Energy gain by induction change.

[broli]

Hi,

I am still in office where I do  not see the pictures but a fully empty page (I meant the link works but with no pictures seen). Last night I saw them from home, there was no problem with seeing the pictures and hopefully from home I will be able to see them again.

Ok on your explanation for the third picture I understand it now but it needs a practical test and it is difficult to measure. 
As the flux of the permanent magnet moves out of the core the question is how much input power is needed to keep the core in saturation (or in near saturation) so that a minimal loss should occur from the attraction momentum. Present science says that the same flux should be needed to keep it in  saturation like the permanent magnet established in it at the facing position moment and I hope that hysteresis and / or viscosity of the core may modify it to the ou area...
Cores with rectangular hysteresis do exist but I wonder if the B-H curve needs the rectangular shape with a narrow area in between, I tend to believe such feature is needed for the curve, what do you think?

Thanks,  Gyula

A rectangular hysteresis is probably the worst shape you can have with this. What you need is a shape that has very little remnant magnetic field after the current is removed.

http://www.emeraldinsight.com/fig/1740250114012.png

Edit: I also attached an idealized hysteresis for this setup. This shows a constant permeability all the way to the saturation current where it very suddenly becomes 1 (air). In our setup the magnet first provides I_sat, then the coil is energized with permeability = 1 to I_sat. From the core's point of view all you did is double the current so the flux is not going to increase which means no induced EMF. Then as the magnet moves away that 2* I_sat current becomes I_sat again, not changing the flux thus no induced emf, until you discharge it now with the constant permeability. I guess I could simplify this whole thing by saying: The magnet charges the inductor mechanically and the coil discharges it electrically. But the electrical gain overshadows the mechanical loss.

[gyulasun]

Ok, I stand corrected for the rectangular shape,  your explanation sounds good to me now.   I hope your explanation holds in practice too, I really wish.

Thanks, Gyula

[danmarius7]

When you collapse the field you get huge amounts of energy but for a very very very small amount of time t=0.0001 seconds. But the amount of power you put in your coil for the time needed for the other magnet to move away is some watts x maybe 1 second! Do the math it doesn't add up. (Maybe just at very very high rotation speeds)

[broli]

When you collapse the field you get huge amounts of energy but for a very very very small amount of time t=0.0001 seconds. But the amount of power you put in your coil for the time needed for the other magnet to move away is some watts x maybe 1 second! Do the math it doesn't add up. (Maybe just at very very high rotation speeds)

I advise you to go over the presentation again. The coil isn't energized to allow the magnet to leave easily it's the contrary. You should redo your math and logic. You can do this experiment step wise but you'll need a super conductor so current keeps flowing without a voltage source.

step 1: Let magnet attract to core => mechanical energy gain
step 2: Add current to already saturated core due to magnet => inductive energy loss, but is little due to low inductance
step 3: Move magnet away => mechanical energy loss, is more than the gained in step 1 since coil field is constant as magnet moves away
step 4: Discharge coil => inductive energy gain, at first sight this is a lot more than the mechanical loss and inputted inductive energy

You see, there's no time variables.

[danmarius7]

So, you say the current you put in the coil at 2 just hangs around there for a couple of seconds until the step 4 can take place ? I hope you know current isn't just laying around in buckets.