How do i power a 4 pin connector cpu fan

[mnesg]

I have 5 used tower fans that I want to improvise to cool my laptop,maybe, even use just 2 of them. How do I power my fans just like regular laptop fan that plugs into usb port or by using usb adapter to regular outlet?

 

[awknathan]

Instead of going through all the trouble I would just go out and buy a $10 laptop cooler.
But if you wanted to you could find an old USB device you have and don't need and split the wires.
Connect black to black, red to red.
Easy enough.

\Awknathan

 

[puttsy]

look at the pinout for a USB plug, the outer 2 are RED and BLACK. You need to connect red and black from the Case fans to red and black from a USB cable/plug/etc...

http://en.wikipedia.org/wiki/Pinout

Look at the USB, now, take whatever the plug you are planning to use on the laptop and connect fans red/black to the usb red/black accordingly. If the case fans use colors other than red/black (such as blue/green/yellow/black) connect yellow to red and black to black