Here is my paper on the Gunderson-Smith Effect. Looking back over my files I have more material on this subject. If everyone agrees I will not clutter this thread but will start a new one devoted to using ferro-magnetic resonance as a means to obtaining OU.
Smudge
Woops, I made a mistake in the table with the energy gain for PE22 material.
Here is the corrected paper
Hi Smudge
Thanks for your hard work, the paper is very interesting, how hard would it be to setup to test a core material 4D2, what is needed in the way of electronics, if it's a fairly easy setup i would give it a go, i can start a dedicated thread if you wish.
Regards
Peter
Quote from: Smudge on 2016.09.27, 14:19:14
Here is my paper on the Gunderson-Smith Effect. Looking back over my files I have more material on this subject. If everyone agrees I will not clutter this thread but will start a new one devoted to using ferro-magnetic resonance as a means to obtaining OU.
Smudge
I will disagree since I have the impression that you are like my girlfriend who is such a good dancer that nobody wants to ask her to dance at a party.
Quote from: Smudge
The second possibility relates to the frequency response of the core material where its permeability can have different values for different rates-of-change of flux.
You forgot to account for the well known behavior of a coil, which responds to an increasing permeability (decreasing reluctance) of the magnetic circuit with a decrease of the current flowing through its windings.
To be more precise, I mean the response of an energized, shorted ideal solenoid coil, which is subjected to a changing permeability/reluctance as in a scenario in which a soft ferrite slug is being inserted inside it. Note that the coil's current decreases as the ferrite slug approaches the coil.
Quote from: Smudge
... one being the possibility that energy could be stored in the compression of the Mylar film situated between the two core halves, and that mass inertia might play its part in slowing down the change in compression when the flux changes value.
During the slow flux change between secondary interrupts the compression would follow the flux, but in the fast flux change period the core faces would not move hence creating an imbalance between the magnetic energy and the stored compression energy.
After exploring this in some detail it has been found that this imbalance does not lead to over-unity.
1) How did you determine that?
2) Did you ever prove the 3
rd possibility, that the kinetic energy gained by an approaching soft ferrite slug (or approaching ferrite core halves) is
not greater than the difference between ½L
MIN*i
MAX2 - ½L
MAX*i
MIN2 without using the CoE law ? ( notation is according to
this article (http://www.overunityresearch.com/index.php?topic=2684.msg43698#msg43698) )
First, thanks greatly to Cyril for his good work on this introductory paper.
I would agree with Cyril's intention at the end of the paper that a new thread be started. May I suggest "Magnetic Compression Studies" as a title for the thread?
I would not agree that an "effect" be named an "effect", before it is proven by replication that "the effect" actually exists.
In other words an "effect" should be observable and testable by anyone who sets up the experiment, based on a full disclosure of the details of the experiment by the party that first notices the "effect"
In light of the fact that Graham, although given ample time to fully disclose either to this community or elsewhere, has not done so, I believe the title should be changed to something more generic e.g. "Magnetic Compression Study" by Cyril Smith.
I use the word "study" because that is exactly what it should be. A hypothesis is presented and it should be studied to see if an "effect" can be demonstrated and observed in the lab and then replicated, which could thus lead to a "theory".
When it is determined that such a study leads to an novel "effect", then IMO, it should be first named "The Smith Effect" after Cyril who has hypothesized and identified and freely given the necessary structure for replication, without reserve.
When it is determined that the Gunderson transformer and associated circuitry is indeed operating according to Cyril's named effect, then perhaps Gunderson's name can be included in the title or perhaps in the text, but again, only if he fully co-operates with Cyril and / or the community with full disclosure and participation.
It is sad to see that because of Gunderson's non-cooprative stance, much guesswork has ensued and time has been wasted, when everything could have moved along much more quickly. This is not the way of science.
There is a somwhat a danger in posting a paper with such a title, because there are those entities that are poised looking for something exactly like this to buttress the next commercial release, which will probably be named " Beyond The Secrets of the Implosion Transformer" .You can be certain this paper and anything that follows will be scooped up by certain for profit entities and used in future commercial releases as a "proof positive", even though such proof has not yet been established, and worse yet, even if the hypothesis fails it will be probably be given a "pass" by those entities.
