Introduction: USB Fan Out of Old Computer Fan

Picture of USB Fan Out of Old Computer Fan

In this instructable I took a USB cable and a old computer fan and made the fan USB compatable.

Step 1: Getting the Usb.

Picture of Getting the Usb.

Cut the USB cable to the desired length. Then Strip the cable so you see 4 wires. Cut or isolate the green and white wires. Now strip the red and black wires.

Step 2: Connecting the USB to the Fan.

Picture of Connecting the USB to the Fan.

Twist the red wires with each other and the black wires with each other. Now your done, plug in and be cooled down.


MhikeiD (author)2016-05-07

This is great because i have a laptop that doesn't have a fan built-in, and it gets pretty hot while using it. Great solution!!

energy123 (author)MhikeiD2016-08-17

You can also make a free energy fan so you don't need to use power source at all magnets at the ends of the blades and to magnets diagonal of each other to make it spin without energy. a push and pull effect. Although great idea. Will try in free energy fan to charge phone, might need transformer...

AndreM166 (author)energy1232017-12-15

I must inform you that your solution with magnets violates conservation of energy, and will not work. The fan blades will keep spinning for a short while, but not forever.

MhikeiD (author)AndreM1662017-12-15

True. Energy cannot be created or destroyed, only transferred so the energy in this case is being used to move air, so the fan WILL stop unless you put it in space, where it will spin forever until it hits something.

kadoshys made it! (author)2017-10-25

My cooling fan's motherboard was ruined so i took it out and plugged useless usb cable to make it that way
Thanks a lot ...

ahmedf6 (author)2015-07-25


rsfluffy (author)ahmedf62015-08-04

This idea occurred to me as well but Power Supplies pump out a lot of heat, my budget for AC would not like that. Now if the PS was outside.... move it in in the winter.....hum.

energy123 (author)rsfluffy2016-08-17

This is what I said down below except intended for you.

You can also make a free energy fan so you don't need to use power source at all magnets at the ends of the blades and to magnets diagonal of each other to make it spin without energy. a push and pull effect. Although great idea. Will try in free energy fan to charge phone, might need transformer...

jnrincon made it! (author)2016-02-25

Good build, added a power switch that I salvaged from the busted power supply I built this from.

IIsayiahA (author)jnrincon2016-06-25

Is it just the fan, USB cable, and switch in the circuit? I am doing a project similar to what you just described

FreePvp (author)jnrincon2016-04-11

Does the charger size matter? Mine is kinda small. Its flat and wide

php99 (author)2009-08-13

mine doesnt work :( I have on my USB wires Red, green, yellow & white and on the fan i have black,red &yellow.; What can i do to make them work? thanks Paul

MhikeiD (author)php992016-05-07

This is extremly late but what you would do is link the 2 red wires, and link the link the black and white wires.

RyanD128 (author)MhikeiD2016-06-12

lol just a bit late hahahaha

FreePvp (author)2016-04-11

Does the charger size matter? Mine is kinda small. Its flat and wide

JeremyH66 (author)2016-02-25

I have an 5v fan, just perfect, thanks

JesusC23 made it! (author)2015-09-24

Pretty easy and fun my first one

Idodav2004 made it! (author)2015-09-05

this is my first one

rsfluffy (author)2015-08-04

Thinking of using this idea for an air filter. Already have the carbon filters ordered and am working on the housing. I'll let you know how that works. Heck may write my first instructable.

PrncssGeek made it! (author)2014-08-15

Made this to help keep my ASUS laptop cool! Thanks for the help! Hooked it up to my cookie cooler stand! :) Geek Chic! LOL

Mohammad WJ (author)PrncssGeek2015-07-29

Thats what I wanted to do for my Lenovo Y50-70. Didnt want to go out and buy a laptop cooling mat when I carry carry this little thing around. I took apart an old Dell computer I have. Took the fan out. Will make an instructable.

TestType (author)2015-07-23

TheNecromancer13 (author)2015-07-20

Didn't work

JasonS24 (author)2015-05-13

Thanks. This is exactly what I was looking for. I have an old liquid cooling cpu unit that I used to make a makeshift airconditioning coil to put in front of a fan. the unit is 4 pin and i wanted to power it with the computer via usb so it can pump the liquid through my coil.

koroxus made it! (author)2015-04-24

Used this instructable to make my own mini dehydrator

mpaulino3 made it! (author)2014-11-24

It's great! I made it, though instead of a USB Cable, I used a power cable that goes strait into the socket.

BuddyB1 (author)2014-11-15

I don't feel like taking a picture, but I made it! It's actually pretty nice for cooling off my hand as I use my computer because one of the corners gets hot.

Justin_Bailey (author)2014-05-26

Thanks for the idea I'm gonna splice an old pc speaker power supply that plugs in to the wall and attach the fan to it so the fan will get the 8 volts it needs!!!

kkitchell (author)2012-10-08

I made a real good fan out of an airsoft machine gun and its wicked. I hooked up two nine volt batteries and its amazing. i even made my own blades out of card board box.

