Re: Error in Wikipedia article: Faraday's law of induction

On Sat, 12 Jul 2008 22:13:01 -0700 (PDT) Benj <bjacoby@xxxxxxxxxxx> wrote:

| Yes, the dual Faraday generator used flanged disks with a copper mesh
| belt around them. This places (if you choose magnetic polarity
| correctly) the two generators in series which doubles the voltage (I
| think Tesla had the idea of a series of these to get voltages to
| useful ranges) and also lets the brushes be on the disk shafts rather
| than sliding on the disks (which has lots of friction and losses at
| the low voltages and high currents).

The original I idea I had was to have 2 parallel disks. Each disk would
have a magnet (same size as the disk) on each side. Looking down the axis
one disk would have both of its magnets with N-pole facing at you. The
other would have S-pole facing at you. These 2 disks would be spaced a
bit apart due to the S-poles facing each other. There would be field
lines reaching around each disk as well as going through each disk. Wires
would cross connect the two disks at their edges. The axis between disks
would be non-conductive.

This design is flawed because both disks would have the "extraneous" field
intersecting the cross-connect wires.


| The spiral one was interesting too in that he was trying build a "self-
| excited" Faraday generator. The idea was that the high currents in the
| spiral rotor automatically generate a stator field without a field
| supply or permanent magnets.

I'd have to see the geometry of this to know where the field lines would
be causing problems for this.


| The OPFHG actually produces voltage (which seems rather amazing at
| first) But if you use Lorentz arguments you have to say that since
| there is no relative motion between the magnet and disk there can be
| no Lorentz voltage. Thus EITHER the field rotates with the magnet and
| ALL the output voltage comes from the non-disk part of the circuit OR
| the field does NOT rotate with magnet in which case the voltage comes
| from the disk [no relative motion then between magnetic field and
| external wiring].

One or the other it seems.


|> There is the counter argument that if the magnets rotate, and the disk
|> does not (wires are attached to measure), then this should induce some
|> voltage in the attached wires as well. ?Yet this configuration nets no
|> EMF.
|
| The actual counter argument actually involves the case with the disk
| stationary and the brushes and meter are moving around the disk. And
| that DOES produce a voltage.

Another thing I have been wondering about is treating the Earth as a
OPFHG. While there are not conductors as we think of them extending
outward from the Earth, there actually are some, as well as a stream
of particles. So I wonder how much of this is charge from the Earth
rotating in its own magnetic field. There are some strange things like
"lightning sprites" emerging from the tops of storm clouds, suggesting
electrical fields extending much higher.


|> If the OPFHD really produces no EMF at all, then there was no paradox?
|
| But is does produce voltage. In fact the SAME voltage as if the
| magnets didn't move.

But is it really the OPFHD producing the voltage? Or is it there is
a voltage in the whole system consisting of the OPFHD and the wires
that are stationary, attached to brushes to extract current?

If those wires were constructed in a way that they were very loose
so that small forces could move them some distance to one side or the
other, would the rotation of the OPFHD mechanically deflect the wires?
If the voltage is being induced on these wires, shouldn't there be at
least some mechanical force, as well?

Of course one problem with this is, since these wires are carrying
current, and there is a magnetic field (we claim is stationary even
if the magnets are rotating), then I'd expect the wires to deflect
even if they are not where the EMF is induced. They would have their
own magnetic field, and that would interact with the rotor field.


|> I plan to buy some strong neodymium magnets to try things with when I do pick
|> an experiment to try.
|
| Me too! But right now I"m using Speaker magnets. One experiment is to
| encase the whole thing in an iron magnetic circuit (as Tesla did)
| Iron elements complicate the picture but I'm wondering what the effect
| of such flux concentration would be on output voltage and current.
| Especially if you spin the disk, magnets AND iron circuit! The thing
| I'm building needs a bit more machining before I try it.
|
|> I don't know what you mean by "measurement cannot be made with a loop". ?I am
|> not suggesting some kind of loop coupling to sense the EMF in the disk/wheel.
|
| It means that if you are measuring output using a meter and a
| "circuit" there is a loop of wire there and you MUST consider the
| ENTIRE loop for Lorentz forces. Consider the following: A spinning
| magnet. a "Loop" consisting of a wire down the axis of the disk shaft.
| A wire vertically up the face of the magnet. A wire away from the
| magnet following a "line of flux" and finally a vertical wire back
| down to the shaft where it is twisted with the other wire and goes to
| the meter. The standard thought is that if you make the flux line
| wires long enough, the downward wire will be in such a weak field that
| you can ignore any induction there. That is totally wrong!

There is an "extraneous" field going around a magnet between poles.
There is a field inside the magnet between them as well.

