Computer cooler fan connection diagram. Computer coolers: starting from scratch. How to properly organize cooling in a gaming computer
A processor cooler or CPU cooler is one of the components of a personal computer that a significant portion of users do not pay much attention to. Moreover, it is quite possible that many users probably do not know about the existence of such a component. Meanwhile, the processor cooler hardly deserves such a disdainful attitude, since its function in the system unit is quite important. We can say that without this auxiliary device the functioning of the heart of the computer - the central processor - is impossible.
It's no secret that one of the main features of a central processor is its significant heat generation. This property of the processor is quite natural, because it has to work “by the sweat of its brow”, processing a huge amount of data in a split second and performing billions of operations simultaneously. As a result, a significant amount of fluid flows through the processor crystal. electricity, causing it to heat up greatly.
Consequently, if the processor is not specifically cooled, its temperature will constantly increase. However, the processor cannot heat up above a certain value, as this may cause it to fail. Moreover, constant exposure high temperature may adversely affect the performance and longevity of the processor.
Therefore, cooling devices are used to cool the processor and keep its temperature within safe limits. Cooling devices are usually divided into passive and active. Passive coolers remove heat from the source and disperse it into space. An example of a passive cooler is a radiator. However, the disadvantage of cooling devices of this type is that they do not use the flow of cold medium into the heat generation zone. The latter method is used in active cooling devices.
Radiators are an example of passive processor cooling.
An example of such a device is a processor fan, or, as it is also often called, a cooler. And if we take the fan itself separately, it can be considered one of the most common cooling devices in a computer. Its scope of application includes not only cooling the central processor, but also cooling other heat-intensive components, such as the power supply, graphics card, hard drive, motherboard chipset, etc. The main advantages of the fan are simplicity of design, low cost and fairly high reliability.
As a rule, most processors are equipped with standard coolers by their manufacturers. However, such cooling devices have rather average characteristics, and therefore, in some cases, in order to provide sufficient cooling of the CPU, the user may need a more efficient CPU cooler than the stock one.
Principle of operation
The name "cooler" comes from English word“cooler” – cooler. Meanwhile, not every cooling device can be classified as a cooler. Typically, a cooler in computer terminology is a cooling device whose main component is a fan. Often the cooling fan itself is called a cooler, although strictly speaking, a cooler is actually a combination of a fan and a radiator. Thus, the cooler uses both active and passive cooling methods.
Radiators are devices made of metal with high thermal conductivity, such as aluminum. There are also coolers made of copper, which has an even higher thermal conductivity than aluminum, but copper radiators are more expensive and less common. One of the main features of the radiator is its complex profile. As a rule, a radiator consists of many metal plates located parallel or at an angle to each other. Thanks to this, the radiator has a large surface area, which also contributes to intensive heat dissipation. In addition, a radiator can usually be divided into two parts - the base, which is in direct contact with the processor, and the main cooling section.
There are also coolers that use not only a radiator, but also special aluminum or copper tubes, which contain a certain amount of coolant. The principle of operation of the tubes is that the liquid having low temperature boiling, evaporates in the area of intense heat input, while taking away a large number of energy, and then gives off heat, condensing in the cold area of the cooler, blown by a fan. This design cooling device came into computer use from the field of industrial cooling systems. Although not so long ago, coolers using heat pipes seemed like exotic devices, they currently occupy a significant part of the market. There are two main types of coolers with cooling tubes - coolers in which the tubes border directly on the surface of the processor, and coolers in which the tubes are soldered into the radiator, but do not directly touch the surface of the processor.
An example of a heatsink design with heat pipes is shown below:
Cooler with cooling tubes in contact with the surface of the CPU (left) and soldered into the radiator without contact with the processor (right)
Despite great importance radiator, fan is an equally important component of a processor cooler. It is designed to create a powerful air flow, thanks to which the warm air passing through the radiator is removed into the internal space of the system unit. Typically, the heat flow created by a fan has a direction coinciding with the axis of its rotation, but there are also fans that create a radial flow, that is, perpendicular to the axis of rotation. Such fans are called blowers. Today, it is also often possible to find a cooler that has not one, but several fans at once.
