Many times we have talked about the power supply as the heart of the computer, how important it is that these are good quality. But have you ever wondered exactly how a computer’s power supply works? And, why is it so important that it does its job well? In this article we will explain in detail (Note: this article is technical and extensive, and is for those who like me are curious about the inner workings of things).
First of all, I have to say that in this article I’ll try to use vocabulary and terms that everyone understands, because although it may be easy for a person who has studied electronics, it may be very difficult for someone who isn’t as technical. I will try to speak in a balance of technical and comprehensible lingo, but keep in mind that we are talking about electronics after all and that, therefore, technical terms of this matter must inevitably be introduced. That said, let’s go.
How Power Supplies Work
The most essential function of a PC power supply is to convert AC (Alternating Current) to DC (Direct Current). Old power supplies converted alternating current into multiple DC voltages (+ 12V, + 5V, + 3.3V) simultaneously. In contrast, modern power supplies convert all AC power into + 12VDC, and once converted, other DC-DC converters convert the + 12V + + and + 3.3V, everything that our equipment needs. This last technique is more efficient because the voltages that are less used (the + 5V and + 3.3V) and are not converted if they are not needed, in fact converting from DC to DC is much more efficient than from AC to DC since it requires less electronic components that are smaller in size.
Once we have the voltage (remember that the voltage is the electric voltage, while the amperage is the intensity, not to confuse the terms) converted to direct current, it is filtered through inductors and capacitors. This is where two parameters come into play: voltage regulation, to ensure that it is stable, and electrical noise, because a higher noise results in more damage caused in the components as a result of heat. Let’s explain this.
Electrical noise and how it is filtered
PC power supplies use a switching technology to convert AC power to DC. Whether the rectifier is on or off, DC pulses are generated at a rate set by the AC input, which in the case of Spain is 50 Hz (this is important because this depends on the country, in Mexico it’s 60 Hz for example). This is called noise.