I have given this a lot of thought and believe that we should work the science of discovery carefully, and not skip the proper steps.
FWIW, do as you will.
Kind Regards
ION
Quote from: ION on 2016.09.27, 23:11:41
First, thanks greatly to Cyril for his good work on this introductory paper.
I would agree with Cyril's intention at the end of the paper that a new thread be started. May I suggest "Magnetic Compression Studies" as a title for the thread?
I would not agree that an "effect" be named an "effect", before it is proven by replication that "the effect" actually exists.
In other words an "effect" should be observable and testable by anyone who sets up the experiment, based on a full disclosure of the details of the experiment by the party that first notices the "effect"
In light of the fact that Graham, although given ample time to fully disclose either to this community or elsewhere, has not done so, I believe the title should be changed to something more generic e.g. "Magnetic Compression Study" by Cyril Smith.
I use the word "study" because that is exactly what it should be. A hypothesis is presented and it should be studied to see if an "effect" can be demonstrated and observed in the lab and then replicated, which could thus lead to a "theory".
When it is determined that such a study leads to an novel "effect", then IMO, it should be first named "The Smith Effect" after Cyril who has hypothesized and identified and freely given the necessary structure for replication, without reserve.
When it is determined that the Gunderson transformer and associated circuitry is indeed operating according to Cyril's named effect, then perhaps Gunderson's name can be included in the title, but again, only if he fully co-operates with Cyril and / or the community with full disclosure and participation.
I have given this a lot of thought and believe that we should work the science of discovery carefully, and not skip the proper steps.
FWIW, do as you will.
Kind Regards
ION
I agree ION,and i would be most interested in this,as i have carried out a few experiments in this area,based on a paper verpies once sent to me.
Yes,please start a dedicated thread on the subject matter O0
Brad
Hi ION
I agree totally, i have left this in the Buzz thread for the moment but split it from the original Gunderson thread, lets see if we can see an effect first.
Regards
Peter
Quote from: verpies on 2016.09.27, 21:56:54
You forgot to account for the well known behavior of a coil, which responds to an increasing permeability (decreasing reluctance) of the magnetic circuit with a decrease of the current flowing through its windings.
To be more precise, I mean the response of an energized, shorted ideal solenoid coil, which is subjected to a changing permeability/reluctance as in a scenario in which a soft ferrite slug is being inserted inside it. Note that the coil's current decreases as the ferrite slug approaches the coil.
I think you have missed the point here. This is not something that is going on outside the core (like your moving slug) but something inside the core. It is not an absolute permeability change, it is an incremental permeability change. The absolute permeability doesn't suddenly change when going from charge to discharge, so there is no change of flux at that point in time. But the incremental permeability is different because the domain wall resonance comes into play, so the flux
change during the discharge (for a given change of current) is greater than that during the charge. And that creates the CW loop.
Quote1) How did you determine that?
Considering a gap where the fringe effects are negligible, the formula for pressure at the mating faces is identical to the formula for magnetic energy density within the gap. That equivalence mean that any mechanical work done when the gap changes exactly matches the change in magnetic energy. And it is that energy that the usual Li
2/2 relates to. It is not necessary to invoke CoE. Whether whoever derived the pressure formula used CoE to get it I know not. If in reality the pressure differs from that formula I am of the opinion that the difference would be very small, so any gain in COP would be lost due to the usual losses.
Quote2) Did you ever prove the 3rd possibility, that the kinetic energy gained by an approaching soft ferrite slug (or approaching ferrite core halves) is not greater than the difference between ½LMIN*iMAX2 - ½LMAX*iMIN2 without using the CoE law ? ( notation is according to this article (http://www.overunityresearch.com/index.php?topic=2684.msg43698#msg43698) )
I think my answer above covers that
Smudge
Quote from: Smudge on 2016.09.28, 10:45:03
I think you have missed the point here. This is not something that is going on outside the core (like your moving slug) but something inside the core.
I think you have missed the point that the slug IS the core and it is moving into the INSIDE of the coil.