CPU cooler fan:
Blower and cooler creating a radial air flow cooling the processor
Connecting the cooler
To connect the cooler to the motherboard, use a special connector located on it. This connector supplies power that rotates the fan. In addition, the connector may have one or two auxiliary data lines. The cooler connector, depending on the type of motherboard, may have 2, 3 or 4 contacts.
Let's briefly look at the features that each connector has. The two-pin connector only supports the power lines that correspond to the black and red wires in the fan cable. The three-pin connector means that there is another additional control line designed to control the rotation speed of the cooler. The four-pin connector supports another line – the PWM fan speed control line. As a rule, modern motherboards have a four-pin connector, although it can also include fans that have cables with fewer wires.
The cooler is installed, more precisely, the cooler radiator is installed on the top cover of the processor. Typically, between the heatsink and the processor there is a layer of special conductive paste - the so-called thermal paste. The purpose of thermal paste is to ensure a tight fit of the base of the heatsink to the surface of the processor and to prevent the appearance of air cavities between these devices. A fan is installed on top and sometimes on the side of the radiator. To secure the cooler to the motherboard, special latches and clamps are used, and in many cases, screws.
Main parameters of the cooler
The main requirement for a cooler is its ability to effectively cool the central processor. As a rule, to determine the efficiency of a cooler, a parameter such as thermal or thermal resistance is used. This parameter determines the number of degrees by which the processor temperature will rise when it emits a watt of thermal energy. From this we can understand that the lower the thermal resistance of the cooler, the better the cooling capacity it has, and, as a result, the lower the temperature of the processor chip on which it is installed will be. It is worth keeping in mind, however, that a cooler with a high thermal resistance is not necessarily of low quality; it can simply be designed for a processor with relatively low heat dissipation.
However, thermal resistance is not the only criterion characterizing the efficiency and quality of a cooler. Also, a good cooler should, if possible, have the following properties:
- Compatible with a wide range of processor types.
- The presence of a reliable and easily removable mount to the processor.
- High wear resistance and durability.
- Low vibration and noise levels.
- Small dimensions and light weight.
Also, when choosing a cooler, you should pay attention to whether it supports adjusting the rotation speed depending on the processor load. This feature allows you to significantly reduce the noise level produced by the cooler fan. On this moment Most cooler fans are equipped with a similar function.
Setting cooler parameters in BIOS
Almost any modern BIOS has options related to various fan operation parameters. These can be either purely informational options, like the option that shows the fan rotation speed, or options that allow you to adjust the cooler parameters, in particular, its rotation speed. There are options, for example, that allow you to set the cooler speed indirectly, by linking it to a specific CPU temperature.
In many BIOS you can also find options such as CPU Smart FAN Mode, which allow you to select the type of fan rotation control - by changing the voltage or by direct speed control.
Conclusion
CPU cooler is one of the most important auxiliary devices a computer, without which its normal operation would be impossible. As a rule, a cooler is a combination of a powerful cooling fan, which can be connected to any motherboard via a special connector, and a radiator made of metal with high thermal conductivity - copper or aluminum. The main purpose of the cooler is to cool the central processor and ensure normal temperature conditions for its operation. Therefore, the quality, reliability and efficiency of the cooler should never be neglected.
Coolers for processors, coolers for hard drives, coolers for video cards and system chipsets. Add to this card coolers, system blowers and laptop coolers. With so many cooling devices, you can easily get confused, and little by little you begin to believe that coolers are the main component of today's computer. Fortunately, or unfortunately, this is not the case yet, and today there is no need to hang noisy fans on your favorite PC until it takes off. In this article we will try to figure out what are the heat sources in a computer, what methods exist for cooling these components, and whether it is necessary to deal with the increased temperature of the computer at all.Theoretical basis of cooling
So, a little theory. From a physics course we know that any conductor through which electric current flows generates heat. This means that absolutely all components of the computer, from the central processor to the power cables, heat the surrounding air. The amount of heat generated by one or another computer component directly depends on its energy consumption, which, in turn, is determined by many other factors: if we are talking about a hard drive, then the power of the electric motor and the controller electronics, and if we are talking about a processor or other chip, then the number elements integrated into it and the technological process of its production. This is the physics of our world, and there is no escape from it. But no one has yet come up with the idea of gluing radiators to electrical wires and blowing air over, say, internal modems! This is because different components of the computer affect the temperature in the case in different ways, and if such a “cold” device like a modem does not require any additional cooling, then we pay too much attention to the same video card, which is why they put huge coolers, sometimes even with two fans.But first of all, let's review what a cooler is. A cooler (from the English Cool - cold) is a device for cooling something. The main task of any cooler is to reduce and maintain the temperature of the cooled body at a given level. And depending on the type of device being cooled, be it a transistor, a chip, a processor, or even a hard drive, different types of coolers are used. In our minds, a cooler is like a “big piece of iron with a propeller,” and the bigger it is, the better it is. However, coolers can also be more complex devices, costing hundreds of dollars. Typically, coolers used in computers consist of a fan, a radiator and a mount.
