How to connect a fan with three wires

Connecting the cooler to a PSU or battery

If you want to change the speed. you just need to decrease the supply voltage to the cooler, and it is done very simply by changing the wires on the socket:

connect, wires

You can connect any fan this way, and the lower the voltage, the less speed and therefore the quieter it runs. If your computer is not too warm but gets very noisy, you can use this method.

To power it from a battery or battery pack, simply connect the plus wire to the red one and the minus wire to the black one. It starts rotating at about 3 volts, the maximum speed will be about 15. It is not allowed to increase voltage more than that. motor windings will burn out from overheating. The current consumption will be about 50−100 milliamps.

The correct installation of coolers in the system unit

Once the coolers are selected and purchased you can begin to install them in the system unit. For proper installation, it is important to understand how the air moves inside the computer and how the coolers will affect it.

Convection causes the hot air itself to rise to the top of the case, and to maximize cooling, coolers must be installed to take advantage of and amplify this natural air movement, rather than to counter it.

Therefore, traditionally the top of the case coolers are installed on the blow out, this allows the heated air to be removed from the case.

pin cooler pinout

The simplest two pin cooler. The most common colors are black and red. Black is working “minus” of the board, red is 12V power.

Here, the coils create a magnetic field that makes the rotor spin inside the magnetic field created by the magnet, and the Hall sensor evaluates the rotation (position) of the rotor.

How to connect a fan in the bathroom | Electrician’s notes

How to choose a fan for the bathroom

I chose a fan for the bathroom according to the following criteria.

It has long been known to all that the high level of noise over a long period of time causes a harmful effect on the person.

It turns out that the noise level of a fan during the daytime (7 a.m. to 11 p.m.) should be within the range of 23-58 (dB) and at nighttime (11 p.m. to 7 a.m.) within 13-50 (dB) at average frequencies of 63, 125, 250, 500, 1000, 2000, 4000 and 8000 (Hz).

By experience I can say that all the fans with a noise level of 35-40 (db) is quite acceptable for the installation and no discomfort do not create.

The design of the fan is directly related to the place of installation and the size of ventilation shafts.

The duct of the ventilation shaft is in a corner of the bathroom. I have already covered the walls with moisture-resistant drywall, and the through hole in the shaft (outlet) is cut in the wall a diameter of little more than 100 (mm).

Accordingly, I need a wall-mounted fan with a flange diameter of no more than 100 (mm).

How To Convert A 3 PIN Into A 2Pin Fan

By execution fans are divided into: axial, centrifugal, radiator, duct, roof, etc.д. I will not go into details of their differences and uses, you can read about it on other specialized sites.

My choice was an axial fan, t.к. they are easy to install, have good performance and reasonable cost.

In my article about installing outlets in the bathroom, I told in detail about the zones into which this room is divided. I recommend that you go to the above link and read in detail about them in detail.

For my bathroom we use the case of the shower with a tray, but without the stationary partition.

Let me explain, in the corner will be installed bathtub, and on the wall. a watering can of the rain shower. A little further will be installed sink.

The fan will be located on the opposite wall at a distance of 1.5 (m) from the edge of the tub and 0.75 (m) from the edge of the sink, so the third zone applies. In this regard, the degree of protection of fan’s casing should be no lower than IPX1, or better yet IPX4.

Modern fans are equipped with many useful, and sometimes useless, functions of automation, such as the presence of built-in electronic timer, humidity sensor, motion sensor, phototimer, remote control capabilities.

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Initially, I planned to buy a very simple fan, but thinking about the convenience, comfort and economy decided that the fan will be controlled by a timer, so I looked at models with electronic timers.

To power it from batteries or accumulators, simply connect the plus to the red wire and the minus to the black wire of the cooler. It starts to rotate at about 3 volts, the maximum speed will be about 15. You can’t increase the voltage more than that. motor windings will burn out from overheating. The current consumption will be about 50-100 milliamps.

So, the question “why are there three contacts in the cooler” can be answered that the first two are plus/minus power, and the third wire performs a signal function: either transmits information about the emergency stop rotation (R type) or transmits the frequency of rotation (F type) yellow. signal wire.

Every home has accumulated a lot of computer fans: coolers from the CPU, graphics cards and power supplies PC. They can be put to replace a burnt-out one, or you can connect them directly to the power supply. This can be used a lot: as blowing air in hot weather, to ventilate the workplace from the soldering smoke, in electronic toys, and so on.

The fans usually have standard sizes, of which today the most popular are 80 mm and 120 mm coolers. Their connection is also standardized so all you need to know is the pin-outs of the 2, 3 and 4 pins.

On modern motherboards based on sixth or seventh generation intel processors, as a rule, only 4 pin connectors are soldered, and 3 pin connectors are a thing of the past, so we will see them only in older generations of coolers and fans. As for the place of their installation. on the PSU, video adapter or processor, it does not matter, because the connection is standard and the most important thing here is the connector pin.

