What powers the power supply. Power supply connectors

Useful tips

Secondary power supplies are an integral part of the design of any radio-electronic device. They are designed to transform a variable or constant pressure mains or battery in constant or AC voltage required for the operation of the device are power supplies.

Power supplies can not only be included in the circuit of any device, but can also be made in the form of a separate unit and even occupy entire power supply workshops.

There are several requirements for power supplies. Among them: high efficiency, high quality output voltage, availability of protection, network compatibility, small sizes and mass, etc.

The tasks of the power supply may include:

Transfer of electrical power with a minimum of losses;
Transformation of one type of stress into another;
Formation of a frequency different from the frequency of the source current;
Change in voltage value;
Stabilization. The power supply must output stable current and voltage. These parameters should not exceed or fall below a certain limit;
Defence from short circuit and other malfunctions in the power supply that may lead to breakdown of the device that provides the power supply;
Galvanic isolation. Method of protection against the flow of equalizing and other currents. Such currents can damage equipment and injure people.

But often power supplies in household appliances have only two tasks - to convert alternating electrical voltage to DC and convert the frequency of the power supply.

Among power supplies, two types are most common. They differ in design. These are linear (transformer) and impulse blocks nutrition.

Linear power supplies

Initially, power supplies were manufactured only in this form. The voltage in them is converted by a power transformer. reduces the amplitude of the sinusoidal harmonic, which is then rectified by a diode bridge (there are circuits with one diode). convert the current to pulsating. And then the pulsating current is smoothed out using a filter on the capacitor. At the end, the current is stabilized using .

To simply understand what is happening, imagine a sine wave - this is exactly what the shape of the voltage entering our power supply looks like. The transformer seems to flatten this sine wave. The diode bridge horizontally cuts it in half and turns the lower part of the sine wave up. The result is a constant, but still pulsating voltage. The capacitor filter finishes the job and “presses” this sine wave to such an extent that an almost straight line is obtained, and this is D.C.. Something like this, perhaps too simply and crudely, can describe the operation of a linear power supply.

Pros and cons of linear power supplies

The advantages include the simplicity of the device, its reliability and the absence of high-frequency interference, unlike pulsed analogues.

Disadvantages include large weight and size, which increase in proportion to the power of the device. Also, triodes coming at the end of the circuit and stabilizing the voltage reduce the efficiency of the device. The more stable the voltage, the greater its losses will be at the output.

Switching power supplies

Switching power supplies of this design appeared in the 60s of the last century. They work on the inverter principle. That is, they not only convert direct voltage into alternating voltage, but also change its value. The voltage from the mains entering the device is rectified by the input rectifier. The amplitude is then smoothed by the input capacitors. High-frequency rectangular pulses with a certain repetition and pulse duration are obtained.

The further path of the pulses depends on the design of the power supply:

In blocks with galvanic isolation the pulse enters the transformer.
In a power supply without decoupling, the pulse goes directly to the output filter, which cuts off the low frequencies.

Switching power supply with galvanic isolation

High-frequency pulses from capacitors enter a transformer, which separates one electrical circuit from another. This is the essence. Thanks to high frequency signal efficiency of the transformer increases. This makes it possible to reduce the mass of the transformer and its dimensions in pulsed power supplies, and, consequently, the entire device. Ferromagnetic compounds are used as the core. This also makes it possible to reduce the size of the device.

This type of design involves converting current in three stages:

Pulse width modulator;
Transistor stage;
Pulse transformer.

What is a pulse width modulator

This converter is otherwise called a PWM controller. Its task is to change the time during which a rectangular pulse will be given. changes the time during which the pulse remains on. It changes the time at which the pulse is not given. But the feed frequency remains the same.

How is the voltage stabilized in switching power supplies?

All pulse power supplies implement a type of feedback in which, using part of the output voltage, the influence of the input voltage on the system is compensated. This allows random input and output voltage changes to be stabilized

In systems with galvanic isolation, they are used to create negative feedback. In a power supply without decoupling Feedback implemented by a voltage divider.

Pros and cons of switching power supplies

The advantages include lower weight and size. High efficiency, by reducing losses associated with transition processes to electrical circuits. Lower price compared to linear power supplies. Possibility of using the same power supplies in different countries world where power grid parameters differ from each other. Availability of short circuit protection.