Radiators
A radiator (from the English Radiate - to radiate) is used to remove heat from a cooled object. It is in direct contact with the cooled object, and its main function is to absorb part of the heat generated by the body and dissipate it into the surrounding air. As you know, again from a physics course, an object gives off heat only from its surface, which means that in order to achieve the best heat removal, the cooled object must have as large a surface area as possible. Today's radiators increase the surface area by installing more fins. Heat from the cooled object moves to the base of the radiator, and is then evenly distributed along its fins, after which it goes into the surrounding air, and this process is called radiation. The air around the radiator gradually heats up, and the heat transfer process becomes less efficient, so the efficiency of heat transfer can be increased if cold air is constantly supplied to the radiator fins. Fans are used for this today. But we'll talk about them a little later.The radiator must have good thermal conductivity and heat capacity. Thermal conductivity determines the rate at which heat spreads throughout the body. For a radiator, the thermal conductivity should be as high as possible, because often the area of the cooled object is several times smaller than the area of the radiator base, and with low thermal conductivity, the heat from the cooled object will not be able to be evenly distributed throughout the entire volume, over all the fins of the radiator. If the radiator is made of a material with high thermal conductivity, then at each point the temperature will be the same, and heat will be released from the entire surface area with the same efficiency, that is, there will be no situation when one part of the radiator will be hot, and the other will remain cold and will not release heat to the surrounding air. Heat capacity determines the amount of heat that must be imparted to the body in order to increase its temperature by 1 degree. For radiators, the heat capacity should be as high as possible, because when it cools by one degree, the body gives off the same amount of heat. The heat capacity and thermal conductivity of the radiator depend on the material used for its manufacture.
Table of thermal properties of materials
As you can see, it is most profitable to use two materials for the manufacture of radiators: aluminum and copper. The first is due to low cost and high heat capacity, and the second is due to high thermal conductivity. Silver is too expensive to be used to create radiators, but even if you do not take into account its high price, due to its good thermal conductivity, this metal is best used for the manufacture of radiator bases only.
The design of the radiator is also of great importance. For example, the fins can be installed at different angles to the air flow. They can be straight along the entire length of the radiator, or cut across; they can be thick and with burrs if the radiator is made using extrusion technology, or thin and smooth if it was cast from molten metal. The ribs can be flat, bent from plates and pressed into the base. The radiator can generally be needle-shaped, that is, instead of ribs, it can have cylindrical or square needles. Today it is known that needle radiators perform best in terms of fin design.
Thermal interface
Radiators are adjacent with their base to the object being cooled, and heat from it to the radiator passes only through the surface of their contact, so we must strive to make it as large as possible. But even the usually available contact area (for example, the surface of the processor core) must be used one hundred percent. The fact is that when two surfaces come into contact, tiny cavities filled with air remain between them. This cannot be avoided, and no matter how even and smooth the surface of the radiator may seem to you, it still has cracks and depressions where air collects. Air conducts heat very poorly, and therefore the cooling efficiency will be significantly lower than the capabilities of the radiator.To get rid of air cushions and increase cooling efficiency, various thermal interfaces are used. They have high thermal conductivity and, due to fluidity, fill all the unevenness of the radiator base. As a result, those places where there was previously air that bothered us are now filled with material that conducts heat well, and the radiator is already working at maximum efficiency. Thermal interfaces come in different types: thermal paste or conductive pads. Gaskets are rubber-like polymer plates applied to the base of radiators. When heated they change their state of aggregation and softening, they fill in all the irregularities. Nowadays thermal pastes are supplied with the vast majority of branded coolers. More often, thermal paste is simply placed in a box with a cooler in a syringe or a small plastic bag. But it happens that it is already applied to the base of the radiator. In this case, it will only be enough for one or two installations, since assembling it from a cooled chip or processor will be more difficult than buying another bag of paste. When choosing a thermal interface, I would recommend using thermal pastes rather than thermal pads. The greater fluidity of thermal pastes allows them to better fill all the unevenness of the radiator, and due to the use of materials such as silver or aluminum in their composition, they have higher thermal conductivity. Today you can find thermal pastes with 90% silver content on sale. And although silver is an excellent electrical conductor, manufacturers guarantee that the thermal paste will not short-circuit the contacts of the elements of the board or device on which it is applied, but they still recommend not checking the insulating properties of their product and, if possible, avoiding contact of thermal paste with the electrical components of the computer.
