How do Computer Fans Work? - LFC
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- เผยแพร่เมื่อ 29 ส.ค. 2020
- By request, a deeper dive into how 3 and 4 pin (PWM) fans work. Turns out that PWM fans are a lot smarter than I thought, and 3pin fans are a lot simpler than I thought, and neither work the way I expected!
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I thunk these videos should be in a new series called 'lets talk computers'
lol "I'll leave the dust there, just to trigger some people"
This is my new favourite channel. I watch one every night these days. Helps me chill and unwind. I enjoy learning something new about pcs and his chill personality and clear explanations make for an interesting, relaxed, entertaining watch. Bravo!
Very cool video explaining something fairly complicated that really doesn't seem like that when you look at what it does. I think you nailed it in accordance to what you want this channel to be. Thank you!
Man this is REALLY clever! Thank you so much for this video! I've sat through this and enjoyed every bit of it!
Really interesting content and very well delivered
Had not thought about hall effect sensors being used as tachos and schmitt triggers to covert their output from analogue to digital. Nice work....clarity.
I hope he gets sponsorships someday. His clear knowledge and expertise, to me, make him one of the top tech tubers there out there!
Wow thanks Adam yet another great video and I have learnt allot from it. Kevin
Hi there, this is my first message here. I like the honesty, straightforwardness and non commercial attitude. So big thumbs up!. I would like to suggest an review on a case : DeepCool DeepCool MATREXX 70 ARGB 3F. In the Netherlands it's about 95 euro. I've got an MATREXX 70 ADD-RGB 3F and i like multiple things about it, especially things you don't see or hear about with reviews like the front usb and power connectors on the top of the case which are luminated. Also the big space inside the case and psu shroud which is hidden with a temperated glass, which i have never seen anywhere. You also got the DeepCool MATREXX 50 ADD-RGB 4F which is 70 euro.
Also i would like to see more video's on buying the right soldering stuff, what do i have to look for for a reasonable amount of money (soldering iron / solder, heat gun) i know you did some video's but i can't seem to solder a 6.3 inch headphone jack properly, well i did manage to make it, but it's not the prettiest thing i've made. Keep up the good work, and please stay down to earth like you were in your previous video's, i believe thats why the huge amount of subscribers by now. Good times seeing your video's, greatings from the Netherlands!
When I was a kid in the 70's TV wasn't available 24/7, not in the UK anyway, so if you got up early on the week end, I could never sleep as a kid, there wouldn't be anything to watch, except for the Open University on BBC 2, and that's what this reminds me of of.
Super interesting video, thanks for that! I came here because I was scratching my head while trying to understand how it works when people are "PWM"-controlling 3-wire fans, such as demonstrated in many Arduino-tutorial. Through your video, I understood that that is actually a brute-force method, because that kind of PWM turns the SUPPLY VOLTAGE of the Hall-sensor IC On and Off thousands of times per second! I'm amazed that it still works "somehow", especially because there's no buffer capacitor in the 3-wire fan that would remain charged during the PWM Off cycles. Would be very interesting to see what the coil voltages look like when a cheap 3-wire fan is supplied with a PWM modulated supply voltage. Also, I'm wondering whether it would make any difference to the noise of a 3-wire fan if it's controlled by PWM-modulated Vcc versus a linearly regulated, variable DC voltage. Something to investigate! Cheers!
Your sleeve ends look like they’ve been caught in the fan many times 😂 great video! Very informative 👌
Thank you for posting this
For PC fan repairs, you can take out the PCB by holding the coil part in a vise and carefully twisting the casing. If you're lucky, the fan board will come right off.
But since the bearings are still in the casing, it wouldn't work.
Hey man. Greetings from Brazil. Your corsair sp120 pro video helped me a lot.
Im enjoying your videos. I think I’m becoming a fan :)
I see what you did there
How do Graham Fans Work?
- her notified
-click vid
- like
- leave a comment for algo
- view vid
- check for thumb hast been set
- thank Graham for another great vid
Using your videos I have been able to fix my PC thank you
You are a genius with computers , awesome video . I learn so much watching you :)
a mundane fan is such a sophisticated device.
Thanks man I leaned something from you
HA! lol. That is smart! I didn't even think my fans would turn on. I thought they would turn on and lock. Recasing an HP Compaq Elite 8300 CMT to a DF600 Antec case. Little documentation. I have the Fan Hub but wasn't sure. Now my board has the 4 pin Chassis Fan header. Eventhough it's 12 yrs old.
Great video
That 'maze' is an H bridge.
