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The ins and outs of a 4-wire computer fan.
Used 4-wire fan for these two projects:
Temperature Feedback Control: • (#0038) Temperature Fe...
Air-Speed Feedback Control: • (#0040) Air Speed Feed...

[@terryheimerl8674]

Just watched this on 11/05/2024 and it is the only video I have found that comes close to explaining 4 wire operation. Thank you. Terry from Australia.

[@nadirabbas4402]

21may2024 from Pakistan

[@blackturbine]

Finally A person that explained a 4 pin fan in a simple and efficient way that everyone can understand

[@Seadogstudio]

Black turbine short and sweet. Really great.

[@vanmanmarc]

I struggle to learn things, even things I want to. This tutorial was easy enough for me to understand. I haven't looked at a circuit diagram since I was at school, over 25 years ago. Thank you for putting this video out there so the likes of me can tinker with out having to spend time working it out.

[@michaelgasperik4319]

A 10 year old video and it's still the best 4 wire fan tutorial on the internet! Thanks buddy

[@zachary4225]

Man it’s 2023 and this video is still gold! Thank you

[@325iaddict]

This wasn't just a BIT helpful... it learnt me all I ever wanted to know in just over 6 minutes. The best spent minutes today!! Thank you very much for this clear and detailed description.

[@ihatesignupsgrrrrrrr]

Only thing lacking is the description for people who can not watch the video or hear the audio :/

[@442jetmech]

It's a six-year-old video, but I just wanted to let you know that you helped solve my problem as well. Thanks for the very clear video and the drawing.

[@kalliebronner2330]

Thanks for all the info it helped alote. I used a 50k ohm potentiometer between the blue and black wires and works perfectly. Your videos is 7 years old and still comes in handy.

[@ElectronicTonic156]

You're welcome! I've taught myself a lot of useful tidbits of information over the years and I'm happy to share it.

[@rodriguezfranco3839]

When are you going back to make videos ?? Please we need more 🙌🙌

[@truthful3777]

You are life Saver.. I just order a fan from Farnel and got a 3 wire fan.. I was like what?? My amplifier need a 2 wire fan.. A check on data sheet reveal sensor.. Its so misleading as i thought connet to a thermistor to control speed fan but in actual fact it is a open collector tachometer. By watching your video, my worries gone and i knew exactly what to do. You save time and effort to experiment and might blew up the fan or give up as that yellow wire is not an input but an output.

[@EZDinero]

It's 2024 and this video helped me out. Man i love KZbin University. Thanks professor. 👍

[@kiwigurn]

Ditto😊

[@PoeLemic]

Wonderful video. I watched -- just to get a better understanding. Used these forever in 3 pin on my computer, but I was wondering how 4 pin worked. Well, you knocked out of park on this.

[@matambale]

Best explanation of 4-wire muffin fan operation and use since the 4-wire muffin fan was manufactured. Thanks!

[@justinhall3073]

Man!... Thank you! Working on a lap top stand project and had a ton of these old fans around. I'll be using them hard wired at low speed to reduce noise... You're video was sound, thorough and has saved me a ton of time

[@karlbe8414]

Well, you answered my question of what the blue and yellow wires do. I just soldered up a 5" maglev fan that is rubber mounted in a cowling, attached to a ~4" 2x4 for a window cooling fan. I used a power supply that has a switch for 2 -12 volts. Used just the red and black wire. Switching volt switch gives me 4-5 different speeds. Very quiet and energy efficient for those 5 hot nights per year. EZ peezy!

[@vinnychose2435]

thank you. very clear instructions. even 10 years later you're helping people!

[@DiscoPumpkin]

I can't thank you enough! You have no idea how much time I spent looking for this answer!

[@TheOldKid]

Im sure the diagram and explanation seems simple to those more familiar with circuits but im pretty green in this area. To have pwm control of the fan would i connect blue and ground to potentiometer?

