Power Supply

• A power supply is installed in the back corner of the PC case, next to the motherboard. 

• It converts 120vac (standard house power) into DC voltages that are used by other components in the PC. 

• A 20 conductor cable carries +5vdc, -5vdc +12vdc, -12vdc and ground to the motherboard. 

• Another pair of cables, each with four conductors and two 4-pin connectors daisy-chained along it, carry +5vdc, +12vdc and ground to the drives (hard, floppy and CD/DVD). 

• Typical PC power supplies are rated at 200-250 watts and sell for about $50 - $75. Higher wattage supplies are available.