Stay Cool This Summer: PC Fan Mod




Introduction: Stay Cool This Summer: PC Fan Mod

About: Awesome Electronics Tutorials, Projects and How To´s

Who does not have a dozen of those PC Fans laying around? In this build I will show you how to use those fans to produce a nice adjustable breeze during hot summer days. And it runs at least 4 hours with an ordinary 9V battery.

Step 1: Watch the Video!

The video gives you a pretty nice overview on how to build this mod. But I am going to give you some extra information in the next steps.

Step 2: Order Your Parts!

Step 3: Build the Circuit!

Here is the schematic for the circuit. I recommend to build the circuit on a breadboard first. And then move it over to the sides of the fan. But it is a pretty simple circuit and perfect for beginners.

Step 4: Success!

There you go! Now you can refresh yourself pretty easily with only a 9V battery.

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31 Discussions


Question 2 months ago

If my Fan is 24 Volts and input Volt is 24 Volt, what changes are needed ? please your kindly advice.
thank you Scott

i mimic this projects.. but my power supply is 5volts/power bank... tip29 transistor... 5 volt fan...ceramic cap 2nF and it works excellent! :)

i use different components cuz some of it are not available or out of stock on our local electronics store...


Can i use a Ne555N instead?

I used the same designee and I 3d printed a case for it. Thanks so much for this awesome demo works great

1 reply

Sorry for such a late request, but could you possibly post the files for the 3d printed case on Thingiverse, or a similar site? That is, if you still have them of course.

Something worth noting is that some fans (including the one I tried) have a voltage cutoff point, where it will not spin at all if it is too low. For the fan I used, it happened to be around 8 V before cutting out, which caused a lot if confusion for me.

For simply testing the circuit, I'd suggest hooking it up to a bare motor with no internal circuity.

can NE555 works properly if we use 12V in the same design?

pls can you tell how much volts does the 2.2 and 10 nf are??????

1 reply

greatt Scott u do great videos n I suggest u to do an laser security alarm for your next project so can you do this project for me

Thanks for this instructable! I've learned about the existence of PWMs! :P
I bought this LED dimmer for 3.57€ and tried it out on some PC fans.
The fan slows down, but makes noise, as if the frequency of the PWM was too low. Is it possible?
For now I have no speed regulation. Uh, I'm using a 12V 1A DC power adapter.

2 replies

The frequency of the signal is hearable due to the vibrations of the coils of the fan. You would need to increase the frequency. But that is not possible with such a product.

i think we can use more cheap battery charger AA 1.5v, using dc to dc step up module to get 9v, how about that ??

Could I use 3.3nF capacitors or even two 1nF capacitors in parallel to use in place of the 2.2 ones?

And also, why is there two positive 9v poles in the circuit? Isn't there just one battery in there? Isn't the ground of the circuit the negative of the battery?

(I know its a pretty dumb question, but hey, there's always a first time for everything" xD)

somehow it didn't work for me :\ I wasted my entire day, check every connection and it just didn't work

Why all the electronics? Just connect the 9 Volt battery to the fan. It should run. When the battery runs flat, plug it into the charger.

Here's a suggestion, if I may. A good project might be to make a 9 Volt battery charger in the fan, so that when you plug into a DC supply (like a plug-pack, wall-wart, whatever people call them) you can both run the fan and charge the battery. When the battery is charged up again you can remove the DC supply and move the fan to where ever you like on your desk or bench.

A fan is good when soldering too, to blow away the fumes.

You did a nice project, thanks for showing us.

1 reply

>> Why all the electronics? Just connect the 9 Volt battery to the fan. It
should run. When the battery runs flat, plug it into the charger.

Um.... the circuitry allows you to vary the speed of the fan.