DIY Fan Controller for PWM Fans

Overclockers.com · 01-17-11, 06:00 AM

Quote:

This neat fan controller project requires only a little time, expense, and commitment, and the circuit is relatively easy to build and very satisfying to use!

... Return to article to continue reading.

David · 01-17-11, 06:07 AM

Nice writeup

bing · 01-17-11, 06:52 AM

Hey Dave, great article, nicely done and well consolidated too !

Love the intro, and those illustrations too, thanks.

DarkWarrior · 01-17-11, 07:42 AM

Nice , very good.

Jmtyra · 01-17-11, 08:51 AM

Awesome article, I may have to build one of those!
Thanks for writing this up.

LennyRhys · 01-17-11, 09:16 AM

Thanks guys - couldn't have done it without the oc forums community!

madhatter256 · 01-17-11, 10:15 AM

Damn, those fans are loud!!

Jmtyra · 01-17-11, 10:45 AM

260 CFM fans? You betcha! And he only cranked them to 75%.

I.M.O.G. · 01-17-11, 12:20 PM

Dave, really happy to see this article on the frontpage - great read, very clear, and a cool project spawned out of the forums. Getting the fans to you was no problem, and I'd be happy to do it again anytime! Thanks for putting this together!

Brutal-Force · 01-17-11, 05:54 PM

Awesome, thanks for putting this into words. Many people can benefit from this write up.

Seebs · 01-17-11, 10:05 PM

Hell yeah... Great write up. I'm sure there will be plenty more controllers built because of this; I, for one, am going to be putting my bread-boarded controller down on perf-board pretty soon. And once the first one is all done there will be a few more coming behind it.

MIAHALLEN · 01-17-11, 10:22 PM

Very cool write-up Dave

CompuTamer · 01-17-11, 10:52 PM

Nice write up! Glad to learn how to build these things.

Those fans are insane... i need a few to build a hovercraft with!

macklin01 · 01-18-11, 01:14 AM

Nice work and write-up!

Brings back great memories of when men were men, and we had to make our own controllers or do the 5V/7V tricks. (Back before Zalman and everybody else flooded the market with pre-made controllers.

)

Very nice design. Best -- Paul

LennyRhys · 01-18-11, 03:30 AM

I highly recommend getting one of these fans for kicks

Paul - thanks, and it's nice to see somebody else putting Dundee on the map!!

slavik · 01-19-11, 02:50 AM

Is it possible to replace the manual control with a thermistor and let the temperature control the fan speed? (with a rheostat as an adjustment). haven't been able to find such a circuit anywhere

and commercial offerings are way too expensive.

macklin01 · 01-19-11, 03:13 AM

I should think that would be possible.

Two configurations to think about:

(1) rheostat + thermistor in series: net resistance is additive

(2) rheostat + thermistor in parallel: net resistance is R1 * R2 / (R1 + R2)

Option (1) involves soldering your thermistor after or before P1.

Option (2) would be a matter of soldering the thermistor in parallel with potentiometer / rheostat R1.

There are pros and cons to both to think about. -- Paul

Brutal-Force · 01-19-11, 04:13 AM

It would be possible, but I think your dealing with two kinds of temperatures. One inside the case and the temperature of the CPU Cores. Since you could only go off of the core temperatures for your CPU, you would have to tap those temps from the Motherboard. In that case a lot of the newer motherboards use PWM to control their fan circuits, especially the higher end ones.

The problem (you will find out if you read my whole thread) is with the stepping of those PWM circuits. This is where this controller comes in. In all honesty, you really only need about 3 or 4 speeds for this fan. Low/Med/High would work in almost all cases, except that different fans at this speed exhibit noises that can only be eliminated if you turn them up or down ~50 RPMs. In essence your are tuning them. It would be too much work to try to tune a 3 speed controller.

I run my fan daily at about 900 RPMs. I turn it up to about 2000 while gaming and then I turn it to 6000 while benching. All of these are +/- 50-100 rpms. You just can't do that with switches. Well actually, you could... on a non PWM, but then you would deal with Undervolting which would also produce annoying noises.

I could have built a thermistor into this circuit, but PWM really was probably overkill for most computer users, and a thermistor controlled PWM would be definitely overkill. Essentially a thermistor is just a variable potentiomter, just like the 10 or 100k Poti used in this circuit. So one would just replace the Poti with the thermistor.... Problem solved. You just have to tune it/

bing · 01-20-11, 10:32 AM

Just came out of my mind on one simple thing, Lenny, how many fans maximum that controller capable of driving ? Ever tested 4 of that beasts altogether ?

This is interesting since as original circuit without the booster (inv sch buffer) couldn't drive even one as Brutal experience.

