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Chapter Overview
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Power Supplies
Power Supply Problems
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Overview of Power Supplies
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The standard power supply
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Converts AC to DC
“Conditions” power by evening out fluctuations
Requires a fan
Standard power in U.S. is 110 volts
alternating current (VAC) oscillating at 60
hertz (Hz).
You must consider physical size, wattage, and
connector types when replacing a power
supply.
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Power Supply Sizes
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Power supply sizes are based on the type of
case and motherboard connections.
The AT-style is found on older computers and
earlier Pentium systems.
The ATX-style (current technology) is found
on Pentium II and later systems.
You should compare the existing power
supply with the new one before replacing it.
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Power Supply Wattage
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A watt is a unit of electrical power equivalent
to one volt-ampere.
Total wattage needs are determined by
adding the power required for each device,
plus more power for startup.
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General-use computers require 130–205 watts.
Servers and high-performance workstations
require 350–500 watts.
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Power Supply Connectors
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Connections to Peripheral Hardware
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Extenders and Splitters
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An extender lengthens the reach of a power
connector.
A splitter increases the number of
connections.
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Power Failures
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Power failures can have internal or external
causes.
External failures, which are more common,
include
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Surges
Spikes
Sags
Brownouts
Blackouts
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Power Protection Devices
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A surge suppressor
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Filters the effects of voltage spikes and surges
Smoothes out power variations
An uninterruptible power supply (UPS) is an
inline battery backup.
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Power Supply Problems
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Chapter Summary
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The AT-style power supply is used for older
motherboards and the ATX-style power
supply is used for newer motherboards.
Peripheral devices use Molex connectors and
mini connectors.
Different types of power failures can cause
computer problems and can damage
computer equipment.
Surge suppressors and UPS devices can
protect computer equipment.
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