Voltage controlling PWM Fans

GiraffePencils · 20 Jan 2015 at 10:35

Hello all,

I have a plan I'm hoping to bounce off you guys, check if it's possible.

I was hoping to 'daisy chain' together some fans (by soldering wires) and control them through an Aquearo 5's 3 pin headers.

But the fans were originally PWM, would this work fine?
Is there any problem with doing this?

Thanks

P4Clock · 20 Jan 2015 at 10:39

yes, but what fans and how many, you down want to overload the Aquearo and burn it out

GiraffePencils · 20 Jan 2015 at 10:43

I was planning on the EK Vardars, 2 per header.
I think that'll handle it fine yeah?

P4Clock · 20 Jan 2015 at 11:26

each fan as a power draw of 5.64W(full load)
depending on the model of Aquaero 5 they can take upto 10 channels so that would say your running 20 fans @ 5.64w so upto 112w i would say NO!

What number of fans do you plan to run in total

GiraffePencils · 20 Jan 2015 at 11:35

Sorry If I misunderstood,
I Was meaning 2 per header, talking about the fan headers on the board, Not including the expansion boards you can buy.

So 8 fans.

P4Clock · 20 Jan 2015 at 12:13

At just over 45w i cant see you having a problem, but i would invest in one of the cooling blocks you can get

Five.Stars · 20 Jan 2015 at 14:48

GiraffePencils said:
Sorry If I misunderstood,
I Was meaning 2 per header, talking about the fan headers on the board, Not including the expansion boards you can buy.

So 8 fans.

I am pretty certain that each header can take a maximum of 30W. You will be absolutely fine doing what you are planning. Although I wouldn't bother butchering and soldering. Just buy some fan splitter cables.

vsg28 · 20 Jan 2015 at 15:03

Don't use voltage control on these fans, or most PWM devices for that matter unless specifically mentioned by the manufacturer that it is ok. You can't use the single PWM header on the Aquaero 5 LT for these?

Aquaero 5 LT headers are about 20 W each with heatsink and waterblock, and closer to 12-15 W without unless I am mistaken.

GiraffePencils · 20 Jan 2015 at 15:19

Five.Stars said:
Although I wouldn't bother butchering and soldering. Just buy some fan splitter cables.

Could do, But it's all far neater when you connect them together.

vsg28 said:
Don't use voltage control on these fans, or most PWM devices for that matter unless specifically mentioned by the manufacturer that it is ok. You can't use the single PWM header on the Aquaero 5 LT for these?

Aquaero 5 LT headers are about 20 W each with heatsink and waterblock, and closer to 12-15 W without unless I am mistaken.

If I use the single header then they all go up and down together, no real control.
What problem would there be with using voltage control? as I started this thread mainly to see if someone would tell me about some huge flaw in the logic, you seem to know of some issue.

vsg28 · 20 Jan 2015 at 15:26

Well mostly to do with how the fan was designed, wasn't it? PWM for PC components is a steady 12 V with the motor providing power based on changing current draw instead. If you are lowering voltage also, then the motor won't really function as designed and this leads to bearing and motor noises that people complain about at times. In this case anyway, I had asked EK about this and they had said to run on PWM only. For more specifics, maybe hit up EK_Luc and see?

Tealc · 20 Jan 2015 at 17:26

As above. It is possible to run pwm fans on voltage control but it isn't ideal. I find them to be noisier and have poor starting speed. The onboard controllers just don't react well and can refuse to spin up. One of my pwm fans won't even run much below 9v, which is pants really.

Your fans may be better though.

GiraffePencils · 22 Jan 2015 at 08:33

I have Received an Email from EK, they say there is no problem with voltage control.

I am most likely going to go with a PWM fan controller, I just thought it best to put the response here

vsg28 · 22 Jan 2015 at 12:28

Umm what? Who said that? Peter?

Niko was the guy responsible for developing this along with the rest of the EK products and he was the one who said PWM only to me. I will clarify again and see.

GiraffePencils · 22 Jan 2015 at 13:25

Yes Peter
So might be a more marketing answer than a tech guy

vsg28 · 22 Jan 2015 at 14:01

Asked Niko again, he said it's not recommended but not like the fan won't run.

ErikN · 26 Jan 2015 at 10:06

Got this from their support:

Dear customer,

Thank you for contacting EK Support.

You can also use voltage regulation using ex. a 3-pin fan controller.

If you need any further information, please do not hesitate to contact me.

Kind regards, Peter Šajn

GiraffePencils · 26 Jan 2015 at 10:10

ErikN said:
Got this from their support:

yeah, that's what I got.
But a general customer support guy saying you should have no problem,
And an enthusiast support guy telling you to avoid it, I'd go with the latter

ErikN · 26 Jan 2015 at 10:21

GiraffePencils said:
yeah, that's what I got.
But a general customer support guy saying you should have no problem,
And an enthusiast support guy telling you to avoid it, I'd go with the latter

I suppose so, yes, kinda hard to know as customer tho.

I already ordered 4 of them, going to connect them to a lamptron cw 611, if it turns out bad I guess I have to get me something like a aquaero 6 pro, despite the hefty cost.

(anyone have any recommendations for a PWM fan controller which can handle about 4 fans per channel and have a configurable auto mode from temp sensors?

)

GiraffePencils · 26 Jan 2015 at 10:25

I'm gonna make a fan controller.....
Only coz I'm poor and don't want to buy an aquearo 6

It was this thread that made me give up voltage control and make it