If you have 2 flat magnets, with poles on their flat faces, and they are
placed with the N-pole face of one close to the S-pole face of another,
you have a strong field between them. But there is also that "extraneous"
field going around the outward face of one to the outward face of the
other. Both of these fields have to be the same strength in much the
same ways as an electric circuit has the same current at two points.


| Dig. The wire down the shaft follows a fluxline and has no induction.
| The upper wire following a flux line has no induction. The twisted
| wire pair has no induced voltages. The wire up the magnet face will
| have the Lorentz force you expect due to the relative motion of the
| magnetic field and the wire. So far the experiment has everyone fat
| and happy. But wait. If you look closely, you'll find that the SAME
| flux lines that cut the wire on the magnet face ALSO cut the DOWNWARD
| connecting wire and do it in the OPPOSITE sense. You can show the
| induced voltages are equal and opposite! Hence you can experiment
| until you are blue in the face and you get NOTHING! And that also
| includes no conclusions! So long as there is a loop in the field you
| simply can't get around this cancellation! It turns out the loop shape
| makes no difference. This is why people suggest using electrostatic
| measurements which do NOT use a closed circuit to measure emf.

This is why I want to explore a modification of the field.

Consider a disk with 12 radials (so clock hour positions are easy ways
to identify specific radials).

The magnets I would use are half-donut shaped, with poles at the ends,
somewhat like a stubby horse-shoe magnet. These would be placed so that
the N-pole faces the disk from the top at radial 1, and S-pole faces the
disk from the top at radial 2, of the same magnet. Below the disk is
another magnet with its S-pole facing radial 1, and N-pole facing radial 2.
Several of these "facing pairs" would be placed along the radial, from 3/4
of the way away from the axis to the edge (so this is all in the outermost
1/4 of the disk, measured radially). Repeat for radials 3 and 4. Again
for 5 and 6. Then 7 and 8. Then 9 and 10. Then 11 and 12.

The conductor runs outward along radial 1, then jumps over to radial 2 at
the edge, then runs inward along radial 2, then jumps over to radial 3 at
the 3/4 distance. It repeats this back and forth until it reaches back
to radial 1 where it began. This is where we can insert the small light.

The disk itself is not a conductor. It would be a plastic frame holding
the conductor and the magnets.

The fields of these magnets are closely confined. The space between the
magnets above and below is kept close relative to the space between the
radials.

The orientation of the conductor is reversed where the magnetic field is
reversed. So any induced EMF should add up in each radial.

There are no "off the disk" stationary conductors (yet). If this does
induce EMF in the parts of the conductor directly between the magnets,
and if this EMF is going to be "bucked to zero" by other parts of the
conductor not directly between the magnets, then it will have to be in
the part where the conductor runs in the direction of disk rotation
between the radials. Even if there is magnetic field there, it's not
changing (since it is all rotating as one piece) so changing flux will
not be an influence. And the conductor direction is the same as the
motion direction, so that leaves insufficient conditions for any field
to induce an EMF by Lorentz law.

This configuration could also be done on a drum by having the radials
run parallel to the axis, with half the magnets outside and half inside
of the tubular surface of the drum.


|> The loop is to generate a larger EMF potential. ?Putting the light on the
|> wheel itself is a means to directly measure without using brushes on the
|> disk.
|
| Tried it. But if you think about it, you see that wires going to the
| light are the part of the light-loop! No light is seen.

So how can the configuration I describe above have this issue, where there
is enough "extraneous" induced EMF to fully buck the expected inducted EMF?

I hope my description of the configuration is clear enough. I'm very bad
at drawing, and even worse at 2D drawing of 3D depictions. I can imagine
my own ideas in 3D rather readily. I suppose what I need to do is learn
to use the POVRAY program to make my 3D ideas at least show up visually.


|> I'm also considering the drum configuration. ?The conductors would run along
|> the drum parallel to the axis. ?The field would be radial to/from the axis.
|> And of course the motion would be circular around the drum.
|
| Yes the drum configuration is good, See the old EM books by E.G.
| Cullwick who derives a lot on the drum and notes the "meter and
| brushes" relative motion thing.

I want to avoid the brushes as much as I can, at least until I can raise the
voltage and lower the current enough to make it not so much of an issue. In
the big design I gave above, if it really does induce an EMF, then I guess I
could take off power by having one end connected to one axis, and the other
end connected to the other axis (the axis in the middle being non-conductive).


| Good luck!
|
| WARNING: Due to extreme spam, googlegroups.com is blocked.
|
| Hey, I'm posting in GoogleGroups.com! How am I getting through? Is
| this evidence of superluminal transmission?

It seems you get through because you did followup on either a non-blocked post
or maybe my post, or a thread I posted in.

--
|WARNING: Due to extreme spam, googlegroups.com is blocked. Due to ignorance |
| by the abuse department, bellsouth.net is blocked. If you post to |
| Usenet from these places, find another Usenet provider ASAP. |
| Phil Howard KA9WGN (email for humans: first name in lower case at ipal.net) |
.

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