If you have got an old computer case lying in a closet, you can salvage the case fan and turn it into a personal USB-powered desk fan. When it's not blowing air onto your face, you can use it to cool your mad-hot typing fingers.
And if you don't have any old PC cases, you can pick up a case fan for as cheap as $6. As for the other parts -- you've probably got them all lying around your house or the office, too.
1. What you'll need
- An old (or new) case fan, preferably 5V or 9V, but 12V can work too
- USB cable
- Soldering iron
- Solder
- Wire cutters
- Electrical tape
- Scissors (optional)
2. Cutting the Cable
Near one end of the USB (the one you intend to plug into the fan, not the computer), cut the cord. You can toss the end you just cut off. If you want to make the USB cable shorter so it better fits on your desk, you can trim some of the cable from the middle.
3. Make the Connection
If your case fan is new, it may have a three-pin connector at the end of its wires. You can tin the ledes from the USB cable (coat the bare wire with a thin layer of solder, which aids connectivity) and then connect black wire to black wire, red wire to red wire, through the connector. Don't worry about the ground wire on the fan (it's usually yellow). In fact, you can just snip it off.
4. Plug it In
Final step is Just plug the USB cable into any computer USB port to turn it on.5. Tweaks and Adjustments
USB cables deliver 5V, so a 5V fan is best. But 5V fans are uncommon in modern PCs, and you'll probably only find one if you're salvaging a fan from an ancient desktop. You can sometimes find lower-voltage fans in laptop PCs, but otherwise, you're probably stuck with a 9V or, most commonly, a 12V fan.If you're using a 12V fan, it will still work, but the fan will just spin with a very low RPM. Ours worked, but blew only gently (probably not at its full 4500 RPM potential).
You can fix that by adding a switching regulator to your setup, a pretty simple circuit that will boost the voltage from 5 to 12V. This is a component that you'll have to solder together yourself, but it's a simple circuit and you can find everything you need in your local electronics supply store.
If you'd like your fan to blow at an angle (up at your gorgeous face, perhaps?), you can also use a coat hanger or similar thick wire to create a stand for your fan.
