Chapter Overview

1
Chapter Overview

• Power Supplies
• Power Supply Problems

2
Overview of Power Supplies

• The standard power supply
• 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.

3
Power Supply Sizes

• 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.

4
Power Supply Wattage

• 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.
• General-use computers require 130205 watts.
• Servers and high-performance workstations require
  350500 watts.

5
Power Supply Connectors
6
Connections to Peripheral Hardware
7
Extenders and Splitters

• An extender lengthens the reach of a power
  connector.
• A splitter increases the number of connections.

8
Power Failures

• Power failures can have internal or external
  causes.
• External failures, which are more common, include
  
• Surges
• Spikes
• Sags
• Brownouts
• Blackouts

9
Power Protection Devices

• A surge suppressor
• Filters the effects of voltage spikes and surges
• Smoothes out power variations
• An uninterruptible power supply (UPS) is an
  inline battery backup.

10
Power Supply Problems
11
Chapter Summary

• 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.