Hello dear friends!
When your processor starts to overheat, it threatens to frequently freeze system processes. How to solve the problem? Of course, you can buy a new cooler and install it instead of the old one. But here's the problem: if you have old computer then it is not easy to find exactly your type of CPU cooler.

And the fact is that a new cooler, even if it fits your processor, does not always have enough power (even if it is new and the label indicates a higher RPM).

In addition, if the user does not live in the city, but somewhere on the periphery, then not only may it not be possible to buy a new cooler. Yes, that's the way it is!

However, this is not at all a reason to hang your nose: there is always a way out! We look.

Let's start with the old power supply that is out of order. You, of course, replace it with a new one, and throw the old and broken one into the trash. So: do not rush to do this, because the old power supply can do you a good job. More precisely, not a unit, but its cooler. And now for more details. So!

If you disassemble the power supply and take a close look at the cooler, you will see exactly how it is connected to the power supply board: there is a whole wiring harness, and there are also two separate thin wires - red and black. Now carefully remove the cooler (unscrew the four fixing bolts) and also carefully unsolder these two wires - red and black. Now the cooler is in your hands.

But this is half the battle: now it remains to connect it correctly. Remove the wall of the system unit and look at your power supply (working, of course). Each power supply has two types of connectors: flat inlet and round inlet. You are interested in the rounded ones. In turn, rounded connectors are divided into “male” and “mother”.

You are interested in the "mom" entry. A colored wire is connected to each “socket” in the rounded connector. You are only interested in two: black and yellow. You plug the black wire of the cooler into the "socket" with the black wire, and the red wire into the "socket" with the yellow wire (exactly like that). Secure the wires with a piece of electrical tape. Turn on the computer - the cooler should start spinning immediately.

If everything is in order, then it remains to fix the cooler. Depending on the purpose, you can solve this issue yourself. For example, if you need to attach a cooler to the processor, then this can be done using ordinary copper wire.

It is enough to pass the wire under the places where the heatsink meets the processor platform, thread the holes of the cooler (there are four of them) through the wire "antennae" and simply twist the wire in several turns, after pressing the cooler to the heatsink. In short, you yourself will understand everything right away: you just need to look at the cooler and the four holes in it. By the way, with a video card - the same algorithm.

Everything is extremely simple, if you only show a little intelligence and attention. Good luck!

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In the process of resuscitation and modernization of the Solntsev amplifier, it was necessary to get rid of the bulky power supply unit made on the TS-180 transformer. A 200 W impulse power supply was manufactured on IR2153. However, in the process of operation with the removed power of about 130 W, heating was detected pulse transformer... Not critical, but still present. In addition, the stabilizers L7815, L7915 warmed up quite noticeably. Installing large radiators did not allow tight mounting on the board.

To eliminate this effect, I decided to use a cooler. The choice settled on a small-sized fan with a power of 0.96 W with a power supply of 12 volts and a consumption current of 0.08 A. Since the transformer power supply unit for it will have unacceptable weight and dimensions, I decided to assemble it with a quenching capacitor.

Scheme

In general, a transformerless power supply is a symbiosis of a rectifier and a parametric stabilizer. Capacitor C1 for alternating current is a capacitive (reactive, i.e. not consuming energy) resistance Xc, the value of which is determined by the formula:

where f- network frequency (50 Hz); WITH- the capacity of the capacitor C1, F. Then the output current of the source can be approximately determined as follows:

where Uc- mains voltage (220 V).

With a consumption current of 0.08 A, the capacitance C1 should have a nominal value of 1.2 microfarads. Increasing it will allow you to connect a load with a high current consumption. Approximately, you can focus on 0.06 A for each microfarad of the capacity C1. I had at hand 2.2 microfarads at 400 volts.

Resistor R1 serves to discharge the capacitor after turning off the power supply. There are no special requirements for it. The nominal value is 330 kOhm - 1 Mohm. Power 0.5 - 2 W. In my case, 620 kΩ 2 watts.

Capacitor C2 serves to smooth out the ripple of the voltage rectified by the bridge. Rated from 220 microfarads to 1000 microfarads with an operating voltage of at least 25 volts. I installed 470 microfarads for a voltage of 25 volts.

As rectifier diodes applied 1N4007 from a spent energy-saving lamp.

Zener diode (12 Volts) serves to stabilize the output voltage and its replacement can be achieved by almost any required voltage at the output of the PSU.

When assembling the circuit, it should be borne in mind that the fan must be connected correctly initially. A mistake in the wrong polarity of soldering the fan wires will cause the fan to fail. And the connection itself (soldering) should be done in advance, since the idle voltage at the fan connection points can be 50-100 volts. If the polarity is correct (the red wire is the positive power rail), then when you connect to the 220 V network, the fan will be about +12 volts.

The printed circuit board is made by the LUT method. Etching was carried out with hydrogen peroxide, citric acid and table salt at the rate of 50 ml of peroxide, 2 tsp. acids and a teaspoon of salt.

In addition, I give a diagram (maybe someone will need it) for adjusting the fan speed.

Basically, it is a regulator of the voltage supplied to the fan motor. A change in voltage leads to a change in the fan speed. A constant resistor R2 is specially introduced into the circuit, the purpose of which is to limit the minimum fan speed, so that even at the lowest speed, i.e. at the lowest voltage, ensure reliable starting.

