What are computer power supplies and how do they work?

When we talk about a computer or pcwe believe that it is a very simple piece of equipment or device, and although it is certainly simple in its use, it is made up of for one or various software and by a series of physical devices that are known as the “hardware”, one of them is the power supply wave power supply. This is perhaps the most important element of a computer.

Because it is useless to have the latest computer on the market, with a quantity huge ramand all the features that currently make them magnificent teamsif we don’t have one power supply. Since its operation will depend on this small device, that is, without it nothing works.

Therefore, when buying a computer, it is important to pay attention to this device that almost all of us ignore. Since although it is usually invisible, it is a quite precise and complex piecewho has the most important job, supply the necessary energy to all the components of the PC in a perfect and constant way.

What is a computer power supply and what is it used for?

power supplies for computersare also known as power sourcesand is one of the main elements or components of the hardware of a computer, It is located inside the case of the CPUs. It is a small transformer, whose task is convert the alternating current (AC) it receives. Current which is usually 120v or 220v, to a flow of direct current (DC) from 9 to 12 voltsenough quantity to feed the PC.

Therefore, the power source is the device that is responsible for supply electricity to the equipment. Without power source the PC does not work. Therefore, the main objective of this is supply stable electricity so that the device can work correctly without presenting any type of inconvenience.

That is to say, then, that the power source is the device whose main function is to give it power to the entire computer from the card or motherboarduntil USB devices, optical drives, video, audio and of course so that the computer network works. And it achieves this, thanks to the fact that internally it has a large number of integrated circuits, resistors and diodes, who work as a team to achieve energy transformationall this through heat dissipation and cooling system.

How does a power supply work? Technical analysis

We already know that one power supply, is the main apparatus of a computer, without it it simply does not work. Because its main function or its objective is to convert the alternating current or AC in what we know as direct current or DC. But now, we still need to understand how this process is carried out, that is, as a power supply converts AC to DC.

For this, we are going to explain in detail how a modern source performs this process, remember that previously the oldest power sources allowed Directly convert AC into various DC voltages, usually from +12V, +5V and +3.3V. But with the technological advances that we live constantly, power supplies that we currently have become alternating current into a single DC voltage +12V.

After this occurs, the other components of the power supply. These are the converters DC-DC, whose main objective is to achieve the raw voltage that we already have +12V in voltages of +5V and +3.3V. These new power sources thus separate the energy transformation. Because these last two voltages (+5V and +3.3V) are the voltages least used by the equipment or the PC. In other words, this conversion will only be carried out if it is really required, if the raw voltage is not used normally.

The louder the noise, the higher the damage.

We already have then, the voltages that we require to put into operation each one of the parts of the computer, that is to say, we already passed from AC to DC. When this happens, DC current is filtered through the inductors and the capacitors. Once there, these components carry out their work which is based on maintaining a regulated voltage and stable, At the same time that they control electrical noise, let us remember that more noise, more damage.

This means that controlling noise is essential, since, as we have already mentioned, The higher the noise, the more damage will be generated in the components of the source due to the heat. This happens because currently power supplies are manufactured with a type of technology that is called “switching technology”, a technology that handles convert AC to DC. And when this technology is used, even if the rectifier is in “on or off”, will generate pulses of direct current, and its rhythm will depend on the input of the alternating current, these are current pulses those that receive the name of noise.

It is this input that must be controlled and to achieve this, the voltage crosses the inductor where the process of noise frequency reductionand once the voltage leaves the inductor, the work of capacitors. A job that basically consists of store the electrical charge and let it out at the right time without electrical noise. That is to say, we will obtain a clean voltage from it.

Avoid ripple effect

Everything will depend on power supply design. Because when designing a power source you must take into account the amount of capacitors required (series capacitors) or if a single oversized condenser. Since if the appropriate capacitor or series of capacitors is not taken into account, what is known as “the ripple effect”, that they are nothing more than waves or spikes that are generated in the direct current voltage that comes out, despite the fact that we previously achieved control noise. With the right capacitor, a stable change will be achieved between the highest voltage and the lowest voltagereducing the possibility of generating the ripple effect.

