Can the ML series fans be connected to 2 pin headers?

Hi all,

I'm interested in swapping out a fan from a device that has a 2 pin header and fan. I still want to still be able to control the fan speed so I found a cheap single fan speed controller that has a 3 pin input and output. So here's what I'm thinking:

 

2 pin header --> 2 to 3 pin adapter --> speed controller --> 3 to 4 pin adapter --> ML fan

 

Would this work? I can provide links to the device, adapters, and controller if it isn't against the forum rules.

 

Thanks,

-TheFuriousFish

Without seeing the actual devices, I cannot say for sure but I doubt it.

3-pin speed control and 4-pin speed control are completely different. 3-pin fan headers control speed by altering the voltage, with full speed being 12v, 75% would be 9v, etc. 4 pin fans use Pulse Width Modulation (PWM) to control speed. With PWM, the fan gets a constant 12v and the speed is controlled by a PWM signal on the 4th wire. In both cases, fan speed is indicated on the third wire. So that 3 to 4 pin adapter would have to ensure constant voltage AND convert the variable voltage to a PWM signal. It's actually easier to go from PWM to DC/3-pin.

The Corsair Commander would, of course, handle this for you. You could also use something like this: https://www.newegg.com/Product/Product.aspx?Item=9SIA50M2EM2392&cm_re=PWM_Fan_Controller-_-9SIA50M2EM2392-_-Product.

If you provide the links, we can look at the actual devices to see if they might work.

I'll post links to what I'm thinking of buying

 

AKiTiO Node external GPU enclosure: https://www.akitio.com/expansion/node

(I already have this, and it has one 2 pin fan header)

 

3 pin to 2 pin power adapter: http://a.co/hEVRbOI

 

Fan speed controller: http://a.co/i9ifAa2

 

4 pin to 3 pin power adapter: http://a.co/iYHfyQD

 

And of course a ML series fan. I know that the speed controller varies the voltage to control speed.

Yeah ... that won't generate a true PWM signal. The initial 2 pin line will give you power. Your fan speed controller will control the speed using variable voltage (DC mode). The 3 to 4 pin adapters don't change anything, they are dumb adapters and will pass the variable voltage from the fan speed controller to the fan. And from what I understand, the ML series fans aren't real happy when they don't get the full 12V. Some PWM fans can be controlled with DC control as well as PWM. That said, you could run the ML fan at full speed but that might be a little louder than you'd like. Not that the ML fans are particularly loud but they aren't whisper quiet either when cranked to 2600 RPM. You might be better off with AF series fans; they are voltage controlled and you'll need one less adapter. Since you shouldn't need to overcome a lot of static pressure, they should be just fine with that enclosure. That said, I didn't see anything in the enclosure's manual that stated that it supported add-on fans.

Thanks for the reply Dev. I was really going for the hub LEDs and silence of the ML fans but it looks like the AF fan may be the only way to go. I have an extra 3 pin fan out of the back of my Carbide Spec Alpha case so I'll try that with the adapter.

I agree this might be problematic. We know the ML series must have a constant high voltage (~12v). So while you know you won't be able to replicate a PWM signal, it leaves the two pin option as Full on or Full off. With a ML120 max at 2400 and ML140 at 2000, that is not exactly a livable arrangement.

 

So what is the application? I was wondering if you were trying to set-up a fan to run from a GPU power board, like on a hybrid card.

 

If you are just short usable fan headers, a PWM or other SATA powered fan hub would be a much easier solution. You would need one motherboard header to act a the speed control for the lot, but it seems less complicated and more functional than chained adapters.

The problem is I only have the one 2 pin fan header and an extra pcie power cable since my card only uses 1. The enclosure doesn't have a sata power cable as it wasn't designed for anything but a gpu. I could swap out the power supply as it's a a standard sfx size but that's pushing the budget and it voids the warranty.

So this is a GPU hybrid system? Or something else?

It's a standard open air gpu: https://us.msi.com/Graphics-card/Radeon-RX-570-GAMING-X-4G.html

 

The link for the enclosure is above.

Oh, I see what you are trying to do now with the external GPU box. The above problems still stand for the ML and I would not recommend it. Whatever you choose is going to run at a constant speed and you probably do not want a screamer fan for this application. Since most of the heat release is going to be passive and the single fan is really there to stir the pot, slow to medium speed and quiet is probably going to be the goal. Something with a hybrid blade (like a ML fan) is probably most effective. An AF series should work, but might not displace the air around the card as well.

One last question for you guys, is it safe to use a voltage regulating speed controller with a 2 pin header? Since they aren't designed to change voltage, could it burn out or otherwise damage it?