Many potential buyers in the computer component market are alarmed by the fact that it is impossible to find a fan for a power supply in store windows. For the processor, video card, case, hard drive - please, but for the power supply there is nothing. It really looks very strange and causes a lot of negative emotions, judging by user reviews. However, there is no need to be upset. Any expert will tell you that the power supply has a regular cooler for cooling the case. The only difference can be in the standard size - 120, 80, 60 or 40 millimeters. By the way, any user can be convinced of this by disassembling his power supply unit.

The focus of this article is the fan for the computer's power supply. The reader is invited to get acquainted not only with worthy models, their descriptions and photos, but also with the maintenance of an inoperative cooling system. Indeed, in 90% of cases, replacing the fan is not at all necessary, just a little cleaning is enough.

Fascinating math

It is better to start not with the choice of a specific model or brand, but with the technical requirements that apply to the fan. Yes, such a simple computer component has a number of limitations that the user will have to put up with, because the user's comfortable work at the computer depends on the right choice. Hence, it follows that the basic requirements are noiselessness and airflow efficiency.

The cooling fan in most cases does not know how to independently regulate the impeller speed. By supplying 5 volts to the cooler, the PSU uses the maximum rotational speed that is characteristic of this voltage. This is where interesting events begin, because the characteristics for all fans are indicated for a 12-volt line. There are few options here - to trust the instinct or the recommendations of experts, because it is impossible to calculate the behavior of the impeller mathematically accurately.

How to be?

Here, such a factor as trust in a well-known brand is triggered, which worried about the buyer and independently measured the impeller speed and air flow on the 5-volt line. True, there are not so many such brands on the market, plus the prices for their products are quite high. But this option can be safely considered, because it will satisfy the wishes of users in terms of quiet operation and effective cooling.

It is better to look for a fan for a computer power supply among the products of well-known world manufacturers, such as Thermaltake, Zalman, be quiet, Noctua, Scythe. The cooler package contains data on the fan operation at 5 and 12 volts. Accordingly, data on rpm and noise level are indicated. For example, Noctua NF-P12 - 600 rpm (12 dB). Or Thermaltake Riing 12 - 1000 rpm (18 dB). By the way, in the last example, the fan is backlit.

Basic fan requirements

Having figured out the methodology for choosing a worthy product in the computer components market, it's time to go directly to the requirements. should not exceed 20 decibels. This is a very important factor, because this indicator is a kind of hearing threshold. As for the impeller speed, it all depends on the build quality. There are models that rotate at a frequency of 2000 rpm. However, experts recommend limiting yourself to 1200 rpm.

Many users have already heard many times that all the fans in the system enter into resonance, due to which a terrible rumble appears in and the case begins to rattle. Oddly enough, the computer's power supply may also be involved. The fan in it twitches not only due to a malfunction. The problem may be that the impeller speed is too high. Also, cheap Chinese fans have a problem with a skewed rotor, which is why a constant knocking is heard in the operation of the device, and the cooler itself begins to twitch.

From theory to practice

Having figured out which fan is in the computer's power supply, the user can only buy its analog and replace it. However, here the owner is in for a small surprise. This is an interface for connecting to the power supply. Almost all fans are sold with a 4-pin connector, and there are only two contacts on the power supply board, plus they are soldered. You shouldn't be upset, in most cases there is a dummy soldering on the board. In fact, the two wires from the fan are just in the glue.

Naturally, after unscrewing the cooler from the power supply case, you need to carefully remove the glue from the contacts (you may need a knife). At the end of the cleaning procedure, the user will have a board with two pins in front of him. The main thing here is to remember where the plus (red wire) and where the minus (black wire) are. Then it's a matter of technology: you need to put a 4-pin connector on these two pins so that the polarity matches the color of the cables. And there is nothing wrong with the fact that the two contacts remained unconnected.

Foreboding

Is the fan in the computer's power supply making noise? This event causes a lot of indignation on the part of users who begin to calculate the costs of purchasing a new cooler. It is at this stage that there is no need to rush, the fact is that noise is not a breakdown. This is a signal to the computer owner that there are some fan problems that need to be fixed immediately. Everything is pretty simple here:

• the power supply is removed and disassembled and blown out of dust;
• the fan is unscrewed and removed;
• the protective sticker on the cooler rotor is removed, 3-4 drops of oil are poured inside;
• the sticker is returned to its place, the PSU is assembled and installed in the computer.

The algorithm is quite simple, but very effective. There may be problems with the sticker, which has lost its sticky properties. It is not necessary to put it in this form, it will still fall off and rattle inside the case. Better to install a new sticker. Where to get? Cut from heavy scotch tape, use a chewing gum liner, or purchase any baby sticker of the same size from the store.

Grease

Having decided that replacing the fan of the computer's power supply unit is not needed, it will not be difficult for the user to take measures to clean and lubricate the cooler. However, there is one factor that all readers should pay attention to. It's about lubrication. The fact is that the hum in operation is emitted not by the fan blades, but by the bearing, which, from drying out, begins to distort the movement of the rotor.

The user should only use fluid oils that are capable of lubricating the bearing. However, do not forget about the high viscosity, because the lubricant must remain inside, and not leak out under the influence.It is better to use lubricant for sewing machines (analogue of the I-8 brand). As a last resort, machine oil will do.

