I disassembled an AMD CPU Wraith Cooler, meaning, I took the fan off of the heatsink, because I want to attach the fan on top of a Raspberry Pi that I'm using as a router. The Pi runs quite hot because it transmits several hundred megabytes per second, non stop, and I want to give it some cooling. (It already has its own heatsinks on its various chips inside the chassi and I don't want to use the little shitty Okdo fan, because it's loud.)
Is there any smart solution to how I could power this 4-pin fan? It needs 12V DC.
This is the Pi with its chassi.
And I'm considering something barbaric like this.
~~Are there perhaps conveniently positioned GPIO pins on the Pi that the 4-pin connector could just slide on to and just work?~~ Never mind this. The Pi 4 that I'm using can only output 5V:
Or would I need to cut off the 4-pin connector to expose the individual wires and attach them to a 12V DC adapter?
Or any other genuis solutions? :)
1st, do not power the fan from the pi if possible to avoid any underpower headaches. It should be fine.
Your best bet is to just power it at 5v using a standard USB wall wart and a sacrificial USB cable (old 2.0 ones work best). Strip the USB cable and expose the positive and negative wires and hook them up to the positive and negative fan pins (identify these using a 4pin fan header diagram). You can either try just shoving the tips of the USB cable into the fan header using electrical tape as a quick bodge, or cut and strip the fan cables and twist them together.
Gotcha! Thanks for the directions! Any reason why I shouldn't power it with 12V, since it says 12 on the fan...?
You should indeed power it with 12v
Assuming the supply can saturate the current the fan will use, at 12V it’ll be running at full speed. That’s probably pretty loud. Give it 5V, it’ll run slower and quieter.
I just found a "noise reduction cable" from Noctua. It ads 51 Ohms. I have no idea how to calculate what the new voltage would be on a 12V 2A DC power supply ( https://www.noctua.at/en/products/nv-ps1/specifications ), but Noctua's website says that the cable lowers fan speeds, so I'll give it a try.
Yeah, it’s just an inline resistor
A potentiometer is a resistor that you adjust using a dial. If you want control, you may want to get a PWM fan control module. There’s the Noctua NA-FC1 https://www.noctua.at/en/products/na-fc1 but that’s pretty much just a fancy expensive version, you can find the same concept for as little as $1-2 USD