Fans
Fans provide a continuous flow of air over the radiator, turning the less efficient process of radiation into the more effective process of convection. Convection is a heat exchange process that differs from radiation in that the cooling air is constantly in motion. In active coolers, it is forced into the radiator and, when heated, is dissipated into environment. With the use of a fan, the cooler becomes much more efficient, and the temperature of the cooled object can drop by half, or even more, depending on the performance of the fan. Fan performance is its main characteristic, measured in the number of cubic feet of air it moves per minute, abbreviated as CFM (Cubic Feet per Minute). It mainly depends on the area of the fan, its height, the profile of the blades and their rotation speed. The larger these values are, the more air the fan can move, and accordingly, the more efficient the cooling will be. Today, fans for computer coolers do not have the ability to endlessly increase either the size or the rotation speed of the impeller. It is clear that a fan larger than 80 mm is already difficult to place in the case, and the speed of the propeller directly affects its noise level. In addition, a larger fan will need to have a more powerful and more expensive electric motor, which will affect its cost.All fans used in computers today are powered by direct current, most often 12V. To connect to power, they use three-pin Molex connectors (for Smart fans) or four-pin PC-Plug connectors.
The Molex connector has three wires: black (ground), red (positive) and yellow (signal). PC-Plug has four wires: two black (ground), yellow (+12 Volts) and red (+5 Volts). Molex connectors are installed on motherboards so that the system itself can control the fan speed by applying different voltages to the red wire (usually from 8 to 12 V), and change it if necessary. Via the yellow signal wire, the motherboard receives information from the fan about the speed of its blades. Today, this has become very relevant, since a stopped fan on a processor cooler can damage the processor. Therefore, modern motherboards make sure that the fan is always spinning, and if it stops, they turn off the computer. Connecting via Molex has one drawback: it is dangerous to attach fans with a power consumption of more than 6 W to motherboards. The PC-Plug connector can withstand tens of watts, but when connected to it, you will not be able to find out whether your fan is working or not. Today, more and more often, fans come with PC-Plug - Molex adapters to connect them to the power supply, or even both connectors at once: PC-Plug and Molex, to receive power from the computer's power supply and communicate to the motherboard via the Molex signal wire about the speed of the motor.
Fans can also have different type rotor hangers. For this purpose, sliding bearings (Sleeve bearing) or rolling bearings (Ball bearing) are used. A fan may have one or two bearings, and sometimes they combine different types- Sleeve and Ball. Fans with rolling bearings (ordinary ball bearings) are considered the most reliable. Manufacturing companies promise them continuous operation for 50,000 hours, which is more than five years, and those that use plain bearings promise to live no more than 30,000 hours, about three and a half years. Today there are already fans with ceramic bearings, which are promised almost immortality - 300,000 hours of continuous operation, and that’s thirty-six years! However, on the one hand, the stated life times of fans very rarely correspond to reality, and often they must be divided by two or even three, and on the other hand, believe me, a computer will not live for thirty-six years. You should expect that a regular fan can last a year or two. Then it starts to hum, and it needs to be lubricated, but even lubricant will solve the problem only for a while, and soon the fan will have to be replaced with a new one.