LennyRhys · 01-21-11, 02:32 AM

I'll get round to it soon bing. Problem with four fans is the enormous power draw of nearly 200 watts and 14-16 amps.

I think I'll buy a cheap PSU specifically for testing the fans - don't want to short my system again!!

01-17-11, 06:07 AM	#2
David Forums Super Moderator Overclockers.com Lead Editor Join Date: Feb 2001 Location: Hiding from Americans and making pretty colours in a drybox in St Andrews	Nice writeup __________________ David J. Nelson MChem(Edin) PhD(Strath) AMRSC [Academia Profile] OC Forums Super Moderator // Overclockers.com Editor The Workhorse: [Lenovo W510] Intel Core i7-720QM / 8 GB DDR3 / nVidia Quadro FX880M / Crucial M4 256 GB SSD / Windows 7 The HTPC/Server: AMD Phenom X4 9650 / 6 GB DDR2 / nVidia 8300 / 5 TB of HDDs / Antec Solo II Case / Windows 7 The Gaming Rig: AMD Llano A6-3650 / 4 GB DDR3 / nVidia GTX260 / 2x 500 GB HDD in RAID0 / Antec Dark Fleet DF-85 Case / Windows 7 The Benchmarking Setup: Various LGA775 chips / Asus Rampage Formula / 2 GB OCZ 1066 MHz DDR2 / nVidia Quadro NVS 285 / 320 GB HDD / Windows 7 My research fellowship is eating all my time, so I may be slow to reply to emails and private messages.
	QUOTE Thanks

01-17-11, 06:52 AM	#3
bing Low Profile Senior Join Date: Jul 2006 Location: Indonesia	Hey Dave, great article, nicely done and well consolidated too ! Love the intro, and those illustrations too, thanks. __________________ █ DIY Fan Controller for 4 Wires PWM Fan \| █ Inductors are hotter than mosfets \| █ Are you HHH ? █ DIY 90 Watt Fan Controller \| █ Vintage OC-ing Gears Anyone ?
	QUOTE Thanks

01-17-11, 07:42 AM	#4
DarkWarrior Join Date: Sep 2010 Location: Denmark	Nice , very good. __________________ AMD Phenom II X4 965BE @ 3.8Ghz , ASUS Crosshair V Formula , 8GB DDR3 , Gigabyte GeForce 460GTX 1GB OC Intel Core I7 980X @ 4Ghz , ASUS P6X58D Premium , 6GB DDR3 , ASUS GeForce 7600GT
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01-17-11, 08:51 AM	#5
Jmtyra Premium Member #21 Join Date: Aug 2010 Location: Dallas/Fort-Worth	Awesome article, I may have to build one of those! Thanks for writing this up. __________________ Team 32 Super Sticky -- 4P Mega Thread -- EVGA SR-2 Build -- ASUS Z8NA-D6 Build
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01-17-11, 09:16 AM	#6
LennyRhys Member Join Date: Nov 2010 Location: Dundee, Scotland, UK	Thanks guys - couldn't have done it without the oc forums community! __________________ i7 990X @ 4702MHz, 1.43v \| TRUE Rampage III Extreme 6GB Dominator GT @ 2000MHz 8-9-8-24 GTX480 SE Toughpower 775w U3011 & 2007FPB
	QUOTE Thanks

DIY Fan Controller for PWM Fans

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01-17-11, 10:15 AM	#7
madhatter256 Member Join Date: Jul 2008 Location: CFL	Damn, those fans are loud!! __________________ Heatware
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01-17-11, 10:45 AM	#8
Jmtyra Premium Member #21 Join Date: Aug 2010 Location: Dallas/Fort-Worth	260 CFM fans? You betcha! And he only cranked them to 75%. __________________ Team 32 Super Sticky -- 4P Mega Thread -- EVGA SR-2 Build -- ASUS Z8NA-D6 Build
	QUOTE Thanks

01-17-11, 12:20 PM	#9
I.M.O.G. Glorious Leader Join Date: Nov 2002 Location: Rootstown, OH	Dave, really happy to see this article on the frontpage - great read, very clear, and a cool project spawned out of the forums. Getting the fans to you was no problem, and I'd be happy to do it again anytime! Thanks for putting this together! __________________ The OC Forums Way We are a team. We are a community. We are a fellowship made strong by mutual respect and shared dedication to the task of enriching all who come here. The OC Forums Thank You Thread Put your computer to work for our OC Forum Teams! Try out our POST TEMPLATES, they save you time answering common questions! I spend half my money on CPUs, GPUs, and Liquid Nitrogen. The other half I waste.
	QUOTE Thanks

