degrees
Blue sky
Grey sky
Sun light at midday
Electronic Flash
Fluorescent bulbs
Incandescent bulbs
Candle light
 |
|
| LED YACHT LIGHTING MARINE LIGHTING |
|
Choice of BIN and Colour temperature
The choice of colour temperature is important to get the right lighting for every room. The current trend is to use cold white light for exteriors and warm white light for interiors. However it’s technically very important the choice of the BIN code of any LED producer.
What is the BIN?
When white L.E.D.s are produced some substances determining the colour temperature are dropped on the LED chip. Actually the L.E.D.s produced come in different shades set in specific areas of the Planckian locus. In short, there can be white L.E.D.s with a specific colour temperature showing some little differencies in the shades of white so that some of them can look yellowish and some others reddish, etc. These areas can be singled out by codes called BIN so that in the following orders to forward to the supplier one can always get the same type of shade by simply referring to the specific BIN code. Cantalupi Lighting pays his L.E.D. suppliers 7% more to be assured of a homogeneous colour temperature and thus obtaining a colour uniformity rate of 95% on each L.E.D. supply.
ie:. Cold white about 7000°K x=0.300 y=0.320. BIN = WE
Warm white about 3000°K x=0,440 y=0,410. BIN = 7C
Colour Rendering Index (Ra o CRI):
The Color Rendering Index (CRI) is one of the most important parameter allowing us to qualify a lighting source. It indicates how a source can reproduce the colour of the illuminated object. This value can vary from 0 to 100, where 0 stands for the minimum and 100 stands for the maximum achievable colour rendering. Colour rendering depends on how much light spectrum (sun light Ra=100) is full and regular. Unfortunately efficiency and high colour rendering are two parameters scarcely ever compatible.
 CRI=90 |
 CRI=70 |
 CRI=50 |
|
|
|
|||||||||||
|
A high Ra index means that a lighting source will render good colours. |
||||||||||||
 LOW CRI |
 HIGH CRI |
Colour mixing system
There are many systems for colour mixing. The most used with LEDs is the RGB system that use the primary colours Red, Green and Blue to make all the other colours. By mixing all three colours in a balanced way we get the white.
Through the use of RGB technology Cantalupi Lighting can offer the possibility of creating, with its products, special scenarios and atmospheres with delicate colours capable of enhancing interior and exterior environments; such as light outfits that can enhance the yachts broadsides and lights that can enhance the natural beauty of the precious decorations so often used in the boats interior design.
|
RGB colour mixing system |
Colour shades produced by RGB mixing |
Reference laws
CE mark
This mark guarantees customers that the product has been designed and manufactured following precise technical directives for Low Current Appliances (2006/95/CE) and Electromagnetic Compatibility (CEE 89/336) finalised at the secure use of products. It includes the following regulations:
Enforced norms for the compliance with the Low Current Directive.
· EN 60598-1 “Lighting outfits- General rules and tests” and EN 60598-2-1 “Specific rules – Fixed fixtures for general use” stating the identification by the manufacturer of the risks the product can present in case of use or misuse and the consequent definition of the safety measures through the following points:
- Correct marking and right documentation
- Correct way for network connection
- Protection against direct or indirect contacts
- Safety dimensions (both as for surface distances and for materials selection)
- Limitation of high temperatures, electric arcs or dangerous radiations
- Appropriate dimension of sheaths and IP degree
- Guaranteed safety in case of failure and overload
Enforced norm for optical safety
· EN 60825-1 – Safety of Laser devices – Part 1 : Classification of the devices, rules and instructions for the user”. This norm prescribes a LED classification in order to supply a set of rules to protect the user or the observer from potential photochemical and photobiological damages.
Certifications concerning our dimmers
Conducted emissions - EN 60945 (2001)
Tests and methods for controlling the absence of disturbances of Cantalupi devices to the lines to which they are connected.
Radiated emissions– EN 60945 (2001)
Tests and methods for controlling the absence of disturbances of Cantalupi devices in respect to other apparatus even if not connected directly (via radio)
Radiated interferences – EN 60945 (2001)
Tests and methods for controlling the resistance of Cantalupi devices to disturbances produced by other apparatus even if not connected directly (via radio)
Electrostatic discharges – ESD EN 60945 (2001)
Tests and methods for controlling the resistance of Cantalupi devices to ESDs by mean of contact as well as in the air
Conducted low-frequency interferences – EN 60945 (2001)
Tests and methods for controlling how much Cantalupi devices could keep operating in presence of low-frequency noises on the power supply line.