So, as we can see the proper functioning of each of the components of a power supply for computersdepends on a correct design and that when acquiring it we make the right decision, depending on the need or demand of our equipment.

Now, it is already clear that the power source regulates the voltage to deliver +12VDC at 2A of intensity. But what happens when the computer for some reason ddraws more amps. In this case, a good quality power source is capable of responding to this demand, through internal monitoring that is carried out by the “IC monitor”, a component of the power source which is responsible for indicating pwm controller that the rectifier is required switch to a different frequency, frequency that will allow adjust output voltage to the required demand.

What are the main types of power supplies and how do they differ?

It is already clear that the power supply or power source must stop being a forgotten device, and that on the contrary it must become one of the hardware elements to which we pay the most attentionbecause it depends on him computer life. We can say then, that this is the heart of the team, the one that pumps the blood (electricity) and if this fails the team can suffer serious failure and even be completely unusable.

That is why it is important to know the types of power sources that exist, for what kind of computer were createdwhich its power, its quality, among others. And after this analysis select the one that is compatible with our PC.

The main types of power supply are:

switching power supplies

This type of power supply is also known as switch mode power supply, and was designed for computers that require work 24 hours a day, seven days a week. So its performance and build quality are quite high. Well, it is an electronic device, which is responsible for transform electrical energy through switching transistors.

converting the current of an alternating network to direct currentand in turn, is also capable of cutting it to turn it into alternating current again but at higher frequencies, but with a normally lower tension, which allows it to be rectified again to transform it into DC.

The sources of switched power supply They differ from voltage regulators because the latter use transistors biased in their active region of amplification, while switching power suppliesthey work with them actively urging them to frequencies that are within the range from 20 to 100 kilohertzCome in cut and saturation.

In turn, these power supplies are subdivided into 4 types:

• AC power, DC output: They are used by desktop computers, and are composed of: the rectifier, the commutator, the transformer, the output rectifier, and the filter.
• AC power, AC output: This type of power supply is used by variable speed drives or motor drive. And it is composed of frequency converter and frequency inverter.
• DC power, AC output: It’s the type of food they use generators 220 va 50 Hz. That they are the type of generator that are suitable for what is specified in European standards.
• DC power and DC output: This type of food is used by cell phone battery chargers that are used in automobiles.

Linear or simple power supply

Linear or simple power supplyis another of the types of power sources commonly used and it is about a single power supply who is capable of provide the computer with the energy it requires to function. It is a circuit made up of a series of electronic componentswhose main function convert alternating voltage to direct voltage. Voltage that will be stored inside a battery, dry cell or accumulator.

Redundant power supply

Is composed of two power supplies who work independently. This means that if one of the two fails, the other will continue with the work, offering the possibility that her partner will be repaired without having to stop the computer or the server.

External power supplies

And finally, we have the sources of external power supply. This is the type of font they work with laptops or laptops. As in low-power computers and external boxes for hard drives. They are usually very practical power suppliesIdeal for small teams

And as for its physical characteristics, it is a plastic blockwhich comes with two cables, one to connect it to the computer and the other to be connected in the electrical power source. Their power consumption is much lower than that of a normal power source, since they are consuming only what is necessary, so do not need ventilation, To keep it within its ideal temperature, the user must place it on a surface where it is not covered by any element.

Switched versus linear power supply, what is the difference between the two?

Though there are 4 types of power supplies the most common or used in computers They are switched power supply and linear power supply.. However, both are different, so it is important to know what their main features Y What type of PC is each of them ideal for?.

the size and weight

A linear power supply is characterized by having a weight of approximately 10 kilograms and use a transformer designed to operate at a frequency of 50 or 60 HZ.

The switched sourcealso uses a transformer but this is much more littleand it works with a frequency ranging from 50 kHz to 1 MHz. Since by design, the higher the frequency they allow transistorsyou can decrease the size of passive components of the system, which are none other than transformers, capacitors and inductors.

