Making a coil

[Edward Rose]

Hi all!

I'm new here, and I'm having a hard time finding the info on how to wind a coil. I've looked through otherpower pretty well, but couldn't find the detailed info.

I'm making a "micro" wind powered generator for a "Dancing LED'S" front porch lamp.

I'm using 5/8" dia magnets that are 1/8 inch thick. I thought I was supposed to make round coils... with the center about the same size as the dia of the magnet, but I'm seeing this odd eliptical shape in some of the other experiments at otherpower.com.

I'm seeing this odd eliptical shaped coil even when people use round magnets like mine.

***** Can anyone point me to the technical info for winding a coil? *****

Thanks,

ER

[Flux]

I don't think there is a perfect coil. In your case round coils with holes the size of the magnet would seem the logical thing. You might as well make use of all the magnet as a slight increase in size of the machine will be of no consequence.

If the hole in the coil is as big as the magnet then all the flux will link it. The round coil will have the lowest resistance, but for driving LEDs that may be of no great benefit.

For bigger machines, squeezing the width of the coils slightly makes little difference to the total flux linked and there is a reduction in resistance so you end up with a bit smaller and lighter machine for virtually the same output.

Voltage alone is not always the most desirable thing to aim for, but for a very small machine to drive LEDs it probably is.

Flux

[powerbuoy]

Ed:

I know I am not answering your question directly.

But here is a link:

http://www.windstuffnow.com/main/minigen.htm

He sells them for a few bucks. Maybe that is a faster alternative for you.

Powerbuoy

[Edward Rose]

Thanks. I'll just stick with round.

ER

[Edward Rose]

Interesting. Thanks for the link. I can probably use one of those for other ideas... but this only requires 2.1v @ 60ma

ER

[kevindtimm]

Isn't the point of an elliptical coil simply one of practicality?  In other words, this creates a coil that is the 'best' shape for mounting in the stator?

[tecker]

You want the coils to have long legs to increase the pole diferntiation and 90 degree

orientation to the magnet plane.

[tecker]

That's  pole differentiation the spelling is smelling.