Magnetics and transformers and materials, it's a pretty big subject if you are hard core.  I am too tired to comment on previous postings right now, but let me mention something interesting.  I saw this thread on a science forum but didn't try to read it, it looked like way like too much work and my interest level was not high enough.

The subject was what happens in the magnetic core of a transformer under normal operation.  It's not so obvious.  Think of a good quality fairly large 1:1 transformer.  You put a nice pure 60 Hz sine wave into it and there is a resistive load.  We don't really need to worry about values.

Here is the thing:  The primary current creates magnetic flux in the core.  But the secondary also reacts in perfect synchronicity and its current also creates an equal and opposite magnetic flux in the core.  Since we know that flux in one direction can be cancelled by equal flux in the opposite direction, then what is going on in the core?  If there is no net flux in it, what's happening?  What are the magnetic domains doing?  Are they flipping or not flipping?

We know that each coil in the transformer is creating a "blast of flux."  But between the two blasts there is a kind of mutually assured destruction going on and there is no flux.  It's almost like electrons and holes in a diode smashing into each other and self-annihilating (in a figurative sense).

I honestly have never read up on this subject at all.  I just saw the subject line and it got me thinking.

MileHigh

MileHigh


Are you interested ? Really ? Here I proposed experiment which will prove what is going on ! Nobody is interested....I have done my tests with 1:1 isolation transformer when JackNoSkills posted thread , but lack of experience and analog scope would not allow me to get final conclusions...


I'm tired writing again and again when nobody sees the importance of the experiment. I thought maybe gotoluc would be interested because his reactive power setup is very close but unnecessary complicated.


Ok, in short : it is about resonance power and transformer. If we have pure resistor (I assumed bulb , but that's not ideal however easy to measure lumens) - we can power it in parallel tank circuit down to almost zero input real power. That's easy part. Now what if tank circuit is on primary side of transformer and resistor (bulb) alone  is on secondary ?


Please tell, why it is SO IMPORTANT to measure such circuit precisely !!!???

Forest:

Resonance is not a form of power that can be applied to the input of a transformer.  In very general terms, resonance is often misunderstood by beginning experimenters and they attribute "amazing" properties to it when the truth is that with more understanding and knowledge, then it's not so special.

Please tell, why it is SO IMPORTANT to measure such circuit precisely !!!?

Because that's how you learn.  Another problem is that people sometimes make two measurements and then they conclude that they have over unity or something that "conventional electronics can't understand or explain."  It's simply not true.  They only make two measurements and they ignore what is going on in the rest of the circuit which is a mistake.

If you are beginner and you really want to understand how a circuit works, then with your scope and some current sensing resistors and by making multiple measurements where you change certain parameters (eg: a load resistor) you can understand how your circuit really operates.  If you are serious and determined you will look at every single voltage and every single current in the entire circuit.  You will construct a timing diagram for the circuit and show how an event on one signal creates a response event on another signal.  Nobody ever does it and that's just the way things are.  The collective group progress is very very slow.

I will give you one example:  How may times have you seen a discussion about selecting the correct base resistor value for a transistor on the forums?  For me the answer to that question is zero.  On the other hand, every time you use a transistor in a circuit, you can simply blindly do what someone tells you to do or you can blindly copy the value for the resistor in the schematic.  What you should be doing is understanding how you select a base resistor value for your transistor.

Farmhand:

About flux in transformers, the document you linked to says this:

For example, one would think that increasing the number of turns would increase the flux density, since there are more turns contributing to the magnetic field. In fact, the opposite is true, and for the same input voltage, an increase in the number of turns will decrease the flux density and vice versa. This is counter-intuitive until you realise that an increase in the number of turns increases the inductance, and therefore reduces the current through each coil.

I am not comfortable with this statement.  No matter what, the flux density is proportional to the ampere-turns and the relative permeability and the current.  The author is implying a set of initial conditions - AC excitation of the primary and more turns equals higher inductance equals less current.  However, more turns with less current is still multiplied out to give you ampere-turns.

If you just look at DC excitation for a second, then for the same DC current more turns gives you more flux density.

One thing for certain is that your document clearly reminds people that unchanging (call them "DC") magnetic fields do not affect an inductor or a transformer.  So there are hundreds and hundreds of experimental clips out there that get this basic fact wrong.  And I am NOT referring to certain special cases here, I am referring to the generalized case and the vast majority of the video clips fall into that category.

MileHigh

MileHigh


With my old analog 10Mhz scope I cannot do much without big experience and to get more experience I should have good tools and teacher who can shown and ANSWER questions. Sorry, I can't follow that path due to various reasons.


What I tried to do is to attract more experienced person , preferably with extended knowledge and having proper tools to answer some important questions.


AS it failed I will explain WHY I did it , talking is cheap.   


What everybody was told after some time of learning about resonant tank circuits is this :
1.
"it is not free energy , it just accumulate the impulses , so if impulses has enough energy the energy level accumulated in tank circuit rise . Sure, energy is oscillating in unloaded tank circuit, and with proper input frequency related to resonant frequency the input energy required to sustain oscillations is very low while the apparent power circulating in tank circuit is high. You however cannot tap this energy, because doing so will destroy resonant condition"


that is first sentence I would like somebody with better then my experience would correct....please




The next sentence is about transformer , and it is also told to newbies as one of first "laws":
2.
Transformer is electro-magnetic device transforming electrical energy from primary circuit to the secondary circuit through the magnetic field. Then it is explained how to electric energy in primary is converted into magnetic field which induce current in secondary winding.It is stated that magnetic field is produced by primary and then "converted" into current in secondary - I mean energy of magnetic field is used up to create secondary current. So while the electrons from primary do not pass to secondary then energy is passed.


I'm not sure if I described that concept clearly so also please correct me.




Now the essential point. We know we can re-use the same current in tank circuit to heat up resistance for example, with carefully matched resistance placed in the path of oscillating current of tank circuit at resonance much lower input energy is required to get the same heat output in resistor then when powered by simply DC. Of course assuming temperature stable resistance and not disturbed resonant condition.


Let's now place tank circuit on primary side of transformer when transfor,er primary winding is a coil for tank circuit and ca matched capacitor placed in shunt (in parrallel to the primary), when resistor is placed across seondary winding.


If we could match input power supply frequency to the tank circuit to minimalize input power (real) and get the same heat on the resistor on secondary we would have kind of contradiction.


According to 1 tank circuit do not create energy from vaccum and according to 2 current in secondary was created by passing energy from primary via magnetic field link. Both cannot be true in the same time.


That's why it is important to experimentally test such condition.

And a related comment:  In the Bedini enthusiast world there is a debate about the rotor magnets.  Should they be North facing out or South facing out?  Some people claim that one is better than the other.  I believe that even Bedini himself has made comments expressing favouritism for one pole over the other.  It's assumed that when people do experiments and observe differences it's attributable to other factors, including the human factor.  If you are pushing yourself too much and expect to see a difference then you risk being like the guy that was convinced that his horse could do additions and subtractions.

There is no difference between North facing out and South facing out beyond the expected differences.  For example, the EMF induced in your coil will be opposite.  Some beginners will rewind the coil from clockwise to counter-clockwise to compensate not knowing that all that they have to do is cross the drive coil wires.

MileHigh