The Magneformer-lenzless transformer ?

[tinman]

Hi Brad,

Please remember that the permeability of a permanent magnet is very close to that of the air (a PM is almost a 100% saturated piece of material) this means that you should not replace the magnet with a ferrite core because by doing so your coil would have a much higher self inductance than with the magnet inside. The best approach would be not to insert any core into the same coil when you remove the permanent magnet. Permeability figures for ceramic (i.e. ferrit) magnets is around 1.1 to 1.3 and for Neo magnets it is around  1.05 to 1.1 or so.  If you have an L meter and some air core coils around (or you can remove the core from a multiturn coil), you could see how small the inductance changes (increases a few percent) with a permanent magnet inserted into an air cored coil.

On your Atten scope: perhaps the best would be to contact the Atten service people to have the software in the scope check and reload once the Measure Menu does not have any content in it to choose from. 

Gyula

Hi Gyula
I will not be changing the core in the electromagnet,but only the generating inductor core-the tank coil. It will be set up the same as the picture i posted with the two horse shoe shaped magnets-1 electric,and 1 PM.

In regards to the scope-it seems that all who have this scope,have the same problem. This i have found out by browsing some reviews on the scope. Some seem to be loading software from another scope onto the atten(same scope,different name) ,but it comes at a risk.If the software dosnt take,then you just have a box full of parts,and it cant be reversed. I have contacted atten,and there is no software update for my modle yet.

[MileHigh]

Tinman:

I have to retract what I said in my posting #32 about your diagram and questions in your posting #19.  The reason is because your diagram confused me.  You use the exact same symbol for the permanent magnet and the electromagnet, right down to the red and blue rectangles.  So I thought the "electromagnet" was a second permanent magnet with a coil wrapped around it.

I read through Gyula's comments and pretty much agree with them.  I also believe that I see what your train of thought is.  You see the permanent magnet on the left as being the agent that is responsible for the change in flux through the inductor when the electromagnet switches off.  So the logic is that the permanent magnet is doing the work to change the flux through the inductor which then creates current to flow through the resistor.

That's all true but you have to look at the whole story as it unfolds in time.  This is in a way related to the SMOT thread where people are not comfortable with the concept of magnetic potential energy and how it "came from somewhere else" by virtue of position and it is being invisibly stored like a compressed invisible spring.

When you first switch on the electromagnet you have to pump an amount of energy into the electromagnet to generate the field to counteract the flux going through the inductor from the permanent magnet.  That will also cause changing flux with respect to time in the inductor and some energy will also flow through the resistor.

Then when you have DC current flowing through the electromagnet maintaining zero net flux through the inductor core (there are equal and opposite flux streams in the one-half core slices for net zero flux), you have magnetic potential energy stored in the stressed magnetic fields.  Then when you switch off the electromagnet the collapsing field from the electromagnet allows the permanent magnet to "take over" putting flux through the inductor core, and that also causes the current to flow and energy is burned off in the resistor.

I am just giving you a general description of what is happening.  The key thing is that the permanent magnet is not "doing work," rather, it's being stressed and storing some magnetic potential energy, and then when it is unstressed it's releasing that magnetic potential energy.  There are no gains here.

Even though your diagram is relatively simple, if you had this problem in an electronics class, you would make a timing diagram where you have the switch closing and then opening, and you track all of various variables.  If you constructed a timing diagram you should see how everything balances.

Another way to describe what is happening is as follows:  When the electromagnet is off, the permanent magnet is responsible for the flux through the inductor core.  Let's call that the unstressed condition of the core.  When the electromagnet switches on, it "pushes out" half of the downwards flux inside the core due to the permanent magnet and sets up a counter stream of flux going in the opposite direction.  Here we have the rare occurrence of a real true to life Bloch wall going down the center of the core.  This is the stressed condition.  It took work to create the stressed condition, and that's now stored magnetic potential energy.  So the permanent magnet is being stressed and storing energy that the electromagnet put into it.  When you cut the current to the electromagnet, the permanent magnet pushes back with its stored potential energy and "reoccupies" the inductor core with its flux and you are back to the unstressed condition.

It's all about accepting the notion that any permanent magnet can only appear to be a source of energy because someone or something else did some work to store potential energy in the magnet in the first place and the magnet can only give back as much as you put into it.

MileHigh

[MileHigh]

Dammit Janet... I love you!  lol

My idea is to make a transformer that is as efficient as it can be made here at home,and to show that PMs improve efficiency.

Got it.

