Will it hurt the pi if I run a fan on the 3.3v gpio? I have a hdmi lcd screen on mine and I don't want to use the usb ports for a fan. I have a raspberry pi 3 by the way
asked Mar 9, 2017 at 22:35
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Also I am a noob– kyran bullardMar 9, 2017 at 22:37
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Why not use 5v instead of 3v3? You will get more power.– anonymooseMar 9, 2017 at 23:40
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The 5v are already taken by a lcd screen and I don't need much air flow and I know it won't make the fan run 100%, I just need to know if it could damage the pi?– kyran bullardMar 10, 2017 at 0:14
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Do you mean the 5v pin is physically blocked?– anonymooseMar 10, 2017 at 1:28
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Yes it is, it powers my lcd– kyran bullardMar 10, 2017 at 2:08
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3 Answers
The short answer is yes.
The long answer is yes, but...
3.3VDC is enough to run a low speed fan provided its designed for 3.3VDC.
I wouldn't try anything larger than a 40mm fan like this one, and this is why: the larger the fan blades are, the more torque is required to turn them, in in turn requires more power.
When you only have 3.3 volts, it takes 4 times the amount of current than with 12 volts most computer case fans run on. Also, the fan speed will not be as fast as the regular computer case fans either.
But yes, it can work for you.
A quick google search found a few pre-made options like this one on Amazon for one with a fan running on the Pi GPIO pins. .
I can neither speak for nor against either of these fans as I have not used them, they were just the first reasonable hits in my google search for "3.3v case fans".
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The 5v are already taken by a lcd screen and I don't need much air flow and I know it won't make the fan run 100%, I just need to know if it could damage the pi Mar 10, 2017 at 0:15
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@kyranbullard No, it won't hurt the RPi to connect a 12v fan. A fan is just a DC motor, it will spin or it won't. But it won't draw so much juice that it will fry something. Mar 10, 2017 at 0:24
You can draw up to 800 mA from the Pi 3.3V. See Raspberry Pi Power Limitations
Why you would want to run a fan (3.3V or other) on the Pi is a mystery.
answered Mar 9, 2017 at 23:12
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The RPI3 can require a fan in certain circumstances to avoid throttling. That being said I wouldn't want a 3.3v fan, but if nothing else that should suffice. Mar 10, 2017 at 14:10
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After making the portable gaming system I played it for quite some time, and when I went to the command screen there was a little icon of a thermometer flashing on the right side of the screen and I could feel it getting warm, so I put a small fan by it and it stops. I don't want to have to carry around a usb fan for it, so I'm putting a small fan in the case Mar 10, 2017 at 17:10
You can safely run a 5 V fan from Pi 3.3 V standard supply (Pin 1).
Using a Geek Pi 4-level Raspberry Pi case that comes with a 120 mm LED fan. Supplied at 5v the fan is a bit loud. At 3.3 V the fan is quieter. Although at 3.3 V the LEDs don't light up as brightly.