Therefore, we can say that linear power supplies they have a much larger transformer, and of course more expensive. While the commuted thanks to the fact that they have a higher frequency have a smaller transformer. And in turn has less weight, volume and cost than a linear.

The output voltage

linear power supplies are characterized, because they are in charge of regulate energy output using a high voltage the previous stages. To later be able to dispose of the energy as heat and thereby generate a low voltage. While switched sources, work backwards, that is, they are capable of produce an output voltage that is much lower, than the voltage you received or the input voltage.

Efficiency, heat, and power dissipated

As usual, linear or simple fontsthey take care of regulate the output current by dispersing excess energy which is produced as heat. A process that currently turns out to be ineffective and archaic.

While one switched Source, is characterized by using control signalswhich allows them to take only the energy that is truly required by the load. Being then a type of power supply that is considered 100% efficient. So the only heat they generate is given by some of the characteristics of the components that turn out to be non-ideal.

This means, then, that generally linear sources waste large amounts of energy in the transformer. While switching power supplies tend to have higher performance, if your design is correct, only this will guarantee its efficiency.

The complexity

A linear power supplyis a power transistor, with a Voltage regulation IC and a noise filter capacitor. And one switching power supply is composed of a regulator ICdepending on your design one or more transistorscontains power diodes, a transformer, inductors, and filter capacitors. Generating from it multi voltage transformer core.

This means then that the sources linear do not have complex components, since all Are they passive or discreet?. But switched sources do require an active control circuit. That allows them to adjust the starting, the output voltage, and other protections, because these have more components. components that make them be more complex than a line source.

radio frequency interference

In this case, linear power supplies are characterized by not cause interference. That is why this type of fountain is ideal for supply power in places where radio interference cannot exist.

While switched sourcesare characterized by abrupt changes, In addition to being composed of a large number of high-frequency spectral components. generating unwanted electromagnetic interference. For its use it is then necessary to accompany it with RF shields and EMI filters, these are responsible for reducing said interference.

electronic noise

When working with power supplies cheap linearit is normal that present electronic noise at its output terminals, much more so if its regulation is poor. When this happens, you experience a small ac voltage, which is mounted on DC of at least twice the supply frequency. process that in turn produces a ripple which occurs on the order of several millivolts, and which can be suppressed with filter capacitors larger or with voltage regulators of higher capacity or quality.

Meanwhile in switching power supplies not perceive the ripple in power frequency. This is perceived in the outputs, and the higher the frequency, the greater the noise.

acoustic noise

As usual, a linear power supply It emits a rather weak hum, almost imperceptible and is generally due to the vibration that occurs in the coils and in the transformer core plates.

And in the case of switching power suppliesalthough its operation is higher frequencies, acoustic noise is also not perceptible by the human ear. However, desktop computers come with a fan and this noise is perceptible. The only way a source computed generate soundis when any of its components is working incorrectly.

power factor

When it comes to the power factor, linear sources are characterized by having low levels of this. Since the energy is obtained from power line voltage spikes. And in the case of simple switching power suppliesthey work in a similar way to linear fontssince it gets the energy of the highest part of the sine wave.

electrical noise

in the sources of switched Power, it may be perceived switching electrical noise, especially in the main power line. This is a noise that can cause some kind of interference with A/V equipment, that are connected in the same phase. And in linear power suppliesthis effect does not occur.

That is, generally a power supply switched usually generate noisyon the switching stage. Therefore, they need additional components that allow them to dissipate it. As well as a ground connection, since this is responsible for conduct electrical noises. While the linear ones do not generate any type of noise.

In addition to all the differences mentioned above, it is also worth noting that:

• In linear power supplies, the current usually goes in only one direction through all the stages. Meanwhile in switching power supplies control signals must be used that go from the current output to the regulator. So the repair of a linear font is simpler than one switched source.
• linear power supplies, are capable of responding instantaneous to changes in load. While the commutedthey take their time to respond to load variation.
• linear fonts They are characterized by using standard transformers. While switching power supplies use customized transformers for each model. That is why a switched source is much more difficult to repair than a linear source.

What are the main components of a switching power supply?

