this post was submitted on 03 Jul 2023
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Making a USB desk fan from spare CPU fan (lemmy.world)
submitted 1 year ago by Devils69Advocate@lemmy.world to c/askelectronics@discuss.tchncs.de
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If I wanted to make a USB desk fan from a spare CPU fan (input: 12V, 0.15A), could I just solder a resistor to the positive lead of the USB wire? I plan on getting an adjustable voltage booster, but I was curious if this was possible. I think I would need a 13 ohm resistor for USB 3.0.

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[–] sweafa@discuss.tchncs.de 3 points 1 year ago (1 children)

usually fans have a min start voltage. u can try if your fan starts at 5v and if the resulting RPM is ok for you, just solder it without any resistor on USB

[–] Devils69Advocate@lemmy.world 1 points 1 year ago (1 children)

I actually tried that and it moved a little, then stopped.

[–] sweafa@discuss.tchncs.de 1 points 1 year ago

ah well, then it doesn't work proper with 5v unfortunately

[–] sexy_peach@feddit.de 1 points 1 year ago

I have made this but with a couple of batteries in series, it works fine so why wouldn't it with 5v USB power.