Quote from: Smudge on 2016.09.28, 10:45:03
It is not an absolute permeability change, it is an incremental permeability change.
I know the difference between absolute permeability and differential permeability, but what of that difference?
The moving slug affects the reluctance of the magnetic circuit absolutely and differentially, all the same.
Quote from: Smudge on 2016.09.28, 10:45:03
The absolute permeability doesn't suddenly change when going from charge to discharge, so there is no change of flux at that point in time.
There wouldn't be any flux change even if the absolute permeability changed inside an energized shorted ideal coil.
So I just don't see the point you are trying to make about the lack of change of flux being caused by the lack of absolute permeability change.
Quote from: Smudge on 2016.09.28, 10:45:03
But the incremental permeability is different because the domain wall resonance comes into play, so the flux change during the discharge (for a given change of current) is greater than that during the charge. And that creates the CW loop.
I understand the CW BH loop but in the end the charge and discharge energies are related to the absolute permeability which affects the inductance in the ½Li
2 relation, which in turn affects the current waveforms during charge and discharge.
Quote from: Smudge on 2016.09.28, 10:45:03
Considering a gap where the fringe effects are negligible, the formula for pressure at the mating faces is identical to the formula for magnetic energy density within the gap.
Yes, the fringing is negligible but pressure/force is not the same as energy, and energy density is customarily calculated from the integration of that force over the thickness of that gap and the gap's area and using the CoE.
Quote from: Smudge on 2016.09.28, 10:45:03
That equivalence mean that any mechanical work done when the gap changes exactly matches the change in magnetic energy.
In the gap, but not inside the ferrite. What about the energy represented by the alignment/magnetization of the soft ferrite's domains? Alas, that energy can be recovered as the ferrite relaxes.
Quote from: verpies on 2016.09.28, 11:40:44
I think you have missed the point that the slug IS the core and it is moving into the INSIDE of the coil.
I'm sorry, I thought you were talking about a slug moving into an air gap in the core. I was not looking into slugs moving into coils, I was looking into variable air gaps. I don't see the relevance of your original question in relation to variable air gaps.
QuoteI know the difference between absolute permeability and differential permeability, but what of that difference?
The moving slug affects the reluctance of the magnetic circuit absolutely and differentially, all the same.
I wasn't looking at moving slugs.
QuoteThere wouldn't be any flux change even if the absolute permeability changed inside an energized shorted ideal coil.
So I just don't see the point you are trying to make about the lack of change of flux being caused by the lack of absolute permeability change.
Here your original question related to the change of permeability between slow charge and fast discharge where you introduced the effect of a moving slug changing the permeability. The point I am making is that the change is not due to a moving slug. The permeability doesn't change at the point where the discharge starts. The permeability is a dynamic thing relying on rate-of-change of current.
QuoteI understand the CW BH loop but in the end the charge and discharge energies are related to the absolute permeability which affects the inductance in the ½Li2 relation, which in turn affects the current waveforms during charge and discharge.
I disagree that those energies relate to the absolute permeability. The voltage developed (hence also energy) relates to the differential permeability. I can imagine a non-linear core biased at some point by the use of a PM, then a coil being charged and discharged where the flux changes over a small region of the BH curve. The coil is not aware of the PM bias and its charge and discharge is related to the differential permeability at that bias point. The absolute permeability doesn't come into it.
QuoteYes, the fringing is negligible but pressure/force is not the same as energy, and energy density is customarily calculated from the integration of that force over the thickness of that gap and the gap's area and using the CoE.
Well perhaps that answers my question, our recognized formula are derived using CoE. Then no wonder we can't get OU from theory. I had thought that magnetic energy density B
2/2*mu was derived some other way.
QuoteIn the gap, but not inside the ferrite. What about the energy represented by the alignment/magnetization of the soft ferrite's domains? Alas, that energy can be recovered as the ferrite relaxes.
My analysis assumed ferrite permeability sufficiently high that the (conventional) energy internal to the ferrite was negligible.
Smudge
Here is something to think about regarding soft materials.
Smudge
Another interesting paper thanks Smudge.
