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Author Topic: MH's ideal coil and voltage question  (Read 477872 times)

tinman

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Re: MH's ideal coil and voltage question
« Reply #225 on: May 12, 2016, 01:35:37 AM »
It is true only for an ideal inductor that has an infinite inductance.
In an ideal inductor having a finite inductance, in series with an ideal voltage source, the current will be able to flow and it will increase linearly in time without a limit.



 
Specifically, one current, that would flow due to the nature of a shorted voltage source and a second current, that would flow in a shorted ideal inductor (shorted by the voltage source). 
That's all, that I was able to decode, so far.

Quote
Anyway, that statement above is so awkwardly worded.
First you write about two currents flowing and at the end you write about currents not flowing - that sounds contradictory.

No,i said currents being produced,not flowing.

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I think you wanted to write about two currents, that would flow if they were not opposing each other.

And that is what i wrote.
The current produced by the EMF of our ideal voltage,would meet the equal and opposite from the CEMF produced by the ideal inductor.

When dealing with ideals,we deal with absolutes,and there for the CEMF is ideal,meaning that it is equal and opposite to that of the EMF.

Brad

tinman

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Re: MH's ideal coil and voltage question
« Reply #226 on: May 12, 2016, 01:49:22 AM »
 author=verpies link=topic=16589.msg483812#msg483812 date=1462987219]






Quote
It is true only for an ideal inductor that has an infinite inductance.
In an ideal inductor having a finite inductance, in series with an ideal voltage source, the current will be able to flow and it will increase linearly in time without a limit.

And how would it do that if the CEMF is equal to the EMF that created it?


Brad

verpies

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Re: MH's ideal coil and voltage question
« Reply #227 on: May 12, 2016, 08:06:53 AM »
And how would it do that if the CEMF is equal to the EMF that created it?
The current would not increase if CEMF = -EMF, but they would be so only in the case when the ideal inductor had infinite inductance.

Note that I was explicitly writing about the current increase through an ideal inductor with finite inductance.

verpies

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Re: MH's ideal coil and voltage question
« Reply #228 on: May 12, 2016, 08:11:04 AM »
But can we say for sure that our understanding of those 2 forms of reactance is not derived from
some existing level of resistance?
No, the resistance behaves significantly different from inductive reactance.  The former converts current to heat and the latter converts current to magnetic flux.

...and sheesh it's like, definitely ultra confusing, when we have different variables measures in the same unit but they are somehow working entirely independent.
They both have the same units, but mathematically they are in different complex dimensions which are orthogonal.

You don't seem to have a problem with distances in different orthogonal dimensions, that are not affecting each other despite being expressed by the same units: meters or feet.

minnie

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Re: MH's ideal coil and voltage question
« Reply #229 on: May 12, 2016, 11:37:15 AM »



    What a silly thing this has turned out to be. Ideal seems to have caused total confusion.
  The whole thing is just a matter of  a bit of maths,which I can't do!
   I would love to do the experiment, a good quality choke and a couple of forklift LA. cells
  would make an ideal power supply. I can see smoke in the equation.
    I don't see superconductors as the equivalent zero resistance.
   Another point I'd like to make is the continual appearance of things like "You lied MH."
   to me lying is deliberate fraud whereas misinformation due to incomprehension
   isn't lying.
      I lied when I said I knew the answer when in reality I didn't.
    Have a great day you all,warmest regards, John.

tinman

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Re: MH's ideal coil and voltage question
« Reply #230 on: May 12, 2016, 12:10:08 PM »


Note that I was explicitly writing about the current increase through an ideal inductor with finite inductance.

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The current would not increase if CEMF = -EMF, but they would be so only in the case when the ideal inductor had infinite inductance.

And so the reverse would apply.
The moment an EMF is placed across the ideal inductor,and a current started to flow,then the CEMF produced would be the same as the EMF that created it. That being the case,then the inductor would act as though it had infinite inductance.

Just thoughts :)


Brad


tinman

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Re: MH's ideal coil and voltage question
« Reply #231 on: May 12, 2016, 12:20:10 PM »
 author=minnie link=topic=16589.msg483887#msg483887 date=1463045835]


   
   
    I don't see superconductors as the equivalent zero resistance.
   
      I lied when I said I knew the answer when in reality I didn't.
    Have a great day you all,warmest regards, John.


Quote
I would love to do the experiment, a good quality choke and a couple of forklift LA. cells
  would make an ideal power supply. I can see smoke in the equation.

Of course you will get smoke,as you will have resistance,and be far from an ideal inductor.It is the resistance that causes the heat loss,no resistance=no heat.
Remember,the ideal inductor dose not dissipate power. The ideal inductor is wound from ideal conducting wire.

