(n.) Also called a power supply unit or PSU, the component that supplies power to a computer. Most personal computers can be plugged into standard electrical outlets. The power supply then pulls the required amount of electricity and converts the AC current to DC current. It also regulates the voltage to eliminate spikes and surges common in most electrical systems. Not all power supplies, however, do an adequate voltage-regulation job, so a computer is always susceptible to large voltage fluctuations.
Power supplies are rated in terms of the number of watts they generate. The more powerful the computer, the more watts it can provide to components.
PC Mechanic - online guide to computer hardware Contains overviews, purchasing and installation information for PC motherboards, memory, drives, expansion cards, and power supplies. Also contains links to companies and manufacturers and PC hardware related links.
PC external power and power supply reference A reference guide looking at the power systems of the PC from the inside and out. Covers electricity basics, power problems, UPSs, power supply functions, form factors, and sizing and output.
Power Supply Function and Signals Describes AC-DC voltage conversion, different voltages supplied, the Power Good signal, and power loading. This page is part of "The PC Guide".
Troubleshooting Power Sources and Power Protection Devices Lists some typical problems related to the system power, including external power problems, power protection devices (surge suppressors, UPSes, etc.) and the internal power supply. This page is from "The PC Guide."
A Different Perspective on Power Supplies With the latest system components putting ever-higher stress on a computer’s power supply, how do you know how much power your system needs? And with transformers, rectifiers, filters and voltage regulators to consider, how can you pick a good power supply?