What are they?
How much energy do they use?
The incandescent light bulb or lamp is a source of electric light that works
by incandescence, which is the emission of light caused by heating a
filament. They are made in an extremely wide range of sizes, wattages,
and voltages.
Parts of a Light Emitting Diode (LED) bulb
A LED is a "solid-state
lighting" technology, or SSL.
Instead of emitting light
from a vacuum (like an
incandescent bulb) or a gas
(like a CFL), an SSL emits
light from a piece of solid
matter. That piece of matter
is a semiconductor.
History of the light bulb
Incandescent bulbs are the original form of electric lighting and have been
in use for over 100 years. While Thomas Edison is widely considered to be
the inventor of the incandescent bulb, there are a number of people who
invented components and prototypes of the light bulb well before Edison
did. One of those people was British physicist Joseph Wilson Swan, who
actually received the first patent for a complete incandescent light bulb
with a carbon filament in 1879. Swan’s house was the first in the world to
be lit by a light bulb. Edison and Swan merged their companies and
together they were the first to design a bulb that was commercially viable.
http://www.sielement.com
How does a LED light bulb work?
Parts of an Incandescent light bulb
Parts of Compact Fluorescent Light (CFL) bulb
Why make the switch?
There are two main parts in a CFL Bulb:
1.The gas-filled tube (called the bulb or burner is
filled with argon and a small amount of mercury
vapor)
2.The magnetic or electronic ballast.
The horse-and-buggy era light bulb we still rely on, wastes up to 90
percent of the electricity it consumes as heat, burning up hundreds of
dollars every year in each American household and increasing air
pollution that harms human health and the environment.
Electrical energy in the form of an electrical current
from the ballast flows through the gas, causing it to
emit invisible ultraviolet light. The ultraviolet light
then excites a fluorescent white phosphor coating on
the inside of the tube. This coating emits visible light.
Beginning in 2012, new energy efficiency standards will phase out the
inefficient incandescent light bulb that dates back more than 125 years,
and require new bulbs to use 25 to 30 percent less energy. The transition
to more efficient light bulbs will provide massive consumer, public health,
and economic benefits.
http://www.bulbs.com/learning/incandescent.aspx
http://www.gardnerkansas.gov/cfl_light_bulb_information/
How does an incandescent light bulb work?
A light bulb has three main parts: a metal base that conducts electricity, a
thin wire called a filament and a glass bulb that surrounds and protects
the filament. The bulb protects the filament by keeping air away from it.
When the electricity pushes its way through the filament, the filament
heats up and gets so hot that it begins to glow. The filament glows
brightly enough to create light.
Stated very simply, a LED produces light when electrons move around within
its semiconductor structure. A semiconductor is made of a positively charged
and a negatively charged component. The positive layer has "holes" -openings for electrons; the negative layer has free electrons floating around in
it. When an electric charge strikes the semiconductor, it activates the flow of
electrons from the negative to the positive layer. Those excited electrons emit
light as they flow into the positively charged holes.
Light bulb safety
Modern light bulbs and CFLs are safer than the old candles and lamps they replaced, but they
still need to be handled carefully. If a regular light bulb breaks there will be sharp glass that
needs to be cleaned up. It can be even more dangerous if a CFL breaks, though, because the
chemicals inside are poisonous, especially a a liquid metal called mercury. If one does break, stay
away until an adult cleans it up.
Just imagine the following benefits:
•Savings of $100 to $200 plus per year in the form of lower electric bills in
each American household
•Energy savings equivalent to 30 large power plants
•Reductions in carbon pollution of approximately 100 million tons of
carbon dioxide (CO2) per year (equivalent to the annual carbon pollution
from more than 17 million cars.)
Replacing all the nation's inefficient bulbs with energy efficient ones will
save as much electricity annually as that consumed by all the homes in
Texas.
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