01-17-11, 05:54 PM	#10
Brutal-Force Member Join Date: Feb 2009	Awesome, thanks for putting this into words. Many people can benefit from this write up. __________________ HTPC/Main Rig: 42" LG 1080p - Windows 7 Professional EVGA P55 FTW - i7 860 4914.3 MHz Max and 4412 MHz 24/7 Venomous X - SANYO DENKI - 9SG1212P1G01 - 260 CFM @ 6000 RPMs Corsair TX850 - Super Talent 2000MHz 8-8-8-24 (1320MHz 6-6-6-19) BFG GeForce GTX 260 OC MaXcore 55(SLI) Coolermaster HAF 932 Heat My Homemade PWM Controller for "The Beast"
	QUOTE Thanks

01-17-11, 10:05 PM	#11
Seebs Fronting as a Mod Member Join Date: Aug 2010 Location: Sunshine State	Hell yeah... Great write up. I'm sure there will be plenty more controllers built because of this; I, for one, am going to be putting my bread-boarded controller down on perf-board pretty soon. And once the first one is all done there will be a few more coming behind it. __________________ Daily Driver: GA-890FXA-UD5 - Ph II X6 1090T - 16GB DDR3 1333MHz - HD 5670 - Venomous X Black + 260 CFM San Ace - VX450W - CM 690 II Advanced Join the "Benching Team" - We have secret sauce! - OptyTrooper: GPUs are for burning not playing games anyway Kona on League of Legends: This game sits about as well with me as a gallon of prune juice does, and the results are just as nasty. I done got Pinked... Be sure to pre-tin everything (even soldered stuff!) with leaded solder. None of the RoHS junk. You want good old fashioned toxic heavy metals. ~ Bobnova
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01-17-11, 10:22 PM	#12
MIAHALLEN Senior Member Join Date: Aug 2007 Location: Northern Japan	Very cool write-up Dave __________________ THE POST COUNTER IS NOT AN INTELLIGENCE METER! Intel i3, i5 and i7 Overclocking Guides Heat "Water & Wood" computer desk build log My HWBOT Profile MAX11Lv3 - "It kind of reminds me of going to the circus and seeing a mini drive around and then 83 clowns jump out of it!" - ollien33 i7 3820 @ 5GHz \|\| 32GB G.SKILL @ DDR3-2000 \|\| GTX580 tri-SLI \|\| Corsair AX1200 \|\| Custom water cooling
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01-17-11, 10:52 PM	#13
CompuTamer Member with Some Fancy Text Under His Name Join Date: Jan 2009 Location: Brandon Mississippi	Nice write up! Glad to learn how to build these things. Those fans are insane... i need a few to build a hovercraft with! __________________ Intel Core i7 C0 @ 4.01GHz with 1.388 vCore ..........................................Intel C2D T8100 Intel DX58SO Motherboard IOH + QPI @ 1.250 Volts..............................HP 6910p Notebook Sony Optiarc Blu-Ray Drive.................................................. ...............DVD-RAM 8 GB G-Skill Sniper DDR3 1600 @ 1.65 Volts ...........................................4GB Hyundai DDR2 800 60GB OCZ Solid 3 + 320GB WD Blue+ 1TB WD Green...............................Intel 320 80GB Antec 900.................................................. .......................................Titanium Lid BFG GS-650.................................................. .....................................Various HP AC Adapters XFX Radeon HD 4850 (660/1060 53C Idle 62C Load) @ 1.31 vCore............ATI X2300 Pro Dual Dell E2311H LED 1920x1080.................................................. .......14.1" 1440x900 Windows 8 ProMC.................................................. .............................Windows 8 ProMC Those specs up there? They're silent. Silence is good. Very good. Your Core 2 Quad is based off of the Pentium pro in a few ways.
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01-18-11, 01:14 AM	#14
macklin01 Computational Oncologist / Biomathematician / Moderator on Vacation, Ph.D. Join Date: Apr 2002 Location: Pasadena, CA	Nice work and write-up! Brings back great memories of when men were men, and we had to make our own controllers or do the 5V/7V tricks. (Back before Zalman and everybody else flooded the market with pre-made controllers. ) Very nice design. Best -- Paul __________________ My heatware (macklin01) Need image I/O for your science apps? Try EasyBMP My biomedical research: Mathematical Cancer Modeling & Simulation I'm on vacation as a moderator as I devote more time to my faculty position. Thank you for your understanding if I don't respond to your PM. -- Paul
	QUOTE Thanks

