MH's ideal coil and voltage question

[minnie]

The tinman doesn't seem to believe in theoretical guys.
  I watched this thing on YouTube.
  "Harold Black and the invention of the negative feedback amplifier"
  He had the idea,got it down on paper and his colleague built it.
  It's men like those who have given us all these marvellous
  communication devices.
        J.

[MileHigh]

It really comes down to this,the EE guys are always right,and need no such test to prove they are,and the rest of us are wrong--it's that simple.

Brad

I asked you a couple of times to give a concrete example of where the CEMF must be less than the EMF for current to flow using a simple example with a coil and voltage source with actual numbers and you refused.  You can't actually put substance to your beliefs.

So, we often hear, "This is what I believe but I can't really explain it and I cannot give you a concrete example illustrating my theory with numbers."  And that is just plain bogus.  Here is a classic example, "Repeatedly shorting a coil gives extra energy."  The thread name is , "Shorting coil gives back more power."

With respect to the discussion, there is more than one way to skin a cat and so different ways of explaining the whole EMF/CEMF business have been explored.  Then there is the pure reality of doing tests on your bench.  And within that reality you must have the full conscious realization that within the real coil on your bench, there is actually an ideal coil, and that ideal coil is functioning exactly like the EE equations state it should function like.  Saying, "I only deal with real stuff on my bench" is almost a strange thing to say because the exponential response of the real coil comes directly from the ideal coil that is the basis for the real coil.

I suppose what I am really saying is that if you take the top five old wives' tales that you see on the forums and actually demand that people put substance to those tales and show that they are REAL, you end up coming up goose eggs.

And it's bizarre when you look at somebody on YouTube like TheOldScientist.  He uses all the cliches and the old wives' tales all the time in his presentations, but when it comes to the nitty-gritty, and you really look for substance in what he is saying and demonstrating, he comes up short.  And he has fantastic test equipment!  The other guy that comes to mind is that Quanta Magnetics guy, talk about empty calories.

And you fell into the trap (or the trance) yourself when it came to graphene supercapacitors.  In one of your clips you make this claim, something like your home-brew capacitor is 10,000 Farads - but you make no attempt to measure it.  Just like my "buddy" RMS.  All that you have to do is do a few test runs with a few different resistors to discharge your graphene capacitor and measure the time constant and then crunch the numbers to give you a capacitance value - and you don't.  I could smell that your claimed capacitance was grossly exaggerated.

MileHigh

[partzman]

I asked you a couple of times to give a concrete example of where the CEMF must be less than the EMF for current to flow using a simple example with a coil and voltage source with actual numbers and you refused.  You can't actually put substance to your beliefs.

[snip]

MileHigh

Actually MH doesn't every scope shot of an inductor with a voltage applied across it's terminals generating a linear current rise give proof that Emf = L*dI/dt or rearranging di = Emf*dt/L? Where is the evidence of Cemf? So, anyone adhering to the notion that Emf = Cemf in a single inductor has the burden of proof IMO to show by experiment or math derivation that it exists.

By definition, Cemf is opposite to Emf.  The current increase in the above example is in phase with the applied Emf and follows Faraday's law without Lenz. How do we justify any amount of negative Cemf to be added to the Emf and still adhere to Faraday's law? I am willing to change my view if and when I see something convincing.

pm

Edit

[Magluvin]

Been thinking a bit on the emf=cemf as in if there would be current flow of an ideal inductor when input is supplied.

One conclusion as to how cemf could be always less than emf is probably distance. Distance from one winding to all others. Some are adjacent and some a couple or several or more wire thicknesses away from each other. Emf through the inductors windings, as in each winding will create its own field, and those fields are weaker the further they are from their origin. Like if we apply current to a length of wire, the field around that wire is stronger close to the wire and weaker the further out from the wire we go. So if we placed another length of wire next to the wire to be powered up, the further that second wire is from the powered wire, the less effect the field will have on the second wire.  I can see that as an issue in thinking that current would not flow in ideal wires and inductors.

And even in a single wire, the fields of the moving electrons have distance from other moving electrons, and the field from one to another is weaker than closer to the point of origin.

Dont know if that sounds right for sure. Just came up with it this morning at work.

So with that, I can say that ideal wires and inductors can flow current most likely and I can agree that cemf is most likely always in some way less than the emf. 

Mags

[tinman]

         

PW

I have repeatedly stated that current will not flow if the EMF and CEMF are equal.

And you have repeatedly stated that the EMF and CEMF are equal,but current will still flow.

or as I stated, if you are just being contrary for the sake of argument.

This is always how it is always seen--an EE says this is how it is,and anyone that disagrees with them,is the one who is doing the arguing. It could just as easy be seen to be the other way around.

That is the basis for how an inductor limits the rate of change.  I truly wonder if I would have as much difficulty explaining any other negative feedback mechanism to you,

If the negative feedback is slightly lower,then yes,i can see how that would work. But as we are dealing with an ideal coil,and none of that negative feedback energy is dissipated,then i see a balance--such as i have tried many times now to explain. The mere fact that current would continue to flow through this coil,if the coil was bridged,and became an ideal loop,shows that there is no losses in any way shape or form--not even to the magnetic field.
It also tells us that we would get back every bit of energy that went into that coil,when we open that loop,and collect the stored energy.

So are you saying that you believe the "EE guys", as you put it, have not heavily investigated zero resistance inductors, that is, tested and proved, that as the resistance is removed from an inductor it behaves more and more like an ideal inductor?  The study of the properties of devices made from superconductors is a very large field of research.

If you can point me in the direction of such tests,then i would be happy to read the results.

Below is a couple of diagrams.
Do we have diagram A showing the correct relationship of the CEMF to that of the EMF polarity,or diagram B showing the correct relationship between the CEMF and EMF polarities ?.


Brad