[@ElectronFunCom]

Great, informative video! Until now I couldn't find much on the 4-wire fans, thank you very much! I've just subscribed :)

[@derekvanderbyl4]

Brilliant explanation, thanks. Was about to strip the fan and try reverse engineer, this was very useful!

[@eliasmagallanes7884]

Amazing video, you solve my problem!! I was measuring the tachometer output without a pull up resistor, therefore didnt existed a signal in my oscilloscope. Thanks for this video!!

[@ElectronicTonic156]

+Elias Magallanes Glad to help!

[@oklachick007]

Elias Magallanes ii

[@nitroboom1282]

This was so helpful! Thank you for posting this I would’ve never known how to use the blue wire ❤

[@bobharrison9620]

Very old Vidio, Very old computer, Very old man. Thank you.. Now I need to make it work. 4 wire 12v 140mm fan in the front of a box pulling air in and have a 3 wire 5 volt motherboard supply.. What a mess I just want it to play old games.. This has been more than a game... Thank you. Bob

[@danbrit9848]

omg omgomg...thank you so much ...ive wanted to connect my fans to a car tach for a long time...and you gave me the key to it ...thank you

[@Xperto_]

Finally a good informative video on fans!

[@LucasGarrow]

Thanks for getting this info out there. I've found that connecting the blue to black makes minimum speed, but also connecting yellow to blue a slightly higher speed.

[@tayro7265]

Put a pot between the Sig/PWM in and the Tachometer out. The Tachometer out will provide PWM. The pot will give speed control.

[@galenbean3606]

Hooking tach output to speed input results in 50% speed ( 50% duty cycle). Speed control : at ground = Min, connected to tach output = Med, left open = High.

[@hightttech]

Excellent. Just what i needed. I need to test 4-wire refrigerator fans by LG, and information is scarce.

[@alexgray552]

Thank you - just what I needed. A clear explanation - good job!

[@shvideo1]

Thank you for this great informative video. Very well explained. I just pulled out a CPU cooling fan from an old HP laptop that has 4 wires and was wondering how to get it working.

[@maxpolaris99]

Love the calculator, I had a TI that looked just like it circa 1979. Can't remember the model # it was a scientific that came with a cool learning book.

[@matter45]

yep, not alot of info out there or google search inconclusive. Thanks Eric for the schematic, it was what i was looking for. Recently had a 4 pin fan controlled via pwm. worked at first, then strange behavior. Cheers Eric

[@neilburris1314]

Still useful years later - Thanks

[@claytontanner7631]

Follow up on running it slower with a 9v is because of vibration btw the fan is rated at 3000rpm so running it at 3/4 of the speed will be suffice if this method will work. Any feed back will be considered

[@rangorangila1306]

i have a computer fan with 4 wires white blue red and black. red and black give full speed. Accidentally when i short white and blue wires the speed went lower to my requirements. But i m not sure if would be safe for the fan or supply. I am still looking for the answer. A little education will be appreciated. Thanks for the detailed video.

[@theblogfather]

Excellent. Thank you. I couldnt find the spec sheet for my fan, so this helped me figure it all out.

[@Jorgem1010]

I have a question? I have been using a 12 VDC fan and a 12 VDC really both connected to turn on 110 V compressor. This is used for a fridge. Well now this company which makes refrigerators I won’t say its name has installed a four cable fan and now it says it’s a 13 V fan. So I’m having issues because the fan stays on so the compressor stays on. So I’m wondering if there’s anything else I can do. I need the compressor to turn off when fan turns off and on.

[@wadestanfill8756]

Thank you so much. I have a couple of these and had no understanding. Now I can use them.

[@stevecha3612]

Wondering if you can help troubleshoot, I replaced a fan with another one that should have the same specs (12v and 4 wire PWM). On the new fan I had to splice a new connector on the 4 wires so that it could plug into the original harness plug. My problem is that the fan just seems to spin a it’s minimum RPM at all times. The other original fans that are operating at the same time are either off or running at some variable speed but this fan just runs at a slow speed during all situations. Is it possible that the tach and pwm wire backwards and need to be flipped?

