Chapter 14: Power Supply and Electrical Issues^319
Dealing with Static Electricity
Static discharge can be avoided through good preventive measures that help to eliminate, or
at least reduce, static electricity. Here are a few ways to prevent static discharge problems: Treated carpeting A major source of static electricity is the carpeting in an
office or home. The carpet can be treated fairly inexpensively with antistatic
chemicals that help to reduce static buildup in the carpet.
Antistatic bags When not in use, electrical components should be stored in
antistatic bags. Never stack up electronic boards whether they’re in antistatic
bags or not.
Grounding pads Placing a grounding pad under a PC provides a place to
ground you or the PC before it is worked on. If you touch the pad before you
touch the computer, all built-up static electricity will be discharged.
Environmental Dry air can cause static electricity. The humidity around a PC
should be kept above 50 percent to minimize the amount of static electricity
generated. Installing humidifiers to add moisture to the air can raise the
humidity in an area or room.The best and most effective way you can avoid the threat of ESD damage to a PC is by al-
ways wearing an ESD grounding stra pon your wrist or ankle when you are working inside
itscase.ThestrapshouldbeconnectedtoeitherthechassisofthePCortoagroundingmat.Using Antistatic Bags
Replacement components are generally shipped in plastic or foam bags or wrapping that
has been treated to be antistatic. Understand that this means that they are treated so that
they are conductive. An antistatic bagabsorbsstatic electricity from the components
placed in or on it. This is a commonly misunderstood fact. Most people believe that anti-
static bags are insulators. However, just the opposite is true; they are conductors.Antistatic Hazards
Never, ever dismount the motherboard, or any other electronic circuit board, and place it
on antistatic material while still connected to the PC or peripherals, and then turn on the
PC’s power. The conductive antistatic material will short every pin and component on
the part of the circuit board in contact with the antistatic material. Count on every 5V
component that is connected to a 12V component to be destroyed.The Power Supply
The primary job of a PC’s power supply is to convert AC power to DC power. In making this
conversion, the functions the power supply performs are voltage conversion, rectification,