E-Orbo replications

[Omega_0]

Setup is shown below. Vin was measured across the coil+sensing resistor Rs. Iin was measured across Rs, which is 1 ohm carbon resistor, not so precise, but I have no high end sensing resistors at the moment.
The reason I included Rs to measure voltage across the coil, was that the RDC of the coil is tiny and so is the voltage drop across it, and my scope captures just noise at such low values. Anyway Rs was included in the calculations as a part of RDC. So Rin = RDC + Rs.

I have no precision meter to measure the Rin, so I used scope itself and the Rin is an average of 800 measurements of V/I at the steady state part of the pulse.
Rin must be measured to at least 1/1000th of the ohm. Even small deviations of 0.001 ohm changes the Ein landscape totally. This is the critical part.

So things are not very accurate at this stage but everything is going towards a positive direction, so I'm happy.

[Omega_0]

More about material T38.
I'm attaching here the specs of toroids that I'm using in current version and also of the alloy T38 (which I guess is MnZn Ferrite). Its EPCOS part no. B64290L618X38, dimensions : 25.3X14.8X10 coated with blue epoxy.

Its Mu_i is 10000 and H(sat) is around 100 A/m from the datasheet. So from
H = N*I/lc
where N is number of turns, I is current and lc is flux path length, we can get the saturation current for say, 100 turns of coil:

100 = 100*Isat/lc
lc = pi*( 25.3+14.8 )/2 = 63 mm = 0.063 m
Isat = 100*0.063/100 = 63 mA

Or say you want Isat = 1 Amp, which gives N = 6.3 or 7 turns. So you would expect that just 7 turns at 1 Amp or 100 turns at 63 mA shall saturate the core completely and the rotor will not be attracted to the core at all. Sounds like free lunch.....

But, don't be surprised if the core refuses to follow the text book in presence of a strong neo. In my case the coil is taking max 2.8 Amps@100 turns and the core still shows strong attraction for the magnets ! I have no idea why this is.......... anyone knows ? Isn't the core supposed to "disappear" for magnets when saturated ?

Either the formula I'm using is wrong or something else is happening here. This is an unknown land for me.

[Omnibus]

@Omega_0,

Good job. I'll focus on this as my first post here:

But, don't be surprised if the core refuses to follow the text book in presence of a strong neo. In my case the coil is taking max 2.8 Amps@100 turns and the core still shows strong attraction for the magnets ! I have no idea why this is.......... anyone knows ? Isn't the core supposed to "disappear" for magnets when saturated ?

You know, I had the same problem and I never resolved it. The only thing I could achieve is what Naudin is showing in his video--when using a ceramic magnet. Could never achieve it with neos. As you know my approach is to use a pulse generator rather than the way Steorn are doing it and I blamed my pulse generator for that--the max current that it can supply is on the order of several hundred mA only. If you wanna get pulse generator capable of supplying amps you have to part with probably ten or twenty grand. Tried it with a battery and a relay and so on but never got it to work. Hope you'll be more successful because, as far as I understand, you're at least capable of powering it properly. Luckily, somehow I got into the research I'm doing right now and got away from that nightmare. I would still be interested in a pulse motor but only as a curiosity. 

[Omnibus]

As for the current measurements, the metal-oxide 10Ohm resistors from RadioShack as shunts are just fine. That was confirmed with my current probe. Recall @LarryC was insisting on that (I had to verify it, though). So, you're all set on that, I think. Stay away from industrial standard shunts if you're working at high frequencies as well as, of course, from wound precision resistors. All there develop inductance voltage and are no good as my current probe indicated.

[Omnibus]

I think no one else has published such plot before this. So its important one.

I agree. Keep up the good work.