Bài giảng Computer - Chapter 05

Chapter Overview Power SuppliesPower Supply Problems 1Overview of Power Supplies The standard power supply Converts AC to DC“Conditions” power by evening out fluctuationsRequires 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. 2Power 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. 3Power 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. 4Power Supply Connectors 5Connections to Peripheral Hardware 6Extenders and Splitters An extender lengthens the reach of a power connector.A splitter increases the number of connections. 7Power Failures Power failures can have internal or external causes.External failures, which are more common, include SurgesSpikesSagsBrownoutsBlackouts 8Power Protection Devices A surge suppressor Filters the effects of voltage spikes and surges Smoothes out power variationsAn uninterruptible power supply (UPS) is an inline battery backup. 9 Power Supply Problems 10Chapter 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. 11