In the starter panel, connect the power cable to the circuit breaker and lead to the junction box. From where the lighting fixture is installed, lead another piece of wire to the junction box as well.

Important! Switch off the power supply before you do any work on the electrical system! This is done with the help of fuses in the switchboard.

Important to know! Wire stripping is different between a surface-mounted switch and a flush-mounted switch. In the latter case, it is necessary to leave a reserve of about 10 cm of wire to strip it, place it smoothly in the terminals and then recess the mechanism in the socket. When installing a surface-mounted one, the wires should be trimmed strictly under the switch.

Wiring diagram for a single-handed switch

Important: the connection of wires in the junction box is made by twisting. You can use the long nose pliers to hold the wires at the base and twist the ends into a spiral.

Important: it is not necessary to put plastic elements simply on strings, but to apply a small effort to press wire ends in a metal part of the cap. This helps to achieve a better contact at the joints.

The pinout of a computer 3-pin cooler

The size and connection options for PC fans have long been standardized, they differ only in the presence of connection cables. Gradually, 3-Pin coolers are giving way to 4-Pin, but such devices are still used. Let’s look in detail at the circuit diagram and the pinout of the mentioned part.

Electronic scheme

In the following screenshot you can see a schematic representation of the electrical diagram of the fan in question. Its peculiarity is that besides plus and minus there is a new element. tachometer. It allows you to monitor the speed of the blower, and it is attached to the foot of the sensor itself, which is shown in the diagram. Note the coils. they create the magnetic field responsible for the continuous operation of the rotor (rotating part of the engine). In turn, the Hall sensor evaluates the position of the rotating element.

Color and meaning of wires

Companies that make fans with 3-Pin connections may use different colors of wire, but the ground always stays black. The most common is a combination of red, yellow and black, where the first is 12 volts, the second is 7 volts and goes to the tachometer pin, and black, respectively. The second most popular combination is green, yellow, black, where green is 7 volts and yellow is 12 volts. However, you can see these two pinouts in the image below.

Connecting a 3-Pin Cooler to a 4-Pin Connector on the Motherboard

Although 3-pin fans have a RPM tracker, they still cannot be adjusted via special software or BIOS. This function only appears in 4-pin coolers. However if you have some knowledge in electrical circuits and know how to hold a soldering iron, pay attention to the following schematic. This is used to modify the fan and after connecting it to the 4-Pin you can adjust its speed via software.

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If you are interested in a simple connection of a 3-pin cooler to a motherboard with a 4-pin connector just plug the cable in leaving the fourth pin free. This way the fan will work fine, but the spinning will be static with the same speed always.

The pin assignment of the considered element is not something complicated due to the small number of wires. The only difficulty arises when encountering unfamiliar wire colors. Then you can only check them by connecting the power supply through the connector. When the 12 volt wire is matched to the 12 volt leg, the rotation speed will increase, when you connect 7 volt to 12 volt it will be less.

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Good afternoon! Very helpful and informative article. I have two 3pin power supplies, one on my motherboard (auto volt regulation) and one on a rebox (manual regulation) with separate molex power supply. The task of switching the fan power line with the button from one circuit to another. Button for 3 groups of contacts, 2 in the On-On position (ideally, the same switch for 3 groups of 3 contacts, but it is a curiosity, it is difficult to find). Actually switching circuits GRD12 is not a question, the question is the tachometer sensor linet.к. there is no group on the switch, is it safe to combine (twist-solder) the tachometer line from both three-pin sources and the fan tachometer line? When switching circuits, won’t there be a logical physical conflict just on the tachometer line? Т.е. tachometer lines are connected by a switch, switch the circuit from the mother to the fan for automatic adjustment. does the mother see the speed and whether it is not affected by the fact that the same line goes tachometer signal from re-obas (currently powered off at the switch, but with power on the pins from molex) and vice versa when you switch to re-obas? My first thought was that there shouldn’t be a problem, like the switch cuts off the incoming voltage from the reobass to the fan, but I read the article and noticed that the tachometer line is connected to 7, which, as I wrote above hangs power from the molexhere the thought process came to a standstill1 Please help if possible!

Nowhere have I found an answer to the question: is it possible to make the 3-pin fan rotate always, without control. like 2-pin ? My laptop doesn’t spin for some reason (no mechanical reasons), HDD overheats.

Hello Jack. If it is the only cooler that is installed in your laptop, you can not set its continuous rotation mechanically. This can only be done with firmware from official laptop manufacturer or with auxiliary software. Have you tried it this way? No effect? If the cooler refuses to spin at all, most likely the problem is really mechanical or it is disabled in the BIOS / UEFI. Check the software first, and if that does not help, it is worth disassembling the laptop and look at the cables and clogged fan. If possible, contact a specialist for further diagnosis and repair.

