Practical advice
What does a 50,000 hour lifespan mean for LED lighting purposes?
50,000 hours means 5.7 years lifespan on the assumption that the light is switched on 24 hours a day; 7.6 years if the light is switched on 18 hours a day and 11.4 years if the source is switched on 12 hours a day.
What are the benefits of LED technology?
The use of professional LED lighting is means predominantly energy-costs saving, comfort of use and protection of the environment. Below is a short list of advantages of using LED lighting:
- Saving energy
- Durability - the lifespan of LEDs is can be 50,000 hours of continuous illumination, which means that at the same time you would have to use 50 ordinary incandescent bulbs.
- Decorative lighting - thanks to the use of multicolor lighting and unique designs, it has never been so easy to obtain interesting illumination effects in the illumination of our spaces. Thanks to LED technology everyone can create individual decorative illuminations.
- Safety - professional LED light sources do not produce UV radiation which means that continued exposure to LED light sources is completely safe.
- Efficiency - LEDs are currently the most energy efficient source (using much less electricity) than traditional light sources.
- Impact resistance, temperature - in contrast to traditional lighting, the advantage of LED lighting is the fact that it does not contain fibres and glass elements that are very sensitive to impacts and shocks.
- Heat dissipation - LEDs, compared to traditional lighting, generate small amounts of heat energy due to their high efficiency. The energy produced is mostly converted into light (90%), which allows for prolonged periods of operation.
Are LED light sources more durable than traditional sources? If yes, how significant the difference is?
As commonly accepted, LED product lasts four times as long as a compact fluorescent lamp and 25 times as long as a conventional incandescent lamp that generates the same amount of light.
What are the economic benefits of using LED products?
LED light sources have a longer life span, which reduces their maintenance and replacement costs . Since LED products need to be replaced less often, the user spends less time on buying new lamps and replacing them. LED light sources consume less energy than conventional light sources. Investment pays for itself quite quickly.
Does the increase in power means an increase in the luminous flux emitted by LED products?
An increase in power in watts translates into a slight decrease in efficiency. A 3W LED light source will emit slightly less light than three 1W light sources. In general, the characteristics of components (e.g. optics, heat sink, chips, LED modules and driver) have a greater impact on the light output than the wattage output.
Warm white or cool white colour temperature? Which one to choose?
Some types of lighting can cause tiredness, create a sense of relaxation or deliver a sense of energy. In order to describe the colour of light we shall focus on the colour temperature measured in Kelvin SI unit.
Here is a brakdown of LED lighting according to the color temperature scale (CCT):
- 2500 - 2900K - Very warm light creates a mood of relaxation. Recommended for quiet and private spaces where a cozy and relaxing climate is to be created.
- 3000 - 3500K - Warm light which adds coziness. Very popular range, willingly chosen for apartments and houses. It gives a pleasant, quite warm light. It adds coziness to the interior.
- 3600 - 4000K - White, daylight, neutral light maximising concentration. This colour temperature is ideal for general applications. It can be used in offices, homes, kitchens and bathrooms. This colour is ideally suited for use in the workplace.
- 4100 - 5000K – cool shades of white colour. Ideal for use in offices and public spaces. This LED light colour has a stimulating effect. Cool lighting is more formal and energetic. It improves concentration and boosts up energy.
- Above 5000K - highly cool white temperature ideal for professional use. It is a great match for business purposes, corridors, garages and parking lots. It can also be used as decorative lighting.
Which power supply to choose for LED strips?
Each lighting system using LED strips requires a power supply with appropriate amount of power for proper functioning.
NOTE: In order to ensure durability of the LED lighting system, it is necessary to choose the wattage of the power supply which is at least 10% higher than the required power for the given section of LED strip. This guarantees that the PSU will not be overloaded, which translates into its durability and reliability.
The below tabel should help you to choose the appropriate PSU for your LED strip:
Type of LED Strip: | 300 LED | 150 LED | 600 LED | 300 LED 5630 | 300 LED |
---|---|---|---|---|---|
Power of PSU | (4,8W/mb) | (7,2 W / mb) | (9,6 W / mb) | (18 W / mb) | (14,4 W / mb) |
15 W | 2,8 mb | 1,8 mb | 1,4 mb |
| 0,9 mb |
18 W | 3,3 mb | 2,2 mb | 1,6 mb |
| 1,1 mb |
20 W | 3,7 mb | 2,5 mb | 1,8 mb | 1 mb | 1,2 mb |
30 W | 5,6 mb | 3,7 mb | 2,8 mb | 1,5 mb | 1,8 mb |
36 W | 6,7 mb | 4,5 mb | 3,3 mb | 1,8 mb | 2,2 mb |
45 W | 8,4 mb | 5,6 mb | 4,2 mb | 2,2 mb | 2,8 mb |
60 W | 11,2 mb | 7,5 mb | 5,6 mb | 3 mb | 3,7 mb |
80 W | 15 mb | 10 mb | 7,5 mb | 4 mb | 5 mb |
100 W | 18,7 mb | 12,5 mb | 9,3 mb | 5,0 mb | 6,2 mb |
120 W | 22,5 mb | 15 mb | 11,2 mb | 6,0 mb | 7,5 mb |
150 W | 28,1 mb | 18,7 mb | 14 mb | 7,5 mb | 9,3 mb |
200 W | 37,5 mb | 25 mb | 18,7 mb | 10 mb | 12,5 mb |
The above table takes into account the necessary power reserve of the PSU
How to determine a “flicker free” index
The flicker free label can be applied to a product on the basis of three separate measurements taken using GL Spectis 1.0 + flicker equipment supplied by the GL OPTIC brand.
Flicker index: its value shall be below 0,1.