Conducted radiofrequency interferences – EN 60945 (2001)
Tests and methods for controlling how much Cantalupi devices could keep operating in presence o radio-frequency noises on the power supply line
Compass safe distance – EN 60945 (2001)
This test is simply used to determine the minimum distance at which we can place the device in operation by the magnetic compass without creating deviations when pointing to the North
L.E.D. LIGHTING DEVICES
The entry of Power L.E.D. in the lighting world has revolutionized the construction and function of lighting outfits by creating new products.
LED Lighting range
The wide range of LED products can offer many solutions to get the desired lights and illumination.
The possible applications range from ambient and decorative lighting, also by using lighting strips, wall washing systems, RGB effects, courtesy lights, under water lighting for swimming pools, baths, fountains and for the submerged outer sides of yachts, up to lighting outfits such as Spotlights, Ceiling light fixtures, low-recess Panels, exterior illumination of drives, mansions, parks and gardens right to illuminating streets and very large surfaces.
Choice of LED
The choice of LEDs is of primary importance for a correct operation of the various lighting devices.
Their quality will determine the efficiency, the durability and the colour temperature stability in the course of time.
Their power and shape will determine the specific use the lighting outfit will be designed for.
Cantalupi turns to the best producers in the market: CREE, SEOUL and CITIZEN
LED Lighting lamp composition
Besides one or more LEDs, basically all LED lighting devices are composed of:
Power supply circuit
Considering the particular power supply system in direct current at a proper voltage of about 3.2V, LEDs always need a steering system allowing them to operate at the best-known voltages such as 10/30 VDC or 110-220VAC.
Most power supply units 10/30VDC are placed inside the devices and are dimmer compatible with PWM system by using our dimmer CLL and CLL CH1.
110/220VAC power supply units are usually placed outside of the devices and can be used with the most common dimmers used for traditional lights.
A good power supply circuit:
- Must have the control on the LED temperature, so that the LED maximum operating temperature does not exceed 80-85°C.
- Must be protected against voltage peaks and jumps.
- The power supply unit and the LED circuit must be protected to allow a proper IP protection in case of installation in environments ex posed to weathering agents.
- Must comply with the radio frequency regulations to prevent any interference with the electronic devices installed on the yacht, causing malfunctions during the regular operation of the product.
10-30 VDC Power Supply Circuit
Heat Sink.
Except for small low power LEDs, heat sinks must always be designed and used to keep the LED temperature within the limits recommended by the producer. The use of special design softwares for thermal dissipation has allowed Cantalupi Lighting to design compact and very efficient cooling systems. The use of special light alloys made in aluminium and anti-corrosion treated has made possible for our technicians to develop products with excellent performances and suitable for the low recesses available in the naval sector.
Study of thermal dissipation
- The study of thermal dissipation for the correct LED operation is very important. A good temperature dissipation increases the LED life and improves its performance.
- The operation temperature of the LED+Circuit+Dissipator set in standard conditions must be below 80° C
- The choice of the heat sink material is very important; aluminium is usually used
- Surface treatment on heat sinks must guarantee a perfect resistance against weathering agents, but at the same time it must guarantee a high heat transmission rate.
 |
 Example of Heat Sinks |
Optics
In order to get the maximum illumination of an area by exploiting as much as possible the LED lighting power we can use lenses and reflectors of various types.
Cantalupi Lighting can get the maximum lighting efficiency from any single source by using high technology software engineering tools, therefore making any source dedicated to a specific application.
Study of optics (lenses and reflectors)
- Reflector is designed considering both the technical features of LED and those of the product where it must be installed; in fact there’s a specific reflector for each type of product: spotlight, fixture, step light, reading light…
- The design of optical devices customized for LEDs makes possible an increase in illumination (lux) on the surface since the design intervention affects the angle spread of the luminous flux, going from 120 degrees stated by the LED manufacturer down to 30 – 40 – 50 – 60 degrees conceived for specific uses.
- The choice of the material by which the reflector is made is very important because it will affect the surface treatment, that will ensure a better lighting output according to the project specifications.
This technology allows Cantalupi Lighting to design optical systems and reflectors capable of fully meeting the target.
By using these sophisticated technologies our product range can satisfy all lighting requires, from decorative lighting to wall washing lighting
|
|
| 30° | 50° | 75° | Wall Washing |
Materials and shape.