Some modern fans have automatic speed control, depending on the ambient temperature or radiator temperature. We will tell you about one of these at the end of the article. Almost all of them have a temperature sensor located directly on the fan itself and may not reflect the actual temperature of the object being cooled. That is, when the processor temperature rises, the cooler on which such an automatic fan is installed can only increase its speed after a couple of minutes. Another thing is fans with stop alarms installed on them. When the rotor speed drops below a certain limit, a special electronic unit on the fan wire emits a loud squeak, and you know for sure that it’s time to turn off the computer and replace the cooler.
Passive coolers
Passive coolers are ordinary radiators installed on the cooled object. They remove heat only by radiation, if they are not blown by any computer fans, and are used to cool low-power and small-sized elements, for example, memory chips or transistors. Radiators are installed today on video cards, some motherboards that do not yet have full-fledged coolers, memory modules, and in general on almost everything that needs to be cooled, and even on central processors if they have low power.
A special case of a passive cooler is a heat distributor. It looks like a “bald” radiator made from a plate, without ribs and with a small surface area. Heat spreaders are used today to cool system memory. In particular, Thermaltake produces special kits for DDR SDRAM DIMM modules. The disadvantage of heat spreaders, like passive coolers, is their low efficiency.
Active coolers
Coolers that operate by convection are called active. Simply put, this is a radiator with a fan installed on it. Most often they are used to cool processors. And today, when we say the word “cooler,” we mean, first of all, exactly them. Active coolers are used almost everywhere where cooling is required, replacing conventional radiators. The advantages of such cooling include significantly greater efficiency compared to conventional radiators. Active coolers are able to cool hot processors while being small in size. But fans are always a source of noise in computers, and sometimes vibration. Therefore, they only need to cool very hot elements, otherwise working behind a noisy machine will become unbearable. Another disadvantage of active coolers is that they are short-lived. The fan blades rotate, and sooner or later the bearings on the rotor will fail and it will stop. Naturally, in this case the cooled element will overheat and possibly fail. But more often than not, the fans begin to hum loudly before stopping, so you will be warned in advance.
Now that we understand the basics of computer cooling, we can move on to look at the heat sources in a computer and how to cool them.
What heats up in a computer and how does it cool down?
Well, having an idea about coolers, let’s now get a picture of what gets heated in computers and how (if necessary) it needs to be cooled. We'll start with the most basic element of any PC - the central processor. Today, processor cooling is given Special attention, and therefore every manufacturer of PC coolers necessarily has CPU coolers in its assortment.Processors
If we do not consider server and laptop computers (including laptops), today personal computers use processors from two manufacturing companies: Intel and AMD. They use three main platforms: Socket 370, Socket 478 and Socket 462 (Socket A). The numbers in the platform designation indicate the number of pins of each processor. Naturally, all these standards are not compatible with each other, and Pentium III for Socket 370 cannot be installed in a motherboard with any other socket. Until recently, the Socket 423 standard was also widespread for the first Pentium 4, but with the advent of the more modern Socket 478, it almost disappeared and is now being successfully forgotten. Each type of processor has its own cooler standards.
Socket 370 uses Intel Pentium III, Intel Celeron (except new ones for Socket 478) and VIA C3 processors. Processors made by AMD (Duron, Athlon on the Thunderbird core, Palomino and Thoroughbred) use the Socket A connector. Coolers for Socket 370 and Socket A are almost compatible with each other. More precisely, we can say that they are fully compatible, but this does not mean that you can install a cooler for an Athlon on a Pentium III. The fact is that although the Socket 370 and Socket A sockets have the same dimensions, the standards by which AMD recommends building motherboards differ from Intel’s. First of all, look at the photo. Socket A has three teeth on the front and back for attaching the cooler. Initially, it was assumed that more powerful coolers would be installed on Athlon processors, which would require a more rigid mount, and one tooth could break under the cooler spring. In addition, AMD recommended that motherboard manufacturers leave a so-called free zone to the left and right of the socket. There should be no elements in this area that could interfere with the installation of rectangular coolers longer than 55 mm (slot width). Thus, on Athlon and Duron processors you can install coolers with a size of 60x80mm and as high as your case allows. The Pentium III, of course, is unlikely to have such large coolers, but this again depends on the motherboard.