It can reverse the polarity of the coil.
It might therefore reacts as a dual coil setup?
Kind regards
That face at 6:39 haha... cracked me up :)
What’s that signal generator? Looks cool! Have you done a video on it?
Many thanks for the answers that I get from you, without the need to disassemble thinks on my own. I don't have equipments for electronic measurements.
Only one left... What will happen if I send PWN 12V signal to a 3pin fan? Of course with external transistor.
Wow it's full of sience I like this man I should watch this many time
22:50 That 'Maze' of MOSFETs is called an 'H-Bridge'
Pin FG on the 4 pin fan I remember it's for feedback to the computer. The motherboard has a pullup and the fan controller pulses if the fan is spinning so if the motherboard detects no pulses it knows that there's a problem.
I also think that this is the third yellow pin on the 3 pin fan. In very very cheap fans it's tied to ground because who cares about fire.
It seems so.. At 8:34 he states that the transistor puts through 1V.. But shouldn’t it short the yellow wire (the tach-wire, that you would feed with a pulled up signal) to ground, or how exactly does it work? Unfortunately no videos I’ve found shows how this work…
The Anpec chip alternates the current direction in the coil hence the H bridge output, the waveform in the pulses you see which if you had 2 probes 1 on each output, you would see was only on the high part of the waveform so when one output is at ground the other is pulsing at the PWM frequency which is approx 23kHz not what you are feeding in. The PWM input frequency can be anything from 300Hz up to 50kHz but the speed controlling factor is the duty cycle of the pulse.
So if you feed in a 300Hz pulse with a duty cycle of 20% i.e. the pulse is 20% high and 80% low the fan speed would be 20% of full speed.
A 3 pin connector has ground, volt, and tachometer signal wire. A 4 pin connector carries a PWM signal as well. Basically, both are PWM and voltage-controlled fans but 4 pin fan carries a dual PWM controller while a 3pin has only one. On every motherboard, PWM controller is used for decreasing and increasing voltage but why another one on the fan (you may ask).
1- It decreases the size and power loss of PWM mounted on the motherboard(b/c it is no longer carrying 12V and several amps), it could be 1.5V signal.
2- Since the Voltage duty cycle from the motherboard (based on temperature) will not always match the working voltage range of Fans (water colling pumps) manufactured by different companies having different Voltage-performance curves. So, a PWM chip on Fan decreases or increases the voltage after receiving a signal from PWM of motherboard and then adjusting the voltage according to working range of that fan.
-For example, A 12V fan with 3 pins at 50% duty cycle will be running at 6V and may stall and actually perform at below 50% performance-wise. A similar size 12V fan with 4 pins at 50% duty cycle will be running at 9V(assume) and will not stall, perform at 50% of its performance.
3-pin vs. 4-pin ?...
What about my 2-wire molex fans ??
lol, i recommend you throw anything molex in the trash.i kid i kid. no but really, i hate molex connectors.
as for the fan, same as 3 pin, but without the sensor to detect rpm.
EDIT: or who knows, they might not even use the circuit if they do not have the hall sensor and simply use the brushless dc motor that are found handheld fans and toys.
We don't talk about that here
Do you think you are smart ?
If you're actually curious they're basically the 3 pin fan without the feedback.
Sarcasm does not exist on teh internets.
How did you wire the pwm module to the four wire fan? That's exactly what I'm trying to figure out myself. My pwm module will be using 5v, rather than the 12v wired to the positive and ground wires of the fan. My module has a + and - output, where the - is the actual pwm signal and the + output is directly wired to the modules input + terminal. I'm just not sure what to do and it looks like you've got it figured out
APX9173 it is use on Arctic P12 Static Pressure 120mm PWM PST Fan 4 Pin Black too . You have discovered modulations ...
That's good. Thank you very much
Thank you man
I'd like to know how the coils look in the pwm version. Is there only one pair of coils or one quatro?
Good punch with the screw driver...😅
It's basically just functionally an AND gate. If in_phase AND pwm_on send power to motor.
Hi ,
on the 4 pin fan , if 12v is applied to the pos and neg , will / should the fan still turn or does it need a signal to the pwm to make it turn ?
And if so , with it connected to the pc , what signal could I give it ?
I just wanted to test the fan to see if it works , as I think I might of killed the fan as I was poking round on it
Can't wait for a lesson on fans been waiting since you posted the snapshot on discord
I thought all motors were effectively AC as they don't power any single magnet continuously. The way I remember it the only real difference between AC and DC fans is that in DC the controller produces said AC signal whereas a true AC fan is usually built much simpler and just uses the raw current to get the job done either directly or via a transformer to produce a lower voltage.
