Magnetic Permeability ... I can't find anyone talking about this !!!!!

[Charlie_V]

Hey Observer, you bring up some good points.

Then is mentioned (in the wiki article on transformers) that V in = V out... I in = I out... therefore P in = P out. Where IN is the primary and OUT is the     
    secondary.  V is Voltage, I is Current and P is Power.     P=IV    or     PIV as I like to say.

Wiki is not so correct about this.  The power in equals the power out but the voltages and currents do not have to equal each other.  Vin can be way larger than V-out, I-in can be way lower than I-out.  But they are ratioed with each other.  So whatever  V-in or I-in are, V-out can be equal, larger, or smaller.  In the case that V-out is smaller, I-out will be able to be larger than I-in.  If V-out is larger, then I-out will be smaller than I-in.  It works just like mechanical gears. 

Now the reason they say that the primary does not consume any energy is because typically the inductance is very large.  So the power factor of the primary circuit is close to zero - meaning the power in the primary is mostly reactive power.  There is still resistance losses in the primary (plus things are never ideal and the power factor is probably greater than zero, meaning there is some real power consumption).  When you apply the secondary, the secondary should have its impedance matched with the primary winding.  This allows real power to transfer to the secondary (the turns ratios between primary and secondary can scale the voltage/current - but typically not the power). 

The efficiency of a transformer is Pin/Pout.  In the case of your test question, a stove generates heat through resistance.  However, you want current to flow so you will make sure the resistance is lower so more current flows.  The heating elements will then be made of a metal (and a size) that is not rated for the amount of current flowing in them.  Clocks have a high resistance too, but usually have inverters inside to step the voltage down to probably ~12V or so.  So, 12V divided by a large resistance is much lower current than 120V divided by a resistance.  I would imagine a stove has a fairly low resistance compared to a clock - since you want more current to flow in the heating elements.  I've never measured either of them so I wouldn't know.

You are correct that a transformer is just like a radio receiver.  Also, I didn't say your idea would not work, I said it wouldn't work easily, I believe back torque can be overcome - I'm still working on that though.  And I agree that they do not explain the way metals tend to amplify the magnetic field without any input energy - the energy required to align the poles is usually very very little - depending on the material of course. 

[The Observer]

Hey Charlie,

Actually I owe you an apology in that, I may have insinuated that you said my idea (or something like it could not work).
   Indeed you said 'work easily'.  Thank You.
     I think you can see what I am talking about... and greatly appreciate your input.
       I am surprised  more haven't jumped in on this.         

It is nice to get feedback, because that causes new questions that need to be correctly answered.
   Something I apparently find... fun.

Now you said,          '"It works just like mechanical gears."

As in     Pin = Pout   and I and V match up when all is said in done to make       P=IV  (primary)   =    P=IV  (secondary).

I know, this is what is accepted.
  In fact my College Physics book says that everything I say that I am wrong.
   Well, not quite, there are holes in their assertion, but anyways...
     That is, they say .....Pin always ='s Pout,
        where I am saying,   "I'm not so sure about that !"

Here is what I say.
   
       You (not you Charlie, the misinformed) are comparing apples to oranges.

Gears are a Newtonian device ... a transformer is a Quantum Mechanical device.
  The rules are so different that old Lorentz's head would spin just looking at all the free lunches.
   
It is very useful, in understanding quantum physics to observe a stone that is thrown in a pond.

  There is plenty I know I'm not seeing, but this is what I do see.

    1) The wave created by the stone goes out in all directions.

    2) The wave created by the stone has a constant speed.

    3) The wave created by the stone makes a leaf on the water bounce up and down when it passes by.

    4) The wave created by the stone can make many leaves bounce up and down.

    5) Because of the finite and constant speed of the wave in water, when the wave passes a fixed object (say a stick in the mud),
        The resultant wave from this interference can never interfere with any other portion of the original wave.

     6) Oh, wait a minute... here comes a water bug, Let's call the bug Charlie.
         Charlie's top speed seems to be the same as the wave of water's speed.