In addition, many motherboards for Athlon/Duron have four holes around the socket. This is another way to attach the cooler - not to the socket, but to the motherboard. On the one hand, it is more convenient, since the cooler will no longer fall off, breaking off a tooth, but on the other hand, to replace it or upgrade the processor, you will have to remove the motherboard. For better or worse, AMD recently stopped requiring four holes in the clear area near the processor socket, and all future coolers will be attached only to it, and not to the motherboard.
Athlon processors generate up to 73 W of heat when not overclocked. For powerful servers, such heat dissipation from the processor is common, but for desktop computers it is a lot, and besides, the area of the processor core is constantly decreasing, so coolers for modern processors actively use copper in their radiators. And on sale you can see coolers not only with aluminum radiators, but also with a copper base, or completely copper. Some manufacturers, trying to increase the efficiency of coolers, also coat the copper with nickel, silver or other materials with high thermal conductivity. Fans on such coolers most often have a size of 60x60x25 mm, although now widespread get 70mm and 80mm models. They have a lower rotation speed and are much quieter.
| CPU | Heat dissipation, W |
|---|---|
| AMD Duron 1100 | 51 |
| AMD Duron 1200 | 55 |
| AMD Duron 1300 | 57 |
| AMD Athlon Thunderbird 1400 | 73 |
| AMD AthlonXP (Palomino) 2100+ | 72 |
| AMD AthlonXP (Thoroughbred) 2600+ | 68.3 |
In the case of coolers for Socket 370, everything is much simpler: they all cling to two teeth of the socket and have dimensions that do not exceed the size of the socket. Typically from 50x50 to 60x60 mm. The heat dissipation of Pentium III processors is approximately half that of the Athlon, so they are easier to cool, and coolers with all-aluminum radiators or with a copper base are most often used on the Pentium III. They are cheaper than all-copper ones, which are also not necessary.
If we continue talking about Socket 370 and remember about VIA C3 processors, then we can completely forget about coolers. The fact is that VIA C3 have a reputation as “cold” processors, because they emit too little heat and can also work with passive coolers - ordinary radiators, or very simple coolers. For them, heat generation is not a problem, and therefore computers based on them operate very quietly.
Today it is more profitable to produce coolers for Intel Pentium 4 and Celeron processors for Socket478. The fact is that the market for Athlon coolers is already quite saturated, and besides, the prices for computers with AMD processors are low, and not every user is willing to pay dearly for a good cooler. The situation with Pentium 4 is completely different, since they are much more expensive than competitors from AMD, and coolers costing several tens of dollars can be sold to the high-performance processor market.
In computers with Pentium 4 and Celeron processors under Socket 478, the cooler is attached to a special rack on the motherboard. There is an opinion that Pentium 4 processors do not overheat at all. It is fundamentally incorrect, and the first Pentium 4 actually ran cooler than their Athlon counterparts, but now the power consumption of the Pentium 4 with a frequency of 2.8 GHz is around 64 W, and the Pentium 4 3.0 GHz promises to require up to 80 W. Of course, modern technological processes and the Pentium 4's design with a built-in heat spreader help it handle heat better, but it also requires a large cooler, just like the Athlon. True, boxed versions of processors are already supplied with coolers, but if necessary, you can find a wide range of coolers for Pentium 4 in stores.
Coolers for Socket 478 have basically one type of fastening: with two steel brackets they cling to the plastic stops of the motherboard and are firmly pressed against the surface of the processor. Sometimes the motherboard bends slightly due to too strong cooler springs, but by and large this is not a big deal. For computers using Pentium 4 in low-end or server cases, there are coolers that attach to the motherboard without using racks around the processor.
Just as is the case with some coolers for Athlon, the mount in them goes through holes in the motherboard (to do this you will have to remove the standard holders for the cooler) and is fixed on top of the processor. In this case, much less is supplied to the board exercise stress. Unfortunately, such coolers are not very common.
Coolers with various radiators are available for Pentium 4. There are both pure aluminum ones and those with copper bases, or all copper ones. Fans for such coolers are usually kept quiet, because their low performance is compensated by large sizes radiators. Although, loud models are also a common occurrence among coolers for Socket 478.