The materials with which the device is made are important both from an aesthetic point of view and from a functional one. Therefore the choice of materials such as stainless steel, brass, treated aluminium, is also dictated by the usually “aggressive” environment, like the yacht “salt” environment, where they will be used. For the same reason the choice of a particular shape will have also to consider the LED heat dissipation.
Dimmer
In addition to LED lighting device range Cantalupi Lighting produces two types of dimmers especially designed to be used with LED lights:
Dimmer CLL manages 3 separate channels that, if needed, can be controlled either by 3 separate pushbuttons or by a single pushbutton.
Depending on the demand this dimmer can operate with tensions ranging from 10VDC to 30VDC. Each channel can supply up to 6A and is equipped with two serial lines: one making it possible to connect more dimmers controlled by a main dimmer (Master/Slave system), the other which enables the connection of the dimmer to intelligent managing and monitoring systems by using the Modbus communication protocol or the DMX one on request.
Dimmer CLL CH1 controls just one channel with the same characteristics as a Dimmer CLL’s single channel.
Dimmer CLL CH1 has no serial lines. It can be connected to other dimmers CLL CH1 through the Master/Slave system and can be controlled not only with pushbuttons but also with a 1-10V analogue signal. Therefore it can be interfaced with domotic systems that have the same type of control.
Varilight
Cantalupi Lighting has also designed a little standard system to control RGB-type led strips allowing a very easy creation of colours and control of colour-change programs. This system is composed of a small operation panel with touch screen and the operating software plus a CLL dimmer already loaded inside.
Advantages in using LED technology
Using LEDs instead of traditional halogen, incandescent and fluorescent bulbs brings many benefits such as:
- Long lasting;
- High efficiency and energy saving with reduced operation costs;
- Strong heat reduction and minimum heating of illuminated objects:
- Very low maintenance costs if we compare the average duration of an led with that of one of the longest lasting traditional sources;
- High performance compared with halogen and incandescent bulbs;
- Safely operating;
- The absence of IR (light heating factor) and UV rays (environment aging factor) makes light clean and enhances forms and volumes.
- Instant turn-on;
- Humidity and vibration free;
- Very limited environmental impact thanks to the absence of toxic and harmful substances among its components. Besides, thanks to the LED lighting performance electricity consumption can be reduced by 4/5 with significant savings in the electricity bill and with important results as for the environmental regulations that, in accordance with the Kyoto Protocol, aim to reduce CO2 emissions.
- Colour and light intensity can be various: a complete range of tones (colour temperature) and of colour renderings (CRI: Colour Rendering Index) is available. For instance white LEDs give out a light with typical colour temperature of 5600°K and have a CRI of 80, which is a value very close to that of incandescent light sources, therefore offering an excellent colour rendering. “Warm white” LEDs on the contrary give out a very bright light, with a colour temperature of 5250°K and therefore are a good alternative to incandescent bulbs, still maintaining a CRI of 80.
- Miniaturization: small dimensions together with a high light efficiency eliminate many size restrictions.
- Dynamic effects: RGB colour variation. LEDs can be controlled to obtain rapid flux and colour variations in order to create scenarios.
- Spot light installation flexibility. It is possible to set the light source on rigid or flexible supports with serial/by-pass connections.
Choice of an LED device (in comparison with competition)
- Check whether the electronic circuit used on the device is protected against voltage shocks and polarity reversals.
- Ask whether the power supply circuit is certified against any radio-frequency interference and ask for the certificate
- Verify whether the material with which the heat sink is built and the surface treatment allow a good thermal dissipation.
- Require the thermal test for any product type to the manufacturer.
- Lighting test, made 4 hours after the light is on, with the indication of the real LUX and LUMEN values and not the ones stated by the LED constructor.
- Check out the IP protection degree of the power supply unit and of the LED board.
- If possible, make sure the LED used is produced by a known manufacturer and that colour temperature and luminous flux selections have been carried out to ensure always the same product type. (Cantalupi uses selected LEDs by the best manufacturers: CREE, SEOUL SEMICONDUCTOR and NICHIA with well defined luminous flux and colour temperature BIN).
- Check the type of glass used as diffuser and/or anti-glare screen and, if necessary, make a comparison with a similar system.
- Check colour temperature of the LED used in the device (WARM = about 3000°K NATURAL = about 4500°K COOL = over 6000°K).
The last point is very important in case of product comparison based on a light real use. For instance: if we want to compare products considering furniture and colours in a room, the choice of a WARM, NATURAL or COOL light is essential for the colour rendering of the room’s details.
