Rotating Magnetic Field's and Inductors.

[poynt99]

The frequency returns to that as if there were no PM's near it.

The tests i have done are as follows;
1- simply to use my inductance meter to measure inductance,and find that as i slowly bring a magnet toward the inductor,the inductance rises. Then while the magnet is stationary at the center of the core,the inductance go's back to it's original value-or very slightly lower. Then when the magnet is slowly moved away from the core,the inductance once again rises.

Your results are indeed strange. In fact opposite to would you should see.

Do you have a coil with a ferrite core you can test? I tested a 35mH ferrite cored coil with a magnet and here are my results:

While measuring inductance, as I bring a strong magnet nearer the coil the inductance decreases until finally it touches the coil and goes to a minimum, and remains there. Similar results whether magnet is brought to the middle or end of the coil. Moving the magnet away from the coil, the inductance increases until it finally reaches its original value of 35mH.

If I stop part way to the coil, the inductance remains at the lower value it was before I stopped, it does not return to its original value.

You may want to check your meter or method, or something else, because your results are odd.

[tinman]

Your results are indeed strange. In fact opposite to would you should see.

Do you have a coil with a ferrite core you can test? I tested a 35mH ferrite cored coil with a magnet and here are my results:

While measuring inductance, as I bring a strong magnet nearer the coil the inductance decreases until finally it touches the coil and goes to a minimum, and remains there. Similar results whether magnet is brought to the middle or end of the coil. Moving the magnet away from the coil, the inductance increases until it finally reaches its original value of 35mH.

If I stop part way to the coil, the inductance remains at the lower value it was before I stopped, it does not return to its original value.

You may want to check your meter or method, or something else, because your results are odd.

I do have a coil with a ferrite core-i will try it.

The only inductance meter i have is the one on my DMM.

Using the self oscillation mode-should the frequency rise or fall when the inductance rises?- i assumed it would rise.

Brad

[citfta]

Hi Brad,

Here is a link to a formula to calculate frequency when you know the inductance and capacitance.  It can also be used to calculate for either inductance or capacitance if you want to calculate for a given frequency.  According to the calculations, frequency will go down with an increase in inductance.  I thought I remembered it being that way but wanted to check so found this site;

http://www.1728.org/resfreq.htm

Carroll

[poynt99]

I do have a coil with a ferrite core-i will try it.

Excellent.

The only inductance meter i have is the one on my DMM.

Probably not so good.

There are other ways you can measure the inductance, or even the change in inductance, that don't require an inductance meter.

Using the self oscillation mode-should the frequency rise or fall when the inductance rises?- i assumed it would rise.

Brad

Brad, "assuming" will get you into trouble more often than not. Folks seem to assume too much too often when working in what is unfamiliar territory for them.

I honestly am beginning to think that one reason folks seem to learn too little around here, is because they are being spoon fed the answers all the time; yes by guys like me, verpies, MH, TK et al. Check out citfta's link, or google "inductance" and "frequency" together. Here is another link. Perhaps you'll learn more by digging some answers up yourself. 

[MileHigh]

Here is my very first paragraph in this thread
Quote: I posted a quick video showing how having a rotor with alternating magnetic field passing a pulsed inductor can improve the efficiency of that inductor as far as the inductive kickback output go's.

Brad

I can sense that this is most likely the end of this thread so we can end it properly.

Your initial statement is generic - it suggests what you are claiming applies to a generic inductor coupled with a rotor in a pulse motor can improve the average inductive kickback power-out to average power-in ratio.

That statement is dead wrong.  It's just as bad as "acceleration under load" or the "delayed Lenz effect" which are two nonsensical and incorrect statements that took on a life of their own and misled and hoodwinked tons of amateur experimenters for years.

The only thing you found out was that with your particular very lossy coil when you added the rotor you got better performance because the addition of the rotor ultimately helped reduce the excessive losses.

If we assume a generic coil with an expectation of reasonably decent efficiency is used in a similar setup then your statement will be false.  It will be false because common sense is telling you three things, 1) magnets cannot in any way, shape, or form produce power themselves, and 2), when you add the spinning rotor it will require additional input power, and 3), never, ever ignore the waste heat generated by the system in all of your measurements and calculations.

There is going to be no bait and switch for this one - your initial statement is false.