Solid State Orbo System

[lumen]

Let me clear it. Flux should leave the core at on time, it is not a problem.

Now how much flux should couple with the pickup and how much should remain ? This is the question. Ideally, one would want all of the flux to leave the core and couple with the pickup windings, not only half of it, to induce max power.

I'm sorry, I could not come up with any clever ideas on this today (except the one for placing the core such that the hole faces the PM instead of edge on).

Perhaps the best designs are those posted very early in the bigger steorn thread.

I'm not sure you are only getting half the flux. It appears that all the flux from the magnet is pushed to half the core. So in the end you get all the flux, just out one side of the core.

I think the magnet itself needs to put the core very close to saturation along both sides. Then when the coil is energized, the flux is pushed to one side which by itself is more than one side can handle, so flux leaves the core at very little expense to energize the pickup coil. Any BEMF would have little effect on the coil drive current because the coil only sees the core material and excludes outside fields.

[Bruce_TPU]

Evening ALL,

I have wound myself silly, and the three layer, 1.2 ohm bias winding is completed.

I am going to experiment with it tomorrow evening and we will see what we see...

Cheers,

Bruce
http://www.energyfreedomreport.com

EDIT:
Bottom drawing is the next logical conclusion to my idea, if it works.

[gravityblock]

Episode 10: Influence of the magnet on the hysteresis curve of ferromagnetic core (with and without the magnet), http://jnaudin.free.fr/2SGen/indexen.htm#hysteresis

Bruce, I like your flux diode idea.

GB

[exnihiloest]

Look at the full FEMM simulation in Naudin's experiment.  You will observe the magnetic field outside the toroidal coil is null, http://www.youtube.com/watch?v=6Uo0s7boCPc

I think your interpretation of what we observe is biased.

GB

FEMM is not real life. Not only real life is in 3D, FEMM in 2D, but also FEMM doesn't handle properly saturation without severe precautions (see their FAQ section 3).
Leave your PC and check yourself by making experiments instead of blind belief in 2D simulations! Flux leakages are obvious.

[exnihiloest]

Why would the flux leaving the core during the coil on time be such a problem?

It is not the problem, it is the solution: the "leakage" flux is the useful flux that the pickup coil recovers.

If the magnet alone has already pushed both sides of the core to near saturation, then only a very small amount of power will cause all the flux from the magnet to over saturate one side of the core, pushing some flux outside the core.

I don't believe you have measured the energy for saturating the core. It is not small, it is big and always less than the energy recoverable by the pickup coil.

Even if there could be any BEMF, it would not directly be related to the supplied coil current.

Proof?

In fact, if half the flux in the core was from the magnet and half from the coil, you would only get half the expected BEMF in the coil max.

During the coil collapse, the field will induce an opposite current through the coil winding and again over saturate the other side of the core as the field sloshes back and forth through the core like water in a "U" shaped tube.

By creating an opposing flux, the field collapse tends to saturate the core, opposing the desaturation. It is the reason why BEMF is not strong: the desaturation increases mu thus moderates the field collapse. The collapse is extended in time. There is an exchange between the internal energy of saturation which is released, and the energy in the field which is partially refilled.

We must remember that it is only the change of flux that induces current in the pickup coil. The change of flux is due only to the coil field, not to the constant permanent magnet field. The magnet field is just the way for unbalancing the saturation along the toroid core. It doesn't provide energy (Naudin is right on this point).