The
overwhelming majority of us think LED lights have no business with us, as a
matter of fact; they are bound up with our lives. They work very much like the traditional
light bulb. Only they fit directly into an electrical circuit. They last longer
than the traditional light bulb.
In
fact, we see LEDs every day. They're in lots of stuff. A light-emitting diode
(LED) is a semiconductor diode that radiates light when current passes through
it in the forward direction. Electrons move though semiconductor medium and
"fall into" other energy levels during their transit of the p-n
junction. When these electrons make a transition to a lower energy level, they
give off a photon of light. This photon may be in the infrared region or just
about anywhere across the visible spectrum up to and into ultraviolet - but we
have to pick a color when we make them. That means we can get an infrared LED
to work in our remote controls, and get other ones of different colors to make
indicators or, in large arrays, displays - even color ones.
LEDs usually are made to emit one color of light, though bicolor
ones and more can be fabricated. Intensity is being improved as well. That broadens
the applications considerably. The device has a pair of leads, and a plastic
body molded around the leads and the semiconductor crystal itself. That way the
light can get out through the plastic. There is frequently a "round
dome" at the top of the LED which serves to focus the light headed out
through it. Remember that it is the material of the semiconductor crystal that
determines the light given off by the device. A normal LED isn't really voltage
dependent. When obtaining the LEDs, a manufacturer or hobbies specifies the
color. Red, green and blue are most popular, and, though there are other
colors, it might be tough to find them. Note that the big LED color displays
use a three-LED pixel, and by driving it appropriately, a wide range of colors
can be obtained.
This is an introduction to the LED. An electronics student will
review semiconductor fundamentals and then more closely examine the chemistry
and physics of the particular p-n junction that is fabricated to exhibit
electroluminescence. A link is provided to the Wikipedia article on the
light-emitting diode(http://en.wikipedia.org/wiki/Light-emitting_diode)
and another link is gave to the online store which I frequently go(http://www.leddoes.com). I will give further
introduction about LED lights, if you have the same taste of LED lights as me,
plz come to see me frequently, and you can get the fullest information of LED irregularly
I wish u have a good time!
没有评论:
发表评论