Ever gotten a zap from a doorknob in a
carpeted room? That is static electricity. Static electricity is the
buildup of an electric charge resting on a surface. If there is a
buildup of static electricity, it may end up zapping something that
can be damaged. A "zap" is formally known as an Electrostatic
Discharge (ESD). ESD is the worst enemy of the fine electronics found
in computer systems. This is why it has been discussed in almost every
chapter in this course.
In order for a person to feel an electrostatic discharge, there
must be at least 3000 volts built up. If the discharge causes pain
or makes a noise, then the charge was most likely above 10,000
volts. Most computer chips run on less than 5 volts of
electricity. If there is less than 3000 volts of static built up,
a computer component could be damaged without knowing or feeling
it. The table in Figure
summarizes some of the important Do's and Don'ts of static
electricity.