Back EMF vs. Collapsing Magnetic Field Spike

[Matthew Jones]

Well the issue I have with this is the way I run my coils. I have 2 magnets slamming into them before to hitting it with a charge. I know it presaturates, and I can see this on the scope. But I was trying to imagine the way to look at the grand total. Maybe some pre calculation for future project.

But that math of yours is above my head. LOL.

I am a trial and error technician.

Matt

[nilrehob]

@matt

I guess You could determine the 5*T point for a coil if You have a steady train of square-wave pulses going into the coil and then estimate when the coil is saturated by looking at the oscilloscope.
R is obtained by using a ohm-meter.
Then L=T*R

[lighty]

@nilrehob

OK now I see what you're getting at. However I see a few problems with your logic.

First of all high voltage doesn't do anything for energization of coil. In order to produce inductive collapse you first need to have magnetic field. In order to produce magnetic field you need current and not voltage. Of course, higher voltage will help overcome resistance of the coil as dictated by Ohm's law and by having a higher current you will need less time to saturate core (stronger magnetic field because of the different ampere/turns ratio). However then you'll have a shorter, higher current impulse and I suspect you will see pretty much the same net energy consumption and that's of course if you don't subtract from your calculations wasted energy due to higher power dissipation of the coils due to resistance. You could of course try to compensate for power losses by optimizing Q factor for some given frequency or impulse length equivalent but then you're stuck with some limited frequency range.

Also, the shorter the impulse the more you have to take into account the hysteresis curve because core material need some time to saturate. Of course you can use HF materials with much narrower hysteresis curve but then you'll be stuck with less energy stored per cycle.

Sorry, but I still don't see the way to overcome some basic rules of magnetic engineering. I'm not saying it's not possible but maybe I'm still getting your idea wrong?

[nilrehob]

@lighty

OK, conclusion: test it
I'll get back about this once I have done some testing.

[lighty]

LOL I think all has been said and done regarding core saturation in switching systems for the last hundred years- especially with the advancement of SMPS techniques. But if it gives you pleasure to experiment please do do. It can be fun. I experimented quite a lot with all different kind of setups just to get a more practical grip of the theoretical stuff I was taught. It always helps to see theory put in practice.

However be careful to do the proper measurement of current, voltage and precise impulse durations. Otherwise you might come to the erroneous results. It would also be of great help if you have RMS measurements on your scope.

[cody]

Aaron,


"LOL, agreed. But I do want to lead to that eventually in a different thread."

Are you ready to let us know what these other ways are? Are they relating to leedskalnin? Please post whatever it is you have, im interested

[nilrehob]

I just stumbled across a patent by Rosemary Ainslie the other day:
(WO/1999/038247) HARNESSING A BACK EMF

In the 44-page pdf there are three descriptions of experiments on this subject well worth reading.

[petersone]

Hi Hob Nilre
I read the doc.but could'nt see anything that a lot of people on the forums are'nt doing now.
peter

[nilrehob]

Hi Hob Nilre
I read the doc.but could'nt see anything that a lot of people on the forums are'nt doing now.
peter

Hi petersone,

Further back in this thread I asked for an experiment that would show me something that could not be explained by conventional textbook reasoning.
I thought I found that experiment within the patent above and so I wanted to share it with anyone else looking for the same.

Hob

[Aaron]

other stuff

Hi Cody,

I just saw this. I may do something with this this spring.

Aaron

Aaron,


"LOL, agreed. But I do want to lead to that eventually in a different thread."

Are you ready to let us know what these other ways are? Are they relating to leedskalnin? Please post whatever it is you have, im interested

[pha3z]

... like Jehovah or Yahweh or Elohim or Lucifer are names for the same god.

What bible you are quoting from?

[pha3z]

In PMH seems there is static magnetic field created which holds a lever,but I bet there are others configurations of iron and copper coils which create PULSATING magnetic field FOR FREE.

Either device such constructed will break from large current or create large and sustaining power output.

I've always said so, theory is simple and you will see that A LOT of free energy devices are using this scheme :

- create a lot of very weak but overunity 'kicks' in completely closed path
- use weak magnetic field generated by kicks to produce current (mostly on conductor surface)
- use positive feedback
- use a regulator to prevent damage to device

The simplest regulator is to CLOSE positive feedback loop using LOAD of some minimum resistance or impedance (vide Sweet VTA)
That's not a very good way but it seems to work.

I know its been over a year since this post, but whatever boguslaw is trying to do, he (or anyone else) might find Jean Louis Nadin's replication of the Steorn Orbo motor valueable. Here's the replication page: The Steorn Orbo motor replication by JL Naudin

The Orbo motor works like this:

Toroid Coil sits as the stator.
Rotor contains magnets which are attracted to the coil simply by natural magnetism. The coil is energized to temporarily eliminate magnetic field interaction (YES its the complete opposite of what you normally do with an electromagnet)!! Momentum carries the rotor on past.

It may relate to the unusual effects boguslaw is talking about.

[kaosad]

Inductive spike vs. Back EMF

Back EMF is the same as Counter EMF and in either case, including Forward EMF, none of these are the inductive spike from a coil.

If he is saying in the book that forward emf is the inductive spike then he is misusing the entire concept of force as in electromotive force. Is there force with zero work or pure potential moving through a coil and out of it? It might sound good but is is like an oxymoron...kind of like "military intelligence."

I have the same book from a friend it is a great reference nevertheless.

Inductive spike or back EMF or counter EMF, they are all the same thing. The only difference is how the EMFs are generated.

[Aaron]

back emf and inductive spike completely different

Inductive spike or back EMF or counter EMF, they are all the same thing. The only difference is how the EMFs are generated.

You're free to believe what you want.

Back EMF voltage is ALWAYS LOWER than the source voltage. Not
higher such as the spike. They are not the same.

Back EMF is there DURING THE POWERING OF THE LOAD.
The INDUCTIVE SPIKE is there AFTER POWER IS REMOVED.

Please do your research. There is plenty here.

[kaosad]

You're free to believe what you want.

Back EMF voltage is ALWAYS LOWER than the source voltage. Not
higher such as the spike. They are not the same.

Back EMF is there DURING THE POWERING OF THE LOAD.
The INDUCTIVE SPIKE is there AFTER POWER IS REMOVED.

Please do your research. There is plenty here.

It does not matter how great the resulting voltage is, the most important thing is that they both appear due to the effect of countering the contraction of magnetic field in the coil (directly or indirectly). They boil down to the same equation which governs the voltage measured, i.e.,

v = - N dO/dt (Faraday's law of induction),
where O is the magnetic flux, N is number of turns, t is time and v is back EMF.

(Note that I mentioned they boil down to the same equation, however they can appear in different form of equations. It is just a matter of derivation to convince yourself that they are the same.)

Whether you see the induced voltage high or low basically is due to the initial conditions of your electronic components that form the connected circuit. This is under your control, if you have the knowledge. For example you can make the inductive spike be merely over 0.7V in the first few cycles, by just placing a very large and fully discharged capacitor connected in series with silicon diode as in the famous SSG circuit.

As like what you have observed, the back-EMF appears during or after powering of load. This is just a matter of how you generate it, as what I have said in my first post. The phenomena is still explainable through Faraday's law of induction -- nothing surprising about that.