The Power Supply Unit also known as (P.S.U) is a crucial element in any personal computer since its the only element that provides the electrical juice neccessary for a PC to function. Just like a car has an engine to motor around, the PC has a PSU to control the power of its internal engines.
PSU can be easily identified in
a computer system. Take a look at the back of your computer and you should see a medium sized silver
or gray box with an opening containing a the PSU fan and electrical circuitry, as well as an electrical voltage switch and a 1 or more openings for ventillation purposes.
Its main job is to supply power to
all devices within the system through
the use of connectors. The power
supply must be, of course, attached to
some electrical outlet usually located in
The PSU has a central fan that circulates air through a system to prevent peripheral devices from over heating. The fan is dependant on a good
supply of air to operate efficiently because the fan pulls air through the power supply through the
vent at the front and back sides of a case, and it circulates this air throughout the entire system and then sends air back out through the main
supply fan vent.
Computer power supplies are rated by wattage, or the amount of power they can produced. Typical power
supplies come in 220 watt configurations, but some may go as high as 500 watts.
The older Baby AT style power supplies were the most common type of
power supply suitable for powering AT boards only. They lacked support for ATX motherboards and as a result were quickly phased out by the newer, better ATX technology.
The ATX motherboard
requires a special ATX power supply connector which contains special
circuitry that allows software to control the power signal of the supply.
The pages contained within this section will provide a fundamental understanding of how the power supply works as well as explain the main characterisitics that seperate the good power supplies from the bad.