Q1. What is an LED?
Answer: LED as popularly known is a light emitting diode -is a semiconductor device that emits visible light when electrical current passes through it.
Q2. What color of light can LED emit?
Answer: Most LEDs are monochromatic,however,not all. Color of light is associated with the light wavelength. LEDs made with different semiconductor materials emit lights in different wavelengths. The colors of popularly available LEDs in the market are red, orange, amber, yellow, green, blue and white.
Q3. Can LEDs be replaced with conventional incandescent / florescent light bulbs?
Answer:Mostly yes and no. LEDs have increasingly been used in many different applications to replace old incandescent light bulbs. Examples include LED indicator lights such as calculators, cell phones, LCD back-lighting, etc., LED seasonal decoration lights for festivals. LED traffic signs and other LED direction signs, LED flashing lights, and so on. However,most recently it has started replacing in Spot lamps,Home Lights,garden Lights,Street Lights and so on.
Q4. How bright are led light bulbs?
Answer:Led bulbs available for standard fixtures vary in brightness from less than 40 lumens up to about 1000 lumens. The brightest led bulbs for standard fixtures are the floodlights and spotlights. The brightest of these uses about 25 watts and produces light comparable to a 120-watt incandescent.
The brightest LED bulbs with approximately the same size and shape as ordinary incandescent bulbs produce up to 600 lumens. With a few exceptions these bulbs are mostly directional ,hence effective ,when pointed at the area to be illuminated.
Q5. How efficient are led bulbs compared to incandescent bulbs?
Answer:The efficacy of the newer led light bulbs is more than five times higher than comparable incandescent bulbs. In other words, led light bulbs use only about 20% as much electricity to produce the same amount of light. However, because led bulbs direct a larger percentage of light where it is needed, in many applications they are as much as ten times as effective as incandescent bulbs, reducing energy use by 90%.
Q6. How much life is expected out of a LED bulb and why the life of LED is much higher than Incandescent bulbs?
Answer:The approximate average working life of LED is about 60,000 hours compared with 1,000 hours of incandescent bulbs.
LEDs emit cold lights as working LEDs generate very small amount of heat, so LEDs are much safer than equivalent incandescent light bulbs in terms of danger of fire. LEDs don’t have filaments to heat up in order to emit lights just like the case of incandescent bulbs. Lights are emitted from LEDs as a result of energy exchange occurring in the different semiconductor materials an LED is made of.
LEDs are usually shielded with solid transparent plastic materials so they are more rugged than incandescent and florescent bulbs that are usually sealed with glass.
Q7. What are the disadvantages of LED bulbs compared with incandescent or florescent bulbs?
Answer:The most significant disadvantage is the light output limitation of LED. Currently available LEDs emit limited amount of lights at a relatively small angle range, while incandescent and florescent light bulbs illuminate in all directions and give out much more brightness of light. And this is the reason why LEDs currently can not be used for general lighting applications,however,the technology is changing everyday and we have reached to a point,where it has come to use in most of the applications.
The second significant disadvantage is the high prices of LEDs. The currently available LEDs in the market are 3 ~ 10 times more expensive than equivalent incandescent light bulb.Due to this reason,only the high end and rich people have preferred it so far to their advantage.
Q8. What LED products are currently available for general customers?
Answer: The most popular LED products available in volume at the market place are various kinds of LED decoration light products as they save up to 95% energy, have much longer working hours, are more rugged, and safer in terms of danger of fire and electric shock.
At present, people can buy anything from Street lights,garden Lights,Pool lights,Drive way lights, Strings, LED rope lights, individual round LED bulbs with changeable colors, LED pipe lights, and more and more er LED products will be put into market in the near future after writing of these answers.