Do I have to resort to moddin on this? 3-4 pin Molex to usb?

I am looking at building a laptop cooler out of some spare 140mm fans I have.

I don't really want to splice stuff if I don't have to, but is it possible to just buy something that would let me plug into my usb slots, to hook to the power adapter for these fans and run them that way?

An external power supply may be the easiest route. The USB power is 5V with a 500mA nominal current limit. The fans will be 12V and will probably need higher current to run. Many fans fall in the 850mA range. Unless you get 5V low amperage fans, you will likely have problems. Even if they run at 5V, they may be pulling too much current from the USB controllers. I would not recommend this. It's cheaper to use a manufactured solution than take a chance with non-replaceable parts on the planar.

I see, is it possible to use an atx power supply? I have one that is not being used, but the issue is I don't know how to make it work with out a power switch.


EDIT: Is this what you were talking about? http://www.newegg.com/Product/Produ...re=ac_adapter_to_4_pin-_-12-706-011-_-Product

Also should coolers be facing towards the laptop bottom or away?

I couldn't find what your looking for. I did find out the official name of the 3 pin fan connector is "3-Pin Fan Molex 2510". But that to a USB I could not find. I have dun what your looking to do, but I had the wire from a old dead laptop cooler my wife killed. The fan is just one, a 70mm .2 amp which is 200ma. It runs fine on 5v from the USB but it is a lot slower then 12v. It runs silent on 5v which is a plus. I think you would have to do what you don't want to do "splice it". It's not that big a deal really. You will have to check the fans to see what amperage they run on. If it's not listed I would not use that fan. Above all you don't want to over tax the USB port on your laptop. This homemade laptop cooler has the fan blow across the bottom and exhaust at the laptop fan opening.

I also have a factory laptop cooler with two fans that blow on the bottom toward the laptop.

basically I just am going to take a piece of spare wood I have, make it the size of the laptop (little bigger) put hinges so it can fold open like a tv tray sorta and have it raised if I might be sitting on a bed or whatever. this try would then have two 140mm fans (not sure what way they should be facing)

The adapter in the newegg link will work fine.

An ATX PSU is overkill, but would work. To turn on an ATX power supply that isn't connected to a motherboard use a wire or paper clip to short the green wire (PS_ON) to any one of the black wires (COM). This can be done with a switch across those connectors as well.

The fan may run at 5V, but it's a risk I'd rather not take myself. Laptop motherboards are expensive and a failed component like the USB controller may/may not take other items with it if it goes. If you have a multimeter with an ammeter function, you could try testing the current draw of the fan across 5V connectors from a normal PSU.

Depending on the model and design of the laptop, it may support significantly higher current, but it is not always promised.

Sounds great, thanks for the advice I will just go with the adapter at newegg to stay safe.

Next question which way should the fans be pointing? Does it help to pull air from the laptop or would it be best for the fans to be blowing air upward to the laptop?

Normally, blowing in would be best, exhausting away from you. An exception would be a laptop with an exhaust vent on the bottom. I can't think of any currently, but they could exist. If there is a side intake, you may want to direct the flow of exhaust from underneath away from it as well.

Ok cool looks like it sucks in from the bottom and blows out from the back at least that's the way it feels.

I have seen 3 ring binders used, lighter then wood.



http://ask.jaimeyu.com/2010/01/diy-laptop-cooling.html

That's an excellent idea.