Interesting :), so I take that the second fan has an FG or Frequency Governed servo modulator as part of the IC, which could explain the capacitor as acting as an oscillator (I could be wrong though). I didn't know how the PWM generator operates in the way it effect the fan speed by varying the voltage. So can this PWM generator that you have there be the same as a variable resister? Thank you.
The capacitor is for decoupling.
How is your channel not bigger. This is a diy guys bread and butter.
wow ! thank you !!!
nice cooler master fan, I need that for a low profile case
Did you feed a signal to your 3 pin fan through the yellow wire?
My mobile phone cooler is not spinning thats why Im here but the LED is on, sometimes it does spin but it stops later again. Can u pin point the problem? Im quite sure its not the dust build up because it spins so fast when it spin.
(Xiaomi Xiaomi Funcooler pro)
I have a question is the i9 10900k and a 3070 rtx with 32gb of memory and a mainboard of MSI MAG Z490 TOMAHAWK LGA1200 a good PC
FG is not for the Direction of rotation its for sending fan speed to mother board
Nice, I never knew this.
very informative!! nicely explained too. Keep it up
looks like Hugh Jackman! nice dissection
Now days we see 5pin fans, how are these different from 4pin ones? Eg see this part number EG50050S1-CC10-S9A.
Do you think we can use 4pin fan in place of 5pin fan,
if so, which one of the pin from driver board be left unused ?
My four wire fan not self starting.. What will be the problem.. Could you tell me please...
Wait, so AH276 IC also featured FG signal too? I thought only AH211 and WHS41 ICs that featured FG signal Output...
Hi,
I'm looking for a good, reliable and long lasting hot air rework station that is preferably under 60 pounds. I am intending on doing work on phone and laptop motherboards. Does anyone have a station that they can recommend?
Anyone these days that uses a DVM... I Like immediately..
FANS FOR THE FAN GOD
You've got me really confused. The yellow signal pin is used to send fan speed data to the computer. It doesn't send a signal to the fan to turn it on and off. That's the function of the PWM pin. From my understanding, you can adjust the fan speed by adjusting the size of the pwm square wave. I've watched other people control 12v fans with a pwm signal they built on a circuit board and their oscilloscopes looked WAY different.
I'm trying to convert some voltage controlled fans into PWM fans right now. That's actually why I watched your video. I will be looking up that chip.
2:23 is incorrect; a fan only needs 2-pins to have voltage control. The 3rd pin is a 'sense' / tachometer wire that reports the speed of the fan to the controller (eg. motherboard) so the board can adjust its voltage if the speed is 0 rpm.
It is possible to convert 2/3 pin fans to PWM (4 pin fans) by use of a transistor which "simulates" the 4th pin....haven't tried it though - you may want to make a video about this (Idea ! :)) )
quietpc(dot)dk/zm-mfc1-combo or www.teachwithict.com/uploads/5/5/8/2/5582303/published/potentiometer-fig-1.png?1531059563
I can"t open a sealed cooler. How i clean that? Please help.
Cooler master 212 plus
Wash it??
This channel is fucking cool to me
Had any luck with my 14isk yet?
4:27 - Pirate shirt under that sweater?
The 4pin is not just turning the coil on and off it is reversing the coil, the chip has a H bridge on the output
Can you please explain to me how the 4th pin actually works? How does it send a pwm signal? At what voltage ? I assume the 12v pin is constant current? So there's no pwm signal going over the 12v pin. But what is exactly being sent over the pwm cable? And does that cable need its own ground?
It's a 1v signal being switched on/off at high speed by the fan controller. There doesn't need to be a ground for it because the fan has a common ground (negative) pin already. So yea, the 12v pin is constant, and the the PWM signal works as an interrupt inside the fan to turn it on and off rapidly.
@@Adamant_IT so seeing your videos it's just a signal for the microchip that controls the true 12v signal itself, right? I guess a 12v DC pwm signal doesn't work properly with the 4th pin, or would it maybe work if I converted it to a 1v signal ? I'm trying to make a simple pwm controller for fans. I've been searching for this info for a while now, so many thanks !!
great
I would really like to know what your background is. I myself just started off as a repair technician in a repair shop with no formal education in the field. I am an economist by training. Far off being able to do what you do atm, hence my interest in where you started. I feel like if it interests I should just go ahead and dig deeper piece by piece
No formal training either... But I did have an interest in electronics from a very young age, so I've always had an idea of what basic components are/do, which means it was easier for me to listen to a video saying 'the capacitor then does this...' and follow that explanation.
