Power Supply

What is a power supply?

A power supply is a device used to convert the current from the electrical grid into a form of energy that can be used with the components of an electronic device or system. Generally, a power supply transforms the alternating current from the electrical network into direct current.

What features do power supplies have?

A power supply can be internal or external, depending on whether it is integrated into the device it powers or not. Its capacity varies according to the requirements of the device it powers, and this is measured in watts.

Power supplies may also include other elements that help protect the useful life of devices, such as:

• Voltage regulators.
• Protection from short circuits.
• Protection from overheating.

What is a power supply used for?

The applications for power supplies are as wide-ranging as the variety of electronic devices available. Some of the main uses include:

• Computing: hardware and servers.
• Telecommunications: routers, transmission systems, networked equipment, etc.
• Household appliances.
• Science: laboratory equipment.
• Medicine: medical diagnostic and monitoring equipment, life support systems, etc.

How is the capacity of a power supply calculated for a device?

To calculate the power supply capacity for a specific device, its components must be identified, particularly those with more energy requirements. In computers, these are usually the motherboard, the graphics card, the hard drive, etc.

Each of these components will have an energy requirement expressed in watts. The sum of these values will be the required capacity. However, to ensure the power supply’s proper operation, it is necessary to calculate a margin of safety that’s between 10% and 20%.

For domestic applications, it is possible to consult the manufacturers’ specifications. There are also online tools to calculate the capacity needed in each case, particularly for custom-built computers by users.