Hardware Reference
In-Depth Information
Electrical Circuits
Modern computers work with electricity, so to interface with them, you need to understand
the basics of how it behaves.
Electricity
is the flow of tiny particles, called
electrons,
that carry a charge. Think of elec-
trons as always wanting to get home; for example, with a battery, the electrons want to get
back into the other terminal. As the electrons move through components in a circuit on their
way home they do work. This work might be to emit light in an LED or move a motor
around. If the electrons do not flow, no work is done (and the LED does not shine). Figure 1-6
shows three circuits, but only one has a path for electrons to leave the power source, pass
through a component to do work and return home again!
Figure 1-6:
Electricity needs
a complete
circuit to flow
and do work.
Electronics is all about controlling electrons' journeys! In many cases it is about making or
breaking a complete path for electrons to flow.
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