FAQs

There are lots of questions which may arise when choosing Future Technologies products, so here we have grouped them into different headings. If you don’t find the answer in one section, try another similar one or email us.

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General questions ?

  • What are LEDs?

LEDs†are light emitting diodes. These are electronic components that convert electrical energy directly to light through the movement of electrons within the material of the diode. LEDs are important because due to their efficiency and low energy, they are beginning to replace most conventional light sources.

  • What makes LEDs more robust than other light sources?

LEDs†have no gases, filaments and no moving parts to fatigue. They provide light through a one-step process that takes place within the diode. There is no glass to break or screwed contacts to loosen.

  • What are the economic advantages of using LEDs over conventional light sources?

Although the initial cost of conventional light sources is less than†LEDs, the operational and maintenance costs of LED are significantly lower.†LEDs, having a longer life, reduce maintenance and lamp replacement cost. . Because LEDs need to be replaced less frequently, the owner spends less on new lamps and the labor needed to change them.†LEDs†also consume less energy; thus the overall cost of a†LED†system can be significantly lower than that of conventional lighting systems. Most applications with†LEDs†offer a payback period as low as three to four years.

Dimming with LEDs ?

  • Why do LEDs require powersupply/drivers?

LEDs†are low voltage devices. Therefore, they require a device / Power supply unit / driver, or integrated electronics that convert line voltage to low voltage in order to run the†LEDs. Sometimes the driver has electronics that can interpret control signals to dim†LEDs.

  • How are LEDs dimmed?

LEDs†are dimmed either by Pulse Width Modulation PWM, or by Constant Current Reduction CCR. PWM dimming involves switching current at a high frequency from zero to the rated output current. CCR dimming: The lighting level required is proportional to the current flowing through the†LED. Current flows through the†LED†continuously and is reduced or increased based on whether the†LED†is to be dimmed further or made brighter.

  • What are the relative advantages of PWM dimming?

Following are the advantages of PWM dimming:

  1. Smooth dimming capability
  2. More precise output levels
  3. Better consistency in color over various levels
  • Why do some LEDs flicker when dimmed or turned off?

This is usually due to incompatibility between the driver and the control system. When purchasing an†LED†product, it is important to use the correct driver type as specified by the manufacturer. It is also important to check that the†LED†is dimmable. Some retrofits are not.

  • Is it true that some LEDs can be directly connected to the mains voltage power?

LEDs†are inherently low voltage devices and require drivers. However, many†LED†products in the market come with built-in drivers and hence can be directly connected to the mains voltage.

  • What precautions are to be taken when mounting LED drivers?

LED†drivers need to be mounted in a ventilated space. Access to the driver needs to be provided for general maintenance purposes. The IP (ingress protection) rating of the driver needs to be considered before finalizing the mounting location of the driver (only those drivers designed for outdoor environments can be located outdoors). The distance between the driver and the light source needs to be taken into consideration in order to prevent voltage drop, which results in reduced output of the†LEDs.

LED light fittings ?

  • †What does a life of 50,000 hours mean in the case of – LEDs?

50,000 hours would imply 5.7 years if the light is operated for 24 hours in a day, 7.6 years if the lights are on 18 hours per day and 11.4 years for 12 hours a day.

  • Why is the life of LEDs measured as lumen depreciation?

Unlike conventional light sources that reduce in output and eventually fail,†LED†products do not normally suddenly fail. Instead, the light output reduces over time.
The normal convention is to measure the life from when the output has reduced by 30%, i.e. when there is 70% light output remaining. This is often quoted as the L70 life and is measured in hours.

  • What are the factors that affect the lifespan of the LEDs?

The thermal management of the†LEDs. If†LEDs†come on a standalone chip, appropriate heat sinks have to be designed to prevent premature failure of†LEDs.
The electrical stress: Running†LEDs†at currents higher than specified make the†LED†run hot. This can happen with wrongly matched drivers. For example, if the driver produces 700mA but the†LED†needs 350mA, this will put stress onLED†and reduce its lifespan.
Higher ambient temperatures than the ones that the†LED†is rated for will reduce its expected life

  • Is lifespan reduced if the LEDs are frequently turned on and off?