Time to say good-bye

The only symptom that requires the user's attention when it comes to such an element as the computer's power supply is that the fan is not spinning. In such cases, bearing lubrication can only extend the life of the cooler by several days (if it is possible to spin the impeller after applying oil). But leaving the power supply in this state is not recommended. It is the impossibility of cooling with a faulty fan of the boards that can damage the power supply, which, in turn, can burn the motherboard and other components of the system unit.

Work on bugs

Not every user undertakes to change the fan for the computer power supply. Often, many owners trust this work to service centers that specialize in such breakdowns. In fact, this is the right decision, however, judging by the reviews of the owners, there are exceptions. We are talking about installing used fans in the power supply case that have exhausted their resource in the system unit. For many users, the fan in the computer's power supply does not work after repair because of this.

The second problem that users may face is the lack of contacts in the power supply unit for connecting a cooler. This is only found in cheap Chinese devices where a thrifty manufacturer soldered all the components of the power supply. In such cases, the user must also strip the contacts and solder the fan to the board (there should be no twists).

Finally

As practice shows, in 99% of cases it is not necessary to change the fan for the computer power supply. It is enough just to disassemble the power supply unit, clean it of dust and lubricate the cooler. All this suggests that the electrical component of the computer simply needs constant cleaning (once a year). Yes, there are situations when it is necessary to install a new cooler, but even here the user will not have any problems. Indeed, there is a fairly large range of decent fans on the market that can be safely installed as a cooling system for a power supply.

In amateur radio crafts, it is often necessary to look for alternative solutions to connect nodes or radio components to 220 volts. To our usual network, which is in every house, every apartment.
The point is to use a full-fledged transformer block nutrition is not always rational. It is expensive, cumbersome, and heavy in itself. In this case, the use of a conventional quenching capacitor can solve all these problems. In fact, a quenching capacitor is used in many places. Let's say with it you can connect the LED to 220 volts. We have already talked about such a scheme in the article "How to connect an LED to 220 volts." It can be used to connect almost any radio element. The main thing here is not to get carried away with large currents, since in this case the capacitor may not withstand, well, it will burn out by itself, and even worse, something will burn out instead. Let's conditionally limit the current for such power supplies to 150 mA. This current is quite enough to connect the fan from the computer. For what it needs to be connected, it will be up to you to decide. Maybe it will be used for active cooling of radio components, or maybe for something else. It does not matter. So, how do you connect a cooler or fan to 220 volts? About this in our article

The principle of operation of a quenching capacitor for connecting a fan from a computer to 220 volts

Before we calculate specific example, let's say a few words about how a quenching capacitor works in an alternating current circuit. In fact, in this case, the capacitor works as it should. At the first half-wave, it charges, passing current and voltage. Then, after charging, it simply "closes". Although the half-wave is not over yet. In this case, the power supply for subsequent radioelements is limited. Further, with the reverse half-wave, everything is in the same order, but the direction of current flow and voltage through the capacitor occurs in the opposite direction. As a result, this is how the voltage and current limitation occurs. The capacitor just closes at a certain point, that's all. In fact, its closure will depend on the resistance of the consumer, on the capacitance of the capacitor, on the frequency of the alternating current. We will not delve into the wilds, but immediately give the final formula. There she is.

C (μF) = (3200 * I (load, A)) / √ (Uin2-Uout2)

Let us explain the values ​​in the formula

3200 - proportionality coefficient,
I is the current consumed by the load,
Uin is the mains voltage (220 volts, although this may be less if you use a step-down transformer),
Uout - load supply voltage (lamp). Now that we understand what and where, let's try to analyze the case for a specific example.

How to connect a fan from a computer to 220 volts (calculation example)

Let's say we have a 120 mA fan with a 12 volt supply voltage. We count.

C = (3200 * 0.12) / √ (220 * 220-12 * 12)
C = 384/219 = 1.75 μF.

It just so happened that the capacity of our capacitor coincides with the type of capacitors. That is, such a capacitor exists in nature, we will not need to collect it from several capacitors. Well, to be sure, so that the fan does not cover exactly, we put a 12 volt Zener diode in parallel to it. Here, if there are any jumps, he will take it upon himself, passing current and voltage.
As a result, the scheme will be as follows.

That's all. Now, following the algorithm given here, you will be able to connect a fan, a light bulb, an LED ...

Summing up and summarizing

In fact, a capacitor operates with reactive power, that is, associated with the rise and fall of the voltage. In this case, it differs slightly from the active power with which a conventional resistor operates. However, here, too, it should be checked that the capacitor does not get warm, as this is fraught with its failure. After about 5-10 minutes of operation, de-energize the circuit and check with your fingers that the capacitor is not heating up. Also, of course, it is necessary to use capacitors for alternating current and with a voltage margin of 2 times.

Often used to build a large radiator heat pipes(English: heat pipe) - hermetically sealed and specially arranged metal tubes (usually copper). They transfer heat very efficiently from one end to the other: thus, even the farthest fins of a large radiator work effectively in cooling. This is how the popular cooler works.

