Starting over...Coil geometry

[mbohuntr]

I got my hands on about 100' of AWG 23 wire, and while I was going to build the radial air core alternator, since my magnets are only 1/2x1/2 x 2, would I better off doing a poured  flat stator, with 8 coils, or get a 4-8 pole rotor built and design the coil around it??? Which is easier, I have fabrication expierence, but no longer any access to lathes and milling machines.

[mbohuntr]

Correction, After more reading, Things are easier when number of coils are divisible by three, so we'll go with that. 6 or 9 coils.

[jlt]

 first how many magnets do you have.  and how big do you are your blades , and voltage

[mbohuntr]

no blades yet, I'm just learning here so probably toy sized to start with, maybe 12". I have 8 n48's, I would like to do a trial coil first, but I don't want to repeat my origional mistakes, so I'm gonna ask lotsa questions first. Looking for a simple set up.

[hiker]

you could go with a 8and6 setup ..

8mags on one rotor--6 coils wired 3phase..

or even a single phase setup--8 mags  8 coils...

one of my first alts--had the stator coils mounted on

a roll of steel strapping --heat the strapping first [red hot]

then wind it up--inlay into a piece of plywood then glue your coils over that..

heres a shot of a little dual rotor setup--just some cheap LOWES  mags and a few

neo"s for extra power..

[mbohuntr]

I like that set up. Here comes the questions... What does the strapping do? It's similar to the laminations in a motor, but what's it for? If I use say... 12 coils and 8 mags on a single rotor, the opposing coils (12 oclock, 6 oclock)need to be wired in series. This will add the voltage from each? If I use the half inch wide magnets, do my coils need to have a half inch centers? Thanks!

[KilroyOdin]

Hi, the site listed below gives a good and short description of the all relationships needed between the magnets and the coils.

 http://www.6pie.com/faradayslaw.php

 Live in the present and plan for the future.

Best Regards

 

[mbohuntr]

OK... I made a 3.5"x3.5" coil out of 24 awg (NEW) with 10 turns. I cleaned the ends of the coil, made the connections to the meter, checked for continuity, set meter for 10VAC, inserted the rotor thru the end of the coil so that the shaft runs parallel with the coil. I put four  of the 1/2"sq x 2" on the old rotor shaft at 12,3,6,9 oclock alternating N S N S. the top and bottom of the coil will get both North poles first, then as the rotor turns 90 degrees, the coil gets the south poles.  No volts...  Did I use too few turns? or is the magnet setup wrong? That link to the Faraday site looks like the coil needs to see north at top and south on bottom at the same time. Is that right?

[ghurd]

I don't really understand what you did, or if there is a defined air gap or a return path for the flux.

But try 2 or 6 magnets.  6 is better if they fit.

And with only 10 turns it will take some high RPMs to get much of a reading.

G-

[mbohuntr]

This goes back to the radial air core alternator on windstuffnow.  Ths rotor shaft penetrates the coil at each end. I spun it with a drill. About 1/2" form magnet to coil each side.

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