I should add that it seems to me that almost all coolers in laptops are made in the same way, with the exception of powerful gaming models. They apply to the entire motherboard, but the drive gets the least amount of cooling due to its location. Check if the fan is away from the SSD or HDD, even continuous operation will not cool the component. Here you need to clean the laptop from dust, do not use it, for example, on a bed, laying on a blanket. You can also buy an additional stand with two or three knobs, which provide air circulation across the surface of the device.

Thanks for the answer, but that’s a little off. I know, and it was a question: what is software controllable? pin to give a signal simulating control to get the maximum speed. No mechanical problems, I wrote’l. it spins easily. I have been planning a stand with fans for some time, but it is still unclear if I will manage to do it in time, or if my notebook will be sooner.

You can’t mechanically send the signal to this pin, maybe you can change the control board, but I don’t know anything about electronic circuits, so I can’t tell you anything about it. And it’s better not to do it that way, otherwise if something happens it will be a problem to find a suitable replacement for a broken cooler.

Hello. You need to replace the fan on the power supply. Gradually 3-pin coolers are giving way to 4-pin, but such devices are still in use. Not only that, they are also used 2-pin The difficulty is that we can not find such fans now Is it possible somehow to put a 3-pin connector in the 2-pin ? I think you can, after reading this article of Victor: just leave the side 7 volt pin aside (not connected) and get a static torsion at the same speed, and I do not need anything else, just would guess the direction of rotation Am I right ?

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Hello Yuri. Yes you are absolutely right. This way of connection should definitely work, but I can not help you with the direction of rotation, because you have to look at the device to understand the location of the pins. Here I can recommend just by testing the connection in different directions to find out which way the cooler will rotate, and then leave it as it will be needed. If it does, you can even leave the 12 volt pin free instead of the 7 volt pin to slow it down if you need to, of course. But it would be hard to do, because most of the time the 12 volt pin is in the center of the cooler.

Thank you Viktor for the article and response, I will try it, I don’t need less speed, it blows my mind

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Guys, who can clearly tell me why the yellow wire on the cooler? Google did not help much, here is the exact answer where to put it. I have a small cooler on my computer but it has two wires (red and black) and it is loud. I bought a similar sized cooler, only with three wires (red black and yellow). So where do I put the yellow one to make the cooler work? I read that if you don’t plug it in, it won’t start at all

17 Owners Комментарии и мнения владельцев and opinions on “ Who can tell me clearly why the yellow wire on the cooler ”

speed control. speed reader. don’t connect it. don’t need it.

did you try to connect only two wires? Red and black? If it is working fine then why connect it somewhere. If it does not work best to ask where you bought the new cooler.

You guys google shit! The yellow one sends speed information. Doesn’t change it, it’s a fourth wire.

I just plug the plug from the cooler into the motherboard’s FAN connector and don’t bother if there is a free

will start and run at full speed and make noise

Cool, some Chinese make the speed control to red and power to yellow (I have one)

RPM sensor is. The speed is changed by the supply voltage

Maxim, the cooler on the 3 pin does not change the speed, only on the 4 pin

Eugene, I did not say that the speed is changed by 3 pins. I said it is the RPM sensor

Maxim, You said the revolutions are changed by the red wire. In pin 3 it is 12

Eugene, they do. but not the 4 pins

By myself, I haven’t met any motherboards that change the speed of the cooler on pin 3

Eugene, then you’re ahead of the game.

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Fans with two wires have a standard connection to power and ground. The three-wire version adds a tachometer to the standard pair, which returns a signal with a frequency proportional to the speed of rotation. The fan connected by four wires is also provided with PWM. In short, PWM is a system to control the level of power supplied to the fan motor by varying the relative pulse width of the circuit.

Control the speed of the fan, connected only by two wires, can be linear (by changing the supply voltage), or by low-frequency PWM. However, since this fan has no feedback (tachometer), it is not possible to know how fast it rotates or if it rotates at all. Because, in fact, the control circuit in this case remains open.

The three-wire fan can be controlled in the same way as the simpler version with two wires. by DC or low-frequency PWM. The difference between the coolers with 2 and 3 wires will be in the presence of a tachometer in the latter, so the control circuit will be closed, and with the help of a revolution sensor will be possible to determine both the speed and the fact of rotation of the blades.

20V cooler connection with speed control

The pinout or pinout is a description of each pin of the electronic connection. As you know, it is quite common in electrical appliances to connect equipment where its correct operation is ensured by several wires. This also applies to computer coolers. They have a different number of contacts, each one is responsible for a different connection. Today we would like to talk in detail about the pinout of the 3-Pin fan.

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