So we need to drive a core at a low frequency and extract the energy at the cores ferromagnetic resonant frequency or a multiple of harmonic of the low frequency.
So the hardest thing i can see is finding the cores ferromagnetic resonant frequency.
If we tune the primary as a tuned LC and tune the secondary as a higher harmonic tuned LC.
Quote from: Peterae on 2016.09.28, 17:21:41
Another interesting paper thanks Smudge.
So we need to drive a core at a low frequency and extract the energy at the cores ferromagnetic resonant frequency or a multiple of harmonic of the low frequency.
So the hardest thing i can see is finding the cores ferromagnetic resonant frequency.
If we tune the primary as a tuned LC and tune the secondary as a higher harmonic tuned LC.
Don't bother with making a transformer, just use a single coil. Used a non-gapped core such as a ring core if possible. Then measure its inductance against frequency and at resonance the inductance should be greater than at non-resonance. The published data sheet will show the frequency so you should know where to look.
Then the idea is to charge the inductor slowly then resonantly discharge it quickly at the ferromagnetic resonant frequency,
not a harmonic of the low frequency. So you have a simple charging circuit that need not be resonant, then to discharge it you switch the inductor onto a capacitor of the appropriate value to resonate at the known frequency, allow the capacitor to charge over half a cycle then switch the capacitor onto a load R. Keep doing that at some rep rate.
Smudge
Here is a paper written some time ago on using the slow charge fast discharge scheme. This looks at resonant charging at 100KHz by switching a charged capacitor onto the inductor, that capacitor being two capacitors in parallel. At the point where all the energy is now stored in the inductor, where the capaciitor voltage has fallen to zero, one of the capacitors is removed leaving only one there, and that one resonates with the changed inductance value at the ferromagnetic resonant frequency. The energy stored in the inductor now swings back into the reduced capacitance, and when the current reaches zero the capacitor is disconnected to then be switched onto a load. The formula for COP is derived using published complex permeability data.
Smudge
That is fantastic work Smudge and this test is exactly the type of experiment i really enjoy doing.
I have two fets SiC 1700 V, 5A and two fets SiC 1200 V, 10A sitting in the work shop waiting for a project so we could probably up the voltage somewhat, hopefully they would be ok to switch capacitors in circuit.
I need to think about the driving circuit but should be easy enough.
So to walk myself through the functioning schematic the way i see it.
we switch the psu onto the capacitors and charge to 10v.
Isolate the power supply and switch the inductor across the 2 capacitors in parallel, when the voltage across the capacitors nears 0V we isolate the larger capacitor leaving the smaller capacitor connected across the inductor.
You say in quarter of a cycle we reach 124.1V across the smaller capacitor but surely we are on the negative quarter cycle so would be at -124.1V if so my SICs have body diodes and thats not good for how i was going to use them for switching the ground legs of the psu and caps.
OK more thought required. ???
Thanks for those three latest papers, Smudge.
Now, I wonder if this could be simulated in LTSpice by an expression which changes the inductor's model at the appropriate moment in the cycle.
Any thoughts, partzman, Smudge?
Regards, ION
Quote from: ION on 2016.09.28, 21:51:26
Thanks for those three latest papers, Smudge.
Now, I wonder if this could be simulated in LTSpice by an expression which changes the inductor's model at the appropriate moment in the cycle.
Any thoughts, partzman, Smudge?
Regards, ION
ION,
IMO, it is doable in simulation using gyrator-capacitance modeling. I am looking at Magnetics "P" material because I have it on hand and it has an initial u'=2500 up to 100kHz and peaks with a u' = 3400 at 500kHz so the ratio of change is close to the PE22 material with a narrower frequency spread. I plan to use Smudge's math to calculate the possible COP and will post when finished.
I've attached a paper from Magnetics that contains curve fit equations for their materials that would be used to define the nonlinear capacitance to represent the nonlinear core permeability in the G-C model. The core loss would then be modeled with a nonlinear resistor.
The problem I've found in doing this type of nonlinear modeling is difficulty with convergence. IOW, the sim "sticks" at certain points during the simulation when it is having difficulty resolving internal calculations and may or may not recover.
pm
edit
partzman
Thanks for the Magnetics paper on curve fitting.