     7) Charlie must have seen something, because he suddenly scurried across the water !
         Charlie's movement created a wave.  And Charlie was always the the for front of the wave produced.

     8) When Charlie stopped, so did the creation of the wave produced by Charlie's movement.

     9) A new bug with same top speed arrives on the scene wearing sunglasses and a straw cowboy hat, named Chuck.

    10) Charlie suddenly decides to scamper over to the shore that is a long ways away. (Chuck looks a little strange)
          This produces a wave.

     11) Chuck who was standing near by (look'in cool), finds out that Charlie left when he felt that wave. (these bugs are blind)
           The wake of Charlie's wave let Chuck know that something happened.

      12) After Chuck recieves this information, Chuck decides that Charlie must be Stopped ! from reaching the shore.
           Chuck likes Charlie and just wants a hug.

           Alternately, Chuck is so cool, he doesn't even flinch at this new information, and just rides the wave like the leaves.

       13) Chuck chases... "Must stop Charlie, Charlie cannot get to shore. Must conserve energy."

       14) Do I have to tell you who loses the race?

When something else moves... it is a result of a previous action.
   Sure it has an action (movement), but there is no equal and opposite reaction.
      What happened, happened. 
         An equal and opposite reaction would have to reach beyond the bounds of time and space to achieve this.
            Because of the nature of the medium in which it exists,
               Nothing can really catch up with anything else.

As far a transformer goes, I hope you can see the analogy.
That is, what is forced in first coil, is just absorbed by the other.
The best way for the coil to conserve energy is to just bounce like a leaf in the pond, that's it.

I am pretty sure, but don't quote me yet.
    That the back emf has to with the energy of all the dipoles turning back to their original position from the ferromagnetic material of the core.
       This energy of course doesn't have to be a bad thing.
         In fact, is probably an important factor in finding resonance in a the circuit I am talking about.

Thanks for reading.
There will probably be more as my exploration continues.
Any comments, thoughts, or even a thought experiment that continues the one I started with the pond, would be much appreciated.

      And with that, I wave goodbye,    ~~~~~~~~~~~~
                                                               The Observer
                                                             ~~~~~~~~~~~~

[fritz]

Transformers:

Lets design a transformer.
A transformer is typically designed for its payload.
That means that the flux generated from the primary
coil is compensated by the flux from the secondary -
which gives an overall low flux compared to saturation
densities. N*I1 = N*I2.
If you don?t take the rated payload - the flux in the core
as well as the losses go up.
This means that a transformer has the worst efficiency
without load (gets warm) because of too much flux.
You can design a transformer for low losses without load -
then you need more iron.
You can even make a transformer with very less iron and big
coils - but this restricts your load range.
Another thing are the losses an resistance of the coil ....
....
Build one or think about it. There is no "transformer".
Every transformer is optimized for something.
A pulse transformer is something different than
a mains transformer - and a mains filter ....

[The Observer]

Hello Fritz,

Thanks for your input.

I guess I have a hard time with the word compensated.

I really, really believe that the electrons in the secondary move only as a result of the wave or waves that pass by.
I don't believe they have any momentum, that allows them to create their own magnetic wave in the coil.
When the wave stops, so do the electrons in the secondary.
The wave is what makes them move, the absence of a wave means the absence of movement in the secondary.

Perhaps down line in closed circuit secondary, away from the primary's magnetic field, a new wave can be produced.
   But, I really don't see how a  new wave is created at the secondary to counter act the primary.
      ESPECIALLY when nothing is connected to the secondary.
         How could No Electrons Moving create a field to get back at the primary?

What is being said...(not me) is that...

A current will not run through the primary when there is nothing loaded on the secondary.
Yes, I know they say there will be a little leak do to imperfections.

     Gee Wizz... what would happen if I put in a Thirdary, Fourthary, or even  10aries in the vicinity of the primary.