The disadvantages of switching power supplies are their inability to operate at too high or too low loads. Not suitable for certain types of precision devices as they create radio interference.

Application

Linear power supplies are actively being replaced by their switching counterparts. Now linear power supplies can be found in washing machines, microwave ovens, heating systems.

Switching power supplies are used almost everywhere: in computer technology and televisions, in medical equipment, in most household appliances, in office equipment.

Secondary power supply- a device that converts the electrical parameters of the main power supply source (for example, industrial network) into electricity with the parameters necessary for the operation of auxiliary devices.

The power supply can be integrated into general scheme(usually in simple devices; or when even a slight voltage drop on the supply wires is unacceptable - for example, the computer motherboard has built-in voltage converters to power the processor), made in the form of a module (power supply, power rack, etc.), or even located in a separate room (power shop).

Secondary power supply tasks

Ensuring power transmission- the power source must ensure the transmission of the given power with minimal losses and compliance specified characteristics at the exit without harm to yourself. Usually the power of the power source is taken with some reserve.
Voltage waveform conversion- conversion of alternating voltage into direct voltage, and vice versa, as well as frequency conversion, formation of voltage pulses, etc. Most often, it is necessary to convert alternating voltage of industrial frequency into direct voltage.
Voltage value conversion- both increase and decrease. Often a set of several voltages of different values is needed to power different circuits.
Stabilization- voltage, current and other parameters at the output of the power source must be within within certain limits, depending on its purpose when influencing large quantity destabilizing factors: changes in input voltage, load current, and so on. Most often, it is necessary to stabilize the voltage at the load, but sometimes (for example, to charge batteries) current stabilization is necessary.
Protection- the voltage or load current in the event of a malfunction (for example, a short circuit) of any circuits may exceed permissible limits and damage the electrical appliance or the power source itself. Also, in many cases, protection is required against the passage of current along the wrong path: for example, the passage of current through the ground when a person or foreign object touches live parts.
Galvanic isolation of circuits- one of the measures to protect against current flow along the wrong path.
Adjustment- during operation it may be necessary to change any parameters to ensure proper operation electrical appliance.
Control- may include adjustment, turning on/off any circuits, or the power source as a whole. It can be either direct (using controls on the device body), or remote, as well as software (ensuring on/off, adjustment in specified time or with the occurrence of any events).
Control- display of parameters at the input and output of the power source, switching circuits on/off, protection activation. It can also be direct or remote.

Most often, secondary power supplies are faced with the task of converting electricity from an alternating current network of industrial frequency (for example, in Russia - 240 V 50 Hz, in the USA - 120 V 60 Hz).

The two most typical designs are transformer and switching mode power supplies.

Transformer

Linear power supply

The classic power supply is a transformer power supply. In general, it consists of a step-down transformer or autotransformer, whose primary winding is designed for mains voltage. Then a rectifier is installed that converts the alternating voltage into direct voltage (pulsating unidirectional). In most cases, the rectifier consists of one diode (half-wave rectifier) or four diodes forming a diode bridge (full-wave rectifier). Other circuits are sometimes used, such as in voltage-doubling rectifiers. After the rectifier, a filter is installed to smooth out oscillations (pulsations). Usually it is simply a large capacitor.

Also, filters for high-frequency interference, surges (varistors), short-circuit protection (short circuit), voltage and current stabilizers can be installed in the circuit.

Transformer dimensions

E e f f 1 = S 33...70 , (\displaystyle E_(eff1)=(\frac (S)(33...70)),)

Here S (\displaystyle S) expressed in cm 2, E e f f 1 (\displaystyle E_(eff1))- in volts. Smaller denominator values are chosen for low-power transformers, larger ones for high-power ones.

Another way to increase the power of a transformer is to increase the operating frequency. Approximately, we can assume that for a given transformer size, its power is directly proportional operating frequency. Therefore, an increase in frequency in k (\displaystyle k) times with constant power allows you to reduce the size of the transformer by ∼ k (\displaystyle \sim (\sqrt (k))) times (the cross-sectional area of the magnetic circuit decreases by ∼ k (\displaystyle \sim k) times), or, accordingly, its mass in ∼ k 3 / 2 (\displaystyle \sim (\sqrt[(3/2)](k))) once.