I kind of thought you would have a solution to the simulation of Smudge's ideas.
Is there a sim out there that would help me learn more about the use of gyrators?
I'll do some searching on the subject.
You and Smudge are keeping some of us very busy (in a good way).
Thanks again
Regard
ION
My interest would be modelling in the magnetic domain. Whereas the normal magnetic domain model for an inductor having a closed magnetic circuit (i.e. a coil wound on a ring core) would be an mmf generator of Ni ampere-turns connected across the classical reluctance of the core (l/(mur*munought*A) my model would differ from that. I would use two mmf generators in series connected across the reluctance of the air space occupied by the core. One generator would have the value Ni and the other would have the value chi*Ni where chi is the magnetic susceptibility. Then the reluctance of the air core remains constant and it is the value of chi that exhibits the resonance, that changes value with frequency. If using Spice to model the magnetic domain the frequency variation applies to the "voltage" generator and it is quite simple to model that.
The attached pdf could help in turning published complex permeability data into the frequency variations of chi.
Smudge
Here is another paper that introduces the magnetic domain modelling where the susceptibility chi has the resonance.
Smudge
Quote from: ION on 2016.09.29, 00:02:18
partzman
Thanks for the Magnetics paper on curve fitting.
I kind of thought you would have a solution to the simulation of Smudge's ideas.
Is there a sim out there that would help me learn more about the use of gyrators?
I'll do some searching on the subject.
You and Smudge are keeping some of us very busy (in a good way).
Thanks again
Regard
ION
ION,
I've attached some papers that I used to gain an understanding of G-C simulation.
There are some ready made gyrator models in the files of the LtSpice forum that one can play with but I chose to make my own model with external variables like DCR and number of turns. I started using the H source but would recommend the B source. There are two B sources available and those are Bv and Bi. Basically, a Bv source is a device that produces a voltage across it's terminals that is dependent on any math function that is included in the help file listing on the sources. Bi works the same but as a current source.
In general, a gyrator can be built with two cross coupled Bv sources where one is used as a port for the electrical inputs to a winding whereby the other one is used to represent the magnetic circuit for the same winding. In this manner, any type and/or size of core material in any configuration may be modeled with reasonable accuracy. For example, in Graham's device where the upper U core is high perm while the lower U core is a lower perm material presents a unique situation which can be modeled with the G-C gyrator.
I hope this is of some help.
pm
Quote from: Smudge on 2016.09.29, 08:29:42
Here is another paper that introduces the magnetic domain modelling where the susceptibility chi has the resonance.
Smudge
Smudge,
Thanks for posting these papers. I'm personally a little slow on getting up to speed with mathematical concepts so lots of study is in order. :-[
pm
Just found this paper hidden among my files. It may help in understanding just what complex permeability means and how it effects circuits. It tells how to use published complex permeability data to determine inductance and effective loss resistance. And how to determine the complex permeability from measurements.
Smudge
Quote from: partzman on 2016.09.29, 14:01:52
ION,
I've attached some papers that I used to gain an understanding of G-C simulation.
There are some ready made gyrator models in the files of the LtSpice forum that one can play with but I chose to make my own model with external variables like DCR and number of turns. I started using the H source but would recommend the B source. There are two B sources available and those are Bv and Bi. Basically, a Bv source is a device that produces a voltage across it's terminals that is dependent on any math function that is included in the help file listing on the sources. Bi works the same but as a current source.
In general, a gyrator can be built with two cross coupled Bv sources where one is used as a port for the electrical inputs to a winding whereby the other one is used to represent the magnetic circuit for the same winding. In this manner, any type and/or size of core material in any configuration may be modeled with reasonable accuracy. For example, in Graham's device where the upper U core is high perm while the lower U core is a lower perm material presents a unique situation which can be modeled with the G-C gyrator.
I hope this is of some help.
pm
Hi partzman
Thanks much for the papers. I have been doing some research on gyrators and my fuzzy brain now realizes I built one (an pseudo inductance simulator) out of the National Semiconductor catalog back in 1977 or thereabouts.
