FEATURED Building PWM Controller for 4 wires PWM fan

I'll flash another chip and get some video of it when I have a chance, should be sometime in the next couple days.

@TsunamiJuan,

Where did you source that QFR1212GHE from ?


@inVain,

Thanks for cool video, looks like you're enjoying the kick start feature very much, just love to hear the fans screaming momentarily when you powered it on.

I ordered them from http://www.heatsinkfactory.com, they had the best price by far. it was like 4-10$ cheaper than anywhere else i found so i figured i would give em a shot.

Hello, can one of you guys make me a fan controller? I need it to power 7 regular 3 pin fans and i want it to be able to power 4pin pwm fans too just for future proof. I also want it to fit into a pci slot and use only one knob for controlling. Please PM me if any of you guys are willing to.

Bobnova said:

I'll flash another chip and get some video of it when I have a chance, should be sometime in the next couple days.

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awesome, can't wait to see the vid

bing said:

@inVain,

Thanks for cool video, looks like you're enjoying the kick start feature very much, just love to hear the fans screaming momentarily when you powered it on.

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u'r welcome bing,
yeah I did enjoy the screamer turn in into silent during the start up.
It tells me that the fans are there

leejonnymr said:

Hello, can one of you guys make me a fan controller? I need it to power 7 regular 3 pin fans and i want it to be able to power 4pin pwm fans too just for future proof. I also want it to fit into a pci slot and use only one knob for controlling. Please PM me if any of you guys are willing to.

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hello,
I'm afraid the controller we're discussing here is only working for the 4pin PWM fans only.
for a regular PC fans, this controller will handle that 7 fans of yours with single knob easily.

as for the regular linear (for 3pin fans), handling this large sums of fans can easily introduce the v-drop which lead to drop in fans performance.

most of the controller that I've build was intended to mount at the rear side of my case.
If only you're live in Indonesia, I would happy to build one for you

Here we go, finally got a video uploaded. Ignore the audio, heh. Home life may be involved

sweet... gonna be awesome kickstart for both the inverted, and the non-inverted fans

I ordered the rev2 PCBs too. Don't remember if I posted that or not.
I need to buy some parts, namely the molex connectors, before I can solder them together.
They're coming soon though, I'll post pics when they arrive.

Should have no problem powering and controlling a pair of five amp PWM fans

so much stuff added since i was last here. did anyone ever do a controller where temp controlled fan(pwm) speed?

Not yet that I know of, it's a rather difficult thing to nail down.
It's certainly possible, especially with the microcontroller flavors. The issue lies in getting the calibration right so the fan doesn't do strange things. Plus without a software link you're stuck with ambient (and in-case ambient) temp sensing by and large.

It's on my list to attack, but I'm not there yet.

Part of the fun of the PWM controller is being able to manually configure the speed - after all, most motherboards already have a temp-controlled option for the CPU PWM fan header.

As I mentioned before it would be MUCH nicer to have it software controlled, but also much more work

In any case I love this PWM controller... absolutely love it.

Evilsizer said:

so much stuff added since i was last here. did anyone ever do a controller where temp controlled fan(pwm) speed?

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Bobnova said:

Not yet that I know of, it's a rather difficult thing to nail down.
It's certainly possible, especially with the microcontroller flavors. The issue lies in getting the calibration right so the fan doesn't do strange things. Plus without a software link you're stuck with ambient (and in-case ambient) temp sensing by and large.

It's on my list to attack, but I'm not there yet.

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LennyRhys said:

Part of the fun of the PWM controller is being able to manually configure the speed - after all, most motherboards already have a temp-controlled option for the CPU PWM fan header.

As I mentioned before it would be MUCH nicer to have it software controlled, but also much more work

In any case I love this PWM controller... absolutely love it.

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I knew I had posted about this very same "idea" a long time ago...

xXSebaSXx said:

...

