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Does Clean Mean Extreme Green?
Does Clean Mean Extreme Green? By Bill Knell Growing up in the suburbs of New York City in the 1960s was a pleasurable experience. Venturing into New York City, especially Manhattan, was not. The smell of car, truck and bus exhaust combined with a...
How to Replace Bad Habits with Good Ones: The Science of “Habit Management”
Few things are more difficult than kicking bad habits or developing more positive ones. But it is definitely worth the effort. Bad habits like smoking, overeating or self-criticism shorten lives and lead to underachievement, and unsuccessful...
Hurricane Fact Sheet
Hurricane Fact Sheet A hurricane is a large whirling storm that usually measures 200 to 500 miles (320 to 800 km) across. On the average each year, six Atlantic hurricanes occur. Sustained winds of 100-150 mph (160-240 km/h) occur with a typical...
Super-phones are great tools/toys for ourselves, but let's get tech-creators to work on helping the world and people
This article has an accompanying comic strip that can be viewed
at: http://m6.net/articles/images/supermobile.gif
The world of technology is racing ahead at such an unprecedented
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The FR ( Flawed Reason ) Theory
FR ( Flawed Reason ) theory is a theory that reason itself is ultimately flawed. That is, at some point Reason breaks down. It is not just a matter of human reason but Reason itself. FR theory, at least at this stage, does not say that it is...
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Capacitor: An Overview
Anybody in the field of electronics would doubtless be familiar
with a capacitor, but what exactly is it?
A capacitor is, simply, a gadget that is capable of storing
energy in an electric field between two conductors on which
equal but opposite electric charges have been placed.
It is sometimes also called a condenser. Every multi-conductor
geometry has capacitance, even though intentional capacitors
have thin metal plates that are placed one on top of the other
to form a compact device. But that is getting ahead of the
story. Let us first start with the capacitor's history.
The ancient Greeks were ingenious not only in the arts and
culture but also in the sciences. They also knew how to create
sparks by rubbing amber balls on spindles. This was chronicled
by Thales of Miletus around the year 600 B.C.
They were however, unaware that by placing the insulator in
between the two metal plates, the charge density would be
increased exponentially. It wasn't until the 18th century that
this potential was exploited.
Ewald Georg von Kleist of Pomerania was credited for inventing
the world's first capacitor in October 1745. His capacitor could
be described as a glass jar coated with metal both on the inside
and on the outside. The coating on the inside was connected to a
rod that passed through the lid and ended in a metal ball.
Several years later, Benjamin Franklin investigated the Leyden
jar created by Pieter van Musschenbroek, a Dutch physicist of
the University of Leyden and discovered that the charge was
stored in the glass, and not in the water as others had
previously assumed.
This was the reason why the original unit of capacitance was in
"jars". A jar is equivalent to 1nF.
As mentioned earlier, a capacitor is also known as a condenser.
This term was coined by
Volta in 1782, and referred to the
device's ability to store a much larger density of electric
charge than a usual isolated conductor.
You can compare a capacitor like a battery, in that they both
store electrical energy, although the former is a much simpler
device. It cannot produce new electrons; it only stores them.
A capacitor has two terminals connected to two metal plates
sandwiching a dielectric. Working on this premise, a rough
version of a capacitor can be created with the use of just two
pieces of aluminum foil and a piece of paper.
A natural example of a capacitor is lightning in the sky. The
plates are the cloud and the ground, and the lightning is the
charge. You can just imagine the amount of charge released by
the two plates.
Someone once made an accurate way of visualizing how a capacitor
works. One can pretend it is a cistern that is hooked to a pipe.
A cistern, which naturally has water pressure, stores excess
water pumped from the water system. This excess water then flows
out of the cistern when needed, and keeps the pressure up in the
process. In much the same way, a capacitor can be likened to the
cistern.
An important thing to remember is the unit of capacitance, which
is a farad. A 1-farad capacitor can store one coulomb of charge
at 1 volt. An amp is the rate of electron flow of 1 coulomb of
electrons per second, so a 1-farad capacitor can hold 1
amp-second of electrons at 1 volt.
An interesting thing to know is that 1-farad capacitor can
actually be pretty hefty, depending on the voltage it is
required to handle.
About the author:
James Monahan is the owner and Senior Editor of CapacitorBase.com and
writes expert articles about capacitors.
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