How to power a fan externally (Noctua NF-F12)

[alpha1172]

Hi there, I need to power a fan externally (Noctua NF-F12, specs: https://noctua.at/en/nf-f12-pwm/specification).

My Dell XPS 15 9560 has VRM cooling issues. I've removed the copper shield covering the middle portion of the air grill on the backplate, just where the VRMs are, and I need a static pressure optimized fan blowing there to prevent VRM throttling. I've had success using my laptop on top of an electric fan, so airflow in that area does in fact stop VRM throttling.

I just need a more elegant solution. I have a USB wall adapter that outputs 5V 2A. According to Noctua, the NF-F12 runs at 12V and 0.05A.

Any ideas on the best way to convert that?

P.S. I've tried USB powered fans. When shoved directly in the backplate it doesn't do much. Probably because they're weak and only meant for airflow. They aren't strong enough to push air into the laptop's grills with sufficient pressure.

 

[Eximo]

12V fan will run off of 5V, it will just spin very slow. But if you want full speed you'll need a 12V power supply. They are quite inexpensive.

https://www.amazon.com/Switching-Adapter-Security-100-240V-Charger/dp/B0792261BP/ref=sr_1_1_sspa?ie=UTF8&qid=1528754068&sr=8-1-spons&keywords=12v+switching+supply&psc=1

And they get cheaper if you look for kits on ebay, probably pay more for shipping though.

There is probably 12V inside the laptop you could tap into, certainly the battery pack or charger with a regulator, but that would be getting a bit silly.
I presume you are using this only when the computer is stationary, so the above product should be fine. Just chop the end off and wire it up to the fan's + and -.

You may already have a 12v power brick around, quite common for old modems and routers, external disk drives. (CD/DVD, Zip, etc)

I should add that if you don't want it running full speed, you could also look into 9 or 10v power supplies, which would make it more mid-ranged.

 

[alpha1172]

12V fan will run off of 5V, it will just spin very slow. But if you want full speed you'll need a 12V power supply. They are quite inexpensive.

https://www.amazon.com/Switching-Adapter-Security-100-240V-Charger/dp/B0792261BP/ref=sr_1_1_sspa?ie=UTF8&qid=1528754068&sr=8-1-spons&keywords=12v+switching+supply&psc=1

And they get cheaper if you look for kits on ebay, probably pay more for shipping though.

There is probably 12V inside the laptop you could tap into, certainly the battery pack or charger with a regulator, but that would be getting a bit silly.
I presume you are using this only when the computer is stationary, so the above product should be fine. Just chop the end off and wire it up to the fan's + and -.

You may already have a 12v power brick around, quite common for old modems and routers, external disk drives. (CD/DVD, Zip, etc)

I should add that if you don't want it running full speed, you could also look into 9 or 10v power supplies, which would make it more mid-ranged.

Hi! It will be no issue that the power supply you linked gives 1000 mA while my fan only takes 50 mA?

 

[Eximo]

That is what the rating on the supply is. Key word being supply or rated output. You could plug 20 50ma loads into it and still be within spec (though with cheap electronics, you really don't want to do that) Same with computer power supplies, you always want more than you are going to use.

More load equals more heating on the PSU components. Large supplies have larger components and larger heatsinks. 1A @ 12V is only 12W, and 50mA is practically nothing.