To cool modern high-performance GPUs, the same methods are used: large radiators, copper cores for cooling systems or all-copper radiators, heat pipes to transfer heat to additional radiators:

The recommendations for selection are the same: use slow and large fans, as large as possible radiators. This is how the popular cooling systems for video cards and the Zalman VF900 look like:

Usually, fans of video card cooling systems only stirred the air inside the system unit, which is not very effective in terms of cooling the entire computer. Only recently, to cool video cards, they began to use cooling systems that carry hot air out of the case: the first were and, a similar design, from the brand:

Such cooling systems are installed on the most powerful modern video cards (nVidia GeForce 8800, ATI x1800XT and older). This design is often more justified from the point of view of the correct organization of air flows inside the computer case than traditional schemes. Organization of air flows

Modern standards for the design of computer cases, among other things, regulate the way of building a cooling system. Since the release of which was started in 1997, the technology of cooling the computer with a through air flow directed from the front wall of the case to the back has been introduced (in addition, air for cooling is sucked in through the left wall):

Those interested in the details refer to the latest versions of the ATX standard.

At least one fan is installed in the computer's power supply (many modern models have two fans, which can significantly reduce the rotational speed of each of them, and, therefore, the noise during operation). Additional fans can be installed anywhere inside the computer to enhance airflow. Be sure to follow the rule: on the front and left side walls, the air is forced into the inside of the case, on the back wall, hot air is thrown out... You also need to make sure that the flow of hot air from the back of the computer does not go directly into the air intake on the left side of the computer (this happens at certain positions of the system unit relative to the walls of the room and furniture). Which fans to install depends primarily on the presence of appropriate mounts in the walls of the case. Fan noise is mainly determined by its rotation speed (see section), therefore it is recommended to use slow (quiet) fan models. With equal installation dimensions and rotation speed, the fans on the back of the case subjectively make a little less noise than the front ones: firstly, they are farther from the user, and secondly, there are almost transparent grilles behind the case, while in front there are various decorative elements. Often, noise is created due to the air flow around the elements of the front panel: if the transferred volume of air flow exceeds a certain limit, vortex turbulent flows are formed on the front panel of the computer case, which create a characteristic noise (it resembles the hiss of a vacuum cleaner, but much quieter).

Choosing a computer case

Almost the overwhelming majority of cases for computers on the market today comply with one of the versions of the ATX standard, including in terms of cooling. The cheapest enclosures come with neither a power supply unit nor additional accessories. More expensive cases are equipped with fans for cooling the case, less often with adapters for connecting fans in various ways; sometimes even with a special controller equipped with temperature sensors, which allows you to smoothly regulate the rotation speed of one or more fans depending on the temperature of the main units (see for example). The power supply is not always included in the kit: many buyers prefer to choose a power supply on their own. Among other options for additional equipment, it is worth noting special mounts for side walls, hard drives, optical drives, expansion cards, which allow you to assemble a computer without a screwdriver; Dust filters that prevent dirt from entering the computer through the ventilation holes; various nozzles for directing air flows inside the housing. Exploring the fan

To transfer air in cooling systems, use fans(English: fan).

Fan device

The fan consists of a casing (usually in the form of a frame), an electric motor and an impeller, fixed with bearings on the same axis with the motor:

The reliability of the fan depends on the type of bearings installed. Manufacturers claim this typical MTBF (years based on 24/7 operation):

Taking into account the obsolescence of computer equipment (for home and office use it is 2-3 years), fans with ball bearings can be considered "eternal": their life is not less than the typical life of a computer. For more serious applications, where the computer has to work around the clock for many years, it is worth choosing more reliable fans.

Many have come across old fans, in which the plain bearings have worn out their resource: the impeller shaft rattles and vibrates during operation, making a characteristic roaring sound. In principle, such a bearing can be repaired by lubricating it with solid lubricant - but how many would agree to repair a fan that costs only a couple of dollars?

Fan characteristics

Fans differ in size and thickness: usually computers have standard sizes 40 × 40 × 10 mm for cooling video cards and hard drive pockets, as well as 80 × 80 × 25, 92 × 92 × 25, 120 × 120 × 25 mm for cooling the case. The fans also differ in the type and design of the installed electric motors: they consume different currents and provide different speed of rotation of the impeller. The performance depends on the size of the fan and the speed of rotation of the impeller blades: the generated static pressure and the maximum volume of transported air.

The volume of air carried by a fan (flow rate) is measured in cubic meters per minute or cubic feet per minute (CFM). The fan performance indicated in the characteristics is measured at zero pressure: the fan is operating in an open space. Inside the computer case, the fan blows into the system unit of a certain size, so it creates excess pressure in the serviced volume. Naturally, the volumetric capacity will be approximately inversely proportional to the generated pressure. Specific view consumption characteristics depends on the shape of the impeller used and other parameters of the particular model. For example, the corresponding graph for a fan:

The simple conclusion follows from this: the more intensively the fans in the back of the computer case work, the more air can be pumped through the entire system, and the more efficient the cooling will be.

Fan noise level

The noise level generated by the fan during operation depends on its various characteristics (for more details on the reasons for its occurrence, see the article). It is not difficult to establish the relationship between performance and fan noise. On the website of a large manufacturer of popular cooling systems, we see: many fans of the same size are equipped with different electric motors, which are designed for different rotational speeds. Since the impeller is used the same, we get the data of interest to us: the characteristics of the same fan at different speeds. We draw up a table for the three most common standard sizes: thickness 25 mm, and.

