Identifying Power Supply
The function of a Power Supply Unit (PSU) is to convert AC voltage into DC low voltage power that is required by the internal components of the PC.
The following are the main components of a Power Supply Unit (PSU):
Transformer: It is used to convert electrical energy from one value to another. It can either increase or decrease the voltage and current. In a computer system, transformer is used to decrease the high voltage and current.
Rectifier: It is used to convert the Alternating Current (AC) to Direct Current (DC) through a process called rectification. There are two types of rectifications, half-wave rectification and full-wave rectification. The half-wave rectification is the process in which either the positive half or the negative half is passed and the other half is blocked whereas in the full-wave rectification both the positive and negative half of the input are converted to a single polarity as its output.
Filter and Regulator: Filter is used to eliminate the fluctuation of voltage that is produced by the rectifier. It produces a constant level of DC voltage. Regulator prevents any changes in the filtered DC voltage.
The power supply unit should supply adequate power to all the internal components of the computer system. The output of the power supplies is generally measured in watt. The power supply unit with higher watt can supply more power. The power output rating in a normal desktop is around 200 Watts to 300 Watts. Gaming PC, graphic workstation or audio/video workstation may require 500W or more to deal with high CPU specifications and graphic cards.
The Micro-ATX system is designed for power supplies of lower wattage so that the heat production and power consumption is less in this system. This system is commonly acceptable with reduced and standard Micro-ATX components suite. The Micro-ATX motherboards may require larger power supply if external USB ports are included or bigger cases are used that have additional in-case peripherals. ITX motherboard uses a Small Form Factor (SFF) board which consumes less power.