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DIY Fan Controller for PWM Fans

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project "redemption" :salute:

Untitled3.png


this is my 3rd attempt with extensive smd components.
all my previous ones were FUBAR :chair:

so, wish me luck guys :D
 
Have read everything, also replies, but still have some questions

I'm a total Electronics newbie. I can solder and did make some kits like Arduino, but nothing very small and I have no idea how to make my own stuff. I struggle much to find the items needed even though I get a list as I get A LOT of results when searching for "555 ic"....

I think that clears up my knowledge :)

Someone else asked this, but I'm going to ask Again: This IS for 4 pin PWM fans, right?
Asking as I simply can't find any DIY 4-pin PWM controllers / DIY kits or similar. Also asked as I don't see more than 2-3 wires on any of the images here?!

It must be proper PWM controller with seperate/direct 12v power input to the device.

Means I don't want some modulated DC controller, which is about all I can find when looking for DIY items.
 
I'm a total Electronics newbie. I can solder and did make some kits like Arduino, but nothing very small and I have no idea how to make my own stuff. I struggle much to find the items needed even though I get a list as I get A LOT of results when searching for "555 ic"....

I think that clears up my knowledge :)

Someone else asked this, but I'm going to ask Again: This IS for 4 pin PWM fans, right?
Asking as I simply can't find any DIY 4-pin PWM controllers / DIY kits or similar. Also asked as I don't see more than 2-3 wires on any of the images here?!

It must be proper PWM controller with seperate/direct 12v power input to the device.

Means I don't want some modulated DC controller, which is about all I can find when looking for DIY items.

Mine are for 4 pin fans with 12V input, If you want to, you can PM me with your address and I'll send you 1 or more of my boards, I'll put all the small stuff on it, you can put the big stuff on it when you get it.
 
Mine are for 4 pin fans with 12V input, If you want to, you can PM me with your address and I'll send you 1 or more of my boards, I'll put all the small stuff on it, you can put the big stuff on it when you get it.
Very very kind of you. I've sent a PM.

To everyone else:
If you happen to have a diagram of, or a link to a non-smd based PWM controller (not DC modulation) lying around, I would really love to see it.

I have seen a lot of diagrams based on the 555 ic but most are just for 2 wire fans... I really need proper pwm control and can alternatively feed the 12v signal directly to the unit.
I have a 10 week intro electrician course some years back, but know nothing about Electronics and are struggling to make sense of even these basic diagrams, so please be gentle :p
Edit: I do know how PWM Works, both for DC modulation and the separate PWM signal for computer fans and pumps etc.

My "ultimate" goal is to control waterpump with real PWM pulses and have both PWM % and RPM shown on either 1 or more likely 2 seperate small LCD displays :)
 
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It's working!

Hi,

I built the fan controller (one 555) and it worked first shot!
Thank you very much for your DIY. This is my first electronics assembly project, so I'm pretty proud!

Since I only had 12V supply I added a Traco TSR 1-2450 DC/DC converter to get 5V and it's really fine.

Now I can control the rpm from 0 to max flawlessly, amazing!
 
Hi,

I built the fan controller (one 555) and it worked first shot!
Thank you very much for your DIY. This is my first electronics assembly project, so I'm pretty proud!

Since I only had 12V supply I added a Traco TSR 1-2450 DC/DC converter to get 5V and it's really fine.

Now I can control the rpm from 0 to max flawlessly, amazing!

If your using the same circuit linked to in the 1st post, you will only get 2% to 98% speed, but then again if your using 4000+ rpm fans, who cares about that last 2% :) now if you use the circuit using the 556 chip then you can get 0% to 100% speed.
When I saw how bad the soldering was in the article in the 1st post, I thought I can do better :)

trackbreaks-300x225.jpg

DSCN0598.JPG

I used PCB layout software to layout the board the way I wanted, then I had a board shop Advanced Circuits make the boards.
 
