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...
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.
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.
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.
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.
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
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.
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.
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.
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.
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.
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!
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!!!
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
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!!
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.
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
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.
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
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??
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
OMG I am so glad I clicked your video!!! I was trying to figure out the black box (specifically the PWM signal wire) for hours! Can you please confirm the following - if I take a PWM fan and plug it into the 3-pin header on the motherboard that delivers 12V (100%) and I take the PWM fan wire (blue) and connect it to the ground pin, then I will be able to read the minimum RPM that the fan is capable of? ~~~ I am suspecting that my motherboard has fake PWM headers and I've been trying to troubleshoot and confirm that. The motherboard has three 4-pin headers. One is CPU_FAN and other two are SYS_FAN1, 2. I am suspecting that SYS_FAN1 and SYS_FAN2 are regular 3-pin headers and the PWM pins aren't doing anything. When I connect a PWM fan and use a program like SpeedFan, I can control the RPMs but how can I tell that it's pulse controlled indeed, not voltage controlled like other 3-pin headers? When I drop RPM below 30% the Fan stops, which tells me that it's the voltage that dropped. If it was the PWM frequency then it would still spin slower and slower, correct?
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.
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
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?
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
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?
interesting! I was reading a datasheet earlier showing intel's specs on 4 wire fans, and they stated pwm-in was 0.8v to 5.25v, and the pwm frequency range is 21khz - 28khz. what frequency pwm were you feeding it?
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.
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!
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?
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.
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.
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.
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)
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.
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 !
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?
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?
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.
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?
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.
great video, but can we use thermistor between ground wire and pwm control wire for thermal controlling the fan speed? does it have any negative effect if I apply into my computer? sorry for my bad English
No, the PWM control is not based on a voltage, but a duty cycle. PWM fans use a 25 kHz square wave and the percentage of the time that it spends in the HIGH (I believe 5V) state is the duty cycle. For example, if your signal is HIGH for 40 microseconds , then LOW for 10 microseconds, that's an 80% duty cycle. To generate a custom duty cycle, you need a 555 timer, microcontroller, or similar.
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.
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.
21may2024 from Pakistan
Finally
A person that explained a 4 pin fan in a simple and efficient way that everyone can understand
Black turbine short and sweet. Really great.
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.
A 10 year old video and it's still the best 4 wire fan tutorial on the internet! Thanks buddy
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.
Only thing lacking is the description for people who can not watch the video or hear the audio :/
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.
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
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.
You're welcome! I've taught myself a lot of useful tidbits of information over the years and I'm happy to share it.
When are you going back to make videos ?? Please we need more 🙌🙌
Great, informative video! Until now I couldn't find much on the 4-wire fans, thank you very much! I've just subscribed :)
I can't thank you enough! You have no idea how much time I spent looking for this answer!
Best explanation of 4-wire muffin fan operation and use since the 4-wire muffin fan was manufactured. Thanks!
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.
Man it’s 2023 and this video is still gold! Thank you
thank you. very clear instructions. even 10 years later you're helping people!
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.
Finally a good informative video on fans!
Brilliant explanation, thanks. Was about to strip the fan and try reverse engineer, this was very useful!
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.
This was so helpful! Thank you for posting this I would’ve never known how to use the blue wire ❤
Great video. Straight to the point with a clear explanation, thank you!
Excellent. Thank you. I couldnt find the spec sheet for my fan, so this helped me figure it all out.
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.
Thank you - just what I needed. A clear explanation - good job!
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!
Mate, thank you so much! It was the only well explained video about the 4 wires fan.
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!!!
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
Still useful years later - Thanks
Still helps in 2019..thank man
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!!
+Elias Magallanes Glad to help!
Elias Magallanes ii
Excellent. Just what i needed. I need to test 4-wire refrigerator fans by LG, and information is scarce.
Thank you so much. I have a couple of these and had no understanding. Now I can use them.
Such helpful information. Excellent job on this video. Thank you very much for sharing.
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.
This is what the crip that I searching for. Thanks guy.
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
Finaly someone made a tutorial!!!
Great, exactly what I was looking for.
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
Este video es muy interesante, te agradezco tu ayuda, me sirvió para resolver algo que debía hacer rápido. Muchas gracias.Eric Wssatonic.
Clear as a whistle. Thank you.
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.
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
Very informative , good attempt
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??
Excellent video about 4 wire nidec fan....
Just the right thing that I need.... 👍 😎🖖...
Good job, bro.
Really appreciate.
This is amazing. Thank you!
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
OMG I am so glad I clicked your video!!! I was trying to figure out the black box (specifically the PWM signal wire) for hours! Can you please confirm the following - if I take a PWM fan and plug it into the 3-pin header on the motherboard that delivers 12V (100%) and I take the PWM fan wire (blue) and connect it to the ground pin, then I will be able to read the minimum RPM that the fan is capable of?
~~~
I am suspecting that my motherboard has fake PWM headers and I've been trying to troubleshoot and confirm that. The motherboard has three 4-pin headers. One is CPU_FAN and other two are SYS_FAN1, 2. I am suspecting that SYS_FAN1 and SYS_FAN2 are regular 3-pin headers and the PWM pins aren't doing anything. When I connect a PWM fan and use a program like SpeedFan, I can control the RPMs but how can I tell that it's pulse controlled indeed, not voltage controlled like other 3-pin headers? When I drop RPM below 30% the Fan stops, which tells me that it's the voltage that dropped. If it was the PWM frequency then it would still spin slower and slower, correct?
Thanks for that info, very very helpful easy to understand.
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.
Good video man
Helped me alot
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
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?
Excelente explicación y aplicación! Muchas gracias por compartir!
Thank you for your video it was very helpful. So simple b
ut could not figure out hot to connect to a PWM that a built.
Thankyou, straight to the point.
Very good video indeed. Thank you.
It's 2024 and this video helped me out. Man i love UA-cam University. Thanks professor. 👍
Ditto😊
Thanks a lot. You saved my day .
Very nicely explained :)
Put a pot between the Sig/PWM in and the Tachometer out. The Tachometer out will provide PWM. The pot will give speed control.
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
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?
Awesome mate you answered my question.
interesting! I was reading a datasheet earlier showing intel's specs on 4 wire fans, and they stated pwm-in was 0.8v to 5.25v, and the pwm frequency range is 21khz - 28khz. what frequency pwm were you feeding it?
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.
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!
Great tutorial Thanks
This is most helpfull diagram and video thank you very much !
thank you so much bro!!!.. there is no info of this on internet.
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
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.
Very helpful, thanks.
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?
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.
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.
wow dude, that's is awesome! thanks very much!!!
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.
Great video!!!
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)
That's very helpful, thanks
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.
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 !
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?
Do I need to use PWM or can I use a variable resistor of some sort?
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?
Very useful! thanks!
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.
I've a dozen of cooling fans like these but its bigger got from an cell tower scrap..now I can do something
Very helpful
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.
just what i needed
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?
Good information
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.
i have a 48v fan, does the signal generator have to share ground with fan ground?
great video, but can we use thermistor between ground wire and pwm control wire for thermal controlling the fan speed?
does it have any negative effect if I apply into my computer?
sorry for my bad English
No, the PWM control is not based on a voltage, but a duty cycle. PWM fans use a 25 kHz square wave and the percentage of the time that it spends in the HIGH (I believe 5V) state is the duty cycle. For example, if your signal is HIGH for 40 microseconds , then LOW for 10 microseconds, that's
an 80% duty cycle. To generate a custom duty cycle, you need a 555 timer, microcontroller, or similar.
will a 555ne timer ic work if connect it to the blue cable. if so could you show me how ?
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.