Reversing the polarity of a brushless motor

[Shank]

I have this short and to the point; I have this fan heatsink assembly. Its beautiful. It works. Its inexpensive. Everything I want. 1 problem though: the fan blows toward the heatsink instead of away. Seriously, WHY?!?!?

How do I reverse the polarity or make it spin the other way?

And no, simply swapping the wires doesn't invert the polarity because brushless motors don't work like thay.

 

[legofan623]

I don't know how easy it would be to disassemble such a small fan, and keep it intact, but if these fans work how I think they do, shouldn't you just be able to take the wires from the controller -> fan and reverse them instead of reversing the wires from the PC -> controller? I'm talking about the wires under the "BRUSHLESS MOTOR AND FAN" text here:

If you can't get at it I'm afraid you're in the market for a new microfan.

 

[Shank]

Good help! Here's a picture of the back of the circuit board. I could cut a hole in the plastic to access leads, but I would have to figure out where it all is so I destroy as little as possible. Any idea which wires I should swap?

 

[legofan623]

Picture?

 

[vskid3]

Why do you want it to blow the other way? Almost all computer heatsinks have fans blowing towards the heatsink, slim 360 is one exception I know of.

 

[Blargaman91]

Why do you want it to blow the other way? Almost all computer heatsinks have fans blowing towards the heatsink, slim 360 is one exception I know of.

If you're using it for a portable you'd probably want it to pull hot air directly away from the processors, not blow are onto them where it'll be blown into the system and have to escape somewhere else.

 

[Shank]

Whoops. Heres the picture:

Heres a link to a full size image.
http://i.imgur.com/PhiTABc.jpg

Blargaman is correct. I want to blow the air out of the console and case instead of into it. Most consoles I have taken apart blow air away from the heatsink instead of into it.

 

[Blargaman91]

How about you dremel out a hole in that plastic to access the PCB, find the two through holes where the motor os attached, and rasp the traces and rewire to reverse the polarity. The motor should have 0 ohms of resistance between its positive and negative leads.

 

[Cllinw]

Bumping this thread because I plan to use these and I'd like them to work efficiently.