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Frequently Asked Questions about LED Lights
1. Question: what is an LED?
Answer: a light emitting diode (LED) is a semiconductor device that emits
visible light when electrical current passes through it, it is a special
kind of diode.
2. Question: what color of light can LED emit?
Answer: most LEDs are monochromatic. Light color is associated with the
light wavelength. LEDs made with different semiconductor materials emit
lights in different wavelengths. LED light wavelengths range from 400
nanometers (blue) to 800 nanometers (red). The colors of popularly
available LEDs in the market are red, orange, amber, yellow, green, blue
and white.
3. Question: Can LEDs be used to replace conventional incandescent and
florescent light bulbs?
Answer: yes and no. LEDs have increasingly been used in many different
applications to replace old incandescent light bulbs. Examples include LED
indicator lights for all kinds of electronic devices such as cell phone,
calculators, automotive dash panel, LCD back-lighting, etc., LED seasonal
decoration lights for Christmas and holidays, LED traffic signs and other
LED direction signs, LED flashing lights, and so on. As currently
available LEDs have limited brightness, in most cases, they can not be
used to replace incandescent or florescent light bulbs for general
lighting purposes.
4. Question: what are the advantages of LEDs compared with conventional
incandescent lights?
Answer: there are several obvious advantages LEDs have over traditional
incandescent light bulbs, they are as follows:
, Low power consumption - energy saving,
, Long lasting,
, Cold lighting,
, Ruggedness,
, Small size and weight,
, Fast switch times,
, Simple to use.
5. Question: could you give more detailed explanations about these LED
advantages?
Yes. Currently available LEDs are more energy efficient than incandescent
bulbs, but less than florescent bulbs with the same light output. The
power consumption of popular LEDs ranges from 30mW to 200 mW.
People can save money & energy by using LEDs instead of equivalent
incandescent decorative bulbs.
The rated average working life of LED is 100,000 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.
LEDs can be powered by either AC voltage or DC voltage. The circuit that
is required to appropriately drive LEDs is much simpler than that for
florescent bulbs.
6. Question: we have seen so many advantages LEDs have over incandescent
light and florescent bulbs, are there any disadvantages LEDs exhibit
compared with incandescent or florescent bulbs?
Yes, 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.
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 bulbs. This is why some customers still
hesitate to buy LED products even though LEDs have so many obvious
advantages over incandescent bulbs and people actually can save money by
using LED products in the long run.
7. Question: 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. And in fact,
they are ideal for replacing conventional incandescent decoration light
products, because when compared with incandescent light products, these
LED products 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 beautiful LED light strings, LED rope lights,
LED icicle strings, and individual round LED bulbs with changeable colors,
LED rope lights, LED pipe lights, and more other LED products will be put
into market in the near future.
8. Question: as we notice that in LED light strings, LEDs are in series
connection just like incandescent light strings, how do you compare these
two kinds of light strings in terms of reliability?
Answer: LEDs are more reliable. Most available LED light strings have
series configuration like old incandescent light strings, where lights in
the string are connected in series with each other, so a disconnection of
LED light from the string will always make the entire string fail just
like incandescent light strings. However, in the case of light burning, an
incandescent light bulb will always burn open, namely, the filament of the
incandescent bulb breaks, so the whole string will always fail, while an
LED light may either burn open like an incandescent light bulb or burn
short where a short circuit is formed inside the LED, so the burned LED
will stop lighting but all the rest LEDs in the string still light
normally. And LEDs usually burn short, therefore, LEDs are more reliable
than incandescent light bulbs in that respect.
9. Question: are there any LED strings better than those in series
connection?
Answer: yes, there is. Various LED string products are more reliable than
those LED strings in series connection in market. OUR strings use a unique
patented connection configuration that ensures an LED string will work
normally even one or several LEDs are disconnected from the string while
keeping the low prices and all the features of LED strings.
10. Question: why are LEDs of some colors are more expensive than LEDs of
other colors?
Answer: the reason is that different semiconductor materials are used for
different color LEDs, and some semiconductor materials are more expensive
than others; another reason is that manufacturing costs are different.
White LEDs are the most expensive because red, green and blue LEDs are
combined together to make a white LED.
From
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