In particular, including these considerations, a frequency of 400 Hz with a voltage of 115 V is usually used in on-board power networks of aircraft and ships.

But an increase in frequency worsens the magnetic properties of magnetic cores, mainly due to an increase in hysteresis losses, therefore, at operating frequencies above a few kHz, ferrodielectric magnetic cores of transformers are used, for example, ferrite or made of carbonyl iron.

Modern sources of secondary power supply of various household appliances, computers, printers, etc. are now almost entirely carried out according to circuits and have almost completely replaced classical transformers. In such sources, the galvanic separation of the powered circuit and the supply network, obtaining a set of the necessary secondary voltages, is carried out using high-frequency transformers with ferrite cores. The source of high-frequency voltage is pulsed key schemes with semiconductor switches, usually transistor ones. The use of such devices, often called inverters, makes it possible to significantly reduce the weight and dimensions of the device, and also, additionally, to improve the quality and reliability of the power supply, since pulsed sources are less critical to the quality of the power supply in the primary network - they are less sensitive to surges and dips in the mains voltage, changes in its frequency.

Advantages and disadvantages

Advantages of transformer power supplies. Disadvantages of transformer power supplies.

Large weight and dimensions, proportional to power.
Metal consumption.
The trade-off between reduced efficiency and output voltage stability: to ensure stable voltage, a stabilizer is required, which introduces additional losses.

Switching power supply

The power supply is designed to supply electric shock all computer components. It must be powerful enough and have a small margin for the computer to work stably. In addition, the power supply must be of high quality, since the service life of all computer components greatly depends on it. By saving $10-20 on the purchase of a high-quality power supply, you risk losing a system unit worth $200-1000.

The power of the power supply is selected based on the power of the computer, which mainly depends on the power consumption of the processor and video card. It is also necessary that the power supply has at least 80 Plus Standard certification. The optimal price/quality ratio are Chieftec, Zalman and Thermaltake power supplies.

For office computer(documents, Internet) a 400 W power supply is quite enough, take the most inexpensive Chieftec or Zalman, you won’t go wrong.
Power supply Zalman LE II-ZM400

For multimedia computer(movies, simple games) And gaming computer in the entry class (Core i3 or Ryzen 3 + GTX 1050 Ti), the most inexpensive 500-550 W power supply from the same Chieftec or Zalman will do; it will have a reserve in case of installing a more powerful video card.
Chieftec GPE-500S power supply

For a mid-range gaming PC (Core i5 or Ryzen 5 + GTX 1060/1070 or RTX 2060) a block will do 600-650 W power supply from Chieftec, if there is an 80 Plus Bronze certificate, then good.
Chieftec GPE-600S power supply

For powerful gaming or professional computer(Core i7 or Ryzen 7 + GTX 1080 or RTX 2070/2080) it is better to take a 650-700 W power supply from Chieftec or Thermaltake with an 80 Plus Bronze or Gold certificate.
Chieftec CPS-650S power supply

2. Power supply or case with power supply?

If you are assembling a professional or powerful gaming computer, then it is recommended to select a power supply separately. If we're talking about about office or ordinary home computer, then you can save and buy good body complete with power supply, which is what we will talk about.

3. What is the difference between a good power supply and a bad one?

The cheapest power supplies ($20-30) by definition cannot be good, since in this case manufacturers save on everything possible. Such power supplies have bad heatsinks and a lot of unsoldered elements and jumpers on the board.

At these places there should be capacitors and chokes designed to smooth out voltage ripples. It is because of these ripples that the premature failure of the motherboard, video card, hard drive and other computer components. In addition, such power supplies often have small radiators, which cause overheating and failure of the power supply itself.

A high-quality power supply has a minimum of unsoldered elements and larger radiators, which can be seen from the installation density.

4. Power supply manufacturers

Some of the best power supplies are made by SeaSonic, but they are also the most expensive.

Well-known enthusiast brands Corsair and Zalman recently expanded their range of power supplies. But their most budget models have rather weak filling.