Unlike discharge lamps,†LEDs†are semiconductors and their life span is not affected by the number of times they are turned on and off.

  • How much longer does an LED last than a conventional light source?

Typically, an†LED†will last four times longer than a CFL and 25 times longer than an incandescent source that puts out the same amount of light.

  • What is the best way to compare the output of LEDs with other light sources?

Sometimes simply comparing the†lumen†output of†LEDs†and conventional light sources may not be adequate. The amount of light falling on a specific task area (the lux) gives a more realistic comparison. You should also consider the amount illumination visible on the walls. This helps identify applications where†LEDs†offer better solutions than other light sources.

  • Does increasing the wattage of LEDs increase their output?

This may occur if you are using the same product from the same brand, with the same optics and hardware. However, in general, the nature of the components (like the optical system, the heat sink, the†LED†chip, and the driver) affects the output more than the wattage does. A 3watt†LED†luminaire†from one manufacturer will have a different output to a 3watt†LED†luminaire†from another manufacturer, even if the same†LED†chip is used. Hence, using a high quality chip alone does not guarantee better performance. Note that as the wattage increases, the efficiency drops slightly. An†LEDdriven at 3W will emit slightly less than three times the output of one driven at 1W.

  • Why LEDs are considered more efficient than conventional light sources?

When comparing the†lumen†output between†LEDs†and conventional light sources,†LEDs†may have lower†lumen†value in many cases. However†LEDs†are directional light sources, all the†lumens†emitted from an†LED†are directed towards the task area. Conversely, conventional sources emit light in all directions. The light is then modulated in a given direction with optical systems like reflectors and lenses. The amount of†lumens†that falls in the intended task area from an†LED light source is greater than that of a conventional light source.

The environment ?

  • Why are LEDs considered green technology?

LEDs†are more efficient than most other light sources, so they usually consume less energy for a given task or at a spesific light output. Also, they do not contain hazardous materials such as toxic mercury. Moreover,†LEDs†have a longer lifespan and hence reduce the frequency of disposal of lamps.

  • How can LED lighting help reduce CO2 emission?

LEDs†normally use less power for a given application compared to traditional†halogen†and†fluorescent†sources. As such, the overall kW/hr consumption per year is less, this helps reduce the overall CO2 emissions.

  • How are LEDs disposed recycled?

LEDs†are primarily made of electronic components like PCBs, diodes, semiconductors etc. Therefore, they must be treated in the same way that traditional electronics are treated. They collected separately from household wastes and must be treated the same as standard electronic equipment

How do LEDs produce light ?

  • How is light produced in an LED?

Light emitting diodes produce light by the movement of electrons between the two terminals of diode, which occur by a process called electroluminescence. When a light emitting diode is electrically connected, electrons start moving at the junction of the N-type and P-type semiconductors within the diode. When there is a jump over of electrons at the p-n junction, the electron loses a portion of its energy. In regular diodes this energy loss is in the form of heat. However, in†LEDs†the specific type of N and P conductors produce photons (light) instead of heat. The amount of energy lost defines the color of light produced.

  • How are LEDs different from other light sources in the way they produce light?

LEDs†produce light by direct conversion of electrical energy to light energy.
On the other hand†incandescent†light sources produce light by heating a filament until it grows red hot. Linear and compact†fluorescent†lamps use a UV discharge plus a phosphor to produce the light.†HID†lamps use the ionization of gases in a discharge tube which in turn produce photons.

  • How are LEDs different from other light sources in the way they produce light?

LEDs†produce light by direct conversion of electrical energy to light energy.
On the other hand†incandescent†light sources produce light by heating a filament until it grows red hot. Linear and compact†fluorescent†lamps use a UV discharge plus a phosphor to produce the light.†HID†lamps use the ionization of gases in a discharge tube which in turn produce photons.