Tesla's "COIL FOR ELECTRO-MAGNETS".

[synchro1]

If the two types of coil had the same measured inductance - but different strength magnetic fields - that really would be 'magic'...

The magnetic strength is not a magnetic field feature of the coil per se, but the way in which the coils magnetize the ferrite cores. The major difference in the core materials is super critical and definitely accounts for the huge difference in results.  

Seriously now; Take a close look at the coil cores in the pictures below: One's a soft iron on top, 16 penny nails called for by the test controller; The other Mag's used below are some kind of nickel or zinc coated alloy! Not to mention the threads! How could it be even remotely possible to get similar results with such two entirely different core materials? Give me a break, would you please? This comparison is ludicrous!

[gyulasun]

...
Can anyone tell me wether or not Itsu is spinning his rotor at 2,250 or 9,000 rpm in his resonant output coil video?
...

Synchro1:

In his parallel resonance video, Itsu mentioned his gen coil has 27mH inductance and the tuning capacitor was 40uF, giving 150Hz resonance by the calculation. When he run the motor with the capacitor connected, the scope measured about 146Hz, now if you multiply this by 60, you get 8,760 RPM. If it had measured 150Hz ouput frequency from the generator coil still tuned by the 40uF, then the RPM would have been 9,000 indeed.
And when he disconnected the 40uF capacitor, the rotor speeded up to a higher rpm, surely above 9,000 rpm.

The magnetic strength is not a magnetic field feature of the coil per se, but the way in which the coils magnetize the ferrite cores. The difference in the core materials appears to be critical and probably accounts for the difference in results. 

In those tests I referred to the cores were iron bolts or nails, no ferrite cores were used at all. 

How do you know that the 16 penny nails are made of soft iron? and the bolts are made of  a totally different iron? You measured them?

[synchro1]

Synchro1:

In his parallel resonance video, Itsu mentioned his gen coil has 27mH inductance and the tuning capacitor was 40uF, giving 150Hz resonance by the calculation. When he run the motor with the capacitor connected, the scope measured about 146Hz, now if you multiply this by 60, you get 8,760 RPM. If it had measured 150Hz ouput frequency from the generator coil still tuned by the 40uF, then the RPM would have been 9,000 indeed.
And when he disconnected the 40uF capacitor, the rotor speeded up to a higher rpm, surely above 9,000 rpm.


In those tests I referred to the cores were iron bolts or nails, no ferrite cores were used at all.  However, I agree with your last sentence, there can be and in fact there are significant differences in the magnetic properties of ferromagnetic materials, even between two iron bolts or nails that seem totally identical by the visual inspection. This is why we have to compare apples with apples.

Gyula

Thanks, that confirms my suspicion that Conradelektro's rotor needs to go faster to test his LC resonant coil.


I can tell from looking at the bolts that they are coated with a shiny metal, not soft iron!

[gyulasun]

Thanks, that confirms my suspicion that Conradelektro's rotor needs to go faster to test his LC resonant coil.


I can tell from looking at the bolts that they are coated with a shiny metal, not soft iron!

Synchro1,  that confirms nothing,  what are trying to connect here with what?

[synchro1]

@Gyulasun,

My point here is simply that a  N-S four magnet rotor spinning at 9,000 RPM is equal in frequency to a diametric magnet spinning at 18,000 RPM. Conradelektro plans to start spinning his diametric magnet at between 7,800 RPM and 10,000 RPM. Too slow to cut it!