The most popular fan types are in bold.

Having calculated the coefficient of proportionality of the air flow and the noise level to the rpm, we see almost complete coincidence. To clear our conscience, we consider deviations from the average: less than 5%. Thus, we got three linear dependences, 5 points each. It is not God only knows what statistics, but this is enough for a linear relationship: the hypothesis is considered confirmed.

The volumetric performance of the fan is proportional to the number of revolutions of the impeller, the same is true for the noise level..

Using this hypothesis, we can extrapolate the results obtained by the least squares method (OLS): in the table, these values ​​are shown in italics. It should be remembered, however, that the scope of this model is limited. The investigated dependence is linear in a certain range of rotation speeds; it is logical to assume that the linear nature of the dependence will remain in some vicinity of this range; but at very high and very low speeds, the picture can change significantly.

Now let's look at a line of fans from another manufacturer:, and. Let's make a similar plate:

Calculated data are highlighted in italics.
As mentioned above, if the fan speed values ​​differ significantly from those investigated, the linear model may be incorrect. Extrapolated values ​​are to be understood as rough estimates.

Let's pay attention to two circumstances. Firstly, GlacialTech fans run slower, and secondly, they are more efficient. Obviously, this is the result of using an impeller with a more complex blade shape: even at the same speed, the GlacialTech fan carries more air than the Titan: see the graph growth... A the noise level at the same speed is approximately equal: The proportion is maintained even for fans from different manufacturers with different impeller shapes.

It should be understood that the real noise characteristics of the fan depend on its technical design, the generated pressure, the volume of pumped air, and the type and shape of obstacles in the path of air flows; that is, on the type of computer case. Since the cases are very different, it is impossible to directly apply the quantitative characteristics of the fans measured under ideal conditions - they can only be compared with each other for different fan models.

Fan price categories

Consider the cost factor. For example, let's take in the same online store and: the results are written in the tables above (fans with two ball bearings were considered). As you can see, the fans of these two manufacturers belong to two different classes: GlacialTech operate at lower rpm, therefore they are less noisy; at the same RPM they are more efficient than the Titan - but they are always a dollar or two more expensive. If you need to build the least noisy cooling system (for example, for a home computer), you will have to fork out for more expensive fans with complex blade shapes. In the absence of such stringent requirements or with a limited budget (for example, for an office computer), simpler fans are fine. The different type of impeller suspension used in fans (see the section for more details) also affects the cost: the fan is more expensive, the more complex bearings are used.

The beveled corners on one side serve as the key for the connector. The wires are connected as follows: two central ones - "ground", common contact (black wire); +5 V - red, +12 V - yellow. To power the fan through the molex connector, only two wires are used, usually black (ground) and red (supply voltage). By connecting them to different pins of the connector, you can get different fan speeds. A standard voltage of 12 volts will start the fan at nominal speed, a voltage of 5-7 volts will provide about half the rotational speed. It is preferable to use more high voltage, since not every electric motor is able to reliably start at too low supply voltage.

Experience shows that fan speed when connected to +5 V, +6 V and +7 V is approximately the same(with an accuracy of up to 10%, which is comparable to the measurement accuracy: the rotation speed is constantly changing and depends on many factors, such as the air temperature, the slightest draft in the room, etc.)

I remind you that the manufacturer guarantees the stable operation of its devices only when using a standard supply voltage... But, as practice shows, the overwhelming majority of fans start up perfectly even at reduced voltage.

The contacts are fixed in the plastic part of the connector using a pair of bending metal "tendrils". It is easy to remove the contact by pressing down the protruding parts with a thin awl or small screwdriver. After that, the "antennae" must be bent to the sides again, and the contact should be inserted into the corresponding socket of the plastic part of the connector:

Sometimes coolers and fans are equipped with two connectors: molex-connected in parallel and three- (or four-) pin. In this case you need to connect power only through one of them:

In some cases, not one molex connector is used, but a pair of "mom-dad": this way you can connect the fan to the same wire from the power supply that supplies HDD or an optical drive. If you swap the pins in the connector to get on the fan non-standard voltage, pay special attention to rearrange the pins in the second slot in exactly the same order. Failure to do so could result in incorrect supply voltage to the hard disk or optical drive, which will most likely lead to their immediate failure.

In three-pin connectors, the key for installation is a pair of protruding guides on one side:

The counterpart is located on the contact pad; when connected, it enters between the guides, also acting as a latch. The corresponding connectors for powering the fans are located on the motherboard (as a rule, there are several in different places on the board) or on the board of a special controller that controls the fans:

In addition to "ground" (black wire) and +12 V (usually red, less often: yellow), there is also a tachometer contact: it is used to control the fan speed (white, blue, yellow or green wire). If you do not need the ability to control the fan speed, then this contact can be left unconnected. If the fan is powered separately (for example, through a molex connector), it is permissible to connect only the RPM control contact and the common wire using a three-pin connector - this circuit is often used to monitor the rotation speed of the power supply fan, which is powered and controlled by the internal power supply circuits.