AeroCool power supplies are among the best in terms of price/quality ratio. The well-established cooler manufacturer DeepCool is closely joining them. If you don't want to overpay for an expensive brand, but still get a high-quality power supply, pay attention to these brands.

The FSP company produces power supplies for different brands. But I would not recommend cheap power supplies under their own brand; they often have short wires and few connectors. Top-end FSP power supplies are not bad, but they are no longer cheaper than famous brands.

Of those brands that are known in narrower circles, we can note the very high-quality and expensive be quiet!, the powerful and reliable Enermax, Fractal Design, the slightly cheaper but high-quality Cougar and the good but inexpensive HIPER as a budget option.

5. Power supply

Power is the main characteristic of a power supply. The power of the power supply is calculated as the sum of the power of all computer components + 30% (for peak loads).

For an office computer, a minimum power supply of 400 watts is sufficient. For a multimedia computer (movies, simple games), it is better to take a 500-550 Watt power supply, in case you later want to install a video card. For a gaming computer with one video card, it is advisable to install a power supply with a power of 600-650 Watts. A powerful gaming PC with multiple graphics cards may require a power supply of 750 watts or more.

5.1. Power supply power calculation

Processor 25-220 Watt (check on the seller’s or manufacturer’s website)
Video card 50-300 Watt (check on the seller’s or manufacturer’s website)
Entry class motherboard 50 Watt, mid class 75 Watt, high class 100 Watt
Hard drive 12 Watt
SSD 5 Watt
DVD drive 35 Watt
Memory module 3 Watt
Fan 6 Watt

Don’t forget to add 30% to the sum of the powers of all components, this will protect you from unpleasant situations.

5.2. Program for calculating power supply power

To more conveniently calculate the power of a power supply, there is an excellent program “Power Supply Calculator”. It also allows you to calculate the required source power uninterruptible power supply(UPS or UPS).

The program works for everyone Windows versions with "Microsoft . NET Framework» version 3.5 or higher, which is usually already installed by most users. You can download the “Power Supply Calculator” program and if you need the “Microsoft .NET Framework” at the end of the article in the “” section.

6.ATX standard

Modern power supplies have the ATX12V standard. This standard can have several versions. Modern power supplies are manufactured according to ATX12V 2.3, 2.31, 2.4 standards, which are recommended for purchase.

7. Power correction

Modern power supplies have a power correction function (PFC), which allows them to consume less energy and heat less. There are passive (PPFC) and active (APFC) power correction circuits. The efficiency of power supplies with passive power correction reaches 70-75%, with active power correction - 80-95%. I recommend purchasing power supplies with active power correction (APFC).

8. Certificate 80 PLUS

A high-quality power supply must have an 80 PLUS certificate. These certificates come in different levels.

Certified, Standard – entry-level power supplies
Bronze, Silver – mid-class power supplies
Gold – high-end power supplies
Platinum, Titanium – top power supplies

The higher the certificate level, the higher the quality of voltage stabilization and other parameters of the power supply. For a mid-range office, multimedia or gaming computer, a regular certificate is sufficient. For a powerful gaming or professional computer, it is advisable to take a power supply with a bronze or silver certificate. For a computer with several powerful video cards - gold or platinum.

9. Fan size

Some power supplies still come with an 80mm fan.

A modern power supply should have a 120 or 140 mm fan.

10. Power supply connectors

	ATX (24-pin) - motherboard power connector. All power supplies have 1 such connector.
	CPU (4-pin) - processor power connector. All power supplies have 1 or 2 of these connectors. Some motherboards have 2 processor power connectors, but can also operate from one.
	SATA (15-pin) - power connector hard drives And optical drives. It is advisable that the power supply have several separate cables with such connectors, since one cable can be used to connect HDD and the optical drive will be problematic. Since one cable can have 2-3 connectors, the power supply must have 4-6 such connectors.
	PCI-E (6+2-pin) - video card power connector. Powerful video cards require 2 of these connectors. To install two video cards, you need 4 of these connectors.
	Molex (4-pin) - power connector for older hard drives, optical drives and some other devices. In principle, it is not required if you do not have such devices, but it is still present in many power supplies. Sometimes this connector can supply voltage to the case backlight, fans, and expansion cards.
	Floppy (4-pin) - drive power connector. Very outdated, but can still be found in power supplies. Sometimes some controllers (adapters) are powered by it.

