With a non ideal coil,i have no problem with the current rising,as the CEMF value cannot be, and is not the same as that of the applied EMF,as we have a current rise that has an exponential curve,and this curve starts at T=0. And this is why i said that the resistance of the coils windings are the reason that the CEMF is a slightly lower value than the applied EMF. Even that !minute !amount will start a chain reaction when winding resistance is involved,and so the current can flow,due to the coils ability to dissipate energy. But that just is not the case when talking ideals--that is why they are ideal.

I've already stated this and I know it did not register, so here it is again:

With a non-ideal inductor, the instant Vin is applied, all the voltage appears across the inductance, and nothing across the resistance (assuming a lumped inductance and resistance model), therefore Vin=cemf, and lo and behold, current still begins to flow. In fact this is the moment the A/s is the highest rate!

Now, what happens if we were able to make R smaller and smaller?

    Time to sharpen up your measurement skills tinman!
     If photons can go say 30,000,000,000. centimetres
     in a second it's going to take some doing.
              J.

Why do you wish to single me out PW,when there are more that believe what i believe,than there is those who believe what you believe on this thread.

It would seem that yourself,Poynt,and MH are the three that stand alone on this belief that current can flow when the EMF and CEMF are of the same value--the rest of us seem to be of the opinion that when the EMF and CEMF are of the same value,that no current will flow.

I have repeatedly stated that current will not flow if the EMF and CEMF are equal.  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, or as I stated, if you are just being contrary for the sake of argument. 

You also forget the fact that these !0! resistance inductors have stored energy applied to them in order to make them super conductors.
So no-we do not have !room! temperature super conductors,or ideal coils/inductors that do not dissipate energy--this is a fact,and for you to bring this into the discussion,only diverts traffic in the wrong direction.

Zero resistance inductors are in use daily all over the world.  The fact that they must be cooled is not relevant to the discussion.  As energy is stored or retrieved using those zero resistance inductors, none of that energy is dissipated as heat.  It is the flow of heat towards the superconductor from the outside environment that must be dealt with.

       
The answer is always avoided by way of introducing real world configurations that dissipate power/energy--such as your feed back system.

A quote from my dad's book

And to quote Poynt
 

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.

I thank you for your time PW--and all,but my journey to find those who can see past the known is complete.

Brad

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.         

PW

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

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

I've already stated this and I know it did not register, so here it is again:

With a non-ideal inductor, the instant Vin is applied, all the voltage appears across the inductance, and nothing across the resistance (assuming a lumped inductance and resistance model), therefore Vin=cemf, and lo and behold, current still begins to flow. In fact this is the moment the A/s is the highest rate!

Now, what happens if we were able to make R smaller and smaller?

The above is germane to the argument, yet no comments.

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

Faradays own Faraday disk generator dosnt even follow his own law.
Here we have no rate of change in time between the magnetic field and conductor,but current still flows. We can have the magnets stationary to the rotating conductor,or we can have them spining with the conductor--it makes no difference.
But im sure there has been some tweaking to the laws to account for this--as they often do.


Brad

The above is germane to the argument, yet no comments.

This seems to go against what we discussed before Poynt.
We agreed that the CEMF is what limits the current,and stops it from going straight to its steady state value. A voltage appears across a resistor as soon as it is placed across that resistor. The only reason the current value is far less than that steady state value at T=0,is because we have the added series resistance generated by the CEMF ,that is added to the coils winding resistance. We know this to be true,because if there was no CEMF(as we discussed),then the current would go straight up to the steady state value.


Brad