FEATURED Building PWM Controller for 4 wires PWM fan

[andyrgardner]

That isn't the case. I've tested it and it works?

 

[Arkade]

then why ask if you already know

dropping the PFC1212DE voltage below 5 causes the fan to cut out, it will self regulate the RPM with the controller circuit regardless of what you set it to, it picks the RPM based on a couple things, it should NOT be controlled this way, build a proper PWM controller...

 

[andyrgardner]

I didn't ask if it would work I asked if it would damage the fan. Thanks for the answer.

 

[markus5]

PWM fan (4 cables) Controller circuit with adjustable duty cycle from 2% up to 98%.
This one actually is the same as Nidec's circuit above, its just I added PWM signal booster to cope with fan that might suck higher power than normal at the PWM out that will degrade it like Brutal's Sanyo Denki fan case.

View attachment 88563
Note : Actually that 556 IC is just two 555 ICs packed in one IC body, you could use two separated 555 ICs too,


Another version for purist who wants pure 0% (zero percent) up to 100% duty cycle. All connections to power (molex) and fans are the same as above circuit.

View attachment 88564

This circuit has an additional IC called comparator, it uses LM311, you can change it with other popular comparator ICs like LM393 or LM339, although the pins assignment are different, just map them accordingly.

Update 14th Aug 11 :

Spoiler

Single controller with 2 normal outputs for normal pwm fans and the other one for the inverted pwm fan.

http://www.overclockers.com/forums/showpost.php?p=6935139&postcount=834

Update 9th Aug 11 :

Spoiler

Kick Start Add On
Read the detail explanation here -> http://www.overclockers.com/forums/showpost.php?p=6931080&postcount=822

Also a demonstration video of Kick Start mechanism in action -> http://www.overclockers.com/forums/...ires-PWM-fan?p=7116335&viewfull=1#post7116335

Both circuits are using PWM frequency that is set according to FormFactors standard for 4 wires PWM fan -> http://www.formfactors.org/developer/specs/4_Wire_PWM_Spec.pdf

Bing, if i want to use a single 555 timer like in this link:

http://www.overclockers.com/pwm-fan-controller/

with 470 pF in C1, the pwm signal frequency is stable at 25 khz or depends on the position of the potentiometer or other?

Thanks.

 

[sandrat]

I have had a very nice PCB board made of the 0-100% controller CW/kickstart feature and 12 & 5 volt regulator packages. It is a nice dense package about 7.5cm x 2.5cm. All components are through hole mount.
This package will be used to control a 4-wire fan in a refrigeration application so a independent 12VDC power source will be used. Thus the on board voltage regulators for 5VDC controls voltage and 12VDC fan voltage.

I have three questions for the knowledgeable readers/contributors:

On a 4 wire fan the wire ID is, one for +12VDC, one for 12V GND, one for TACH . . . . . what is the connection point for the 4th wire?

How does the comparator add to the functionality of the circuit? If this is explained within this thread I have missed it.

For demonstration or other application purposes I may test the circuit with other 4-wire 12VDC motors. What is the process to determine if a 4 lead 12VDC will be compaticle with this control circuit?

Looking forward to reading the wisdom of the group.

 

[nishad4949]

Dear Bing, Please guide me how can we add Indicator LED in this 2-98% duty cycle circuit with Lick-start feature

 

[DeepSky1]

I need to be able to control all 5 fans, that circuit seemed to be the one to do it.
Any help?

Thanks!
Scott

Are you need to control them separately or parallel?
If parallel you can use 5 comparators. Connect the PWM IC output to the each comparator Non-inverting (Positive) pin. Negative pin to Ground. each 5 Output you can connect to 5 fans as well.

If separately then you should build them as your picture

 

[DeepSky1]

very useful video about NE555 timer and its PWM function.

 

[DevWolf]

I realize this is an old thread but its the only piece of info i can find thats anywhere close to what im trying to do. Im using the TLC556 circuit on a Delta TFC1212DE fan. It's looking for 30khz. The 25khz schematic produces about 30-98% throttle. Im looking at C1 and coming up with 379pF (so 380pF cap) to produce 30khz. Can anyone confirm? It's been a long time since ive actually had to work out these formulas and im doing so with no formal education.

Bing or anyone else who is still around, I would appreciate the help. Thanks.

 

[2hdass]

I bought the same fan. Where did you find out that the fan is 30khz?
Does plugging the PWM and Sense wire into the Fan headers work for you? As mine doesn't start up at all.