For getting around the common ground issue you could get isolation transformers for your scope, signal generator and use batteries or get a isolation transformer for your power supply.  They might be expensive, I don't know.  When it comes to stuff like that safety is a priority and I would not be comfortable using my own home brew isolation transformers.  I would recommend using batteries and making your own current measurements.  I think it's safe to assume that your multimeter is better at measuring current than what you see on the power supply display.

The driven coil is to neutralise the PMs field in the tank coil.
When the driven coil is switched of,two things happen.
1-we collect the inductive kickback,and charge a battery with it.
2-the PMs field once again is induced into the tank coil. The lenz force is now between the PM and the tank coil. To me this is the PM doing the work,and is the reason we get a continual current flowing through the 18 ohm resistor-even when the driven coils energy has been depleeted.This can be clearly seen in the first scope shot i posted.

The reason you get the continuous current flowing through the resistor is because of the LC tank circuit.  The voltage across the 18-ohm resistor is the tank circuit voltage.  Your transistor pulse going through the primary is continually hitting your LC tank circuit with an injection of energy, so I don't see why you would find it significant that the current is always flowing through the resistor.  The average power being burned off in the resistor plus the average power being burned off in the wire is exactly equal to the average power being supplied by the secondary, which also happens to be the 'L' in the tank circuit.  You might have a Fluke true-RMS multimeter and I would use its measurement as opposed to your scope's measurement for the RMS voltage.  You should be able to make a quite accurate power measurement for that part of the circuit.  Since you know the pulse frequency you know the amount of energy per pulse for what it's worth.

Anyway, your quest is a great idea and a great exercise.  I can see that you are doing filtering to make good current measurements and stuff like that.  It should be interesting to see what your results are.

MileHigh

[MileHigh]

Brad:

As Gyula said your scope may need a firmware upgrade and you should check their web site.  You typically download a file and put it on a flash drive.  Then when you power up the scope while pushing on one or two buttons and that triggers the firmware update.

Gyula:

Please remember that the permeability of a permanent magnet is very close to that of the air (a PM is almost a 100% saturated piece of material) this means that you should not replace the magnet with a ferrite core because by doing so your coil would have a much higher self inductance than with the magnet inside. The best approach would be not to insert any core into the same coil when you remove the permanent magnet. Permeability figures for ceramic (i.e. ferrit) magnets is around 1.1 to 1.3 and for Neo magnets it is around  1.05 to 1.1 or so.  If you have an L meter and some air core coils around (or you can remove the core from a multiturn coil), you could see how small the inductance changes (increases a few percent) with a permanent magnet inserted into an air cored coil.

I didn't know that a magnet would have such a low relative permeability.  You still might be able to take advantage of the polarization though as has already been stated.  Note the excitation from the primary coil is unidirectional.  This assumes the relative permeability is radically different depending on the direction of the external field.  It would be an interesting and easy test.  You just have to look at the slope of the current rise in the coil for same-direction and opposite-direction magnetic field generation by the coil wrapped around the magnetic core.  You cross your fingers and hope that you don't ruin the magnet.

I also wonder if the L-meter will be thrown off by the introduction of a magnet into the coil.  I assume they sample or sweep low-level AC frequency excitation for the coil under test and check the response to measure the inductance.  So if the magnet does indeed radically change in relative permeability depending on direction it may have a small heart attack (throw off the measurement algorithm).  It probably will read out as a high inductance - my guess.

Another point is that this is a transformer setup, not an inductance.  So assuming the core (any core) is coupling the energy properly, you _don't_ see inductance on the primary, you see the load, which is an LCR circuit.  So you see a wobbling resistance!  lol  Note since you are approximately at resonance, you are pretty much seeing the resistive component of the LCR circuit as the load of the primary.  So that means that Brad should see the voltage and current going into the primary winding as mostly in phase, assuming that the core/coupling is doing it's job properly to transfer the power.

MileHigh

[tinman]

Tinman:

I have to retract what I said in my posting #32 about your diagram and questions in your posting #19.  The reason is because your diagram confused me.  You use the exact same symbol for the permanent magnet and the electromagnet, right down to the red and blue rectangles.  So I thought the "electromagnet" was a second permanent magnet with a coil wrapped around it.

I read through Gyula's comments and pretty much agree with them.  I also believe that I see what your train of thought is.  You see the permanent magnet on the left as being the agent that is responsible for the change in flux through the inductor when the electromagnet switches off.  So the logic is that the permanent magnet is doing the work to change the flux through the inductor which then creates current to flow through the resistor.