Check the configuration of power supply connectors on the seller's or manufacturer's website.

11. Modular power supplies

In modular power supplies, excess cables can be unfastened and they will not get in the way in the case. This is convenient, but such power supplies are somewhat more expensive.

12. Setting up filters in the online store

Go to the “Power Supplies” section on the seller’s website.
Select recommended manufacturers.
Select the required power.
Set other parameters that are important to you: standards, certificates, connectors.
Look through the items sequentially, starting with the cheapest ones.
If necessary, check the connector configuration and other missing parameters on the manufacturer’s website or another online store.
Buy the first model that meets all parameters.

Thus, you will receive the best price/quality ratio power supply that meets your requirements at the lowest possible cost.

13. Links

Corsair CX650M 650W power supply
Thermaltake power supply Smart Pro RGB Bronze 650W
Power supply Zalman ZM600-GVM 600W

A computer is now a familiar thing for every person, but not everyone has looked inside the case. Most people use this device and don’t think about what it consists of. It works - and it's great.

And if something breaks, there are specialists. It is clear that not everyone needs to fill their heads with technical details, but it is advisable to know the basics. First, you should ask what a “power supply” is and how to choose it correctly. We'll explain why this part is so important below.

Why do you need a power supply in a computer?

Let’s not write abstruse phrases that will say little to a simple user. Let's try to compare. The power supply is something like power station for all elements of your PC. It creates tension from electrical network, which is necessary for certain parts. It feeds them with energy and makes them work.

It is advisable not to save on the power supply, since it depends on it. You've probably encountered network outages at least once. The lights in the area suddenly turned off, and then, after turning on the PC, you noticed that documents were not saved or that some programs generally refused to open normally.

To avoid such problems, you need to buy reliable and modern power supplies, which, although more expensive, are able to withstand voltage surges. You can save everything and finish your work calmly.

What types of power supplies are there: parameters to choose from

The first thing you should pay attention to is power. It needs to be enough. For execution simple tasks Usually 300-500 W is enough. And if you are a fan of fancy computer games or you are using serious software, it is advisable to install a power supply with a power of about 600 W.

Need exact values? Then use special online services or calculation programs, you can easily find free ones.

When choosing, you should also pay attention to the built-in fans. They are different sizes, but it’s best to stick with 120mm. If something happens, you will find a replacement faster.

Next we'll talk about more complex issue– cables and connectors. Everything must fit together, otherwise, as you understand, the computer will not work. First, pay attention to the connection connector; in modern power supplies it is 24-pin, and some models can be used even in old computers. But old power supplies are not suitable for new PCs.

That's not all. To power the processor, it is best to buy a power supply with two connectors; if possible, do not use old IDEs discs or DVD drive with a 4-pin connector. This will further complicate the task of choosing a suitable power supply.

Also make sure that there is a 6-pin connector for the video card, and that the length of the cables matches your needs. To do this, of course, it is better to choose in person, and not from pictures and descriptions on the Internet.

If we go into detail, we also need to consider such a parameter as the efficiency of the power supply. He talks about the efficiency of energy conversion - the ratio of its power consumption and output to the computer elements. In modern power supplies, the efficiency level is approximately 80-85%, which is quite enough for personal use.

But for large companies with a lot of PCs, 90-95% is needed. They should also take a closer look at power supplies with separate stabilization for each cable. The rest don't have to worry about this issue.

How much does it cost to buy a power supply for a computer?

Focus on your tasks and capabilities, but remember that too cheap is not your option in any case. For 30 dollars you only have unnecessary problems you will purchase. There are also relatively inexpensive, but high-quality manufacturers, which include Cooler Master, Chieftec and FSP.

And if you don’t want to delve into the intricacies of your PC at all, get a reliable assistant. Only a specialist can choose the ideal power supply based on your situation. It’s not worth risking the performance of your computer. The stingy one pays twice. So it’s better not to repeat the mistakes of others and pay a little more.

