A cooler windmill is more of a toy than a real one. It produces 1.5 - 2 volts with a breeze of 4 km / h and a current of 20 mA, which is enough to charge one battery. But you can do more than one, so there is still a prospect. . .
And so let's go!
Let's take a standard cooler from a computer:
We need to disassemble it and connect the wiring directly to the coils and remove the Hall sensor, similar to a 4-pin transistor, we do not need it. In principle, you can do without this, because the cooler can already work as a generator, but if this is not done, energy will be very small.
We are connected by turning on all the coils in series for a single-phase generator, or a triangle for a three-phase, as you like.
Next, we need rectifier diodes, any will do. I think that you can easily assemble a rectifying circuit of them. If not, then look at past publications about the generator for a wind turbine, there is such a scheme.
We connect the LED to the output and blow on the cooler. The LED is on - everything is fine!
Then we need to cut off the blades and the base from the cooler. We don’t need them anymore.
We make new blades. Take a thick-walled plastic bottle.
And cut the blades out of it. Here I think nothing needs to be explained - you yourself will figure out what and how much. I got three lobed.
Glue the blades with super glue.
Next, take a wooden rail and drill a hole, then you will understand why.
And from the other end of the slot for the CD, he will serve as a weather vane.
And this is the foundation of the earth for sustainability.
Evaluate the work and the assembled design in the video:
Good luck !!!