Four-pin connectors have appeared relatively recently on motherboards with LGA 775 and socket AM2 processor sockets. They differ in the presence of an additional fourth contact, while fully mechanically and electrically compatible with three-pin connectors:

Two the same a fan with three-pin connectors can be connected in series to one power connector. Thus, each of the electric motors will have 6 V supply voltage, both fans will rotate at half speed. For such a connection, it is convenient to use the fan power connectors: the contacts can be easily removed from the plastic case by pressing down the fixing “tongue” with a screwdriver. The connection diagram is shown in the figure below. One of the connectors plugs into the motherboard as usual: it will supply power to both fans. In the second connector, using a piece of wire, you need to short-circuit two contacts, and then insulate it with tape or electrical tape:

It is strongly discouraged to connect two different electric motors in this way.: due to the inequality of electrical characteristics in different operating modes (starting, acceleration, stable rotation), one of the fans may not start at all (which is fraught with the failure of the electric motor) or require an excessively large current to start (fraught with failure of the control circuits).

Often fixed or variable resistors connected in series in the power circuit are tried on to limit the fan speed. By changing the resistance of the variable resistor, you can adjust the rotation speed: this is how many manual fan speed controllers work. When designing such a circuit, it must be remembered that, firstly, the resistors heat up, dissipating some of the electrical power in the form of heat - this does not contribute to more efficient cooling; secondly, the electrical characteristics of the electric motor in different operating modes (starting, acceleration, stable rotation) are not the same, the resistor parameters must be selected taking into account all these modes. To select the parameters of the resistor, it is enough to know Ohm's law; you need to use resistors designed for a current no less than the electric motor consumes. However, I personally do not like manual control of the cooling, as I believe that a computer is a perfectly suitable device to control the cooling system automatically, without user intervention.

Fan monitoring and control

Most modern motherboards allow you to control the speed of the fans connected to some 3- or 4-pin connectors. Moreover, some of the connectors support software control of the rotational speed of the connected fan. Not all connectors on the board provide such capabilities: for example, the popular Asus A8N-E board has five connectors for powering fans, only three of them support rotation speed control (CPU, CHIP, CHA1), and only one fan speed control. (CPU); motherboard Asus P5B has four connectors, all four support rotation speed control, rotation speed control has two channels: CPU, CASE1 / 2 (the speed of two case fans changes synchronously). The number of connectors with the ability to control or control the rotational speed does not depend on the chipset or south bridge used, but on the specific motherboard model: models from different manufacturers may differ in this regard. Often, motherboard designers deliberately deprive cheaper models of fan speed control capabilities. For example, the motherboard for Intel Pentiun 4 processors Asus P4P800 SE is able to regulate the speed of the processor cooler, but its cheaper version Asus P4P800-X is not. In this case, you can use special devices that are able to control the speed of several fans (and, usually, provide for the connection of a number of temperature sensors) - there are more and more of them on the modern market.

You can control the fan speed values ​​using BIOS Setup. As a rule, if the motherboard supports changing the fan speed, here in the BIOS Setup you can configure the parameters of the speed control algorithm. The set of parameters is different for different motherboards; usually the algorithm uses the readings of thermal sensors built into the processor and motherboard. There are a number of programs for different operating systems that allow you to control and adjust the fan speed, as well as monitor the temperature of various components inside the computer. Some motherboard manufacturers bundle their products with proprietary Windows programs: Asus PC Probe, MSI CoreCenter, Abit µGuru, Gigabyte EasyTune, Foxconn SuperStep, etc. Several universal programs are distributed, among them: (shareware, $ 20-30), (distributed free of charge, has not been updated since 2004). The most popular program of this class is:

These programs allow you to monitor a range of temperature sensors that are installed in modern processors, motherboards, video cards and hard drives. The program also monitors the rotation speed of the fans that are connected to the motherboard connectors with appropriate support. Finally, the program is able to automatically adjust the fan speed depending on the temperature of the monitored objects (if the motherboard manufacturer has implemented hardware support for this feature). In the above figure, the program is configured to control only the processor fan: at a low CPU temperature (36 ° C), it rotates at about 1000 rpm, which is 35% of the maximum speed (2800 rpm). Setting up such programs comes down to three steps:

1. determining which of the motherboard controller channels the fans are connected to, and which of them can be controlled by software;
2. an indication of which of the temperatures should affect the speed of the various fans;
3. setting temperature thresholds for each temperature sensor and a range of operating speeds for fans.

Many programs for testing and fine-tuning computers also have monitoring capabilities:, etc.

Many modern video cards also allow you to adjust the fan speed of the cooling system depending on the temperature of the GPU. With the help of special programs, you can even change the settings of the cooling mechanism, reducing the noise level from the video card in the absence of load. This is how the optimal settings for the HIS X800GTO IceQ II video card look in the program:

Passive cooling

Passive cooling systems are usually called those that do not contain fans. Individual computer components can be satisfied with passive cooling, provided that their heatsinks are placed in a sufficient air flow created by "foreign" fans: for example, a chipset's microcircuit is often cooled by a large heatsink located near the place where the processor cooler is installed. Passive cooling systems for video cards are also popular, for example:

Obviously, the more radiators one fan has to blow through, the more flow resistance it needs to overcome; thus, with an increase in the number of radiators, it is often necessary to increase the rotation speed of the impeller. It is more efficient to use a lot of low-speed large diameter fans, and passive cooling systems are preferable to avoid. Despite the fact that there are passive heatsinks for processors, video cards with passive cooling, even power supplies without fans (FSP Zen), trying to build a computer with no fans at all from all these components will certainly lead to constant overheating. Because a modern high-performance computer dissipates too much heat to be cooled by passive systems alone. Due to the low thermal conductivity of air, it is difficult to organize effective passive cooling for the entire computer, except perhaps to turn the entire computer case into a radiator, as is done in:

Compare the case-radiator in the photo with the case of a regular computer!

