MH's ideal coil and voltage question

[picowatt]

PW

I guess that it could be looked at that way,but dose not resolve the fact that current still flows when there is no potential difference.

Simply stated, if there is no potential difference, no current flows.  If no current flows, there is no CEMF...  If there is no CEMF, there is a potential difference.  If there is a potential difference, current flows.  Ad infinitum...

Think about it a bit.  An inductor's CEMF is a self regulating feedback mechanism dependent on the RATE OF CHANGE of the current flowing thru the inductor. 

As for the rest, I would never state that an inductor's CEMF, a motor's BEMF, and "inductive kickback" (or flyback) are all identical.

PW

[3Kelvin]

Hello together,

i think that there is no electric field in the ideal Coil (super conductor coil).
If there where a(n) electric field inside, the current have to go to infinity.
In other words, over a super conductive wire is no voltage drop measurable.
A super conductive coil has N turns to build up the 5 Henry.

P lost= i²*R
I= U/R
If R = 0 also U=0

But this is only my personal assumption.

Love + Peace
3K

[tinman]

PW:

Pushing 100 thread pages to get Brad and others to understand how an inductor works and you get this from Brad:

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[Part 2 from Brad]


The CEMF is created by the changing magnetic field,which is due to the increasing current over time,that was induced when the voltage was placed across the inductor
This CEMF creates a current flow that is in the opposite direction to that of which the applied voltage induced.



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However, it appears to be pretty clear that Brad believes that there is a "tangible reverse current" due to the CEMF somewhere in the mix when you connect a battery or EMF source to a coil.

Hence my frustration, and myself and Brad had a little mutual trash talk.  I am very tempted to just walk away.

MileHigh

Lenz's law MH
Quote:  If an induced current flows, its direction is always such that it will oppose the change which produced it.
Quote: Lenz's law states that when an emf is generated by a change in magnetic flux according to Faraday's Law, the polarity of the induced emf is such, that it produces an current that's magnetic field opposes the change which produces it.

This is something you should know by now MH.


Brad

[tinman]

That graphic you made is cringe-worthy and nobody wants to touch it.  All that you are doing is showing is how foolish or ignorant or stupid you can be.  Like I told you, buy yourself a few books on basic electronics and lock yourself in a room for a month and read them and understand them.  You definitely deserve the trash talk in this case.

Please feel free to take a DMM,and measure the voltage drop you speak of in a parallel circuit such as depicted in my diagram,and then post your results here,along with a diagram as to how you measured a voltage drop across the resistor.
Also please remember,that a voltage is a value of potential difference between two points,and a voltage is not a voltage drop.

Quote Fundamentals of electricity

Wires carrying current always have inherent resistance, or impedance, to current flow. Voltage drop is defined as the amount of voltage loss that occurs through all or part of a circuit due to impedance.

We could even add your CEMF producing resistor to this,and say that if there was an EMF drop of 2 volts across the resistor,then your equal and opposite CEMF would return that 2 volt's,and so the total loss across the resistor is 0--nothing. And so by your own analogy(the CEMF producing resistor),an equal and opposite reaction happens,and the voltage drop is counter acted,and so,no voltage drop took place.
Aint that a hoot MH--you killed your own claim.

Brad

[poynt99]

I guess that it could be looked at that way,but dose not resolve the fact that current still flows when there is no potential difference.

There is no "potential difference" with a resistor yet current flows.

BackEMF and CEMF are one in the same.
Inductive kickback is BackEMF. We are now saying that the inductive kickback from our ideal coil,will now give back the same amount of energy it took to create it,when the CEMF value is equal to the EMF value across that coil,as we have no I/R losses.

Brad, IK is not the same as cemf or bemf.

As far as i can work out,if the feedback is going to be the same as the applied,then the net power flowing is 0--we just end up with a tank circuit that keeps self oscillation.

With standard feedback in amplifiers, even with 100% feedback the signal passes through at unity gain. Something to think about perhaps.