windmill

Before you build it, do some basic math to predict how much power it might produce, and how much it will cost to make.

John

I was surprised to know that a classic big windmill of the 15-th century is capable of making about 100 hp. As for the matter of the cost, do you remember how they build a windmill in the Orwell's book :)

Vladimir Vassilevsky DSP and Mixed Signal Design Consultant

Lots of projects, theory, and examples here:

HTH, James Arthur

How much power do you want to make? Would lighting up an LED be enough? If so, you could take a small permanent magnet motor, mount it on a tower and stick a fan-blade on the front. sci.electronics.basics might be a better group for this, but at least this is actualy related to electronics.

Looks like you've received some good links and suggestions. I'll email you a really cool photo of a friend of mine atop a commerical wind generator. Quite impressive as to scale.

-mpm

Why haven't you asked your teacher or your fellow students?

Or studied your textbook?

Or tried the other side of google?

Heck, I could do it for you, if you pay me what you're paying the school that's not teaching you anything.

Good Luck! Rich

That's hardly basic math.

What year are you in at school? This will help people here to give you suggestions, the help for a junior school project will be a lot different to a senior school project.

Why build something you don't understand?

John

Sorry - missed the "high school"

What about visting an automotive dismantler and seeing if you can convice the owner to donate an old thermatic fan to your project.It's wont be super efficient but it will likely be a good start for a school project. Think about how you would mount it so it follows the wind direction and how you might get the electricity down from the motor (now a generator) without the wires twisting up as the head part rotates. I'm not sure if the motors are all suitable. Try shorting the leads together, if it gets harder to spin (you are short circuiting the "generator" output) then its probably suitable.

It is done all of the time, over and over, and occasionally leads to innovation. Edison understood little and invented a lot.

Engineers tend to have constipated minds.

De Forest rode it pretty far with the Audion tube.

Engineeers make things work, because we can do the math.

What do you do?

John

I used to teach engineers and now I taunt them.

Mediocre at both.

John

Nearly all the "low-hanging fruit" has been harvested. The talented tinkerers, like Edison and DeForest, are pretty much gone. Inventing transistors and lasers and gene squencing - all the modern good stuff

- takes increasing analytic skills, and tends to be done by PhDs nowadays.

Edison was terrible with math, which was why he didn't realize how badly a DC power network would scale. And DeForest didn't actually understand how his Audion worked.

Even non-trivial electronic design, which is hardly science, takes a pretty good theoretical background.

John

Are you new to this group? ;-)

A quick description of how to do the math:

Assume that the wind means that all the air is moving at the same speed.

Work out how much air goes through the area of the windmill blades per second.

Figure the mass of this air.

E =3D 0.5 * M * V^2

E : energy resulting from stopping that air M : mass of the hunk of air V : the speed of the hunk of air

Since we are using numbers for one second energy equals power.

This gives a very optimistic value but since the power from wind goes as the cube of the speed, you don't need a very good number.

DeForest was really something of a slimeball, but it should be pointed out that a lot of people who used audions early on didn't understand how they worked -- this led to many patent fights regarding who really invented various flavors of tubes during the those years, hence which patents were valid, etc.

Plenty of contemporary engineers have probably long since forgotten the finer points of how transistors work, even though they would certainly have been exposed to the theory at some point during their formal education. I've known guys who had EE degrees but when the "computer programming" route and would slap down, e.g., a 2N3904 to drive a 5A solenoid...