Perhaps completely passive cooling will be enough for low-power specialized computers (for Internet access, for listening to music and watching videos, etc.)

In the old days, when the power consumption of processors had not yet reached critical values ​​- a small radiator was enough to cool them - the question "what will the computer do when there is nothing to do?" The solution was simple: while it is not necessary to execute user commands or running programs, the OS gives the processor a NOP (No OPeration, no operation) command. This command causes the processor to perform a meaningless, ineffectual operation, the result of which is ignored. This takes not only time, but also electricity, which, in turn, is converted into heat. A typical home or office computer, in the absence of resource-intensive tasks, is usually only 10% loaded - anyone can verify this by starting the Windows Task Manager and observing the Timeline of CPU (Central Processing Unit) utilization. Thus, with the old approach, about 90% of the CPU time was blown away: the CPU was busy executing commands that no one needed. Newer operating systems (Windows 2000 and later) act more sensibly in a similar situation: using the HLT command (Halt, stop) the processor stops completely for a short time - this, obviously, allows to reduce power consumption and processor temperature in the absence of resource-intensive tasks.

Experienced computer scientists can recall a number of programs for "software cooling of the processor": while running under Windows 95/98 / ME, they stopped the processor using HLT, instead of repeating meaningless NOPs, which reduced the temperature of the processor in the absence of computational tasks. Accordingly, the use of such programs under Windows 2000 and newer operating systems is meaningless.

Modern processors consume so much energy (which means: they dissipate it in the form of heat, that is, they heat up) that the developers have created additional technical tools to combat possible overheating, as well as tools that increase the efficiency of saving mechanisms when the computer is idle.

Thermal protection of the processor

To protect the processor from overheating and failure, the so-called thermal throttling is used (usually not translated: throttling). The essence of this mechanism is simple: if the processor temperature exceeds the allowable temperature, the processor is forced to stop by the HLT command so that the crystal can cool down. In early implementations of this mechanism, through BIOS Setup, it was possible to configure how much of the time the processor would be idle (parameter CPU Throttling Duty Cycle: xx%); new implementations "slow down" the processor automatically until the crystal temperature drops to an acceptable level. Of course, the user is interested in the processor not being cooled down (literally!), But doing useful work - for this you need to use a sufficiently effective cooling system. You can check if the processor's thermal protection mechanism (throttling) is turned on using special utilities, for example:

Minimizing energy consumption

Almost all modern processors support special technologies to reduce energy consumption (and, accordingly, heating). Different manufacturers These technologies are called differently, for example: Enhanced Intel SpeedStep Technology (EIST), AMD Cool'n'Quiet (CnQ, C&Q) - but they work essentially the same way. When the computer is idle and the processor is not loaded with computational tasks, the clock speed and voltage of the processor are reduced. Both reduce the power consumption of the processor, which in turn reduces heat generation. As soon as the processor load increases, the full processor speed is automatically restored: the operation of such a power-saving scheme is completely transparent to the user and the programs being launched. To enable such a system, you need:

1. enable the use of a supported technology in BIOS Setup;
2. install the appropriate drivers in the operating system (usually a processor driver);
3. in the Windows Control Panel, in the Power Management section, on the Power Schemes tab, select the Minimal Power Management scheme from the list.

For example, for an Asus A8N-E motherboard with a processor, you need ( detailed instructions are given in the User's Guide):

1. in BIOS Setup, in the Advanced> CPU Configuration> AMD CPU Cool & Quiet Configuration section, switch the Cool N "Quiet parameter to Enabled; and in the Power section, switch the ACPI 2.0 Support parameter to Yes;
2. install ;
3. see above.

You can check that the processor frequency changes using any program that displays the processor's clock frequency: from specialized types, up to the Windows Control Panel, System section:

AMD Cool "n" Quiet in Action: CPU Current (994 MHz) Less Than Nominal (1.8 GHz)

Often, motherboard manufacturers additionally complete their products with visual programs that clearly demonstrate the operation of the mechanism for changing the frequency and voltage of the processor, for example, Asus Cool & Quiet:

The processor frequency changes from the maximum (in the presence of a computational load), to a certain minimum (in the absence of a CPU load).

RMClock utility

During the development of a set of programs for comprehensive testing of processors, (RightMark CPU Clock / Power Utility) was created: it is designed to monitor, configure and manage energy-saving capabilities of modern processors. The utility supports all modern processors and a variety of power management systems (frequency, voltage ...) The program allows you to monitor the occurrence of throttling, changes in the frequency and voltage of the processor. Using RMClock, you can configure and use everything that the standard tools allow: BIOS Setup, power management by the OS using the processor driver. But the capabilities of this utility are much wider: with its help, you can configure a number of parameters that are not available for customization in a standard way. This is especially important when using overclocked systems, when the processor runs faster than the nominal frequency.

