Figure 1-25.—Back panel of system unit showing voltage/line
select switch.
Once you have determined that the type and amount
of power are sufficient to meet the microcomputer’s
needs, you must attempt to prevent abnormal power
fluctuations from damaging your microcomputer. With
alternating current, you have what are called peaks and
valleys. Valleys (also referred to as low voltage or
brownouts) will not harm the computer or any of its
related components. However, peaks (also referred to
as high voltage or surges) can overload and literally
burn up the computer’s internal components. You can
avoid these peaks/surges and protect the computer by
using a surge protector, like the one shown in figure
1-26. This particular surge protector has a power strip
capable of accommodating up to six components. It is
advisable to first plug the system unit and its supporting
devices into the surge protector, and then plug the surge
protector into the electrical outlet, as illustrated in figure
1-26. This lets you turn all your equipment ON or OFF
Figure 1-26.—Surge protector with computer and peripherals
connected.
Figure 1-27.—System unit (rear view).
with the flick of a single switch. There are many
varieties of surge protectors, and there is probably a
particular type already in use in your workspaces.
The System Unit
In looking at the back of the system unit shown in
figure 1-27, you will see a number of places called
connector slots to attach cables. Remember, this is just
an example. Each computer is different; refer to the
owners manual for exact locations of the connector
slots. You will also see the power cord connector. You
will need to connect the monitor, the keyboard, and the
printer to the back of the system unit. Before making
any type of electrical connections, be sure the ON/OFF
switch located on the surge protector is in the OFF
position and that the plug is removed from the wall
outlet. This doubly protects both you and the
equipment; you from being electrocuted, and the
equipment from being damaged.
Connecting the Monitor
Located on the back of most monitors is an ac
power cable and a video input cable. You may also find
a voltage selection switch (for 115/220 vac operation).
Most monitors are designed to operate at either 115 or
220 volts ac, depending upon the setting of the voltage
selection switch (shown in figure 1-28). Normally, they
are preset at the factory for 115 vac operation. Should
Figure 1-28.—Back of monitor.
1-27