[@user-ki3yl3pc9b]

i have a 4 wire fan that is a sort of smart fan with load sensing in it and i dont know how to get it out of idle. red and black wires are powered but the full output of the fan is not met when i put the right power

[@lesleywhite7052]

computer fans usually require at most 0.38 amps at 12 volts i made a desk fan to keep me cool 2x 120mm thunder blade pc fans connected to a pwm dimmer circut for leds powered by a 12v 1 amp adaptor. works great

[@piezoe]

Great. Thanks for the schematic. All I needed. Hard info to come by info!. Thank so much. Most useful Video on computer fans on the internet! Nothing beats a good schematic!!!

[@mk00.01]

Still helps in 2019..thank man

[@d74g0n]

you explained this best. But unless i missed something, the two wire running on pwm; that isn't built for it; is just using the pwm signal as a tiny dc input. But your comment on modulating it on and off is interesting as a speed control method for dc fan... but that's also the same way you start a fire, once you've gained access to any toggle controlling electricity in the hacker world, so I'd be leary of longevity.

[@WolferAlpha]

When connecting the PWM control wire to the GND it sets the minimum speed if using a potentiometer to vary the resistance between the blue wire and the GND would this have the same effect as the PWM?

[@naronghome1968]

This is what the crip that I searching for. Thanks guy.

[@Cesar_III]

Good explanation. Tachometer is open collector, and the PWM can go up to 100kHz, thanks for that. But colors can confuse a little bit: I have a 3-wire where yellow is 12V and red for tachometer, it may be due to the use of yellow for 12V and red for 5V in the PC power supply.

[@brunoabdo8991]

Mate, thank you so much! It was the only well explained video about the 4 wires fan.

[@sajeevsankaran4406]

Thankyou, straight to the point.

[@sambalsamurai9672]

Very informativ thanks! How about 4-PWM fans that have a Black Blue Yellow and Green wire (EverFlow notebook Fans especially) which wire corresponds to which? Is the Green the Red wire??

[@ixamraxi]

On the two wire, why would you PWM at such a low frequency? Most of the time you want to PWM at above 15khz to ensure that its outside the range of human hearing, and at such high frequencies you get better averaging of the voltage output. Doing 1hz to 100hz seems like a recipe for frustration.

[@josephcoylejr.5236]

Very interesting, and helpful. I’ve been playing with fans and basically hooking up my PWM to red and black with some control but it does not work as well as I was hoping. I see it looks like you have the ground from your signal generator going to ground on fan, you have red and black to DC power. You have the blue hooked to the red on your signal generator. I’m about to go try this in my cheap little fans first and then I’m going to attempt it on my big expensive fan. I had been wanting to use the yellow on my frequency meter on the fluke 115 that should give me the RPM frequency/2

[@vahagnmelikyan2906]

There is a 12v dc air conditioning compressor that has 3 wires attached to controller. And some yellow wire coming out from controller saying TX. I wo Der if that's compressor variable speed controller it has 5v positive signal even though the compressor is at 12v.

[@charlesmoradi4057]

I have a 60mm 4-pin fan (12V 3.3A), and I am trying to have the fan always running at a lower speed when the PSU is switched on but I want to increase RPM as the temp increases. Can I do this with one of those Amazon thermostats? Alternatively, I could just run it as a 2-pin and use a thermal switch that completes the circuit at a certain temp, but it will operate at 100% RPM... Any help would be appreciated:)

[@chrisloach9658]

Do I need to use PWM or can I use a variable resistor of some sort?

[@mahiislam4599]

can you please told me any low cost circuit or simple way for controlling 4 wire cooler.(i am a begineer.)

[@shvideo1]

Such helpful information. Excellent job on this video. Thank you very much for sharing.

[@vinna2k884]

I've a dozen of cooling fans like these but its bigger got from an cell tower scrap..now I can do something

[@javiergarciaprieto3769]

Este video es muy interesante, te agradezco tu ayuda, me sirvió para resolver algo que debía hacer rápido. Muchas gracias.Eric Wssatonic.