Every home has a lot of computer fans: CPU coolers, video cards and PC power supplies. They can be used to replace burnt ones, or they can be connected directly to the power supply. There can be many applications for this: as a blower in hot weather, ventilation workplace from smoke when soldering, in electronic toys and so on.
Fans usually have standard sizes, of which the most popular today are 80 mm and 120 mm coolers. Their connection is also standardized, so all you need to know is the pinout of the 2, 3 and 4 pin connectors.
On modern motherboards based on the sixth or seventh generation of Intel processors, as a rule, only 4 pin connectors are soldered, and 3 pin connectors are already a thing of the past, so we will see them only in older generations of coolers and fans. As for the location of their installation - on the power supply unit, video adapter or processor, this does not matter at all since the connection is standard and the main thing here is the pinout of the connector.
4 pin cooler wire pinout
Here the rotation speed can not only be read, but also changed. This is done using an impulse from the motherboard. It is capable of returning information to the tachogenerator in real time (the 3-pin one is incapable of this, since the sensor and controller are on the same power line).
3 pin cooler connector pinout
The most common type of fan is 3 pin. In addition to the negative and 12 volt wires, a third, “tacho” wire appears here. It sits directly on the sensor leg.
- Black wire - ground (Ground/-12V);
- Red wire - positive (+12V);
- Yellow wire - revolutions (RPM).
2 pin cooler wire pinout
The simplest cooler with two wires. The most common colors: black and red. Black - working negative of the board, red - 12 V power supply.
Here the coils create a magnetic field, which causes the rotor to spin within the magnetic field created by the magnet, and the Hall effect sensor evaluates the rotation (position) of the rotor.
How to connect a 3-pin cooler to a 4-pin
To connect a 3-pin cooler to a 4-pin connector on the motherboard in order to be able to programmatically adjust the speed, use the following diagram:
When a 3-wire fan is directly connected to a 4-pin connector on the motherboard, the fan will always rotate, because the motherboard will not have the ability to control the 3-pin fan and adjust the speed of the cooler.
Connecting the cooler to the power supply or battery
To connect to the power supply, use standard connectors, but if you need to change the number of revolutions (speed), you just need to reduce the voltage supplied to the cooler, and this is done very simply by rearranging the wires on the socket:
This way you can connect any fan, and the lower the voltage, the lower the speed, and therefore the quieter its operation. If the computer does not get very hot, but is very noisy, you can use this method.
To power it from batteries or rechargeable batteries, simply connect the plus to the red wire and the minus to the black wire of the cooler. It starts to rotate at 3 volts, the maximum speed will be somewhere around 15. You cannot increase the voltage any more - the motor windings will burn out from overheating. The current consumption will be approximately 50-100 milliamps.
PC cooler installation and repair
In order to disassemble the fan, you need to remove the sticker on the side of the wires, opening access to the rubber plug, which we remove.
We pick up the plastic or metal half-ring with any object with a sharp end (a stationery knife, a flat-head screwdriver, etc.) and remove it from the shaft. The view reveals a motor operating on direct current using a brushless principle. An all-metal magnet is attached to the plastic base of the rotor with an impeller in a circle around the shaft, and a magnetic circuit on a copper coil is attached to the stator.
Then clean the hole under the axle and drop a little machine oil there, put it back together, install a plug (so that dust doesn’t get clogged) and continue using the much quieter fan.
All such fans have a brushless rotation mechanism: they are reliable, economical, quiet and have the ability to adjust the speed.
In modern coolers, the connectors are much smaller, where the first contact is numbered and is “minus”, the second is “plus”, the third transmits data about the current rotation speed of the impeller, and the fourth controls the rotation speed.
It is a simple design, usually consisting of a brushless DC motor and impeller blades that are driven to move air masses. This device has long become a standard component in modern cooling systems, but various technologies and principles are still used for the production of fans. In this material we will try to understand one of the most frequently asked questions regarding these seemingly banal components: the type and characteristics of bearings.
You may have seen manufacturers indicate the word brushless on cooler packaging in relation to the type of fan used. But what is the meaning of this designation? To understand this, you must first understand how a brushed electric motor works.