 

[markus5]

Hi everyone. I know this is an old discussion but i think it is the only place where i can find an answer.
I write from Italy than please sorry for my english.
In my pc i have got several Noctua fans: nfs12a pwm and Noctua nfp12 pwm. The requested optimal pwm frequency is 25 Khz and the pwm signal absorb 1 mA.
I used this simple pwm circuit:

View attachment 199978

I used a 470 pF in order to reach 25 Khz pwm frequency.
I used a GLC555 G50 CMOS timer.
I used multilayer ceramic capacitors for 0.1 microF and 0.01 microF, and polypropylene capacitor 630V 470 pF 5%
I can regulate well the speed of my fans and they start well.
I have only one question: i regulate the fan speed at 700 rpm but values ​​oscillate continuously. For example, sometimes passes from 700 to 715.

These are the registered values each second in one nfs12a pwm:

8 6 9 1 1 1 5 4 2 6 1 1 3 8 2 5 2 9 1 1 6 5 1 1 1 3 1 15 7 2 9 1 5 5 6 1 6 9 2 9 2 9 7 5

Sometimes 15 rpm is more frequent.

Is it normal in your opinion, according to your experiences?

Thanks in advance.

 

[markus5]

Can anyone help me?

 

[DeepSky1]

Can anyone help me?

I think it is normal. Drifing PWM signal between little interval it is normal.
The question is: how are you registering the RPM?

 

[sandrat]

Can anyone guide me to any post that describes how the Kick-Start circuit functions?

 

[Eamoex]

Hello Everyone,

maxfly has redirected me to this thread. Thanks maxfly!

So I'm kind of a noob with electronics, and I would like to build the 556-based PWM control circuit found in this article (which I have found referenced in this thread already). Because I think it's fun.

I've made some progress, but I don't get how the PWM signal is "interpreted" by the fan. The 556-based circuit does change the signal's duty cycle (something like 2-98%), but fan speed follows some indetermined curve, going slow in the middle and fast at the ends.

Here's a video of my being ignorant: http://www.emyamstein.ch/media/forums/IMG_0410.MOV

The fan is this: https://www.amazon.com/Noiseblocker-NB-BlackSilent-Quality-Axial-1500rpm/dp/B00839GBC6

If anyone can help I'm all ears!

 

[neonkev]

Hi Guys,

It's been a while since I've used this site. Since building the original 555, 311 based fan controller on a radioshack breadboard way back, I've decided to revisit this controller and use it for practice with PCB design. I'm laying out a low profile board using SMD components; when I've built it and verified my board, I'll be glad to share it on OshPark for anyone wanting to adopt it. I know I could've used a more organized approach 5 years ago when I first built this circuit (in high school).

View attachment 202825

 

[neonkev]

Hi Guys,

Here is a build log with the completed board, order link from Osh Park, and a complete bill of materials. I hope this helps anyone trying to build this circuit!

https://neonkev.com/2018/12/26/a-small-circuit-discrete-pc-fan-pwm-speed-control/

Here is a vid of it in action:

Enjoy!

 

[WhitehawkEQ]

Hi Guys,

Here is a build log with the completed board, order link from Osh Park, and a complete bill of materials. I hope this helps anyone trying to build this circuit!

https://neonkev.com/2018/12/26/a-small-circuit-discrete-pc-fan-pwm-speed-control/

Here is a vid of it in action:

Enjoy!

Is that a 78L05 voltage regulator on your board?

 

[neonkev]

Is that a 78L05 voltage regulator on your board?

The voltage regulator I'm using is a TS2938CS50. It is an 8-SOIC SMD package, and can regulate up to 30 volts on the input side down to 5 volts output.

I also ordered a few TI LM2936HVMAX-5.0/NOPB voltage converters after the fact, as I have a few 48 volt fans I wish to use with this circuit. This regulator accepts up to 60 volts on the input for a fixed 5 volt output. Same package and pinout as the TSMC.

Here is a bill of materials for all the exact parts I used in demo:
https://drive.google.com/open?id=1iwtzoplmZF2ddBEZk2xw1l7AbuUUEhFi

 

[WhitehawkEQ]

The voltage regulator I'm using is a TS2938CS50. It is an 8-SOIC SMD package, and can regulate up to 30 volts on the input side down to 5 volts output.

I also ordered a few TI LM2936HVMAX-5.0/NOPB voltage converters after the fact, as I have a few 48 volt fans I wish to use with this circuit. This regulator accepts up to 60 volts on the input for a fixed 5 volt output. Same package and pinout as the TSMC.

Here is a bill of materials for all the exact parts I used in demo:
https://drive.google.com/open?id=1iwtzoplmZF2ddBEZk2xw1l7AbuUUEhFi

Check this out: https://www.digikey.com/product-detail/en/ablic-u-s-a-inc/S-1142B50I-E6T1U/1662-1355-1-ND/6601495