[@Paul-uf2ou]

Thanks for that info, very very helpful easy to understand.

[@majesticcarpetcleaning4296]

So could I run the fan with just the ground and positive wires??

[@justDIY]

Great video. Straight to the point with a clear explanation, thank you!

[@DoubleDeeYT]

I'm still slightly confused. Could I just plug positive and negative into a 9v and the fan runs at a slower than fastest speed; then 12v power for full speed. Or do I have to have the speed controller one plugged in to something appropriate?

[@jp040759]

These are brushless DC motor fans. They are not like your standard permanent magnet toy hobby motor. You might see some variance in speed but it is not the way to control them.

[@elnywidjaja9885]

Thanks for the info. Need your advice how to install multi 3-pin fans to power supply at home? The purpose is not installation in PC.

[@ncsrelease647]

I have 3 wire fan (red/black/grey) the grey is Positive or negative

[@filter4now]

The output of the tach (yellow) wire is a true square wave? When I first played around and found it was 2 pulses / revolution I always thought it was just tied to one of the 2 poles and sensed every time it rotated around. Thanks (makes sense digital electronics don't like sine waves)

[@naumanahmadtariq8717]

I connected a 12 volt dc supply to the blue and yellow wire and the fan runs at full speed. Thats really confusing.

[@claytontanner7631]

I plan to use a four wire to cool my telescope but I plan only to use the ground and hot wire. In conjunction with a 9 volt direct in order to run slower would this work or should I get a eight battery connector to do the job?

[@TheAussieRod]

My fan has 4 black wires. How can I find ground and voltage?

[@khanscombe619]

So can I safely control the additional fan speed of a 3 pin fan on a 4 pin motherboard by adjusting the 4th open pin out to ground? Can I create a 3 speed switch to it? My Mobo keeps the Noctua 4 pin fans down to 350rpm (feels too slow & ASUS monitor puts it in red) and I can handle 1000 on my SilverStone 3 pin & still be quiet.

[@gmax341]

Will this work with a car cooling system? I already have the system installed to replace the bad radiator fan and the project works great but I only have one +12V wire to work with and the vehicle supply's a High and Low wire plus ground. I have what I believe to be the low speed wire connected to the fans PWM wire but nothing ever happens. The fans only turns on when the high wire is on. I was thinking of connecting both low and high together but I did not want current returning back to the cars system as not designed. Possibly the relays will prevent this but I don't know if it is set up that way.

[@yesayadanu]

29 dumb person dislike the video. thumbs up for me. really helpful. you're so right, there isn't much info about how the PWM fan really works. it helps alot since i've got a Nidec Ultraflo for my server but the seller cut off the connectors, so i really need to know which color cable is which. this helps clear things up.

[@Therium007]

Excellent! So I bought a replacement fan for my Laptop, but turns out it is a 3 pin (Red, Blue, Black wires) that I have to swap with the plug from my old fan that fits the socket (Red, Blue, Yellow, Black). Except I will leave the Yellow empty. Being that the Yellow wire is only for the Tachometer am I right in assuming that there will be no ill effects leaving this wire out of the equation? I've also read/seen elsewhere that this solution will leave my fan running at maximum speed constantly - which is fine by me as it seems that my laptop needs to be well ventilated anyway. Any suggestions, comments, warnings? Thank you all!

[@BluntForceTrauma666]

*_Oh man, check out that vintage TI-55 scientific calculator!_* A few years ago, I stumbled across the one that my sister used in college. Just for giggles I plugged it in and it actually held a charge - I couldn't believe it. Oh well, one day some millenial will drop by and poke fun at my trusty HP-48SX that I still use every day...

