Hardware Reference
In-Depth Information
Electronics 101
Everyone is exposed to electronics in one way or another. You can i nd elec-
tronics inside your television, your computer, your washing machine, and just
about any device in your house. The electronic boards inside a television are
miniaturized, and look extremely complicated, but every electronic design fol-
lows simple laws of physics.
Electricity is the l ow of electrons through a conductor. A conductor enables
the l ow of electricity, and an insulator does not. A resistor restricts the l ow of
electrical energy.
So, how do electronics relate to electricity? Electronics involve the use of
components to manipulate electricity. This manipulation can be used to pro-
cess information and build logical systems, among other things. For example,
your home computer is i lled with electronic components. It processes things
like input from the keyboard, and by manipulating electricity it renders the
characters you type on screen. When discussing circuits, it's good to keep in
mind that there are two different types of supplying power. Alternating cur-
rent (AC) is the type of electricity that comes from a wall socket. It's good for
traveling over long distances (like from the power station to your home). In an
AC circuit, the direction of electricity switches back and forth rapidly (60 times
a second in North America, 50 times a second in most of the rest of the world)
Direct current (DC) is the type of electricity for circuits you'll be building in the
examples in this topic. It's best suited for small electrical components like the
ones you'll be using. In a DC circuit, electricity l ows in one direction. In most
devices in your home, like your personal computer or television, AC from the
wall is converted to DC for use by the device.
Voltage, Amperage, and Resistance
Electrons are charged particles that naturally move from a location of higher
potential energy to a location of lower potential energy. As the electrons move
through a circuit, they can be harnessed to activate electronic devices to do
work. Light bulbs, your television set, your coffee machine—all these devices
function by harnessing the movement of electrons.
NOTE A circuit is a closed loop that has a power supply and something to use the
power (called a load ). A power supply connected to itself without a load is called a
short circuit, which can cause wires to melt or power supplies to catch fi re.
When describing electricity, three measurements are used: voltage, amper-
age, and resistance.
 
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