magnetic field size question

[mbrownn]

You can make a magnetometer and amplify it to 2x 10x 100x
using an op-amp.
https://www.youtube.com/watch?v=RDAHTKLeQSc

Some classic physics demos are beginning to use animation to help visulize.
https://www.youtube.com/watch?v=NWE9SCRgBv0

We can try to define some terms to make this easier to understand.
This paper 1998 by Bill Beatty suggest the concept needs improvement :
Electrical curriculum: What is Voltage?

I would like to see more progress in this area.

Good info, love the magnetometer

[mbrownn]

We can try to define some terms to make this easier to understand.
This paper 1998 by Bill Beatty suggest the concept needs improvement :
Electrical curriculum: What is Voltage?

I would like to see more progress in this area.

Interesting that its so hard to explain voltage. The point I am making is the larger the voltage, the larger the area that the voltage can influence. Similar things can be said of magnetism even though we believe it is the work of current that causes a magnetic field.

To use a hydraulic analogy, if we pass water over a weir it is only the immediate area after the weir that gets wet. Now if we pas the same volume of water through a small orifice, then with the pressure that will be required to flow that water through the orifice, the water will be projected over a larger area. just like your garden hose on a spray setting. Do you see what I am getting at?

It is almost as though some sort of pressure is required to expand a magnetic field, just as it is with static fields.

[Joit]

Interesting that its so hard to explain voltage.

I dont think the Guy is really right and he did not convince me with this explanation.
You can keep it very simple and say, Voltage is, how fast the magentism runs through the wire.
If you have a standing field you have no Voltage.
His examples of static electricity is nothing else then a storage.
And remember, the static charge between the clouds and the earth still come from the rotation of the earth and the wind.
So there is before a movement what can be later tapped.
Its not much different to the principle from a batterie, you put first charge in, when you connect the poles you got energy moving with a certain speed.
For a batterie and galvanic elements it looks more like that it depends how fast they react.
React, because at galvanic elements is allways one pole what dissolve into the fluid. And that speed gives you the different Voltage.
Same for a simple generator. The Voltage what you create depends allways how fast your magents passing by.
Where wire thickness and strength from the magnet influence the speed from the eddy currents at the copper wires or other material.

[wayne.ct]

There is a formula for that

This topic is interesting to me and I was thinking I might offer some help in explaining it but there are currents in the thread that make me want to back off and say nothing. So, I am going to go out on a limb here and try to help without falling out of the tree.

I think the most basic consideration is how do you compare what you actually observe with what the accepted scientific formula says you should observe.

According to the accepted formula, for example, the strength of the magnetic field created by an electromagnet is proportional to 2 things. 1. The number of turns, and 2. the current. Notice that neither one of these is voltage or resistance. Let's say you double the number of turns and cut the current in half. You SHOULD end up with the same strength of magnetic field.

To get the same current you could keep the voltage and resistance the same, or double the voltage AND double the resistance or halve the resistance and halve the voltage.

If you get what I am saying, there are an infinite number of ways to put this together. Voltage and resistance are additional factors to consider but you have only just begun. If you double the number of turns and want to keep the resistance the same, you need to use slightly thicker wire. This could double the mass of copper in the wire as an example. Which is cheaper in the long run? What is the best way to go?

Joseph Newman and Paul Babcock will tell you to wind a huge massive coil with lots of heavy copper wire and you will have a better chance of success. It seems to me you want to be using an adjustable power supply with built-in volt meter and ammeter in conjunction with various coils you have wound with specific numbers of turns and so on.

Is the formula accurate and correct? I'm not convinced. I'm still doing my own testing and theorizing. Good luck.

[mikrovolt]

Magnetic fields where shaped and distance is a concern could use the term Voltage as pressure would make better sense.

A tapered water nozzle with a 25 degree spray pattern and an orfice size and hose diameter large enough to maximizes 125 psi pressure. The higher pressure being analogous to higher voltage. Increasing the water pressure too high would make a good cutter so that there is an appropriate voltage range.

In discussing the design of a coil for a magnetic field where the shape and distance is a concern both voltage and current are a factor. However the nature of flux and how it is shaped differs from water nozzle in that more is needed to shape a magnetic field than simply treating it as a liquid. In this way the comment that an adjustable power supply be used is an intuitive approach to finding and adjusting for a shape pattern within a voltage range.

[Ernst]

(my interpretation of Tesla's work)

Whatever an electric current is, it is movement of some sort. And movement implies a mass being moved by a force.

Suppose we have a copper ring in which we induce a current using a magnet. We get a circular current. Now define a point A and B on this ring on opposite sides. The copper has a certain resistance so using Ohms law on the trajectory from A to B we find that B must be at a lower potential than A. Doing the same for the trajectory from B to A we find that A must be at a lower potential than B.
We now have two contradictory statements, while in reality A and B will be at the same potential.
So we have a current flowing but no potential difference. That is like water flowing without a difference in height. This means that there must be an external force causing the flow and we already know that there is, because it is the force that we convey using the magnet.
This force we call the electromotive force (EMF) or in electro-dynamics the vector potential (denoted by A).