Many users are in pursuit of high performance personal computer forget about the main element system unit, which is responsible for high-quality and timely provision of power to all components inside the case. We are talking about a power supply that buyers do not pay attention to at all. But in vain! After all, all elements in a computer have certain power requirements, failure to comply with which will lead to component failure.

From this article, the reader will learn how to choose a power supply for a computer, and at the same time get acquainted with products from well-known brands that are recognized by all test laboratories in the world. Tips for ordinary users and beginners, provided by experts in the field of IT technologies, will help all potential customers make their choice in the store.

Definition of need

Before starting to search for a decent power supply, all users need to decide on the power consumption. That is, first the buyer must select the elements of the system unit ( motherboard, processor, video card, memory, hard disks and other controllers). Each system component in its specification has power requirements (voltage and current, in rare cases - power consumption). Naturally, the buyer will have to find these parameters, add them up and save the result, which will be useful in the future.

It doesn’t matter what actions are carried out by the user: replacing the computer’s power supply or purchasing an element with a new PC - calculations must be carried out in any case. Some elements, such as the processor and video card, have two power requirements: active voltage and peak load. You need to focus your calculations on the maximum parameter.

Finger to the sky

There is a strong opinion that for a resource-intensive system you need to choose the most powerful power supply that is on the storefront. This decision has logic, but it does not fit with rationality and economy. Money, because the higher the power of the device, the more expensive it costs. You can buy a price that exceeds the cost of all elements of the system (30,000 rubles and more), but such a solution will be very expensive for the consumer in the future.

For some reason, many users forget about the monthly payment, which is necessary for the operation of a personal computer. Naturally than more powerful block power supply, the more electricity it consumes. Thrifty buyers You can’t do without calculations.

Standards and power losses

The bigger, the better

Many experts, in their advice on how to choose a power supply for a computer, recommend that all beginners pay attention to the number of connectors and cables - the more there are in the device, the more efficient and more reliable system power supply There is logic in this, because manufacturing plants carry out testing before releasing products to the market. If the power of the unit is low, then there is no point in providing it with a large number of cables, because they will still be unused.

True, in Lately Many careless manufacturers use a trick and provide the buyer with a large wire clamp in a low-quality device. Here you need to focus on other indicators of battery efficiency (weight, wall thickness, cooling system, presence of buttons, quality of connectors). By the way, before connecting the power supply to the computer, it is recommended to visually inspect all the contacts coming from the head unit and make sure that they do not intersect anywhere (we are talking about cheap representatives of the market).

Top seller

Seasonic, a company specializing in the production of batteries, is known throughout the world. This is one of the few brands on the market that sells its own products under its logo. For comparison: the well-known manufacturer of computer elements - the company Corsair - does not have its own factories for the production of power supplies and acquires finished products from Seasonic, equipping it with its own logos. Therefore, before choosing a power supply for a computer, the user will have to become more familiar with the brands.

Seasonic, Chieftec, Thermaltake and Zalman have their own factories for the production of batteries. Products under famous brand FSP is assembled from spare parts produced at the Fractal Design plant (by the way, they have also recently appeared on the market).

Who to give preference to?

Gold-plated computer power supply connectors are good, but is there any point in overpaying for such functionality, since it is known for certain from the laws of physics that current is better transmitted between homogeneous metals? But it is Thermaltake that offers users such a solution. As for the rest of the products of the famous American brand, they are impeccable. There is not a single serious negative response from users about this manufacturer in the media.

The trusted products on the shelf include the brands Corsair, Aercool, FSP, Zalman, Seasonic, Be quiet, Chieftec (Gold series) and Fractal Design. By the way, in test laboratories, professionals and enthusiasts check the power and overclock the system with the power supplies listed above.

Finally

As practice shows, choosing a decent power supply for a personal computer is not easy. The fact is that many manufacturers use all sorts of tricks to attract buyers: they reduce the cost of production, decorate the device to the detriment of efficiency, and present a description that does not correspond to reality. There are many mechanisms of deception, it is impossible to list them all. Therefore, before choosing a power supply for a computer, the user must study the market, familiarize himself with all the characteristics of the device and be sure to find positive reviews about the product from real owners.