# What Is A Power Supply And What Is It Used For?

By Tanner Abraham •  Updated: 08/27/22 •  4 min read

You may have never heard of the power supply, although it is difficult to imagine if you are a person who is aware of the world of computers and computing in general. In any case, along the following lines we are going to explain what a power supply is and what it is for, so that, in case you have doubts, you can see them resolved.

## What is a power supply

A power supply, also known as a power supply, is a hardware component whose purpose is to transform the alternating current it receives from the electricity line that is received in homes into direct or direct current.

This is the one used by different equipment and devices, such as computers, televisions, etc. In this way it is able to supply the appropriate voltages for their operation without causing any type of damage to them. Usually, power supplies incorporate protection elements. In this way, the equipment is protected against circumstances that may occur in the electrical supply, as is the case of overvoltage.

In the first place, a distinction must be made between the different types of power supply that can be found today. These can be linear or commutative/transform.

### Line fonts

These types of fonts are those that have a simple design. They follow the scheme in which a transformer is found as a voltage reducer; rectifier for alternating voltage conversion; filter; and regulation to maintain the output voltage.

### Commutative sources

This type of sources has the same power as the linear ones. However, they do convert electricity through high-frequency switching over transistors. They are more efficient than linear but also more susceptible to power outages.

## What is a power supply for?

That said, we can briefly explain what a power supply is for. Its functions are mainly four:

• Transformation. First of all, with the use of this type of components it is possible to reduce the input voltage to the source, which are those supplied by the electricity network. In this way an output voltage of between 5 and 12 Volts is achieved.
• Rectification. The source is responsible for preventing voltage oscillations from occurring. In this way, the aim is to pass from alternating current to direct current through a specific component for this called a rectifier bridge. This means that the voltage cannot drop below 0 volts, being always above.
• Filtered. This phase is responsible for flattening the signal as much as possible. For this, it resorts to the use of capacitors. These have the function of retaining the current and then making it pass slowly.
• Stabilization. At the moment in which there is a continuous and almost flat signal, it is in charge of stabilizing it completely.

## How to choose a power supply

When choosing a power supply it is important to take into account a series of factors, among which are the following:

• The power that the chosen source is capable of supplying, which must be in accordance with the needs of the equipment.
• The format of the source, since there are different types of power supplies. We will refer to them in the next section.
• The accessories that it can include and that can make you opt for one or the other. This is the case, for example, with modular power supplies, which allow better cable management.

## Types of power supplies

The power supplies that are responsible for powering the computer equipment are located inside their PC cases. The most common is that they are of the AT or ATX type. The former were used in the past, while ATX are currently used.

### AT sources

AT power supplies have connectors to the motherboard, which is a difference from ATX power supplies. In addition, the source is activated through a switch in which there is a voltage of 220 V. This means that there is a certain risk when manipulating the computer.

At a technological level they are more basic and are currently hardly used. Its main problem was that by having two connectors to connect to the motherboard, this caused problems and confusion, as well as short circuits.

### ATX power supplies

ATX sources are a more modern source that is always active. That is to say, it is always supplied with a small voltage to be in function of «Stand by» or waiting.

One of its advantages is that they do not have an on or off switch, but instead work with a button that is connected to the motherboard, so that it is easier to carry out connections or disconnections. Depending on the type of box and the power, they can be found in different formats, with which they manage to adapt to them.

#### Tanner Abraham

Data Scientist and Software Engineer with a focus on experimental projects in new budding technologies that incorporate machine learning and quantum computing into web applications.