Jakwiebus (author)2012-08-18

Héhe, nice during these hot days! thanks for the idea :D

bluemetaknight (author)2012-06-20

If you are doing this. Remember to use a 5 volt computer fan

Kissker (author)2011-08-03

As stated, the USB only provides 5 volts power, if you really wanna make it into useful-fan ness, then just splice some battery connectors together out of old toys.

12V = 1x 9v battery clip (which you can buy in bulk for under 0.25 each) or salvage from toys + 2x "AA" battery holder (since most AA are 1.5v each, although rechargable ones vary - so do your math)

Wire em up and add an "On/Off" switch and then encase the whole circuit to make a fully powered, fully recycled (or at least mostly) fully portable fan.

Also make note NOT to mix alkaline based and other based batteries, just because of all the problems and dangers. If you use a alkaline 9v, use alkaline "AA"s as well.

wbwillie (author)Kissker2012-04-27

yes, USB only supplies 5v, but you could use a voltage regulator circuit and increase the voltage that way

williamhaze (author)Kissker2011-11-08

Hi there!

I'm planning a project using a 12vdc case fan to inflate a plastic bag for a school project.

I have located a 9v battery clip and a 2xAA battery holder and was wondering how i'd go on with wiring them together.

I was also wondering if it was possible to reverse the polarity, thus creating a vacuum effect. If so i'd like to have a 3 prong switch to control the case fan.

I appreciate any help you could provide me. Thanks!

kbwillert (author)2011-12-21

I did something similar before seeing this, just spliced an old phone usb cord to the old desktop fan. I bought a tv stand with glass doors and didn't want the xbox to overheat in there, so I cut a hold in the top/back of the stand to put the fan blowing out and plugged it into the xbox. I had figured the xbox usb ports only had power to them when the xbox was on, but I shouldn't have assumed that. But, it will work with my bluray so I'll just make another for the xbox with a master/slave power switch. Fun idea though!

fretted (author)2011-08-17

I just built one of these it works great used an old intel fan dc12v 0. 13A startled be when it first came on thought i was gonna jump out of my chair when it hit my pinky but it works well just enough to keep air circulating around my computer while im using it .....

this nick is invalid (author)2011-07-09

lol 1 9v and 1 aa makes 10.5 v xD

cgman (author)2009-08-23

This works fine when using USB with up to a 9v DC fan. When trying to use the USB port for any12v and up fan, it will not work. I still have not found a way to combine 2 usb ports for these larger fans without causing a short and the PC turning off one of the ports. Any ideas??

ladyharley05 (author)cgman2011-04-02

Just did this with a 4" PC fan 12V .29Amps and plugged it right into the USB port and it works and spins just fine.

Palalaika (author)cgman2010-07-02

if u got 1 fan then im not sure about USB as power source but one 12v fun chills pc very good when useing 12v adapter to power it . I dont think USB fists for 12v fun power source . Best way is to attach 12v adapter with laptop adapter wire and let it be like one wire with has 2 things at the end what can ya put into a wall(thats how i imagine it) xD best way i can tell with my English skills .

wobbler (author)cgman2010-07-02

You can't increase the voltage by "stacking" two USBs in series, it will ALWAYS short out the supply, no matter now you do it. The only way to increase the voltage is, as mentioned elsewhere, by using a DC-DC voltage converter, but that seems a little like overkill when you can just use a 12v mains adapter.

chetan_m.p (author)2011-03-27

i have made one but it spins too slowly...

henrysaunders (author)2009-05-11

this works really great only i used too much usb cable so the fan was underpowered a bit but a really good and easy tutorial

ab727 (author)henrysaunders2011-03-20

Does the length of the cable also play a part? I used a long cable too. Would I get better result if I used a smaller cable? I do not know the length but I used one of those usb extender cables for this.

shabaki (author)2011-02-25

ha i just did this, i need to test a comp fan for aproject and coulndt find any batteries lying around with wenough power :P but i wonder if you spliced a few usbs together...................

BUT if some can get a bunch of these and a nice SMALL power source then i see a rc heli,hovercraft,boat, blimp......need i go on?XD

and anyone know if comp stores might sell old fans for cheap? like a few dollars cheap :P?

beehard44 (author)2010-10-10

you can safely raise the voltage

kyismaster (author)2010-09-24

you always could try a fan controller.

Palalaika (author)2010-07-02

Hello . Looks interesting :) lego tower cooler :) i pet that the hard part was to build that tower . I bought some cheep cooler 300mm x 240mm with tree 60mm x 60mm coolers witch sucks btw and doesnt do the job even when programming ( when gaming pc turns into oven ( made eggs once :) I didn't find anything better from any shops so now im trying to make one and thats the part where i have alot of questions :( Plan next , i want to supply 2x with one 12voltage adapter and question is does they cool less when they have one power source or should i use adapter per Fan ?

harry88 (author)2010-07-02

you could hook to or three usb cords in a parrelel

calikoala (author)2010-06-24

USB provides 5volts at 500ma. most fans are 12 volt so there won't be much power to run it very fast.

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