A desktop power supply is a computing device designed to supply electricity to the various components of a computer. Power supplies can be built in to a computer system and they can also be mounted externally, depending on the type of computing system and the design. Over time, a desktop power supply can burn out and it may become necessary for a replacement. It is important to use a compatible component for replacement to avoid developing computer problems.
Alternating current (AC) directly from the wall is not usable for computers. A desktop power supply converts the AC into direct current (DC) for use by the computer. Power supplies are rated on how much electricity they can process, with standard models ranging form 500 watts to 1400 watts. The size of a power supply is dependent on the system. A small, basic computer has low energy needs, while something like a server will draw substantial power and needs a big power supply.
The desktop power supply most commonly takes the form of a large box, with vents and fans to allow heat to escape. A connector allows for connection of the power supply to the wall, and a set of wires are designed to lead to the motherboard. Desktop power supply design typically includes a number of pins designed to connect to the motherboard. Common variations are 20 and 24 pin power supplies.
The basic principles seen in a desktop power supply are also present in the power supplies used for laptops. Laptops typically have an external converter brick to handle power directly from the wall and a smaller power supply inside the laptop may also be installed. Laptop power requirements vary and one challenge with laptops is designing power supplies small enough and powerful enough to run a laptop successfully. It is very common for laptops with high power requirements to overheat during use, an issue that must be addressed in design to avoid causing damage or injuries.
Replacing a desktop power supply is relatively easy. The computer needs to be powered off and unplugged so the case can be opened to allow the user to unscrew the power supply. Replacement power supplies can be ordered from computer parts companies or directly from the computer's manufacturer, and the new supply simply needs to be mounted in the computer and connected. People who are not comfortable opening their computer cases can pay a technician to replace the power supply; generally the cost for replacement is low as the task does not take very long.