Typically, a switching power supply is made up of the following components:

Bridge rectifier

bridge rectifier, is he in charge of letting go current in one direction. converting alternating current into pulsating current.

EMC filter

EMC filterhas two basic functions with the network, these are: avoid network interference, and absorb electrical problems that it may have, for example: noise, harmonics, transients, among others.

the condenser

This takes care of reduce pulsating current and the transforms into direct current. This direct current will have a stable value.

Power factor corrector

As its name indicates, it is a corrector, therefore it is in charge of repair or correct faults that occur when the current is out of phase with respect to the voltage, since this generates not taking advantage of all network powerand requires immediate intervention of the power factor corrector.

The transistor or transistors

These are the ones in charge of cut and at the same time activate the flow of current. To convert direct current into pulsating current.

the transformer

the transformer also has two functions, one of them is physically isolate the input from the output and the other is to reduce the voltage.

Filter

The filter has function convert pulsating current to direct current.

The controller

The controller is a very versatile component, has several functionsamong which stand:

• takes care of turn transistor on and off
• Protect the power supply against short circuits, overloads, overvoltages.
• control the correction circuit of the power factor.
• takes care of measure the output voltage of the source.
• modifies the signal that is delivered to the transistor. To deliver correct voltage values ​​that allow the output to be kept stable.

the diode

This component has the function convert the alternating current of the transformer into pulsating current.

Optocoupler

The optocouplertakes care of bind source output with the control circuit.

List of the best power supply manufacturers today

As could be seen throughout this post, power supplies are the fundamental device of any computer. This is the heart of the PC, so when choosing the right one, we must be sure that it complies with the desired requirements and above all, be a power supply manufactured under the required quality standards.

That’s why we’ll tell you which are the best manufacturers of power supplies:

Seasonic

The power sources of Seasonicare characterized by being high end fonts, that is, they are Excellent quality power supplies capable of delivering fairly stable power levels and with the right temperature.

Among the most used models of this manufacturer we have:

• platinum series
• Snow Silent 1050w
• X-series / X-series XM2

But, like any brand, they also manufacture models that are usually a bit more economical and of course they are from one lower range. However, they are models that also they are stableremember that your choice will depend on the need of your teamhe will tell you if he requires a high, mid or low end power supply.

Among the mid-range models include:

• G series / G series V2
• M12-II EVO
• S12G series
• S12-II series

Corsair

Corsair power supplies, like Seasonic are very high-end fonts, that meet the quality standards required for its proper functioning.

Among its best models we have:

• All AX / AXi series (760w – 1200w Seasonic (AX) / Flextronics (AXi)).
• AX1500i
• HXi series
• RMi-series
• RM1000x series

Antec

They are high-end power suppliesand one of its most used models is High Current Pro Platinum. But it also has available to its customers certain models of a slightly lower range, among which the following stand out:

• EDGE series
• Earthwatts Series
• Earthwatts Platinum Series
• High Current Gamer Series
• Truepower Classic Series

Cool Master

It’s another one of manufacturers of high-end power supplies and they have at your disposal V Series power supplies.

EVGA

They are characterized by throwing Market High-end power suppliescurrently having at your disposal excellent models, among which stand out:

• SuperNova G2/P2/T2
• Supernova GS
• Supernova PS

thermaltake

He offers you mid-range modelsbut they work very well with the vast majority of PCs that are available today. Among those that stand out:

• Toughpower Gold 850M
• Toughpower Grand 1200F
• Toughpower Grand Platinum 850w and 1200w
• Toughpower DPS Gold Series

XFX

The same thing happens with Thermaltake power suppliesthey are mid-range, but compatible with almost all PCs today. Among its models are:

• S 430w / 550w-SEW
• XTR series

energmax

He offers you very high end models as is the case with: DigiFanless 500W and low-end models such as:

• naXn ADV 650 Watts
• Revolution X’t Series
• Series Triathlor / Triathlor FC

The latter are characterized by be low-end power supplies relatively decent, that is, they are safe sources although they use more components cheap. But they cannot be used for equipment that demands a high-end source.