Auto overclocking video card

A similar method is used by the developers of video cards: the full power of the GPU is needed only in 3D mode, and a modern graphics chip can cope with a desktop in 2D mode even at a reduced frequency. Many modern video cards are configured so that the graphics chip can serve a desktop (2D mode) with reduced frequency, power consumption, and heat dissipation; accordingly, the cooling fan spins more slowly and makes less noise. The video card starts working at full capacity only when launching 3D applications, for example, computer games. Similar logic can be implemented in software using various utilities for fine-tuning and overclocking video cards. For example, this is how the automatic overclocking settings in the program for the HIS X800GTO IceQ II video card look like:

Quiet computer: myth or reality?

From the user's point of view, a computer is considered sufficiently quiet if its noise does not exceed the surrounding background noise. During the day, taking into account the noise of the street outside the window, as well as the noise in the office or at work, the computer is allowed to make a little more noise. A home computer that you plan to use around the clock should be quieter at night. As practice has shown, almost any modern powerful computer can be made to work quite quietly. I will describe a few examples from my practice.

Example 1: Intel Pentium 4 Platform

In my office I use 10 Intel Pentium 4 3.0 GHz computers with standard CPU coolers. All machines are assembled in inexpensive Fortex cases up to $ 30, Chieftec 310-102 power supplies (310 W, 1 fan 80 × 80 × 25 mm) are installed. In each case, a 80 × 80 × 25 mm fan (3000 rpm, noise 33 dBA) was installed on the rear wall - they were replaced by fans with the same performance 120 × 120 × 25 mm (950 rpm, noise 19 dBA) ). On the file server local network for additional cooling of hard drives, 2 fans 80 × 80 × 25 mm are installed on the front wall, connected in series (speed 1500 rpm, noise 20 dBA). Most computers use the Asus P4P800 SE motherboard, which is able to regulate the speed of the CPU cooler. The two computers are equipped with cheaper Asus P4P800-X motherboards, where the cooler speed is not regulated; to reduce the noise from these machines, the CPU coolers were replaced (1900 rpm, 20 dBA noise).
Result: computers are quieter than air conditioners; they are practically inaudible.

Example 2: Intel Core 2 Duo Platform

A home computer based on a new Intel Core 2 Duo E6400 (2.13 GHz) processor with a standard processor cooler was assembled in an inexpensive aigo case at $ 25, a Chieftec 360-102DF power supply (360 W, 2 fans 80 × 80 × 25 mm) was installed. In the front and rear walls of the case, 2 fans 80 × 80 × 25 mm are installed, connected in series (the speed is adjustable, from 750 to 1500 rpm, the noise is up to 20 dBA). Used motherboard Asus P5B, which is able to regulate the speed of the processor cooler and case fans. A video card with a passive cooling system is installed.
Result: the computer makes such a noise that during the day it is not heard behind the usual noise in the apartment (conversations, steps, the street outside the window, etc.).

Example 3: AMD Athlon 64 Platform

My home computer on an AMD Athlon 64 3000+ (1.8 GHz) processor is built in an inexpensive Delux package for up to $ 30, initially it contained a CoolerMaster RS-380 power supply (380 W, 1 fan 80 × 80 × 25 mm) and a GlacialTech SilentBlade graphics card GT80252BDL-1 connected to +5 V (about 850 rpm, noise less than 17 dBA). The motherboard used is Asus A8N-E, which is able to regulate the speed of the processor cooler (up to 2800 rpm, noise up to 26 dBA, in idle mode the cooler rotates about 1000 rpm and makes less than 18 dBA noise). The problem with this motherboard: cooling the nVidia nForce 4 chipset, Asus installs a small 40 × 40 × 10 mm fan with a rotation speed of 5800 rpm, which whistles loudly and unpleasantly (in addition, the fan is equipped with a sliding bearing, which has a very short resource) ... To cool the chipset, a cooler for video cards with a copper radiator was installed, against its background you can clearly hear the positioning clicks of the hard drive heads. A working computer does not interfere with sleeping in the same room where it is installed.
Recently, the video card was replaced by the HIS X800GTO IceQ II, for the installation of which it was necessary to modify the chipset heatsink: bend the edges so that they did not interfere with the installation of a video card with a large cooling fan. Fifteen minutes of work with pliers - and the computer continues to run quietly, even with a fairly powerful video card.

Example 4: AMD Athlon 64 X2 Platform

A home computer based on an AMD Athlon 64 X2 3800+ (2.0 GHz) processor with a processor cooler (up to 1900 rpm, noise up to 20 dBA) is assembled in a 3R System R101 case (included 2 fans 120 × 120 × 25 mm, up to 1500 rpm, installed on the front and rear walls of the case, connected to a standard monitoring and automatic fan control system), an FSP Blue Storm 350 power supply unit (350 W, 1 fan 120 × 120 × 25 mm) is installed. A motherboard (passive cooling of the chipset microcircuits) was used, which is able to regulate the speed of the processor cooler. The video card GeCube Radeon X800XT was used, the cooling system was replaced with Zalman VF900-Cu. A hard drive known for its low noise generation was chosen for the computer.
Result: The computer is so quiet that you can hear the noise of the hard drive motor. A working computer does not interfere with sleeping in the same room where it is installed (the neighbors behind the wall are talking even louder).