Bridging coil to extend the magnetic field of strong magnet

[bs2012]

Hi cristache,

Still a very inefficient biased transformer.
Use Femm 4.2 to simulate. You will see you will have to put A LOT of energy into the control coil if the core is air.
If the core is iron the magnetic field of permanent magnet will penetrate the core
Either way you get the same thing

Thanks very much for your comment.

Any tutorial on Femm?  I've tried but really don't know how to use Femm.

[cristache]

it comes with a pdf tutorial
it's very easy to use, you'll see.
Read the tutorial and you'll be able to do your model in less than an hour from not knowing nothing about it

[cristache]

@TechStuff

Why the value of the magnetic field will make any difference?
Lenz law (the minus in front of Faraday induction law) will still be in effect.
Having 0.1T or 10T makes no difference.

Theoretically and maybe practically if you can decouple action from reaction it will work.
What I mean by that is this
You have a source of magnetic field such as a coil
At a certain distance you have another coil.
If you can produce a strong magnetic field in such a short amount of time such a way that the secondary coil back reaction cannot find the magnetic field in the first coil to push against, you have avoided lenz law.
Let's do some calculations
Let's say we have 1 turn in both coils and the surface is 1 square meter.
The coils are 1 m apart, air core (I doubt a feromagnetic material will work at this speed
Magnetic field travels speed of light, so the distance between is traveled in 3.3 ns
So you need to turn on and off first coil in 3.3 ns so the second coil back reaction doesn't find the action in the first coil.
The inductance of such a coil is 0.1 micro Henry
To get 1T magnetic flux you need aprox 820A.
To have that level of current in the coil in 3.3 ns you need 30,500 volts on your coil, but at 1m distance you wont get much due to magnetic field decay with square of distance
So let's do 2 coil Helmholz configuration with the receiving coil in the middle where the field is more uniform
0.2 micro Henry now, let's say only 10 cm appart
time is now 0.033 ns
voltage is now 3,005,000 volts
Not feasible with current technology, there's no semiconductor we can use, even a capacitor discharged I don't believe can go that fast (33 picoseconds)

[TechStuf]

Lenz law (the minus in front of Faraday induction law) will still be in effect.

I don't dispute your observation.  Many other laws are also in effect at this 'time'.

Magnetic field travels speed of light, so the distance between is traveled in 3.3 ns

The constituents that make up a magnetic field do travel quite fast yes.  It is the field interactions that pose peculiar variables.


One could study both and Halbach ring and the Magnetic Beam Amplifier patent in order to ascertain what beneficial commonalities might be exploited.  Light quanta move through free space in an essentially straight path.  Coherent light, even better.  What is magnetism but quanta of higher order, frequency, and intrinsic packet density?  Light impinges upon the fabric of space, but treads lightly compared to magnetism which, because of it's heavier footprints,  prefers an arcuate path and there's the rub.  Measuring velocity over both straight and curved paths at the same time requires prodigious processing power and heady mathematic linguistics skills.  What happens when both collapsing and expanding magnetic fields are compelled to occupy the same space in time, or nearly so, and at the right relative juxtaposition?  Once one is able to 'see' the flux field, one is better able to manipulate it.  Here's an illustration...Say a ballerina is competing side by side with a rather burly german tap dancer on the "Dancing with the stars" T.V. show.  One is making an impressive, heavy clatter as the floor is roundly beaten beneath her.  Meanwhile, the ballet dancer is doing fast and tight pirouettes and the floor adores her for it. Not so the tap dancer, blazing away until getting too close to the orbital influence of the ballerina's hand, and smack!  Right in the kisser!  Such energy from so small a figure....such that the tap dancer is momentarily stunned, but able to right back into the swing of things, as before.


Of course, the floor remains none the worse for wear for the whole experience, and neither the ballerina nor the tap dancer will pay such fact any mind....


Who does?






TS

[bs2012]

Hi cristache,

it comes with a pdf tutorial
it's very easy to use, you'll see.
Read the tutorial and you'll be able to do your model in less than an hour from not knowing nothing about it

I've followed the tutorial and come up a result that at least 0.1 Amp in the bridging coil is required to induce the magnetic field to the generator coil.  I assume the bridging coil is air coil while the generator coil is of iron core.  Is that close to your result?

Still struggling around with Femm.  Just wondering where to set the direction of the current flow and the pole of magnet as all these might affect the efficiency of the induction.