The power supply or power source is a device that converts alternating current, in one or several continuous currents.It is used to power the different electronic devices , such as televisions, computers, printers, etc.
The essential functions of the source are four:
- Transformation. There is possible to reduce the input voltage to the source (220 v or 125 v), which are the ones that supply the electric network.. The output of this process will generate 5 to 12 volts.
- Rectification. It aims to ensure that voltage oscillations do not occur over time.This phase is tried to pass from alternating current to direct current through a component called rectifier bridge. This allows the voltage does not drop below 0 volts,
- Stabilization. When the continuous and almost completely flat signal is available, it only remains to stabilize it completely.
How a power supply works
The most essential function of a PC power supply is, as we have said before, the conversion of alternating current (AC) to DC (DC). Old sources convert the alternating current into multiple DC voltages (+ 12V, + 5V, + 3.3V). On the contrary, modern sources convert all the AC current into + 12VDC. Once converted, other DC-DC converters are in charge of converting the +12V + + 5V and + 3.3V. This last technique is more efficient because the voltages that are less used (the + 5V and + 3.3V) are not converted if they are not needed, and in fact converting from DC to DC is much more efficient than from AC to DC.
What types of power supplies are there?
Today all PC power supplies meet the ATX standards.There are many sizes that exist such as Flex-ATX, TFX, WTX or AMD GES, so let’s focus on the ones that you can find in stores today.
- ATX: It is the current standard, with dimensions of 150 x 150 x 86 mm, although standard ATX is also considered to be any length, provided that the height of 86 mm and the width of 150 mm are respected.
- SFX: The dimensions are much smaller, and are used in SFF equipment. They measure 100 x 125 x 63.5 mm, and need an adapter to be installed in standard ATX boxes.
- SFX-L: slightly larger version of the SFX to accommodate a larger fan. They measure 130 x 125 x 63.5 mm.
How to choose a power source?
It is recommended that when you buy that you choose a brand source that is recognized and reliable.