That's all true but you have to look at the whole story as it unfolds in time.  This is in a way related to the SMOT thread where people are not comfortable with the concept of magnetic potential energy and how it "came from somewhere else" by virtue of position and it is being invisibly stored like a compressed invisible spring.

When you first switch on the electromagnet you have to pump an amount of energy into the electromagnet to generate the field to counteract the flux going through the inductor from the permanent magnet.  That will also cause changing flux with respect to time in the inductor and some energy will also flow through the resistor.

Then when you have DC current flowing through the electromagnet maintaining zero net flux through the inductor core (there are equal and opposite flux streams in the one-half core slices for net zero flux), you have magnetic potential energy stored in the stressed magnetic fields.  Then when you switch off the electromagnet the collapsing field from the electromagnet allows the permanent magnet to "take over" putting flux through the inductor core, and that also causes the current to flow and energy is burned off in the resistor.

I am just giving you a general description of what is happening.  The key thing is that the permanent magnet is not "doing work," rather, it's being stressed and storing some magnetic potential energy, and then when it is unstressed it's releasing that magnetic potential energy.  There are no gains here.

Even though your diagram is relatively simple, if you had this problem in an electronics class, you would make a timing diagram where you have the switch closing and then opening, and you track all of various variables.  If you constructed a timing diagram you should see how everything balances.

Another way to describe what is happening is as follows:  When the electromagnet is off, the permanent magnet is responsible for the flux through the inductor core.  Let's call that the unstressed condition of the core.  When the electromagnet switches on, it "pushes out" half of the downwards flux inside the core due to the permanent magnet and sets up a counter stream of flux going in the opposite direction.  Here we have the rare occurrence of a real true to life Bloch wall going down the center of the core.  This is the stressed condition.  It took work to create the stressed condition, and that's now stored magnetic potential energy.  So the permanent magnet is being stressed and storing energy that the electromagnet put into it.  When you cut the current to the electromagnet, the permanent magnet pushes back with its stored potential energy and "reoccupies" the inductor core with its flux and you are back to the unstressed condition.

It's all about accepting the notion that any permanent magnet can only appear to be a source of energy because someone or something else did some work to store potential energy in the magnet in the first place and the magnet can only give back as much as you put into it.

MileHigh

Hi MH

Well by now,you will know im not so good at drawing diagrams or schematic's,but do my best to show something that resembles what im trying to show.

In regards to your last paragraph Quote: It's all about accepting the notion that any permanent magnet can only appear to be a source of energy because someone or something else did some work to store potential energy in the magnet in the first place and the magnet can only give back as much as you put into it.

Well some where i have a device that shows different,and i have been trying to find it for the last 3 days. But as we not long ago shifted house,most of my junk stuff is still in boxes,and which box my setup is in?-i have no idea yet,as i havnt found it.

But where im at now was based around the results i got from that little setup. It was based around a mixture of Tom's MEG and the flynn device.
My results were as follows,and the setup was like the one i posted the sketch of.

With just the inductor(electromagnet)on it's own,it would consume !lets say! 300mWatts.
From our inductive kickback ,we could get back !lets say! 150mWatts.

Now with the secondary coil in placeTank coil),with a resistor acorss it.
The P/in to the inductor(electromagnet) rose to say 350mWatts.
Our p/out from the inductive kickback droped down to 130mWatts
And the power across the resistor from the secondary (tank)coil was say 20mWatts
So the total in P/out remained about the same,but the P/in increased.

Now with the horse shoe magnet on the other side of the secondary(tank)coil-as per diagram.
P/in droped back down to 300mWatts.
P/out from inductive kickback rose to 170mWatts.
P/out from the secondary (tank)coil rose to 35mWatts.

So from this we can see that by adding the secondary coil with a load across it,and the magnet,the P/in didnt change.
But we also see that the total P/out rose,and that was only possable with the PM in place.
By replacing the PM with a horse shoe shaped ferrite core,the P/in would rise once again to 350mWatts-infact it was actualy a higher value than that.

(Note-the above figures are to give an indication of the effect in the experiment,and may not reflect the actual values i had back the-memory just isnt that good.)

This told me that the PM could be the only source for the extra P/out,as the P/in was the same with or without the PM and secondary combination there.
Now when i say the PM was the only source for the extra P/out,this can be seen in two ways.
1st-the PM provided the extra energy.
2nd-the PM was the only thing that could make the transformer become more efficient.
But no matter which way you look at it-the PM was the source of that energy gain Wether is was providing energy,or makeing the transformer more efficient dosnt realy matter. What matters is that it dose work- the PM dose make the transformer more efficient than it would be with just the ferrite core there.