How to Convert a Case Fan to USB




In this Instructable I will show you how you can convert an old case fan for a pc to usb power.

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Step 1: Materials Needed

For this project, you will need:
A pc case fan
a usb cable (doesn't matter what the end of the cable is as long as one end is a full size male usb jack)
a wire stripper and electrical tape

Step 2: Cut Fan Connector

The start of our journey is to use your scissors to cut the connector off of the case fan.

Step 3: Strip Fan Wires

Now we need to strip the ends of the black and red wires with your wire stripper. If you want, you can cut the other wires short so they stay out of your way. We will not be needing them.

Step 4: Cut Usb Cable

Now cut the end of your usb cable that is not male off.

Step 5: Strip Usb Cable

Now you need to strip the usb cable to reveal the shielding. peel back this shielding to reveal the red and black wires. You can cut the other ones, as we don’t need them.

Step 6: Strip Usb Wires

Next, you need to strip the red and black wires.

Step 7: Twist Wires

Now we need to twist the red wires together and the black wires together. Make sure to tightly twist them so you get a stable connection. If you want to take this a step further, you can solder the wires instead of twisting them, but twisting the wires should be enough.

Step 8: Tape It Up

Now you should individually tape up the black connections and the red connections. Then you should cover those in a layer of electrical tape as shown. If you want a cleaner look, you can use shrink wrap over the individually wrapped wires instead of tape.

Step 9: Test It

Step 8 is to simply plug it in to either your computer or a usb charger to test it. (The fan is actually spinning in the picture)

Step 10: Enjoy

Have fun staying cool with your new USB fan!

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9 Discussions


2 days ago on Introduction

I have a question. A typical 120mm case fan runs about 1500-1700 RPM, the larger 140mm typical case fan runs 1300-1500 RPM. Those numbers full power numbers. In this case, typical fan headers on a motherboard provide 12v these fans need. A USB connection provides only 5v. My question is: have you tested the RPM of the fans running on the 5v versus the standard full power 12v RPM? That 140mm fans also run at 12v but typically have an RPM of 1300-1500. I have a few older USB hubs and one has two USB to power the whole strip, perhaps if you used two USB pigtailed together with the fan, you’d get close to full power and more RPM. Basically one USB is “low speed” and both USB is “high speed”. I’ll give it a try this week. Good stuff.


25 days ago

Nice Idea... how about converting the car socket (cigarette outlet) to USB? Os it possible...


1 year ago

I made it, but I don't feel like posting images. I'd say not to use just any USB cable because the lower quality ones may not send enough electricity to the fan to have it run at full speed. The one I used was a really old one and the fan is running slowly.


4 years ago on Introduction

Hi, I have made something like this, but my fan is 12volts, and usb is only 5volts, anyone know if it is safe to use a 12 volt fan with a computer usb socket? well, what I mean is will it fry my computer usb socket trying to draw out more than 5 volts to run the fan? Should I just get a 5 volt fan to be on the safe side or am i fine with what I have?

1 reply
HT GeekEthanM2

Reply 2 years ago

Old post but FYI... it won't hurt the fan. It will either work or it won't. If it works, it will run very slow. Whether or not that will work depends on how the fan was designed.


3 years ago

I used this to save a Thermaltake laptop stand. Cheers!


5 years ago

great idea. if you add a voltage regulator and stepup you should be able to get full speed from the fans. computer case fans run of a 12 volt rail. usb is 5 volts


This is a great idea! Instead of buying a USB fan, converting an existing fan into a USB is a great idea. Loved this, I agree though, I'd like to see more from you, other conversions maybe?


5 years ago on Introduction

I think this would be great to apply to a fan with lights. You could put it in an actual case and it would look great.