Foo - Any EE's here?

I am thinking about building a small wind turbine and generator. The turbine part is pretty easy. The generator part is what I am a bit, shall we say, lacking in knowledge. I know I could simply use an automotive alternator, but where's the fun in that.
I want it to be approx. 12V. Is it the # of windings that controls the voltage? Is it the strength of the magnetic field? Need advice!

I think the more windings, the higher the voltage.

I did stay at a Holiday Inn, once.

This not what came to mind when I saw the thread title and the OP.

http://www.amazon.com/s/ref=amb_link_83808091_5/190-5701744-7786248?ie=UTF8&node=15684181&keywords=44447%7C44444%7C44455&brand=Sunforce&pf_rd_m=ATVPDKIKX0DER&pf_rd_s=center-2&pf_rd_r=0SPDH9CM72ZP77WJA673&pf_rd_t=101&pf_rd_p=472117651&pf_rd_i=507846

http://www.amazon.com/s/ref=amb_link_83808091_5/190-5701744-7786248?ie=UTF8&node=15684181&keywords=44447%7C44444%7C44455&brand=Sunforce&pf_rd_m=ATVPDKIKX0DER&pf_rd_s=center-2&pf_rd_r=0SPDH9CM72ZP77WJA673&pf_rd_t=101&pf_rd_p=472117651&pf_rd_i=507846

meh...I want to build it myself, and 400 watts is a bit much to operate a small pump.

This guy did a pretty good instructable (http://www.mdpub.com/Wind_Turbine/index.html)

2003 plan download (http://www.scoraigwind.com/pirate%20oldies/Hugh%20Piggott%20Axial-flow%20PMG%20wind%20turbine%20May%202003.pdf)
Or you can get the current ones here (http://www.scoraigwind.com/axialplans/index.htm)

I'm good with the turbine. Gonna do a verticle turbine so the base can be permanently mounted and wind direction doesn't matter. But I'm not clear on the technicalities of designing a 12-14V generator.

output voltage is proportional to the number of turns. you're going to wind it yourself?

And here I thought you were talking about yer big feets :innocent::innocent:

My feet aren't that wide.

do you know what current and voltage your pump wants? This is pretty important to operate it safely/efficiently.

is it going to be a DC or AC wind turbine?

are you an EE? alot of this stuff is quite basic soph/junior level

output voltage is proportional to the number of turns. you're going to wind it yourself?

yes, and have the magnets already.

is it going to be a DC or AC wind turbine?

are you an EE? alot of this stuff is quite basic soph/junior level

CPA who likes to mess with stuff and should have actually gone to med school.
I may do a DC one and an AC one, just to say I did them both. The first one will be AC though. Probably 3 phase.

There is a reason why people don't make their own motors. You will need to have a strong case (given the forces involved) and be able to mount the magnets very close to the windings (one spins, the other is stationary). Your best bet is to salvage an existing electric motor and go from there. What kind of 3-phase power connection do you need (Y, delta, don't know)?

There is a reason why people don't make their own motors. You will need to have a strong case (given the forces involved) and be able to mount the magnets very close to the windings (one spins, the other is stationary). Your best bet is to salvage an existing electric motor and go from there. What kind of 3-phase power connection do you need (Y, delta, don't know)?

where's the fun in that? And that won't be as educational as I'm looking to get.

Here are some considerations:

- If your generator output is located far from your load, wind for a higher output voltage and step down to your desired voltage closer to the point of load. This will reduce IR losses in the transmission line. You'll have to calculate both the IR loss and the conversion loss to see which is greater.

- You probably want some kind of storage system because, after all, the wind isn't always there. There are a number of ways to do this, from storing mechanical energy in a large flywheel to converting to DC to charge batteries and then back to AC (if AC is your intended use)

- If your intended use is DC, take your HV output and use a high efficiency transformer to step it down to that which a decent DC-DC converter can handle.

- You want to use a good bit of transient protection everywhere.

How high is your windmill going to be mounted?
How much power output are we talking about here (voltage and current requirements)?
What's the distance between your generator and point of load?

The generator/windings part will be the same for a Vawt and a Hawt - Lots of info in that link I posted.

The number of windings, size of wire, and the final winding pattern determine the voltage and the speed that it kicks in.