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If your using the same circuit linked to in the 1st post, you will only get 2% to 98% speed, but then again if your using 4000+ rpm fans, who cares about that last 2% :) now if you use the circuit using the 556 chip then you can get 0% to 100% speed.
When I saw how bad the soldering was in the article in the 1st post, I thought I can do better :)

View attachment 161525

View attachment 161516

I used PCB layout software to layout the board the way I wanted, then I had a board shop Advanced Circuits make the boards.

Oh, that's nice! My soldering isn't astonishing either.. Thank you for the link, I'm sure with some practice the board shop way gets much less time consuming...
 
If your using the same circuit linked to in the 1st post, you will only get 2% to 98% speed, but then again if your using 4000+ rpm fans, who cares about that last 2% :) now if you use the circuit using the 556 chip then you can get 0% to 100% speed.
When I saw how bad the soldering was in the article in the 1st post, I thought I can do better :)


I think the 0-100% will be refer to any speed profile pre-flashed by the fan mfg.
not the ability to scale down the fan speed itself.
So, depend to the fan we used, we'll get different results.

take the cougar vortex as an example (the only fan with available curve speed I can find in the net so far):
15497515415_a087a253e8_o.png



and if we make some scale down the PWM signal, we should see something:
15418459802_23eb62c9bf_o.png



The difference should be negligible, as the curve's quite linear at the bottom and top.
But the obvious thing is, the cougar will never stop spinning even with 0% applied to it.

The curve's quite typical with the "PC class" fans.
Once we move on to the industrial fans realm; that would be a different story :D


ooh...
I forgot to mention that the 0-100% do benefit from the steady output PWM frequency when it compared to the 2-98% version.
But again, most of the "PC class" fans don't care about this.
AFAIK, only the San Ace 9SG and Delta "EFB /C" suffer from this (such as the high pitch noise),
but the list might be added, though. Since there's no way I can get my hand to each fan model on this planet, LOL
 
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I think the 0-100% will be refer to any speed profile pre-flashed by the fan mfg.
not the ability to scale down the fan speed itself.
So, depend to the fan we used, we'll get different results.

take the cougar vortex as an example (the only fan with available curve speed I can find in the net so far):
15497515415_a087a253e8_o.png



and if we make some scale down the PWM signal, we should see something:
15418459802_23eb62c9bf_o.png



The difference should be negligible, as the curve's quite linear at the bottom and top.
But the obvious thing is, the cougar will never stop spinning even with 0% applied to it.

The curve's quite typical with the "PC class" fans.
Once we move on to the industrial fans realm; that would be a different story :D


Ok that sounds right.

For the record I have a NOCTUA NF-B9 PWM fan and when I turn down to 0% it stops spinning. I don't actually know if it goes to max speed when turned to 100% but anyway my goal was to set it to "the maximum speed that makes no noise". Moreover it turns out that that speed is enough to keep the attached heat-sink at a low temperature.
 
Ok that sounds right.

For the record I have a NOCTUA NF-B9 PWM fan and when I turn down to 0% it stops spinning. I don't actually know if it goes to max speed when turned to 100% but anyway my goal was to set it to "the maximum speed that makes no noise". Moreover it turns out that that speed is enough to keep the attached heat-sink at a low temperature.


that looks strange to me.

take a look at this:
http://www.noctua.at/main.php?show=productview&products_id=44&lng=en&set=1

given the worst -20%, the fan should spins at ~240 rpm @0% (slow but it should be keep spinning).
you might want to recheck your controller, or a least add another 555 as shown on the "mega thread"; sorry for the no-link, since I've lost all of my bookmarks.

but if you already happy with it, you can use it anyway :thup:
 
Some variable speed ("PWM") fans do interpret 10% and below as a command to turn off. There are also some that will just go full speed if it gets 0% or very close to it, as a safeguard against the the line becoming shorted to ground. It all depends on what the OEM programmed into the inverter.
 
