käyttöjännitelähde

Käyttöjännitelähde, often translated as "power supply unit" or PSU, is a component that converts electrical power from a source into the correct voltage and current for the internal components of a computer or other electronic device. It takes the alternating current (AC) from the wall outlet and transforms it into direct current (DC) that the computer's motherboard, processors, storage drives, and other parts can use.

The primary function of a käyttöjännitelähde is to provide stable and regulated power. Fluctuations in power can damage sensitive electronic components, so PSUs are designed to smooth out these variations. They also ensure that the correct voltages are delivered to each part of the system. For example, different components may require different voltages, such as +12V, +5V, and +3.3V, and the PSU is responsible for supplying these specific levels.

PSUs come in various power capacities, measured in watts. The required wattage depends on the power consumption of the computer's components. A higher-end gaming computer with a powerful graphics card and processor will need a PSU with a higher wattage than a basic office computer. Efficiency is another important characteristic, often rated with certifications like 80 Plus. A more efficient PSU wastes less energy as heat, leading to lower electricity bills and less heat generation within the computer case.