Ok, here is the latest iteration of the Adams Axial. It has now evolved enough that I'll detail the various aspects for anyone playing along at home.
Physical - To contain the pull force of the magnets I've had to move to a more user friendly design that allowed easy testing of various coil housings, and a way to have them isolated from the bearings. The pine board is ~300mm dia x 18mm and the threaded rods and hardware are M10.
Magnetic - Each of the 6 holes of the rotor has 2 20x20mm N40 (10gm) Neo's (15kg pulling force each), with a 5x10mm N40 between them set in a 5mm shelf to hold it all together. The 6 coil cores on each side of the rotor are 12mm in diameter and are offset 30 degrees. The PCD of the rotor magnets is 80mm. Total rotor weight is around 350gm. Airgap between the coil cores and magnets is approx 6-8mm.
Electric - 6 electromagnets, each made with 28m of 1mm wire, wound on a 40x12mm core, wired in series, 4.2 ohms. 6 generator coils, each made with 70m of 0.5mm wire, wound on a 40x12mm core, wired in series, 50.2 ohms.
My switch leaks current due to the hall sensor being at ~2.4v, which is opening the NMOS just enough to flow (as it grounds a voltage divider) but not enough to hit gate threshold on the PFET - nonetheless, there is no increase above the .109A I see when I turn the switch on without the coils connected.
So with an input of 9V, I'm getting back ~16-20VAC on the EM coils, 18VAC on the Gen coils @ 4600rpm. I'm over the moon with these results. The magnetic reluctance is now so low that there is more resistance in a doorknob.
A couple of anamolies though, as the rotor increases in speed I see VAC at the EM coil rise to 5 almost 6, then the multimeter drops back to 0 before jumping to 16-20. I would have put up a photo of my LED train from previous posts, but as it jumps up to 16-20 it took out 8 LEDs... burnt out, dead, on the spot.
The second anamoly - with high speed I'm generating a great deal of EMF and hammering the PFET, so I can only run it for short amounts of time. I've added a lead to each join between the coils to measure what is happening between each of the coils. So with one lead of the multimeter connected to the join between the first and second coils, the multimeter returned around 20V. Now when I touched the other lead of the multimeter, this increases to 57V - not sure how to interpret that number, did I just become an earth reference for EMF or a path for EMF?
I've had this running briefly at 18V and it is scary how fast it wants to spin and how quiet it becomes.
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