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I have a Noctua NF-F12 computer fan (specs: https://noctua.at/en/nf-f12-pwm/specification). I also have a Samsung USB Wall Adapter (Originally for charging my tablet). The USB Wall Adapter says it can output 5V 2.0A.

My computer fan, according to the specs, runs at 12V 0.05A. How do I go about powering this? Some have said to purchase a 5V to 12V step up module with a USB connection, then solder the fan wires onto that, and plug the USB end into the wall adapter or would it work if I plugged it into a computer's USB port?

I've also seen DC wall adapters for sale. I saw a 12V DC Wall Adapter, and it says it can output 12V 100mA. However, most of them supply 500 mA, 1A, or 2A. My fan says it only needs 50 mA (0.05A). What happens if I solder the fan wires to this DC Wall Adapter? It is 12V but isn't it too much current? Will this burn out the fan?

Edit: With all that said, is it best to just purchase a DC power supply and splice the fan wires, or can I go with a 5V to 12V step-up module with a USB connection and use any of my USB wall chargers instead?

Thank you in advance.

Carlos Resurreccion
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  • The duplicate answers your final paragraph. As for the middle paragraph, a PC fan will typically run ok on 5V, albeit slower. Just connect it directly to your 5V supply and check if it spins fast enough for you. – Tom Carpenter Jun 11 '18 at 21:30
  • How are you going to use that fan? In a computer? To cool your drinks? – Maple Jun 11 '18 at 21:32
  • @TomCarpenter so it's okay to get any adapter that says it can supply at least 0.05A, because my fan will only pull 0.05A? – Carlos Resurreccion Jun 11 '18 at 21:47
  • @CarlosResurreccion correct. – Tom Carpenter Jun 11 '18 at 21:49
  • @CarlosResurreccion, a 12V 500mA power adapter does not "push" 500mA into the load .... it has 500mA available to the load .... if the load tries to pull more that 500mA then the power adapter will overload and either shut down, or the voltage will start dropping ..... your fan will pull 50mA from the power adapter – jsotola Jun 12 '18 at 02:08
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    @CarlosResurreccion, don't forget, in a computer, the fan is powered by a 12V 15A power supply and it does not burn up – jsotola Jun 12 '18 at 02:32
  • Whether you go with a 12V powersupply, or a booster to get 12V from your existing 5V powersupply, you will have to buy something. Why not just buy a proper power supply? – JRE Jun 12 '18 at 04:54
  • @JRE: Why not just use 12V available from PC? The OP hasn't answered my question, so I have no idea what he's planning to use it for, but this "would it work if I plugged it into a computer's USB port" tells me there would be a computer involved. And if that is so then maybe he simply doesn't know there is 12V there? Sounds like XY problem to me, without additional data. – Maple Jun 12 '18 at 05:51
  • I need to cool my Dell XPS 15 9560. The laptop has an air grill on the bottom, where the middle portion is actually sealed by a copper shield. I removed it it's blocking any air to the VRMs. Dell didn't provide any cooling to the VRMs, it's not connected to the heatpipe structure, thus the GPU, though thermally cool, gets power-limit throttled because overheating VRMs cannot provide enough wattage. I've tried it in practice, using the laptop on top of an electric fan. Now I'm just looking for a more elegant solution, i.e. strapping a static-pressure optimized fan to the bottom (Noctua NF-F12). – Carlos Resurreccion Jun 12 '18 at 07:10
  • Ok, now it makes sense. I'll scribble an answer. – Maple Jun 12 '18 at 11:11
  • Oops.. see what happens when you do not describe actual problem. The question was marked as duplicate even though it is not. The best solution to cooling laptop is to buy ready-made "laptop cooling pad". They have flat 5v fans that you can power directly from USB port. If you do want to use your Noctua then I suggest using cheap 5-to-12V boost module for portability reasons. You would be able to power it from your laptop USB port when in a pinch or from cheap USB wall charger when you have wall socket nearby. – Maple Jun 12 '18 at 11:23
  • You don't need step-up module with USB connector, you can use one with solder pads, mount it on or near the fan and use any old USB cable as power cord. And to answer your other question - you only have to make sure that your step-up can provide at least 50mA, 100mA would be better (it will run cooler). If it is rated for more you won't damage your fan. The fan will take only what it needs, not the maximum current available. – Maple Jun 12 '18 at 11:26
  • @Maple So what I've done is I used an old router's 12V 1A DC wall Adapter. I used paperclips. Instead of sacrificing my Noctua just to test if this will work, I used two 92mm fans, each rated at 12V 0.4A. I soldered their 12V and GND wires together, then soldered that onto the GND and 12V of the DC Wall Adapter (using paperclips). The fans work! At full speed. Pretty noisy, but it works. – Carlos Resurreccion Jun 12 '18 at 14:18
  • I am surprised that you are surprised by the result. If you connect 12V device to 12V power supply of course it would work, unless supply is too weak. 1A is enough for 2x0.4A fans. But if you have used dc-dc booster with adjustable output you'd be able to reduce voltage a little bit and cut the noise. Something like [this](https://www.aliexpress.com/item/DC-DC-Adjustable-Boost-Module-2A-Boost-Plate-2A-Step-Up-Module-with-MICRO-USB-2V/32874450951.html) or [this](https://www.aliexpress.com/item/7W-USB-DC-5V-To-6V-9V-12V-15V-Adjustable-Output-DC-Converter-Step-Up-Boost/32825148673.html) – Maple Jun 12 '18 at 17:30

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