A power supply turns alternating current (AC) into direct current, which is a steady source of power that computer parts need (DC).
While some hardware parts, like an SSD, are optional, the power supply is not. Without it, the rest of the hardware inside the computer would not work.
Power supply is often written as PSU, which stands for “power supply unit.” The different sizes of motherboards, cases, and power supplies are called “form factors.”
For these three parts to work, they must fit together well.
A power supply in the box
Back of the case or chassis is where the power supply is. You’ll see that the computer’s power cord, which is plugged into the wall, plugs into the back of the power supply.
Most people only see the power supply from the back. It also has a hole at the back for a fan that sends air to the back of the computer case.
On the side of the power supply that faces the outside of the case, there is a male connection with three prongs that accepts a power cord.
The other prong goes straight into a power outlet.It may also have a power switch and a red voltage switch on very low-level sources.
From the source inside the PC, a large number of cables reach out. The connectors on the other ends of the cables send power to different parts of the computer.
Some connectors only work with the motherboard, while others work with hard drives, optical drives, graphics cards, and so on.
Watts are used to measure how much power your computer’s power supply can give it. Each part of the computer needs a certain amount of power to work right,
so it’s important to have a power supply unit (PSU) that can give that amount.
What is the purpose of a power supply?
The power supply is the only part of a computer that must be there for it to work. Without it, a computer is just a box made of plastic and metal.
In a power supply, switching is used to change high AC voltages into lower DC voltages. Most often, these voltages are used:
About 90% to 95% of the load is now put on the 12V rail. Because of this, the other railways are getting less and less important.
Watts are always used to talk about how much power a power supply has. A watt is equal to the sum of the voltage in volts and the current in amperes or amps.
Now, you press a small button to turn on a computer, and you press a menu item or the button to turn it off. These features were built into the standard PSU a few years ago.
The operating system can then tell the power supply to turn off by sending a signal to it. The push button sends a 5 volt signal to the power supply.
This tells the power supply when to turn on. Even when the computer is turned off, the power supply has a circuit called 5VSB (5 volts standby) that keeps power going to devices that stay on even when the computer is turned off.
This allows the power supply to be turned on and devices that stay on in standby to work. Before 1980, power supplies were usually big and hard to move around.
They used big, heavy transformers and huge capacitors to change 120 volts and 60 hertz line voltage into 5 volts and 12 volts DC.
Smaller and lighter
The power supplies of today are smaller and lighter (there are ATX, SFX formats and other dimensions). They change the frequency of the current from 60 cycles per second (Hz) to a much higher frequency,
which means that there are more cycles per second. This change lets a simple, light-weight transformer in the power supply step down the real voltage from 115 volts (or 230 volts in Europe and most of the rest of the world) to the voltage needed for that specific component.
Compared to the original 60Hz AC line voltage, the high-frequency AC power from a PSU is also easier to filter and correct. This makes it easier for sensitive computer circuits to handle voltage changes and noise.
A switching power supply only takes as much electricity from the AC line as it needs. On the label, the normal voltages and currents of a power supply are written down.
Improvements in Power Supply
Power supplies now have unique designs on the inside, like VRM (voltage regulation modules) that control the voltage on their own.
They are sources of DC-DC power. Its main benefit is that voltages don’t spike when the load isn’t evenly distributed, which happens a lot in modern PCs (remember the 12V load compared to the rest of the rails).
Recently, web server power supplies have been made with a spare power supply that can be switched out while the other power supply is running.
Some modern computers, especially those that are meant to be servers, have redundant power supplies. This means that the computer has two or more power supplies, one of which provides power and the other serves as a backup.
If the main source goes down, the standby source takes over right away. While the backup power source is running, the main power can be switched.
External power supplies
But the power supply in a computer isn’t the only one that can be used. The other choice is to use an external power supply.
Some game consoles, for example, have a power source that must be connected to the power wire that runs between the console and the wall.
In some cases, an external hard drive’s power supply is built in. This is necessary if the device can’t get enough power from the computer via USB.
External power sources are helpful because they let the device be smaller and look better. But some of these power sources are pretty big, which makes them hard to set up.