Summary

Chapter 1: Introduction to the Personal Computer 9Describe Power SuppliesThe power supply, shown in Figure 1-2, converts alternating-current (AC) power comingfrom a wall outlet into direct-current (DC) power, which is a lower voltage. DC power isrequired for all the components inside the computer.Figure 1-2Power SupplyConnectorsMost connectors today are keyed connectors. Keyed connectors are designed to be insertedin only one direction. Each part of the connector has a colored wire with a different voltagerunning through it, as described in Table 1-1.NoteDifferent power supply form factors provide different power output connections, depending on systemrequirements. AT form factors have been slowly phased out by ATX form factor power suppliesbecause of the different case sizes and advanced features. ATXv12 was created to add power supportfor the motherboard by adding another four-pin power connector.Table 1-1Power Color CodesWire AT Power ATX Power ATXv12 PowerVoltage Color Use Supply Form Supply Form Supply Form+12V Yellow Disk drive motors, ✓ ✓ ✓fans, coolingdevices, andsystem bus slotscontinues