However, because of the No Formal Education, there are some gaps and inaccuracies in my knowledge, so sometimes I'm not quite right. Hopefully though I'm never glaringly wrong.
@@Adamant_IT That makes the content you put out even more impressive. I am glad to have found your channel. Seeing you do all these cool and nifty things without a formal background really like encourages me to stick with what I am doing right know and just continue learning about this stuff. Soon I am ordering my first soldering equipment to start getting actually to work. The computer shop I work at at the moment doesn’t do board level repair just yet. The one technician discarded a surface book just yet which potentially could have been saved by reprogramming the bios chip. At least that’s what I came up with after doing some research. Was really sad I am not yet in a position to try it in a spot like this just yet.
To put it simple: you encourage me man!
4 pin fans and heat sinks at cheap as chips. All we care about his how to run a 4 pin fan with a 12 volt signal. I finally found a video which says you just put a 470 uf cap across yellow and black and it works.
Sadly there are not many RGB pwm fans. there are corsairs fans which I would have 200€ worth of fans in my case (which cost 60€) or 3 pin fans.
Hi Graham and viewers,
Sorry this is off-topic for this particular video but just posting on the newest one. I was wondering if you could help me as I had been running my PC as a Ryzen "3"- based system for almost a month still booting my old Windows 10 install from when it was an FX system, from the 7 year old 2.5" SATA SSD. Now I've installed my new M.2 NVMe SSD and installed Windows 10 on it, but it doesn't boot and I get an "An operating system wasn't found. Try disconnecting any drives that don't contain an operating system..." error. While I could do that (and will try it) I shouldn't have to disconnect my two hard drives every time I start up my PC (!) I read that on a UEFI-based system, installing Windows with drives other than the boot drive connected can cause problems, so I'll disconnect my hard drives leaving only the SSD on the system and install Windows again and see if it boots. If it doesn't I'll be at a loss - what could the solution be...?
Thanks either way!
Check your boot order, you should have Windows Boot Manager as your first device. This option will appear when a drive with a UEFI install of Win 10 is present, which should be the case for you.
@@Adamant_IT Thanks very much for your reply and that information! Reinstalling Windows onto the SSD with the hard drives unplugged solved the problem in the end, and the PC is now booting normally even after plugging them back in :)
Да, довольно интересная и простая, от того и надёжная система регулирования, по шим..
PWM does seem over overly complicated, yet pretty elegant.🤷♂️
Protip #1: You can lift the blades off Noctua fans without damaging them (helps with cleaning), Arctic P series are the same (F series don't, but they're crap [About as balanced as my sister]). #2 Buying non-PWM fans is false economy (you can do a lot with fan curves, something most seem to miss). #3 Use the case/ motherboard as the temperature source for case fans, it saves the RPM going all over the place (CPU will take care of itself). [I don't mean to be "that guy". 😉]
Fun fact: Noctua uses 6 pole motors (makes them quieter apparently).
IN MY MACBOOK AIR, CURSOR MOVES PERFECT SOMETIMES BUT AFTER A WHILE IT GIVES UNWANTED MOVEMENT ........... NEED YOUR SUGGESTION??????
Search my channel for trackpad cleaning. I've got a video on cleaning a MacBook Air trackpad which may fix this - if not, you can follow the same video to replace the trackpad.
@@Adamant_IT I found corrosion at one side of the flex cable (of the touchpad) & even clear with alcohol but still the problem is the same when I start my MacBook it looks perfect but after some time cursor start moving. my keyboard is working, USB mouse is working. any guess????
Dust *TRIGGERED* lol
Did you build the scope from a kit or buy prebuilt? Really interesting seeing the PWM "inside" the on signal.
Yea I bought this scope as a kit. Basically costs the same pre-made, but I really enjoy building DIY kits.
I just watched video. I've watched the video for the little dohicky at the top too. I think I'll try that one!
Why fan goes to full speed, when no pwm signal connected?
If there's no PWM, the fan will assume Voltage Control mode, and since I was feeding in 10v (or 12 if it were connected to a PC), that will be full speed.
The white thing you thought was a fuse. Is a capacitor.
Capacitor would be brown, it was an upside down resistor to the transistor. With the 22k one next to it, it was forming a voltage divider.
@@Adamant_IT Some capacitors can be white though not always brown. But thanks for the extra details. Great video and great channel.👍
why dont we just feed 3 pin fans with 12 pwm?? Not voltage?? same thing right??
