What Are Power Supply Units?

One question you might be hesitant to ask is, “What is a power supply?” Don’t be reluctant to ask. The answer is pretty simple, but it should be for us. At Power277, this is our job. For example, after hiring a CPA to file your taxes, you should feel confident that they understand the most recent tax codes to save you the most money on your taxes. The power supply to any device is a crucial piece because without it, the rest of the internal hardware can’t function.

The power supply unit is often abbreviated as PSU, and it is also known as a power pack or power converter. The power supply unit is used to convert the power provided from the outlet into usable power for the many parts of the device. It converts the alternating current (AC) into a continuous form of power that the device needs in order to run normally, called direct current (DC). It also regulates overheating by controlling voltage, which may change automatically or manually depending on the power supply.

Power output is the main factor in deciding which power supply unit to buy. Power supply units transform the 110 -115 or 220 -230 volt AC current from the wall and turn it into usable DC for the device. A power supply is so much more than just a single transformer. Modern power supply units have at least five separate voltage outputs, and usually more. Each different power output is called a “rail.” Common rails are the 12 volt rail, the 5 volt rail, and the 3.3 volt rail. These rails can be seen in different combinations depending on the need. Each rail is its own power source. The most important rail is the 12 volt rail. It accounts for 75% or more of the power output of the power supply unit.