The Wind is Free!

Hi there - sorry to post a possibly unrelated question! I am working with a new renewable energy magazine titled RenewerG and we would like to get in touch about a possible article/interview? Please feel free to delete this post afterwards :oops: I can be reached at catr at renewerg dot co dot za. T...

... on in the global energy crisis! costs $100 (power4home), which I paid and never got my plans ... by blowing things up. ( well hopefully not to much). I also thought I should join a group, since ... if I may: Now for building a generator, how would using an induction motor fair as a wind ...

It all depends on the blade size. With 1m blades, 800W should be attainable.

Windgat,
what would you rate your turbine on this site at? is this a question that can be answered?
I am in the JHB area and I am looking at wind vs sun

... current is drawn. Of course a fan is very low power. Maybe rather get a flat battery (6V is your case) and see how much current goes into that. You should be able to post an attachment ...

Looks good - I look forward to hearing how much power you get!

I have 46x30x10mm magnets (nickel coated), and am getting 50x20x8mm uncoated. Wire can always be arranged, usually by the kilogram.

... by charging at double rated voltage. Also, how could you then draw at 12V while charging (i.e. ... wind speed at the site? Or an idea of how much power you want to generate in that wind? Give me something ...

16.35A at about 28V = 458Watts! Not sure what the wind speed was, but it was a gusting North Wester.

... Attempts were apparently made to show them how the device is supposed to work, but ... circuit, the motor would run for much longer due to it being a monopole motor. This ... 12v DC Computer Fan 12v DC power supply (12v Car battery / transformer) -------------------------------------------------------------- ...

It would great if you could find some figures and how close to the Betz limit such a design can get.

It looks like a cone, so the area would be about 1/4 of a square metre? That doesn't seem like much power could be generated. I guess you would be very lucky to get 50W in a 10m/s wind.

Ok ok, I let you win that one! (mainly because of that nice icon...)

OK windgat, but . .
There's no current without a voltage.

"...in this context..." A wind generator is never run without a load. You are right (of course!) in theory, but I am thinking practically.

windgat wrote:Well I remain confused. I thought that when a conductor 'cuts' magnetic flux, a voltage is induced (which results usually in a current, so in my simple mind voltage/current are interchangeable in this context).

If there's no load, there can't be a current. So what do you propose will happen then

Well I remain confused. I thought that when a conductor 'cuts' magnetic flux, a voltage is induced (which results usually in a current, so in my simple mind voltage/current are interchangeable in this context). For diagrams/simulations, you can download a 30day free trial of magnetic modeling softwa...

Hi guys, I needed to know how much power I can expect from the turbine I'm planning to make. For that purpose ...

:shock: So if a wire moves at a constant speed through a constant magnetic field, no current would be induced? Is it possible that you are confusing "induced voltage" with magnetic force on a current carrrying wire :?: According to some definitions, the term "Lorentz force" refe...

Correct :!: If the field is constant then there is no change in time, and so d ? /dt = emf = zero Oh, and . . . It's not current that's induced, it's voltage . V(emf) = -d ? /dt = the time change of the field in Weber/second. and it's not just a wire moving trough the field . . . it's supposed to be...

So if a wire moves at a constant speed through a constant magnetic field, no current would be induced?

No No, Its the change over time of the fieldstrength that causes the coil response. Not the fieldstrength itself. Why do you fly the magnets past the coils? To create a flux in time of course. When is that flux greatest? When the maximum fieldstrength passes the centre of the coil. The fact that the...

Nice smiley!

I don't get it about the magnets. When the magnet is in between the two legs of the coil, surely the net effect is zero

. . . Does that mean the diagram I posted shows the point of maximum voltage generated? No, In the position you drew, the coil will capture a considerable number of return lines, going down as the magnets approach centre. So its not the best position. The maximum voltage is generated when the magne...

Wow... keep it simple for me, remember! Does that mean the diagram I posted shows the point of maximum voltage generated?

Yes you get a prize! You get the next 100 posts absolutely free of charge

The response of the coil is in answer to d?/dt, the time variation (flux) of the fieldstrenth ?. Obviously the highest voltage can be expected when ? is highest over the same time change, which is obviously at the point when the highest flux is captured, ie: when the magnets are dead centre, and the...