I guess they would all be communicating with each other to make sure Laws that have to do with Conservation of Energy are being upheld.
   This means that a radio transmitter emits no power if no-one is tuned in.
      This means that the radio transmitter could also determine how many are tuned in (with resonant circuits) at any given moment, since
        it's power would be in direct relation to the power being used by the coils in the radios.

          This is Bull Hockey. (that is a bull on ice doesn't stand up very well does he?)

Here is a real question.

     What really happens when I short circuit the secondary of a transformer?

         Let's say the secondary's circuit is made of some really hearty material that won't melt. (like the electric stove)

  Will this blow the AC Circuit breaker in the house or melt the primary ?


I realize there is a lot of theory here, and not much for experiments.
I have taken apart a couple transformers (not an easy task), but I guess I would need to make my own from parts
  and acquire a VARIAC (I think) to produce a variety of voltages as well as frequencies.

Well, this is not over for me.
  Any input is greatly appreciated.

Have a Glorious Day !
                                The Observer

     
   
     

[Charlie_V]

That is, they say .....Pin always ='s Pout,
        where I am saying,   "I'm not so sure about that !"

Yea I agree with you, science in general talks like they know everything - very arrogant if you ask me.

Gears are a Newtonian device ... a transformer is a Quantum Mechanical device.

Yes, gears and transformers are completely different.  A gear does not suffer from an effect like back EMF/Torque.  A gear only has resistive losses.  Really, I've tried to think of a mechanical analogy to Back EMF and there is none - this sets electrical phenomenon on a completely different playing field.

I am pretty sure, but don't quote me yet.
    That the back emf has to with the energy of all the dipoles turning back to their original position from the ferromagnetic material of the core.
       This energy of course doesn't have to be a bad thing.
         In fact, is probably an important factor in finding resonance in a the circuit I am talking about.

I have no idea what back EMF really is and why it happens.  It could be related to the ferromagnetic core but I'm not so sure since you get back EMF in air cores too.  I don't think back EMF is a bad thing, I think it is necessary - I just don't know why haha.

But, I really don't see how a  new wave is created at the secondary to counter act the primary.
      ESPECIALLY when nothing is connected to the secondary.
         How could No Electrons Moving create a field to get back at the primary?

The counter acting wave only occurs when the secondary is loaded.  If the secondary is open, there is no counter acting magnetic field.  You get a voltage.  When the coil is loaded (a short being the highest load it could see), electrons flow in a direction to create a magnetic field that opposes the applied field.  IF your applied field (being a magnet of another coil) is directly coupled, the counter field will fight the movement.

So, if you want to stop them from fighting, you need to find a way that the coil sees a changing magnetic field, but the field it creates is in a position that it can't fight the applied field. 

This means that a radio transmitter emits no power if no-one is tuned in.
      This means that the radio transmitter could also determine how many are tuned in (with resonant circuits) at any given moment, since
        it's power would be in direct relation to the power being used by the coils in the radios.

Radio transmitters "radiate" their power away - their load is the surroundings.  They cannot see nor do they care about the receivers.  They put out X amount of power in all directions.  The receivers collect a small fraction of that, depending on how far away they are.  If you could cover 360 degrees of a transmitter with receivers, you could collect that X power divided by the number of receivers, in each receiver.

Now a Magnifying Transmitter (aka a Tesla coil - made the way Tesla intended) WILL see the receivers.  Thats because a Tesla coil channels the energy directly to the receivers, it does not radiate the energy in all directions into space.  SO the Tesla coil is only loaded when a receiver is on.  The more receivers, the more load on the Tesla coil.  A radio antenna is 99.9% loaded all the time, and whatever the receiver collects is a small fraction. 

A radio antenna is like a water sprinkler spraying water in all directions, the receivers are like cups.  You can place a cup some distance from the spraying sprinkler, you will fill the cup up with a very small amount of water.  The closer to the sprinkler, the more water it will fill.  A Magnifying transmitter shoots a stream of water directly into your cup no matter the distance.  However, the more cups there are, the more streams the MT makes and the less water is available for each cup.