Flicker percent: it value shall be below 0,0333 x Hz (flicker frequency).
The above conditions to be satisfied are suggested by the IEEE organization , known as: "no observable effect level".
Example of how to calculate the flicker value based on a selected Flicker report.
SVM (stroboscopic visibility measure) must below 1.
If all three conditions are fully satisfied, the device is labelled “flicker free".
Types of power supply elements in LED sources and lamps
In terms of design and functionality, power supply methods can be divided into three main groups:
RC power supplies
IC power supplies - linear operation
IC power supplies - switched-mode operation
Each of them serves exactly the same purpose - it directly connects the power network to the LED structure and provides it with conditions for correct operation. It also determines the main parameters of the whole lamp. On the power supply depends, among other things, the level of PF coefficient and the stroboscopic effect.
Here is a summary of the most important properties of each group:
RC power supply
It is a power supply with a very simple structure. However, this is one of its few advantages. Its disadvantages certainly include a very low Power Factor coefficient and very low efficiency. There is also no possibility to modify such a power supply in order to eliminate the stroboscopic effect. Due to the considerable size of the power supply and successively improved eco-design regulations concerning the PF factor, it is used in low-power lamps, usually up to 3W.
IC power supply - linear operation
This type of power supply contains semiconductor components in its structure. However, it is still a simple construction. The use of an IC element significantly reduces the size of the entire power supply, and significantly increases the PF factor, as well as the efficiency. An additional advantage of this design is maintaining good output parameters, which in turn increases the life of LEDs. Still, the lamp provides an unacceptable level of strobe effect, which, however, can be reduced by slightly changing the structure, but at the expense of the Power Factor. So, this entails either a stroboscopic effect and good PF, or a stable light without flickering but with a lower phase shift factor. Power supplies of this type are used in low power lamps, where the most important thing is to achieve minimum lamp size.
IC power supply - switched-mode operation
This type of power supply is a much more sophisticated structure. Thanks to the application of new technologies, we can obtain the advantages of such a solution. The main advantages include:
- A large range of input voltages - incomparably larger than in other solutions. What is important, is that in the whole range of operation, the power supply maintains constant parameters of the LED power supply.
- Very high efficiency, reaching 95%, which directly affects the lamp efficiency, which is after all directly related to the power consumed. New regulations begin to impose appropriate efficiency levels - especially in high-power lamps, which makes it impossible to use other types.
- Obtaining high power and low temperature - this results, among others, from the previous feature - smaller losses of the power supply, whereby less energy is lost in the form of heat. It is therefore possible to generate more energy for the LEDs.
- Stable operation and longer life of LEDs - the operating point of LEDs is precisely maintained, even during large fluctuations in the input voltage, which in turn affects the significant extension of the life of LEDs used.
- No stroboscopic effect.
- High Power Factor coefficient
- Galvanic isolation (optional), thanks to which there is no possibility of shock from the mains voltage.
Taking into account the high requirements for all LED line® sources, the vast majority of the brand's sources use switched-mode power supplies, which take over all their advantages - very good optical and electrical parameters, while maintaining the highest safety standards.
Can the LED Line ® MR16 or MR11 light sources be dimmed using a PWM dimmer dedicated to LED strips?
All MR16 and MR11 LED Line ® brand sources have switched -mode power supplies incorporated. They provide stabilization of LED working points, significantly increasing the life of the lamp. They also provide a constant level of luminous flux within the whole range of supply voltage. What is a great advantage of this type of source, is also the reason why we cannot use PWM type power supply.
Methodology of photometric tests - LM79-08, LM80-08, TM21-11
The LM79-08 is an IESNA approved standard for the measurement of complete luminaires at the LED line® Light Research and Measurement Centre. It guarantees uniform and correct measurements of light and electrical parameters. Using the LM79-08 standard, we are confident that the measurements are always taken under the same conditions and that the compatibility of the measurements is the same in all laboratories.
The testing methodology included in the standard specifies both electrical and photometric measurements carried out under specific conditions and parameters. At the LED line® Light Research and Measurement Center photometric measurements are performed in Ulbricht integrating sphere in accordance with the LM79-08 standards, which requires measurements of the total flux of light, CRI color characteristics, CCT, chromaticity coordinates, electrical parameters and light efficiency. During the measurements it is necessary to ensure the tests are performed in an ambient temperature of 25°C with a tolerance of +/- 1°C and to limit the air movement during the measurements. The AC power supply must provide a harmonic distortion limit of 3%. In addition, measurements should start after the luminaire has been warmed up for 30 minutes. LM79-08 standard also refers to measurements in gonio spectrometer, where additional measurement of light distribution is performed.
A separate LM80-08 – standard - is used for LED light sources without built-in power supplies. According to its requirements, the luminous flux and chromaticity coordinates must be measured at three levels where the temperature of LED/housing connection reaches: 55°C, 85°C, and the third temperature value is specified by the LED manufacturer. Measurements are made for a period of min. 6000 hours with intervals of no more than 1000 hours. The results of the measurements allow to observe how the diode changes its light parameters during the test. Please note that the LM80-08 standard only provides a method for testing the maintenance of the luminous flux.
Estimation of LED source durability/degradation is provided by TM21-11, which uses the LM 80-08 test standard. Based on the test, estimation of light flux loss during 36,000 hours (6k) (or longer if the test is longer than minimum) is made. The test result is recorded as e.g. L70, where 70 means that the LED will maintain a luminous flux of 70% of the initial value after a period of 36,000 hours (6k).
In summary, it should be remembered that the LM79-08 standard applies to complete luminaires and light sources equipped with power supply systems. LM80-08 tests are performed on a single LED or a set of LEDs without power supply systems in order to determine the loss of light flux by using calculations determined in TM21-11 document.