ATX Power Supply

An ATX power supply is one of the most important components in a computer. This is the component that provides electricity to the system by converting alternating current electricity from the wall outlet to direct current to the motherboard on a computer. You will find the ATX power supply at the rear of a computer case. ATX is the acronym for Advanced Technology Extended. This is a computer form factor that was originally designed in 1995 by Intel and is still in use today.

For modern systems the ATX power supply has several peripheral power connectors. There are two connectors for the motherboard now. The power supply will also have a 4-pin auxiliary connector for additional power to the CPU and one main 24-pin connector. Originally motherboards were powered by only one 20-pin power supply.

An ATX power supply is not the same as an AT power supply. The ATX power supply produces three main outputs which are +3.3 V, +5 V and +12 V. It also has standby power of -12V and 5V.

All the various components on a computer have different voltage requirements. For the digital circuitry they use 3.3v and 5v rails. The drives and fans require 12v. Most power supplies nowadays also provide multiple 12v rails to run the processors and a few other components in the pc. The ATX power supply will only draw the current that is needed at any given time. For instance, if the pc has a 450w power supply it will not draw more than 200 watts if the system is not demanding it. Since the components are not all used at the same time the power demand will always vary. Sometimes a power supply will fail. In the past they used to be repaired, but nowadays the power supplies are very inexpensive and it is easier to go out and buy a new one than it is to have the old one repaired. When the power supply fails the computer owner tends to buy the largest ATX power supply available, but this is not necessarily a good thing according to some experts. They suggest only buying the size that you need because the larger ones generate the most heat which is not good for the computer.

When you are purchasing a new ATX power supply you should remember that the most important factor in selecting the correct one for your pc is the output DC current for the motherboard and processors. For instance, for a new Intel P4 processor the 5V supply needs to provide at least 20A. On the other hand, an AMD processor needs the 5V power supply to provide 18A. The +5V standby should be at least 720mA for both types of processors. If the power supply is not sufficient it can cause the system to become unstable. If you are buying your own power supply and not sure about the specifications that you need you should do some research on it or ask a computer repair specialist about the needs for your pc. Common belief is that the heavier the power supply the more current it can handle. ATX motherboards are designed to work with at least a 145 watt power supply. However, motherboards with heavier than normal loaded configurations will require a higher wattage power supply. The motherboard will not power up if it is receiving insufficient current.

A new ATX power supply is not very expensive. The price can vary depending on the wattage. The ATX power supply can be damaged if it does not have an overload protection so make sure you are purchasing one that has over surge protection. You can find the ATX power supply for sale on various websites or at your local computer or electronic retail stores.

This ATX Power Supply Review is Written/Updated on Jan 31st, 2010 and filed under Computer Hardware. Both comments and pings are currently closed.

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