Make a USB Powered 3 pin fan?

[BurningSkyline]

Would It be possible? You can't just leave the yellow wire hangin there you know?
Take a look at my drawing. If you can't read something in the picture, ask me.

[Biased]

You should test it out without the yellow wire, I'm pretty sure it should run, if a fan that size can run on just 5v. I think the yellow wire might just be data to tell a computer system its RPM. What can testing it out hurt? Good luck.

[nevermind1534]

The yellow wire just gives out the fan speed when it's connected to one of the fan headers on the motherboard. You don't have to connect it to anything, as it won't do anything when it's not connected to a fan speed receiver.

It will run slower on 5V than it would off of 12V, though.

[BurningSkyline]

The front of the fan says 12V DC 1.8a on the front,
So I probably won't get enough power through USB

[bassmasta]

The front of the fan says 12V DC 1.8a on the front,
So I probably won't get enough power through USB

1.8A? that seems ... massive.

[BurningSkyline]

Can somebody explain to me what that means? I don't know much about it.

[bassmasta]

Fans usually don't have a very high current draw, which is why I said that it seems massive.

Undervolting electronics usually causes them to (a) not work at all or (b) work slower. So the fan will run slower (if it runs at all). And USB is usually capped at 500mA (.5A) IIRC.

[BurningSkyline]

I can take pics and take off casing later.

[nevermind1534]

Fans usually don't have a very high current draw, which is why I said that it seems massive.

Undervolting electronics usually causes them to (a) not work at all or (b) work slower. So the fan will run slower (if it runs at all). And USB is usually capped at 500mA (.5A) IIRC.

It will run at 5V, but it will be slower. The 500mA cap could be a problem, though. You'll have to try it to know for sure.

[gamax92]

Step 1. Retrieve computer fan

Look online or at your local computer-repair shop for a plastic computer-cooling fan. Or, dismantle an old computer and unscrew the fan inside. Disconnect the two wires that attach it to the computer – one red, one black. The wires will remain connected to the fan.

Step 2. Strip fan wires

Using wire cutters or a wire-insulation stripper, strip off a half-inch of the protective coating from the two wires.

Step 3. Strip USB cable

Cut off one end of the USB cable and strip away two inches of the outer casing. You should see four wires inside – green, white, red, and black. Slice off the green and white wires up to the casing. All you need are the red and black wires.

Step 4. Strip red and black wires

Strip a half-inch of the protective coating from the red and black USB wires.

Step 5. Connect wires

Twist the exposed USB wires to the exposed wires from the computer fan – red to red, and black to black.

Step 6. Tape wires together

Wrap the two individual sets of connected wires separately in electrical tape. Then, tape and wrap both sets together to form one cable.

Step 7. Build stand

Create a stand for your fan. To start, get about 18 inches of sturdy electrical wire and bend it into a square “U” shape the same width as the fan.

Step 8. Install stand

Push each end of the wire through the bottom screw holes in the fan. Bend and push the rest of the wire up, around the fan, and through the top screw holes. Bend the ends of the wire to secure the stand, and cut off any excess. Rest the stand on a flat surface.

Step 9. Plug in fan

Adjust and angle the fan as desired and plug the USB cable into your computer. Ah, feel the refreshing breeze.

[Bdawg]

I made one of these today! What a coincidence haha.
You should probably solder those wires, instead of just twisting them, but other than that gamax92 is spot-on. In fact, I'll be using his(or her) steps to make a stand!

@gamax92: Where would one find sturdy wire like this? I have a crazy idea of bending and cutting a wire-hanger and using that.

[gamax92]

I dont know use a coat hanger.

A: A chair with no back legs.

B: A chair with no front legs.

vvv Heres a video vvv

[bicostp]

USB can push a maximum of 5 volts at 500 milliamps (half an amp). If your fan uses more than that, it might work slowly. If it uses a lot more than that, it won't work at all.

Most PWM fans should just run at full speed if you supply enough voltage to the power leads.

If you really need the airflow (and don't want to buy a laptop stand or low power fans), you might be better off making a stand that runs off a wall adapter.

[Bdawg]

Im using a couple fans to make a laptop cooler, not this . I'll end up making a full stand and mount the fans on rather than making little wire 'U's haha.
How would I get my fans to run off a power-brick/adapter? Is it as simple as cutting the end off, and soldering some wires?

[bicostp]

Yup. Just wire positive to positive and negative to negative. Just make sure your wall adapter can push enough amperage for your fans at the voltage they need. Don't worry about getting the polarity backwards the first time; the worst thing that will happen is the fans turn the wrong way!

You might not even have to chop the wall adapter's cable up. Radio Shack has a decent selection of replacement power jacks (both male and female), so you might be able to find one to match the existing plug. It's a non-destructive option in case you need the power adapter to run what it originally went with again.