Thinking about modding my cooling pad..

[kbronski]

So I got this awesome Thermaltake Massive 23 LX cooling pad, right?

However, I'm disappointed in one aspect: there's no low/hi fan speed option. 230mm fan, and only one speed option.
So, I'm thinking about modding it to have a low/hi switch. However, that would probably mean a new motor that can handle the power differences. The low option would probably run 5V and the high option would probably run 12V, to get some insane cooling when I really need it.

Here's a brief spec overview of the pad's power and cooling.

The motor that's in it is rated at 5V. I'm just hoping I could possibly rig something up. If it involved external AC power it might actually wind up an easier project than attempting to maintain USB power.

Fan Dimension 200 x 200 x 20 mm
Fan Speed 600 ± 10% RPM
Max. Air Flow 54.6 CFM
Max. Air Pressure 0.32 mmH2O
Power Connector USB
Rated Voltage 5 V
Started Voltage 3.5 V
Rated Current 0.21 A

Anyway, does anyone here know how I would rig up a switch to flip between voltage levels? I'm not quite sure how I would do it, and would love some assistance. One person said to simply build my own and I will look into that as well, but if I can simply gut this one out and build a new one inside of it using the same sized fan, that would be ideal.

UPDATE: I found a diagram on OverClockers forums showing me how to wire up the switch.. now I'm not sure how I'd get it all to work on external AC power (I would want to go for that). I would need a way to rig an adapter, or find an adapter. Suggestions?

 

[Lordbob75]

You could just add a potentiometer into the +5 volt line going into the fan motor to regulate voltage that way.

You just need to figure out the lowest operating voltage of that motor, and grab the potentiometer that lowers it to that.
Looks like that should be 3.5V

~Lordbob

 

[kbronski]

I'm looking at getting a new motor for it, though, ideally that would have a max operating voltage of 12-12.5V (12.5 preferably so I'm not running at max voltage when I want the cooling boost) and a min operating voltage of 5-7V. I could probably find one, it's just gonna be a bit of tracking it down.

I just did a wikipedia for "potentiometer" (since I have like, no vocabulary) and noticed what it is. That seems like it would be a rather ideal tool, instead of a toggle switch. I could adjust my cooling on a finer scale with one of those.

EDIT: You are a genius, Lordbob. This project is going to be much easier than I thought now, thanks to you. All I have to do is find a motor that fits both the size and specifications I need, and I'm set to go.

I just hope I don't tear this thing apart with what I do to it. ~600RPM being boosted to ~900min/1500max RPM (estimated at new voltages) is going to provide some truly insane (yet unparalleled) cooling and for my laptop that's a great deal.

 

[Lordbob75]

You might just consider a new fan, as that would be easier. Make sure you consider how it is powered. If it is USB, it can't get more than 5V from the computer for power.

~Lordbob

 

[kbronski]

It would be powered via 12V AC adapter (wall plug-in). The problem with this would be finding a 230mm fan rated at 12V.

 

[Lordbob75]

It would be powered via 12V AC adapter (wall plug-in). The problem with this would be finding a 230mm fan rated at 12V.

You can get a 200mm CoolerMaster fan for $30 that runs off 12V.

~Lordbob

 

[kbronski]

I found this on the Cooler Master website.

MegaFlow

And yes, it is rated at 12V, but it is 12V DC. Will a potentiometer work with DC? I thought it would only work with AC because you need the fluctuating magnetic fields to step voltage up/down? Or does that only apply to transformers? I'm not the most experienced at electronics, and only know what I learned in physics.

EDIT: Slight problem, this fan has a thickness of 30mm and my cooling pad supports a fan with a thickness of 20mm. Hmm, perhaps some full out epic modding is in store? But still, this fan only supports 700RPM. I want a fan that can at least go over 1000RPM. I need force.

EDIT: Nevermind. I just compared the airflow. 54.6CFM for my current one vs 110CFM for the new one. WOW.


UPDATE: I ordered the fan from Amazon ($15.78 w/free prime 2-day shipping). I will let you know when it arrives.

 

[Lordbob75]

Yes, they work for DC (I use them on my computer fans).

~Lordbob

 

[kbronski]

Sweet deal. So, I'm thinking about scratching my current idea, and here's why: I just wanted a better pad for more cooling, right? Well, I just found this.

SF-19 Strike Force (USB 3.0)

1200~2600RPM, 2 x 140 mm fan for laptops. This will be my new cooling pad

I also canceled my order from Amazon for that fan. I may go back later and order 2 of those fans to attempt a custom mammoth pad project, though.