MH's ideal coil and voltage question

[tinman]

Well, you are seemingly making progress,

But I have a question for you:  Way back very early in the thread I posted that formula and told you that it was basically the short answer to the question.  When I did that you went into a small frenzy and you insulted me like a drunk sailor.  So what gives, how do you explain using the formula now when before when I showed you the very same formula you insulted me repeatedly like a drunk sailor?

Im not sure if you read everything i write or post,but you seem to keep missing the fact that i do not agree with the results of your formula,and believe the values are wrong.

I told you right from the start,that using your generic formula would be an easy way out,but the results would not be that that your formula would show.

and I am going to ignore the various errors in what you posted because what you are saying is more important in the "error glitches" in your posting.

How is it i made errors,when the result is correct-as far as your concerned ?.
The method i used seemed to be correct,as the result was what you were looking for.

I do not believe the current value reached at T=7 seconds is correct.
I am not sure that it should be I=I 2.4 - 1/5 integral V dt.
I believe as verpies said,there is a higher order of math required here.
The 2.4 amps that is flowing opposite to that of the current to be induced by the negative value between T=5 and T=7,will be seen as a high impedance to that current to be induced during the negative portion of the cycle. This impedance value is greater than that which would be encountered by the current flow during the negative voltage part of the cycle to that of if the existing current of 2.4 amps was not there.

Our calculated current for T=7 seconds is 3/5 x 2=1.2 amps. This is calculated on the assumption that I=0 at the time of the calculation. But we have an I value of 2.4 amps of the opposite polarity,not a value of I=0.
As i said,i do not believe that subtracting that 1.2 amps from the negative voltage phase,from the previous 2.4 amp value is the correct way to do this,and gives a wrong answer when done like this.
The inductance value seen by the EMF during the negative phase,must be much lower due to the existing steady state current flow that is apposing the current to be induced during the negative voltage part of the cycle. The other problem is,there is no give in the voltage being applied across that coil loop,in that no matter what the load,the ideal voltage source will apply that full selected voltage across the coil. To me,this would be like trying to stop a spinning flywheel instantly.

Perhaps verpies and/or Poynt might think about that a bit,and see if it is as straight forward as some think it is.


And MH--->we need to call a truce here,as all this bickering is doing no one any good.
At the end of the day,we should all be here for the same reason,and that being they very name and nature of the forum.

I am not blaming it all on you ,as i know i have given as good as i have gotten.
Perhaps when we disagree ,we can just agree to disagree.

Don't even bother saying that you don't drink, it's just an expression.

I gathered that. The truth is,i am having a bourbon and coke right now--just one,for a mate(we call friends mates over here-just in case you take the word !mate! the wrong way) that passed away early this morning.


Brad

[poynt99]

Perhaps verpies and/or Poynt might think about that a bit,and see if it is as straight forward as some think it is.

My question to you Brad is what do you think will happen? In other words, please draw out the current wave form according to your theory of how the voltage source and inductor would interact.

[MileHigh]

Brad:

I am going to ask you the question again:

Way back very early in the thread I posted that formula and told you that it was basically the short answer to the question.  When I did that you went into a small frenzy and you insulted me like a drunk sailor.  So what gives, how do you explain using the formula now when before when I showed you the very same formula you insulted me repeatedly like a drunk sailor?

MileHigh

[tinman]

My question to you Brad is what do you think will happen? In other words, please draw out the current wave form according to your theory of how the voltage source and inductor would interact.

As i said,it's not so easy to work out when dealing with a voltage source and coil that form a loop that current can flow through unimpeded.
What happens when two 12 volt batteries are looped in series?.
We now have two voltage sources where a voltage cannot be measured at the terminal's,but we have lot's of current flowing through them. How do you measure that current flow if the series loop resistance is 0 ohms?.

i dont think there is much point in posting my thought's,as it seems you and MH have made up your mind's,and anything i say will just be dismissed anyway.
As MH has said that my current values and the trace i have drawn out are correct,and that you have agreed with MH most of the way through this topic,then it is safe to say that you also agree that my provided values,times and current trace are also correct,as far as your concerned.
So is there any real need to go on?.

Perhaps you could show us how you would calculate the peak current at T=7 second's?.
What is the formula and values you would use?.


Brad

[poynt99]

i dont think there is much point in posting my thought's,as it seems you and MH have made up your mind's,and anything i say will just be dismissed anyway.
As MH has said that my current values and the trace i have drawn out are correct,and that you have agreed with MH most of the way through this topic,then it is safe to say that you also agree that my provided values,times and current trace are also correct,as far as your concerned.
So is there any real need to go on?.

The point of asking you to draw out the wave form not so we can just dismiss it, it is to see how your thinking has caused you to arrive at your theory, and to see how to steer you toward the correct understanding. Yes of course your wave form trace is correct. It is not MH's way btw, it is just how it is, it is physics and it is reality (even with an ideal or near-ideal inductor).

Perhaps you could show us how you would calculate the peak current at T=7 second's?.
What is the formula and values you would use?.


Brad

I would use the formula MH posted. But I prefer to use the sim, which btw, fully supports the formula and the graph you have drawn out.