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I'd be more than happy to make controllers that do it, the tough part is the programming in of values.
There are some chips that I can program that have USB capabilities, so I can make a USB fan controller that you can program via software. The issue is that the board/chip is just a touch more expensive than the attiny85 chip I've been using. The attiny85 runs ~$2.26, the teensy runs ~$16!

It's possible to do a few different ways that I've been contemplating, if I can make something functional I'll let y'all know

So needless to say there's a ton of info in this thread. Any chance we can kind of consolodate some of it? IE the schematic variations, component list (incl P/Ns), etc into either a single sticky post (modified as this thread continues to mutate) or a modified first post in this thread?

I'm looking to build my own here, but the goal is to keep it contained into a single 5.25 slot, with four (maybe six) pots, at least three fan outputs per pot and one 4-pin input. I've got about 23 fans, all but four are AC F12s and the remaining being F8s. The intent is to control as a group of nine (across three rads), six (other case fans), four (top exhaust) and three (HDD/case) with one or two one offs. Each pot will have a corresponding 5v LED that will also run off the PWM signal to control brightness as it relates to fan speed.

As I'm in a compact area, the intent is to use SMD components where possible. My only question seems to be power ratings. I think most of the resistors are .5W where the caps, diodes and whatnot don't seem to call for a value save for C3 at 10v. Is the assumption that all caps are 10v rated (seems so being it's only a 5v supply)?

I'm not necessarily looking to have anything automatically controlled as I don't need that kind of automation. But I am looking to build something that's compact enough for nothining other than aesthetics.

Thanks for all the info so far and any future input.

This is one condensed version: http://www.overclockers.com/pwm-fan-controller

You should be able to use 1/8w resistors without an issue.

Capacitor rating doesn't matter as long as they're at least 7.5v caps.

Good enough for me. Thanks!

Bobnova said:

Here we go, finally got a video uploaded. Ignore the audio, heh. Home life may be involved

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Cool video !

So I can see you're now fully equipped with the probes for your scope, great !

Planning to do a similar video on inVain's controller and also to share here how the kick start mechanism works, its just I'm so busy like hell now.

Railgun said:

Good enough for me. Thanks!

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Railgun, great to hear you're going to do smd style, must be really cool, share it here once you've done building it here please.

About the component's rating, as Bob pointed out, this is a low signal circuit, so just find for the resistors the lowest wattage rating (size wise) that you're comfortable to work with. And all cap's voltage rating should be above 5 volt, maybe 6.3 or even 10 volt should be fine.

Ok...so there's a long way to go and I'm probably going to ask for some assistance in the actual PCB design part, but here's the general schematic for the controller I'm looking to build. I had already determined some parts that I'm going to use, but in my infinite wisdom, I didn't pay any attention to the actual size of these components, so some of the caps were...a little small... .4x.2mm. Oh well.

So I'm getting the component list together. The issue I assume is that the schematic doesn't have the correct components listed yet in terms of size so I'll have to iron that out. But in terms of the overall design, the goal is a single board with six pots. Each controller/pot will have three fan outputs. It will all need to fit behind a single 5.25 panel. The outputs don't need to be on the board as I can run whatever wiring later. Same with the pots and LEDs. If anyone can see any particular issues, please let me know. I haven't yet determined what type of input I'm going to use. Probably the standard Molex connector as it won't require any additional cables for my particular setup.

Again, this is going to drive 20 AC F12 PWMs and 4 AC F8 PWMs.

And to bing...just wanted to confirm something.

Regarding the first drawing on post 486, you have the ground set on the first 556, but in the drawing for the kick start circuit on post 822, you don't, but didn't explicitly mention in as part of the change. Just wanted to ensure that the ground was still intact.

Have fun with the tiny caps, I've done some soldering on tiny stuff like that. It's surprisingly doable if you have a very fine tip iron and steady hands. Just don't drop the parts, you'll never see 'em again!

Heh...I've already opted to not use those. Being as cheap as they are, I'm just calling it an oops and moving on.