Autonomous power supply for computer name. Computer power supply

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Computer power supply (PSU) is electronic device, which generates the voltage required by a specific PC component from the voltage electrical network. On the territory of Russia, the power supply converts alternating current from a 220V electrical network with a frequency of 50Hz into several low values direct current: 3.3V; 5V; 12V, etc.

The main parameter of the power supply is power, which is calculated in watts (W). How more powerful computer, those more powerful block power required. Typically this is 300-500 W in budget and office computers and 600 W or more in powerful stations and gaming PCs. Top-class video cards, which require more than a kilowatt of power, are becoming more and more demanding of PSU power.

The power supply is a kind of energy center of any computer. It supplies electricity to all computer components and allows the PC to work. From the mains, the cable goes to the power supply, and it will then distribute the required voltage throughout the rest of the computer.

Cables come out of the power supply to the motherboard, video card, hard drive, drive, coolers and fans, and other devices. High-quality and expensive blocks are resistant to voltage surges in the electrical network. This allows you to prevent failure of both the power supply itself and all computer components.

What is necessary for stable, uninterrupted operation of a computer?

Powerful processor modern video card, good motherboard. But almost everyone forgets to add to this list a reliable power supply, which acts as the power supply center for all other computer components. He must cope with the assigned tasks 100%. Otherwise, there can be no question of stable and trouble-free operation of the computer.

What is the danger of lack of power in a PC?

If there is not enough power for all elements of the computer installed unit power supply, this can result in either minor problems or a complete inability to turn on the PC.

Here are the main dangers of a weak power supply:

There is a possibility of failure or partial damage hard drive. This is due to the fact that in a hard drive, due to a lack of power, the read heads will not be able to function normally and slide across the surface of the disk and will begin to scratch it. In this case, characteristic sounds may be heard.
There may be problems with the video card (even the image on the monitor disappears). This is especially evident in modern computer games.
Removable hard disks and flash drives connected to USB ports, as well as other devices without additional food, may not be determined operating system or turn off during operation.
At times of highest power consumption, the computer may turn off or restart.

How to get rid of this? It’s very simple to install a more powerful and reliable power supply.

Attention!!! The above problems may occur not only due to a low-quality power supply, but also be a consequence of malfunction of other PC components. To determine the exact reason, it is better to contact our computer repair at home in Moscow.

Hello friends! Despite the perfection of modern components, I will tell you in today’s publication that without which their normal operation is impossible - the computer power supply, what this unit consists of and how it works.

From this article you will learn:

Purpose of the power supply

Even a complete “teapot” knows that the power supply is supplying current. However, such a statement actually explains almost nothing. The power supply performs three main functions:

Reduces the network voltage from 220 V (other values are possible) to the operating voltage required to supply energy to consumers - 3.3, 5 and 12 V, including negative values.
Rectifies alternating current with a frequency of 50 Hz, making it constant.
Stabilizes operating voltage.

Such functions require appropriate electrical diagram. A power supply for a system unit is not at all a simple design, as one might mistakenly think. Let's take a closer look at its structure - what logical blocks are hidden inside, and how each of them works.

Structural Components

The power supply includes three stages - input, output and converter. It is necessary to analyze in more detail how each one works and what it is intended for.

Input circuits

This includes the following blocks:

An input filter that cuts off impulse noise, preventing it from propagating further. It also reduces the discharge of capacitors that occurs when the device is connected to the network.
The power corrector reduces the load on the supply circuits.
The alternating voltage constantly transforms the rectifier bridge.
Rectified voltage ripples are smoothed out by a capacitor filter.

A low-power power supply unit that produces +5 V to support the motherboard standby mode and +12 V for the converter chip.

Converter

Consists of the following elements:

Two bipolar transistors, which are used as a half-bridge converter.
Protection circuits against changes in supply voltages. This capacity is usually performed by a specific microcircuit, for example SG6105 or UC
A high-frequency pulse transformer that generates voltages of the required rating.
Feedback circuits that maintain a stable voltage at the power supply output.
A voltage driver implemented on the basis of a separate operational amplifier.

Output circuits

For their normal operation the following components are needed:

Output rectifiers which are used to supply 5V and 12V voltage with positive and negative values using the same transformer windings.
Group stabilization throttle. Smoothes out pulses and redistributes energy between other circuits.

Filter capacitors that integrate the pulses required to obtain rated voltages.
Load resistors providing safe work at idle speed.

Advantages of such a scheme

Such logic circuit has been used for more than a decade, which once again confirms its high efficiency. The undeniable advantages include:

The relative simplicity of the design reduces the number necessary components, which allows you to reduce the cost of the device. It also makes repairs easier if necessary.
The output produces the required range of rated voltages, with acceptable quality of stabilization, which is required for the normal operation of components in the system unit.
Since the main energy losses occur in conversion processes, it is possible to achieve high efficiency of such a power supply, up to 90%.
Small dimensions and weight, which allows you to assemble more compact system units.
If appropriate design adjustments are made, such power supplies can be used in networks with a wide voltage range - for example, 115 V in the USA or 220 V in the post-Soviet space.

Some features of different models

The effectiveness of the device depends not only on schematic diagram– in most cases they are unified, and some revolutionary innovations are rarely introduced.

In many ways, the efficiency and service life of the power supply is influenced by the quality of components, which may differ depending on the different manufacturers– from outright counterfeit goods budget models, made in semi-handicraft conditions, to high-quality microcircuits that meet all accepted standards, which are used in circuits trustworthy brands.

