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 130–205 watts.
Servers and high-performance workstations require 350–500 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.