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I don't see superconductors as the equivalent zero resistance.

https://en.wikipedia.org/wiki/Meissner_effect
In Type II superconductors, raising the applied field past a critical value Hc1 leads to a mixed state (also known as the vortex state) in which an increasing amount of magnetic flux penetrates the material, but there remains no resistance to the flow of electric current as long as the current is not too large. ;)

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Another point I'd like to make is the continual appearance of things like "You lied MH."
   to me lying is deliberate fraud whereas misinformation due to incomprehension
   isn't lying.

You mean like making an absolute claim about there being no resonant systems in or around an ICE in any way,shape ,or form--only to later say-->well i dont know that much about ICEs :o
So you have given only two option's,fraud,or misinformation.

As much as myself and MH may not get along at times,due to nothing more that a difference in opinion,i would think more-a mistake would be a better word to use--which we have all made.


Brad

tinman

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Re: MH's ideal coil and voltage question
« Reply #232 on: May 12, 2016, 12:53:00 PM »
Perhaps we can actually carry out this experiment :o

Will insulated copper wire become super conductive if submerged in liquid nitrogen ?.
If not,what kind of wire would we need to achieve our super conductive windings at liquid nitrogen temperatures.


Brad

Johan_1955

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Re: MH's ideal coil and voltage question
« Reply #233 on: May 12, 2016, 12:57:57 PM »
Or this one: https://www.youtube.com/watch?v=PIvZJ9xGutI

Hear the: Sorry about the light, and welcome in mine Labrborattorry (Nicky''''''s, kitchen table)!?

tinman

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Re: MH's ideal coil and voltage question
« Reply #234 on: May 12, 2016, 01:31:52 PM »
Or this one: https://www.youtube.com/watch?v=PIvZJ9xGutI

Hear the: Sorry about the light, and welcome in mine Labrborattorry (Nicky''''''s, kitchen table)!?

That almost sounds like TK lol.


Brad

Johan_1955

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Re: MH's ideal coil and voltage question
« Reply #235 on: May 12, 2016, 01:50:17 PM »
That almost sounds like TK lol.

Brad

Hole D-base with different Cookie's remarks collected!

What do you think about:

Always, Independent 3e party validation, all less is don't pay attention, except for: Nasa, Mit, Lewin sometimes, .............

Sweet dreams, and go to bed!

tinman

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Re: MH's ideal coil and voltage question
« Reply #236 on: May 12, 2016, 03:53:19 PM »


PW

Quote
This would more so describe an ideal inductor that also has an infinite amount of inductance.  As such, when connected across a voltage source, no current would ever flow as the time constant would also be infinite.

The time constant is infinite.
Tau=L/R. There is no R,as it's an ideal inductor.
Tau=L/0 = infinity.


Brad

Magneticitist

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Re: MH's ideal coil and voltage question
« Reply #237 on: May 12, 2016, 07:04:59 PM »
the ball, shopping cart, whatever.. floats through the perfect vacuum unimpeded. ok.

well how do we know this if there is absolutely nothing else in this vacuum to compare
its relative motion to. the presence of something else, anything else, could
be considered a resistance. a way to set a Tau. For all intents and purposes, it's at rest.
To say otherwise would be to simply assume it in test parameters. Newtonian Physics
really don't much belong in quantum mechanics anyhow do they? This seems more of
a time paradox. I understand I provide nothing to the convo without being able
to at least properly explain it, but maybe possibly someone else can see where I'm coming
from here. The 'ground' as Webby put it imo seems like light speed. Resistance is what keeps
our energy from traveling at light speed right? Whether, electric current, or whatever?

poynt99

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Re: MH's ideal coil and voltage question
« Reply #238 on: May 12, 2016, 08:06:25 PM »
The time constant is infinite.
Tau=L/R. There is no R,as it's an ideal inductor.
Tau=L/0 = infinity.


Brad
Tau has no bearing on whether current can/will flow or not. The effect it has is how "curvy" the rise of current is, relative to the timing of your test. With an infinite tau, the curve is going to be a straight line, not only because the time is infinite, but also because the beginning part of the curve is almost straight anyway.

Pirate88179

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Re: MH's ideal coil and voltage question
« Reply #239 on: May 12, 2016, 10:09:41 PM »
the ball, shopping cart, whatever.. floats through the perfect vacuum unimpeded. ok.

well how do we know this if there is absolutely nothing else in this vacuum to compare
its relative motion to. the presence of something else, anything else, could
be considered a resistance. a way to set a Tau. For all intents and purposes, it's at rest.
To say otherwise would be to simply assume it in test parameters. Newtonian Physics
really don't much belong in quantum mechanics anyhow do they? This seems more of
a time paradox. I understand I provide nothing to the convo without being able
to at least properly explain it, but maybe possibly someone else can see where I'm coming
from here. The 'ground' as Webby put it imo seems like light speed. Resistance is what keeps
our energy from traveling at light speed right? Whether, electric current, or whatever?

Electrons move at the speed of light even through resistors as far as I know.

Bill