Alternator Inductor Coil Output Equation (?)

[Elektrostatik]

i'm okay with those. It's dels and curls that make me hide under the bed.

Dels and curls are what make Maxwell's equations the next best thing to a nervous breakdown.

Yepp, small steps in the right direction are way better than giant leaps towards catastrophe
I'm glad I decided to post these problems here, your input has been extremely helpful.

Hopefully after some days of milling, winding, soldering and blasphemy,
I should have something resembling a working generator.

Thanks Jim!

 

[Elektrostatik]

I've updated the design to account for adjacent magnetic field geometry at 110 mm centre to centre spacing.

To keep the flywheel size within 1 m Ø I've reduced the magnet count to 20
so at 20 rev/s the frequency is now down to the aviation standard of 400 Hz

This not only improves the sinusoidal output and transducer efficiency but also reduces the cost of N55s to 33%

 

[jim hardy]

Can you get some iron filings and place two magnets under a sheet of paper? That'd let you see what flux does.

Something is counterintuitive here. Dynamos squeeze flux together but you are spreading your magnets apart.

not saying it's wrong, just I'm perplexed by the logical conflict in my alleged brain.
Chewing on it.

Check this thread in General Physics

"" Increase magnetic field density near surface of magnet "
https://www.physicsforums.com/showthread.php?t=584655



Perhaps one of the fellows from that thread will have a suggestion.

old jim

 

[Elektrostatik]

Can you get some iron filings and place two magnets under a sheet of paper? That'd let you see what flux does.

I will pick up 2 sample N55s and put them under my green magnetic field viewer film

I based the design changes on your N42 zero to peak gauss curve - 110 mm centre to centre.
I just assumed it would be more efficient to allow a full zero to peak sinusoid by spacing 40 mm from the edge.

Y component on center 1597 gauss
halfway between center and edge 1417
at edge 879
5mm beyond edge 550
10mm past edge 290
40mm past edge it's 6.3, essentially zero
so the flux is highest in center like a cosine function
and if we take 40cm as distance from peak to zero
879/1597 is arccos of 56.6° but 15/40 of 90° is 33.6°
similarly 550/1597 is arccos of 69.8 but 20/40 of 90° is 45°
so flux from a single magnet only resembles a sinusoid at that distance, it's too peaky.. as one would expect.

But then.. what seems intuitive to me doesn't necessarily make it right.

Traditional dynamos are DC generators that operate on the reverse DC motor principle using a commutator,
so would these same density rules apply to an open alternating principle?

 

[jim hardy]

I just assumed it would be more efficient to allow a full zero to peak sinusoid by spacing 40 mm from the edge.

i was trying to demonstrate that the sine function results from design of the flux field
i don't see connection between its shape and "eficiency". Sine wave is aesthetic though.

best 'efficiency' will be achieved by maximixing the fraction of field flux from your magnets that links (goes through) your windings.

That's why your iron cores in middle of your coils were a good feature IMO.

You do understand that the magnetic path for each magnet is from N to S pole , and you want as much of that path as possible to be through the coil.
Iron core can encourage the majority of flux to take that route. An iron return path will help too.

EDIT :: and yes, a synchronous machine can motor or generate.

 

[Elektrostatik]

I have a habit of relating magnetic field lines to acoustic standing waves
and since inverse acoustic waves (and inverse electronic audio signals) cancel each other out,
I thought the same should be true of inverse magnetic fields.

I was expecting that the Group B iron inductor cores which are 90° out of phase
with Group A on the opposite side of the flywheel would privide a return path for the flux
in the magnets. Would that not be the case?

I think to be safe I will first mill 2 test flywheels in wood, 1 with wide spacing
and 1 with tight spacing to check what kind of power output readings I get with my Ammeter.