Now we make a small cut in this ring and call one side A and the other B.
The force is still the same but the current can not flow from A to B. So this force now creates a high pressure region in A and a low pressure region in B. This we can measure as electric potential.
Looking at a single charge carrier at A we see a force pushing it towards B. But the charge carrier does not move because it can not bridge the gap. This means that the gap must exert an equal but opposite force, which we call resistance.
In general we can state that wherever there is a high pressure, there must be forces present to create and maintain it.
Of course the same goes for low pressures.
A force is a push and a push implies two objects, one pushing and one being pushed. We have already identified the latter being a charge carrier, but we now know there must be another one as well. We also know that the other one is present in magnetism.
At this point we can not be sure whether or not these two objects are the same so we will have to look a bit closer.
- we can have magnetic effects without electric effects
- we can have electric effects without magnetic effects
- changing magnetic fields create electric fields
- changing electric fields create magnetic fields
Einstein postulated that both electric - and magnetic effects are the result of an electro-magnetic field, and whether we experience electric or magnetic effects is dictated by our state of motion.
This however can not be true.
Two identical charges at rest repel each other, while when moving side by side at a sufficient speed they create a magnetic field that causes an attracting force. (known as the z-pinch effect)
This is also a direct conflict with the first principle of relativity.

------

Well.... that is part of a currently 80 pages on Tesla's work that I am preparing. It does not give a direct answer to your initial question but it may serve in finding one...


Ernst.

[mbrownn]

All interesting stuff, the copper ring scenario jumps out at me.

Of course in such a copper ring we have no means to measure the resistance and voltage at various points on the ring but the logic appears sound. If this is the case then there is more to the mathematical model than we have, and at best the model that we have is incomplete, or even possibly wrong. The more we look at it, the less we know.

@ wayne.ct I think we have established that something is amiss in the theory and in the lack of other explanations any insight is equally valid. Feel free to express your ideas.

Huge coils are something I have given thought to, but how huge? I think that at a certain size we reach a point where things will happen differently provided we have low enough resistance. It may be a reason for lack of success with the small inventor, but when we get to an industrial size it may be different.

It seems we cant say for certain what voltage is, but for the most part our mathematical models work.

What do we really know? its always like opening a can of worms when you question an established theory.

[mikrovolt]

In Europe the schools were interested in maglev trains late 60's in particular Eric Laithewaite.
The linear motor technology often levitated and spun non ferrous metals Laithewaite does a good job explaining why
but as a stretch I thought I would bring up the copper ring.

To show one relationship regarding size. The subject of voltage diverges here because AC standing waves are used
however the demonstrations do serve some purpose in the dynamics of induced fields in motors actually seeing iron filings
behave from a perpendicular view keeping in mind that the rack and pinion effect in the stationary mode vs the moving field.


Eric Laithewaite proposed that magnetic motors do better as they get smaller while an electromagnetic motors
improve as they get larger and why this is. That viewing this simply as inductive reactance would leave concept
missing some logic.

https://www.youtube.com/watch?featur...YsRi2Dss#t=405

[mbrownn]

In Europe the schools were interested in maglev trains late 60's in particular Eric Laithewaite.
The linear motor technology often levitated and spun non ferrous metals Laithewaite does a good job explaining why
but as a stretch I thought I would bring up the copper ring.

To show one relationship regarding size. The subject of voltage diverges here because AC standing waves are used
however the demonstrations do serve some purpose in the dynamics of induced fields in motors actually seeing iron filings
behave from a perpendicular view keeping in mind that the rack and pinion effect in the stationary mode vs the moving field.


Eric Laithewaite proposed that magnetic motors do better as they get smaller while an electromagnetic motors
improve as they get larger and why this is. That viewing this simply as inductive reactance would leave concept
missing some logic.

https://www.youtube.com/watch?featur...YsRi2Dss#t=405

Great video. I will watch more in that series. He explains simply one of the reasons for making things large, there are others too.

Inductive reactance and reactive power are another reason for investigating magnetic field size in coils. Reactive power is also a means of inducing a current without voltage.

Generally speaking, it is current we desire to produce work in machines and we have to consume power to do so. In Pulse Width Modulation we can also use the reactive current too and under the right conditions, increase efficiency. Normally we require a variety of loads on our machines which makes optimising this system more challenging. When we generate power, such as in a power station, we look to make the load more constant, so to power such a generator with PWM makes some sense as we can run it at an optimum level. Of course, it is the magnetic field that is supplying almost half the current in this case.

If we can manipulate the magnetic field to produce the current we desire, we can almost double efficiency.

Lets examine how we can do this. I will use a Bedini SSG as an example. Normally the inductive kickback from a Bedini is fed to a charging battery, but we could also pass this pulse through a second coil of low resistance, and if it is placed correctly around the wheel, will add to the torque before being fed to the battery. ie almost doubling the torque with little loss to the charging battery. Do you see how this works? One of the factors involved in getting the increased torque is getting the magnetic field right in the second coil, so placing just any old coil there will give disappointing results.

I use the Bedini as an example as most people are familiar with it. In my experiments I used a modified universal motor.

Taking it a step further we could have a cascade of coils around our Bedini wheel where it is only one that we actually put power into, each on its own Bedini circuit.