Naturally, when buying a new power supply, no seller will allow you to break the seal and delve more thoroughly into the insides of the device.
This is where YouTube video hosting comes to our aid - on appropriate channels that are easy to find, bloggers post the disassembly process and test results of various components.

However, you should only listen to the opinion of the creator of the video, whom you trust and whose competence is beyond doubt.

To delve into the topic in more detail, I advise you to read my publications “” and “”.

Thank you for your attention and see you next time. I thank everyone who shares my articles on social networks.

The most common version of the power supply involves converting 220 Volts of alternating voltage (U) into a reduced direct voltage. In addition, power supplies can provide galvanic isolation between input and output circuits. In this case, the transformation ratio (the ratio of input and output voltages) can be equal to unity.

An example of such use would be the energy supply of premises with high degree danger of defeat electric shock, for example, bathrooms.

In addition, quite often household power supplies can be equipped with built-in additional devices: stabilizers, regulators. indicators, etc.

TYPES AND TYPES OF POWER UNITS

First of all, the classification of power supplies is carried out according to the principle of operation. There are two main options here:

transformer (linear);
pulse (inverter).

Transformer block consists of a step-down transformer and a rectifier that converts alternating current into direct current. Next, a filter (capacitor) is installed that smooths out ripples and other elements (output parameter stabilizer, short-circuit protection, high-frequency (RF) interference filter).

Advantages of a transformer power supply:

high reliability;
maintainability;
simplicity of design;
minimum level interference or lack thereof;
low price.

Disadvantages - heavy weight, large dimensions and low efficiency.

Impulse power block- an inverter system in which alternating voltage is converted into direct voltage, after which high-frequency pulses are generated, which undergo a series of further transformations (). In a device with galvanic isolation, pulses are transmitted to a transformer, and in the absence of one, directly to the low-pass filter at the output of the device.

Thanks to the formation of RF signals, small-sized transformers are used in switching power supplies, which allows reducing the size and weight of the device. A negative voltage is used to stabilize the voltage. Feedback, thanks to which a constant voltage level is maintained at the output, independent of the load.

Advantages pulse block power supply:

compactness;
light weight;
affordable price And high efficiency(up to 98%).

In addition, it should be noted that there are additional protections that ensure the safety of using the device. Such power supplies often provide protection against short circuit(short circuit) and failure in the absence of load.

Disadvantages - operation of a larger component of the circuit without galvanic isolation, which complicates repairs. In addition, the device may cause interference high frequency and has a lower load limit. If the power of the latter is less than the permissible parameter, the unit will not start.

PARAMETERS AND CHARACTERISTICS OF THE POWER SUPPLY

When choosing a power supply, you should take into account a number of characteristics, including:

power;
output voltage and current;
as well as the availability additional options and opportunities.

Power.

A parameter that is measured in W or V*A. When choosing a device, you should take into account the presence of inrush currents in many electrical receivers (pumps, irrigation systems, refrigerators, and others). At the moment of start-up, power consumption increases by 5-7 times.

As for other cases, the power supply is selected taking into account the total power of the powered devices with a recommended margin of 20-30%.

Input voltage.

In Russia this parameter is 220 Volts. If you use a power supply in Japan or the USA, you will need a device with an input voltage of 110 Volts. In addition, for inverter power supplies this value can be 12/24 Volts.

Output voltage.

When choosing a device, you should focus on the rated voltage of the consumer used (indicated on the device body). It could be 12 Volts, 15.6 Volts and so on. When choosing, you should buy a product that is as close as possible to the required parameter. For example, to power a device at 12.1 V a block will do at 12 V.

Output voltage type.

Most devices are powered by stabilized DC voltage, but there are also those for whom constant, unstabilized or variable is suitable. Taking this criterion into account, the design is also selected. If an unstabilized constant U at the input is enough for the consumer, a power supply with a stabilized voltage at the output is also suitable.

Output current.

This parameter may not be indicated, but if you know the power, it can be calculated. Power (P) is equal to voltage (U) times current (I). Therefore, to calculate the current, it is necessary to divide the power by the voltage. This parameter is useful for selecting a suitable power supply for a specific load.

As a rule, the operating current should exceed the maximum current consumption of the device by 10-20%.

Efficiency.

High power supply power is not a guarantee of good performance. No less important parameter is the efficiency factor, which reflects the efficiency of energy conversion and its transmission to the device. The higher the efficiency, the more efficiently the unit is used, and the less energy is spent on heating.

Overload protection.

Many sources are equipped with overload protection, which ensures that the power supply is turned off if the level of current consumed from the network is exceeded.

Deep discharge protection.

Its task is to break the power circuit when the battery is completely discharged (typical for uninterruptible power supplies). After power is restored, the device's functionality is restored.

In addition to the options listed above, the power supply may provide protection against short circuits, overheating, overcurrent, overvoltage and undervoltage.

All materials presented on this site are for informational purposes only and cannot be used as guidelines or regulatory documents.

The power supply is designed to supply electrical current to 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 system unit costing $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-class gaming PC (Core i5 or Ryzen 5 + GTX 1060/1070 or RTX 2060), a 600-650 W power supply from Chieftec is suitable, 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 motherboard, video card, hard drive and other computer components fail prematurely. 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.

Not long ago we expanded the range of power supplies well famous brands for Corsair and Zalman enthusiasts. 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

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 AC voltage to constant (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.