[@josephellsworth4537]

Very helpful. I would have expected the PWM input to work with a TTL signal but if what you say is correct then you would destroy a TTL component because voltage would ride at above 5V. I think it means the same for the Tac. It seems like this would waste power continuously because it will be drawing power through the PWM drive circuit to keep it at ground level when powered off. Am I interpreting this correctly?

[@robloxgamer10146]

THX MEN YOU SAVE MY CPU NOTEBOOK ASUS A LOT OF PAINE CHIP CONTROL FAN DIE AND STILL WAS ON LOW SPEED RISING TEMP OVER 54C TO 65C NOW 35C :) BLUE WIRE DISCONECTED AND FROM 2700 RPMS RISE TO 4500 RPMS

[@NICOLASARTSHAMBOW]

Thank you pkease do more videos i have found and new fun filled excitement in electronic x just need to taught in the way your able explain the basics in plan english, un fortune atley most videos infind are in Filipino or India en

[@eldontyrellcorp]

I have such a 4 wires fan and I trie to connect the pwm input directly to ground to lower the speed but it does not work contrary to what is said in the video. Any help is welcome !

[@joerumaker987]

Thank you so much! Great video!

[@billiamwong7393]

How much current does the signal wire pull per fan? Would it be advisable to split the signal wire coming off say my GPU and have it also control the speed of two additional case fans? The additional case fans would have their own 12v from PSU so I don't fry the GPU header.

[@kyleganse4978]

Im guessing from your drawing that i should tie the tach input High if im not going to use it since it has that npn transistor to ground

[@nazmushsakib5475]

Thanks a lot. You saved my day .

[@bostjantrancar9605]

Excellent video about 4 wire nidec fan.... Just the right thing that I need.... 👍 😎🖖...

[@n8lbv]

Do you know if 4-wire CPU 12V fans work the same exact way? Specifically in Intel "stock" socket 1151 CPU cooler. I will have to try this.

[@danielalarcon2982]

what happen if we connect the blue in the tachometer and the yellow in the pwm? you know, some of these chinese fan sellers don't send the color scheme and they become upset if you ask them.

[@kadirhaldenbilen6149]

I got one of Delta's high speed (4500 rpm) high suction (50 cfm) blower with rated 1.80 amps current. (12V DC). 4 colors, same as described. I connect red to +12V DC and black to ground, it works fine. Starts slow, speeds up great - to a leval which I though to be the maximum as described above. But when I measure the current drawn, at steady state it is only 0.68 amps. It goes very briefly up to 0.70 - 0.75 at the beginning just before reaching th "maximum" speed, and then goes down to steady 0.68. Huge difference between the measured and the rated values. Could it be that I need to give some input to blue? What happens if I connect just 5V DC to blue? No PWM.

[@martinetellerandet8566]

just what i needed

[@alanw5879]

Is there a spec on that pull up resistor on the blue wire to power? I have a 4 wire 5 volt fan.

[@franciscofortunato1864]

Excelente explicación y aplicación! Muchas gracias por compartir!

[@qaisarabbasi2219]

Sir i have vfd drive its showing fan alaram how can i do bypass 3wire fan feed back bypass

[@maxpolaris99]

PWM and Tach oh my! The arduinos and raspberry pi's are gonna love them,

[@Lordosvk]

so i can slow down my 4 wire cpu fan to conect blue wire to the black ? :)

[@fozlurrahman7052]

i have a 48v fan, does the signal generator have to share ground with fan ground?

[@tigranavemian803]

Very helpful, thanks.

[@bendewachter3789]

Clear as a whistle. Thank you.

[@Irish_home_worx]

will a 555ne timer ic work if connect it to the blue cable. if so could you show me how ?

[@mousecursor6521]

OMFG OCT 1. 2010 is when i was BORN

[@taojiang719]

i feel like motor driver is comparing the output with the input pwm signal. and try to make them same. a negative feedback path.

[@yggameplays7448]

i have a laptop fan i want to use with a 9v battery but i can figure out which wire is what. this is a 4 wire. the plan is to use it on an tablet.

[@shivaelectronics4029]

Great tutorial Thanks