01-18-11, 03:30 AM	#15
LennyRhys Member Join Date: Nov 2010 Location: Dundee, Scotland, UK	I highly recommend getting one of these fans for kicks Paul - thanks, and it's nice to see somebody else putting Dundee on the map!! __________________ i7 990X @ 4702MHz, 1.43v \| TRUE Rampage III Extreme 6GB Dominator GT @ 2000MHz 8-9-8-24 GTX480 SE Toughpower 775w U3011 & 2007FPB
	QUOTE Thanks

01-19-11, 02:50 AM	#16
slavik Registered Join Date: Dec 2005	Is it possible to replace the manual control with a thermistor and let the temperature control the fan speed? (with a rheostat as an adjustment). haven't been able to find such a circuit anywhere and commercial offerings are way too expensive.
	QUOTE Thanks

01-19-11, 03:13 AM	#17
macklin01 Computational Oncologist / Biomathematician / Moderator on Vacation, Ph.D. Join Date: Apr 2002 Location: Pasadena, CA	I should think that would be possible. Two configurations to think about: (1) rheostat + thermistor in series: net resistance is additive (2) rheostat + thermistor in parallel: net resistance is R1 * R2 / (R1 + R2) Option (1) involves soldering your thermistor after or before P1. Option (2) would be a matter of soldering the thermistor in parallel with potentiometer / rheostat R1. There are pros and cons to both to think about. -- Paul __________________ My heatware (macklin01) Need image I/O for your science apps? Try EasyBMP My biomedical research: Mathematical Cancer Modeling & Simulation I'm on vacation as a moderator as I devote more time to my faculty position. Thank you for your understanding if I don't respond to your PM. -- Paul
	QUOTE Thanks

01-19-11, 04:13 AM	#18
Brutal-Force Member Join Date: Feb 2009	It would be possible, but I think your dealing with two kinds of temperatures. One inside the case and the temperature of the CPU Cores. Since you could only go off of the core temperatures for your CPU, you would have to tap those temps from the Motherboard. In that case a lot of the newer motherboards use PWM to control their fan circuits, especially the higher end ones. The problem (you will find out if you read my whole thread) is with the stepping of those PWM circuits. This is where this controller comes in. In all honesty, you really only need about 3 or 4 speeds for this fan. Low/Med/High would work in almost all cases, except that different fans at this speed exhibit noises that can only be eliminated if you turn them up or down ~50 RPMs. In essence your are tuning them. It would be too much work to try to tune a 3 speed controller. I run my fan daily at about 900 RPMs. I turn it up to about 2000 while gaming and then I turn it to 6000 while benching. All of these are +/- 50-100 rpms. You just can't do that with switches. Well actually, you could... on a non PWM, but then you would deal with Undervolting which would also produce annoying noises. I could have built a thermistor into this circuit, but PWM really was probably overkill for most computer users, and a thermistor controlled PWM would be definitely overkill. Essentially a thermistor is just a variable potentiomter, just like the 10 or 100k Poti used in this circuit. So one would just replace the Poti with the thermistor.... Problem solved. You just have to tune it/ __________________ HTPC/Main Rig: 42" LG 1080p - Windows 7 Professional EVGA P55 FTW - i7 860 4914.3 MHz Max and 4412 MHz 24/7 Venomous X - SANYO DENKI - 9SG1212P1G01 - 260 CFM @ 6000 RPMs Corsair TX850 - Super Talent 2000MHz 8-8-8-24 (1320MHz 6-6-6-19) BFG GeForce GTX 260 OC MaXcore 55(SLI) Coolermaster HAF 932 Heat My Homemade PWM Controller for "The Beast"
	QUOTE Thanks

01-20-11, 10:32 AM	#19
bing Low Profile Senior Join Date: Jul 2006 Location: Indonesia	Just came out of my mind on one simple thing, Lenny, how many fans maximum that controller capable of driving ? Ever tested 4 of that beasts altogether ? This is interesting since as original circuit without the booster (inv sch buffer) couldn't drive even one as Brutal experience. __________________ █ DIY Fan Controller for 4 Wires PWM Fan \| █ Inductors are hotter than mosfets \| █ Are you HHH ? █ DIY 90 Watt Fan Controller \| █ Vintage OC-ing Gears Anyone ?
	QUOTE Thanks

01-21-11, 02:32 AM	#20
LennyRhys Member Join Date: Nov 2010 Location: Dundee, Scotland, UK	I'll get round to it soon bing. Problem with four fans is the enormous power draw of nearly 200 watts and 14-16 amps. I think I'll buy a cheap PSU specifically for testing the fans - don't want to short my system again!! __________________ i7 990X @ 4702MHz, 1.43v \| TRUE Rampage III Extreme 6GB Dominator GT @ 2000MHz 8-9-8-24 GTX480 SE Toughpower 775w U3011 & 2007FPB
	QUOTE Thanks

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