These fan motors are similar in construction to an LG Direct Drive Washing Machine motor, but obviously the Washing Machine motor is bigger and more powerful, and it has a lot more electromagnets in the stator!
Who knew FANS were so COMPLICATED?
I have a piece of CARDBOARD from a WEETABIX PACKET, which I use to FAN MYSELF when I'm HOT! The principles of its FUNCTION are very SIMPLE! No SHIT TRIGGER required! 👍😂💩
Me thinks you have millions of fans !🤣
This is awesome, I know you already kind of exlpained how a GPU works but I would love a more in depth explanation like this for GPUs
Is a server grade fan (3 phase) built on the same principle?
3-phase AC motors are a lot more complicated. There'll still be the hall-effect sensor to detect the rotor position, but the way the coils are driven is completely different. I'm not sure if you can inject PWM into 3-phase AC in the same way that you do with a DC motor.
@@Adamant_IT Thank you. Wow that was the fastest response I've seen happen from a channel!
Good afternoon and happy Sunday all. Now, let's queue the fan jokes. Though, in anticipation, I'm hoping for a great airflow and optimal video.....let's get comfy and see.
how about those fans just try to start and dont make it just "push stop, push stop, ect" ?
nice informative video.
had to figure this out about 6 months ago as was trying to reuse a pc fan for my "soldering station" fan set up. he he, same oscilloscope, too.
anyway, i was trying to feed it pwm voltage controlled by the attiny thinking it would just be a normal brushless dc motor, which ended up not working. then i looked up the chips and figured they were cycling the coils themselves and thus a pwm voltage would not run the circuit. i did not want to use up one of my voltage converters, so i said "screw it" and simply ended up running the whole thing on full 12v controlling the voltage with a npn transistor and a a potentiometer.
would i recommend anyone doing that? absolutely not since the transistor get so hot i burned 2 of them before i figured that keeping it above 40% would keep it alive. in the end, it was bit useless since it turns out that the best speed for the fans for my use is to simply feed it the whole 12v and i don't need the slower speeds at all.
Thank you M.r
🇬🇧🇬🇧🇬🇧🇬🇧🇬🇧 👍
Great video but you should read and search more information before you try to explain what you are showing. You have the power of stop recording and editing.
First, at the 3pin fan, the one face of the chip goes to transistor and it sends a pwm signal back to the motherboard (yellow wire). This signal is what RPM is spinning. By knowing that the motherboard can control the voltage sending to the fan in order to its speed. Also there is no bearings to the fan. By hitting it with the screwdriver you disform the metal at the back.
At the 4pin fan the mosfet configuration called H-Bridge and provides alternative voltage to the coils. The coils windings is wrapped differently so when the two opposites is south the others is north simultaneously. In the next face of the cycle the coils magnetized reversed.
The white one
we need something like hair dryers lol
I'm not a fan of three pins
Love it
I get Antec PWM/PST fans , dual ball bearing if possible.
Oh, I really wish you did bicycle stuff too.
I actually don't like the naming they have going on with the fans. 3 pin fans and 4 pin fans are both controlled by PWM from the motherboard. The 3 pin fans are just turned on and of real fast by the motherboard, whereas the 4 pin fans are actually ac fans with a variable frequency drive controlled by the PWM logic.
The "network of mosfets" is actually an h-brige that converts the 12v DC into 12v(p-p) AC.
Which is way more efficient than simply pulsing the coils on and off.
That makes sense, but when I was measuring the motor coil, it was DC bias. Screen at 29:45 shows 12v v-max and 0-ish v-min. Surely if it was AC driving, I would've been seeing negative voltages? The H-bridge might be simply so the controller can drive the motor in either direction?
@@Adamant_IT You didn't see the negative pulses because you were measuring L1 with respect to GND, measure L1 wrt L2 and you should see them, the H-bridge is to reverse the polarity of the coil.
aaah of course... I'll have a look again on Tuesday when I'm in the shop, just so I can see it in action. So by running in AC, it can apply force to the rotor on both the magnet poles. So despite only being a single phase motor, it's doing the same amount of work as the 3-pin two phase because it can pull double duty...
@@Adamant_IT That's my understanding of it, I'm learning tonight too. I previously assumed the PWM signal on 4 pin fans was interpreted by the controller chip, I didn't think it would be fed out to the coil.
@@Adamant_IT Hey. I found an old pwm fan and hooked it up to my signal generator that can do PWM. Would you like the video of that?
lol leave some dust to trigger some people
:)