Replacement fans for UMO

[LePaul]

Well I ordered some fans from Mouser that "indicated" two wires but what showed up has plenty.

I'm wondering if I can use these fans with just the red/black wires?

[LePaul]

Here's the spec sheet on the Mouser site

[Dim3nsioneer]

I would say yes. Red and Black should be + and -, yellow the tacho signal and blue the pwm input (you might want to connect this one to a reduced pwm voltage signal from the UMO). However, some manufacturers have other color codes, e.g. ebmpapst uses blue for -.
Some resistance measurements could give more information. Or you wait until JonnyBischof is reading this post. Then you probably get a clear yes or no.

In any case, I'll deny having given some recommendations...

[Izzy]

Mouser has good quality control then and their product description is spot on.

[LePaul]

So just use red and black ignore rest?

[jonnybischof]

So just use red and black ignore rest?

You shouldn't PWM this fan using the two-wire connection, because it has a dedicated PWM pin.

I'm not sure how the dedicated PWM signal is used in practice. The information that "it's there and PCs use it" is easily found, but HOW they do it, what voltages, frequencies and whatever they use isn't common knowledge..

I'd start by looking up Intel's ATX specifications. They specify pretty much everything about PC power supplies, cooling, case design, and so on in these specs.

/edit:
ATX specs can be found here: http://www.formfactors.org/
And here's the document: http://www.formfactors.org/developer%5C ... M_Spec.pdf

Looking at page 10, you can see that the standard defines a 25kHz nominal PWM frequency at 5V or 3.3V logic level. It also says that the signal is active-high (not inverted), so the fan will probably NOT turn when you don't connect anything to the PWM line.

Do not connect 12V (or even higher) to the PWM line!

/edit:
Now, this fan isn't necessarily a dedicated CPU fan (meaning, not necessarily made up to this specification). But I think it is, because usually people stick to these standards once they're established. And the ATX specs ARE established..
You could of course look up your fan model on the delta electronics homepage and search for documentation there.

/edit:
On page 19 you can see that the wire colors are actually defined. That means any industrial fan (such as your delta electronics fan) will match this connector pinout and wire color scheme.
Some manufacturers might use all-black wire, or transparent or whatever, but the connector pinout will still be the same - after all the fan is supposed to work on a PC.

[Amedee]

Agree on everything but:

so the fan will probably NOT turn when you don't connect anything to the PWM line.

On page 14:

If no control signal is present the fan shall operate at maximum RPM

(I searched for that because I remembered I had to use 4 wires fan on older systems, leaving the control line floating.)

So to summarize:

1. Ideally, you should power the fan in 12v and control the speed with a 25KHz PWN signal. This is not something you can do on an UMO out of the box (I mean without changing the firmware and soldering on the board)
2. They will (should) run with just 12v on the black/red wires
3. They might work on PWM 12v on the black/red wires (You can easily test with the sketch from the other post, it is not destructive)
4. If (3) is working, you can consider using them on the UMO, BUT the chances are high that 19v will kill them, so I would suggest you try to use them in series (using the same sketch) -- If they run in series, you are good to go!

There are a lot of 'ifs' there and we definitely will use these out of specs, but as you have them, it is worth trying.

[LePaul]

I'm more confused than ever....

[LePaul]

So....in summary....ignore the other wires and just use red & black?

These things are very quiet and have amazing airflow.

[ivan.akapulko]

Can be embedded in a simple circuit reobus, and have the ability to quickly change speed manually.

[chopmeister]

So....in summary....ignore the other wires and just use red & black?

These things are very quiet and have amazing airflow.

Exactly. Ditch the other wires and hope it works. I've ran several fans that came with 3 or 4 wires like that, and PWM worked on all but one of them somehow. Doesn't mean it will for you though but no harm in trying.