In the simplest case, the so-called commutator DC motor (we repeat the phrase “direct current” again, since it is DC, Direct Current, that serves as the power source for computer fans) is a kind of metal cylinder around which a copper wire is twisted. In more correct language, this pair should be called a rotor with a winding. A shaft is fixed to the cylinder, and together this connection is movable. Thus, when the cylinder moves, rotation is transmitted to the shaft, which, in turn, can already be connected to the following movable components of the system. In particular, it is on the shaft that the impeller of the coolers we are interested in is fixed.
When energy is applied to the windings of a previously neutral cylinder, it turns into an electromagnet, generating a magnetic field between two poles (called north and south). In addition, two magnets with opposite polarity (polarizing magnets, stator) are additionally placed around the motor. At a time when the magnetic field generated by the working electromagnet turns out to be opposite to that created by static magnets, the motor begins to move; a pair of Ampere forces acts (after all, the same magnetic poles repel each other, and opposite ones attract). We have displayed this First stage in the first picture.
However, with the configuration described above, after a rotation of 180 degrees, the cylinder along with the shaft will again come to rest, stopping movement; the system will be in equilibrium.
It turns out that in order to further rotate the motor, it is necessary to invert the polarity of the working electromagnet. In this case, the magnetic field generated by the motor will be reversed, and the cycle with a rotation of 180 degrees until it stops (as in the first step) will be repeated.
Thus, in order to make the motor rotate constantly, a mechanism is needed that would automatically change the polarity of the rotor. The simplest and cheapest solution to this problem is a brush-collector unit. Such units can be technically complex, but for simple example It is enough to consider a motor in which the movable part is connected to a stationary source of current through a pair of brushes. They are located at the ends of the rotor winding and come into contact with the commutator contacts every time they turn half a turn, thereby inverting the polarity. It is worth noting that the brushes got their name because of the first, not very durable and reliable implementations of the idea of sliding contacts. The stages of motor operation described in this paragraph are shown in the following image:
Naturally, the above description is greatly simplified; There are much more complex engines, but the very principle of commutator motors remains unchanged in them. Unfortunately, electric motors operating in this way are not very suitable for personal computers: their service life leaves much to be desired, as does their reliability when rotating on high speeds, not to mention high level noise and the possible occurrence of a spark when the brushes come into contact with the commutator. Such motors are not uncommon in professional electric tools, where brushes are often a consumable item.
In this scheme, the fan or cooler of the cooling system is controlled by a thermistor signal for a specified period of time. The circuit is simple, assembled with only three transistors.
This control system can be used in a variety of areas of life where cooling by means of a fan is necessary, for example, cooling a PC motherboard, in audio amplifiers, in powerful power supplies and in other devices that may overheat during operation. The system is a combination of two devices: a timer and a thermal relay.
Description of the operation of the fan control circuit
When the temperature is low, the resistance of the thermistor is high and hence the first transistor is turned off because the voltage at its base is below 0.6 volts. At this time, the 100 µF capacitor is discharged. The second PNP transistor is also off, since the voltage at the base is equal to the voltage at its emitter. And the third transistor is also locked.
As the temperature increases, the resistance of the thermistor decreases. Thus, the voltage at the base of the first transistor increases. When this voltage exceeds 0.6 V, the first transistor begins to pass current, charging the 100 uF capacitor and applies a negative potential to the base of the second transistor, which opens and turns on the third transistor, which in turn activates the relay.
After the fan turns on, the temperature decreases, but the 100uF capacitor discharges gradually, keeping the fan running for some time after the temperature returns to normal.
The trimmer resistor (shown as 10 kohm in the diagram) should have a resistance value of about 10% of the thermistor resistance at 25 degrees. Thermistor used is EPCOS NTC B57164K104J at 100 kOhm. Thus, the resistance of the substring resistor (10%) is 10 kOhm. If you cannot find this model, you can use another one. For example, when using a 470 kOhm thermistor, the trimmer resistance will be 47 kOhm.
Connection diagram for a fan powered by 12 volts.
Connection diagram for a fan powered by 220 volts
IN printed circuit board you can see two trimming resistors. The first is at 10 kOhm to adjust the fan threshold, the second at 1 mOhm allows you to adjust the operating time after the temperature has normalized. If you need a longer time interval, the 100 µF capacitor can be increased to 470 µF. The 1N4005 diode is used to protect the transistor from inductive surges in the relay.