Some variable speed ("PWM") fans do interpret 10% and below as a command to turn off. There are also some that will just go full speed if it gets 0% or very close to it, as a safeguard against the the line becoming shorted to ground. It all depends on what the OEM programmed into the inverter.
If they turn off they do not follow the specification. All PWM controlled stuff should go to 100% if PWM signal gets too low or is missing eetirely..

Some have a lower limit at like 30 %, and can't be tweaked lower, while others have a "soft" limit at 30 % (like my new noctua industrial fan), but can actual be turned down much farther with some controllers.

(I might remember the above slightly wrong, but it is about right)
 
OEMs often request "nonstandard" programming. Probably the most common example are GPU fans that have a fanless mode.
 
After checking out several DIY PWM controllers on the internet I have finally found this one. About time because it started to get ridiculous. Every second of such projects had fundamental errors pointed out in comments, other projects made by guys who don't impress me as someone who knows what he's doing. So, thank you for the article and thanks to those who helped you!

One million Watts... :)

Now; for the serious answer.

The PWM controllers that this article refers to don't actually power the fans. The fans are powered straight from the PSU (12V) all the time and the controller simply sends ON/OFF signals to a circuit on the fan that switches power ON/OFF very fast (the standard is 25KHz, but some fans work on other frequencies).

So since the fans are not being powered from the controller; the answer to your question is that you can run whatever fans you want (no watts limitation); provided your PSU can power them.
I was also under the impression you need the 556 variant for 12V fans. It would be great if the article was supplemented with the information, highlighted.
Speaking of which. Could anyone please try to explain what specific fan configuration would require the 556 variant and why?

Even though I'm a electrion00b I plan to build a controller based on this one (555) with the following minimum features:
- 4 fans in total, two of which controlled in pair (common control signal)
- on/off switches (not integrated in potentiometers)
- optional: full RPM startup capacitors
- optional: 'fan not operating' leds
- optionsl: integrate the PWM controller with a standard potentiometer-only controller for 3-wire fans sporting the same features as listed above


Few basic questions:
1. You've mentioned short circuits during your work. Why didn't you use a circuit breaker?
2. How many fans can be connected to the common control line with the 555 controller?
3. Does anyone have schematics for any variant of the controller for 2 fans controlled separately?
 
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This circuit seems to be quite good and can provide great accuracy of timing. Thanks for publishing it.

Do you only need the application of the two diodes because of the easier timing, or do they also enhance the stability of the a-stable circuit?

Best regards,
chey
 
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I've just finished re-creating the controller in Fritzing. Change the file extension from 7z to fzz. This is not an archive. Then I'm going to also use Fritzing to create my multi-fan controller by cloning as many of the 555 PWM controllers as needed alongside headers regulated using regular potentiometers only for 3-pin non-PWM fans.

Fritzing also exports bill of materials etc.

NOTE 1: There are no mobo fan headers etc. in the Fritzing library so I've used whatever similar components there were. I couldn't even find single terminals. Also, this is my first elec project so expect everything.

NOTE 2: I have only edited the basic parameters of the components used. For example with a capacitor I only edited its capacitance without altering its maximum voltage, current or anything else.
 

Attachments

  • pwm_555_fan_controller_overclockersdotcom02.7z
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  • pwm_555_fan_controller_overclockersdotcom02_schem.png
    pwm_555_fan_controller_overclockersdotcom02_schem.png
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I've just finished re-creating the controller in Fritzing. Change the file extension from 7z to fzz. This is not an archive. Then I'm going to also use Fritzing to create my multi-fan controller by cloning as many of the 555 PWM controllers as needed alongside headers regulated using regular potentiometers only for 3-pin non-PWM fans.

Fritzing also exports bill of materials etc.

PS. There are no mobo fan headers etc. in the Fritzing library so I've used whatever similar components there were. I couldn't even find single terminals. Also, this is my first elec project so expect everything.

C1 is .01uf or 10nf not 10pf.
 
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