Joule Thief 101

[MileHigh]

I agree, but this is being approached from the other way, discussing an ideal inductor. Ultimately the whole thing is a tempest in a teapot.  If you truly understand a real inductor then by definition you have to understand an ideal inductor.

If all of the coils in your motor point with the same polarity outwards, then you probably have a lot of flux cancellation between adjacent coils.  I am assuming that you measured the inductance of a sample coil with an inductance meter.  Do you know if the inductance meter can be thrown off by the high 650 ohm resistance?

If you are not sure about the total inductance then you could easily measure the time constant for all of the coils in series and see what you get.  I would not be surprised if you get a lower inductance than you think.

[Magluvin]

I agree, but this is being approached from the other way, discussing an ideal inductor. Ultimately the whole thing is a tempest in a teapot.  If you truly understand a real inductor then by definition you have to understand an ideal inductor.

If all of the coils in your motor point with the same polarity outwards, then you probably have a lot of flux cancellation between adjacent coils.  I am assuming that you measured the inductance of a sample coil with an inductance meter.  Do you know if the inductance meter can be thrown off by the high 650 ohm resistance?

If you are not sure about the total inductance then you could easily measure the time constant for all of the coils in series and see what you get.  I would not be surprised if you get a lower inductance than you think.

"If all of the coils in your motor point with the same polarity outwards, then you probably have a lot of flux cancellation between adjacent coils.  I am assuming that you measured the inductance of a sample coil with an inductance meter.  Do you know if the inductance meter can be thrown off by the high 650 ohm resistance?"

The inductance was measured on 1 coil only connected to the meter. Then measured with all 24 in series. It all calculates to be the same even though the coils are side by side in opposing polarities.

Hmm. Havnt read anything that says that I have to recalculate the inductance read with the meter by introducing the resistance value in the equation. Wouldnt the people that make the meters already have the meter do that for you if it is necessary? Like while the meter is connected to the inductor, it could first do a resistance test and sample then calculate the 'proper' inductance. But I havnt seen any dialog that different inductors with different resistances will produce inaccurate inductance reading directly related to the resistance. So are inductance meters virtually useless? There are many coils, transformers and suce that have very low resistance and some with very high resistance.. I mean if your saying that to find the 'true' ideal inductance of my coils helps me any, then Im not sure how or why, because I will most likely never be working with an ideal inductor.

Mags

[Magluvin]

What about the ideal bemf, cemf of the ideal inductor?  Why is that not an issue here? We, Brad, AC, Mags, and(the other mags) and Verpies seem to have the idea that the ideal inductor will not let current flow due to ideal cemf. What is the exact explanation that the ideal inductor will flow current when a source is applied, if we agree that the magnetic field and cemf should also be ideal in an ideal inductor? We cant pick and choose what works and what doesnt when talking ideal things. Then we are truly talking fantasy beyond what is really considered ideal.

Why is it just neglected that we have stated this many times already? Do you not agree that the cemf would be ideal also? I mean there has to be cemf if there is to be an inductance, so why is it not considered ideal and equal to the emf applied where we have a condition that no current would flow?

Mags

[MileHigh]

This is what Verpies said:

<<< 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.  >>>

It makes sense that the inductance meter would do a resistance check but I thought there might be limits.  I don't know, I never played with one.  There is no such thing as "ideal CEMF."  A regular coil or an ideal coil will give you exactly the same CEMF.  This has been stated before.

I think you know the truth.

[Magneticitist]

This is what Verpies said:

<<< 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.  >>>

It makes sense that the inductance meter would do a resistance check but I thought there might be limits.  I don't know, I never played with one.  There is no such thing as "ideal CEMF."  A regular coil or an ideal coil will give you exactly the same CEMF.  This has been stated before.

I think you know the truth.

I think the whole 'ideal CEMF' idea is taken from the general idea that any inductor resists the change in current. the more perfectly it does that the less it wants to return the magnetic field
when there is nothing opposing it.

when we imagine a perfect model of this we picture something that simply will not allow a current rise to begin with so long as it's something that could theoretically become charged and never dissipate over infinite time.
Some are saying this is a simple confusion where that is what would happen if there were infinite inductance but then we are left with the argument of whether or not a true measure of inductance has any relation to resistance in the real world. I just currently do not have the total math understanding to concede that the constitutive equation for the inductor and the calculation of current change over time has no relation to a unit of resistance.