With age I can now claim to have forgotten more than I presently know. The ramifications are that I will arrive at a point where I know nothing and have forgotten everything.
It amazes me that Smudge and yourself can keep the ol' biocomputer working so well. Improved refresh clock cycles perhaps?
Regards, ION
After setting up the variables in Mathcad and solving for the low frequency resonance capacitor Cl in equation (4) in Smudge's paper "On using Complex Permeability Resonance to get OU", it becomes obvious that the lower the ui, Fl, and Lair, the more realistic the value of Cl will be.
In my example, with Lair = 250uh, Fl = 100kHz, and ui = 2500, Cl = 4.053pfd. Does this sound right to you Smudge?
pm
Quote from: partzman on 2016.09.29, 16:17:48
After setting up the variables in Mathcad and solving for the low frequency resonance capacitor Cl in equation (4) in Smudge's paper "On using Complex Permeability Resonance to get OU", it becomes obvious that the lower the ui, Fl, and Lair, the more realistic the value of Cl will be.
In my example, with Lair = 250uh, Fl = 100kHz, and ui = 2500, Cl = 4.053pfd. Does this sound right to you Smudge?
pm
Yes. The Lair is the inductance of your coil wound on air. With the core in place at permeability 2500 the actual inductance is 625mH, and that resonates at 100Khz with a 4pF capacitor. That's a small value for the LF capacitor (if 100KHz is your LF charging frequency), the HF capacitor for the discharge phase would be even smaller. Problems then with scope probes. I would use fewer turns and use larger capacitor values.
Smudge
Quote from: Smudge on 2016.09.29, 18:39:53
Yes. The Lair is the inductance of your coil wound on air. With the core in place at permeability 2500 the actual inductance is 625mH, and that resonates at 100Khz with a 4pF capacitor. That's a small value for the LF capacitor (if 100KHz is your LF charging frequency), the HF capacitor for the discharge phase would be even smaller. Problems then with scope probes. I would use fewer turns and use larger capacitor values.
Smudge
OK I understand. What I don't seem to be able to work out is how you arrived at the 625mH inductance on the ui=2500 core for this coil? The actual measured Lcore ~50-55mH. Using the core dims of le=4.82*10e-2 and Ae=3.91*10e-5 (in meters) I calculate ~76mH so the ui is somewhat lower than 2500. Magnetics specs the Al for this core at 1430mH/1000 turns. Using this I calculate ~44mH for the 175 turn coil.
pm
Quote from: partzman on 2016.09.29, 22:16:49
OK I understand. What I don't seem to be able to work out is how you arrived at the 625mH inductance on the ui=2500 core for this coil?
The only information you gave was the value of Lair=250uH and since the actual inductance is mu times that I got 2500*250uH = 625mH. Using the core dimensions you now quote the value of Lair should be 31.22uH and actual inductance 2500 times that = 78mH. As you say the actual mu is somewhat lower than 2500 and that is reflected in their Al value.
Smudge.
Quote from: Smudge on 2016.09.28, 18:39:19
Here is a paper written some time ago on using the slow charge fast discharge scheme. This looks at resonant charging at 100KHz by switching a charged capacitor onto the inductor, that capacitor being two capacitors in parallel. At the point where all the energy is now stored in the inductor, where the capaciitor voltage has fallen to zero, one of the capacitors is removed leaving only one there, and that one resonates with the changed inductance value at the ferromagnetic resonant frequency. The energy stored in the inductor now swings back into the reduced capacitance, and when the current reaches zero the capacitor is disconnected to then be switched onto a load. The formula for COP is derived using published complex permeability data.
Smudge
Morning Smudge,
Why use a Cap. to charge the inductor/core initially? Just charge it from a power supply till the core is close to or saturated, then disconnect from power supply, connect resonating Cap., rectify the burst and Oscillatory current flow from it till the burst is essentially zero, dump/integrate rectified charge into output circuit and repeat? Much simpler circuitry relatively speaking. With the fixed time to charge the inductor/core known, the resonating frequency of the core known, the length of the burst at resonating frequency known, the circuitry is pretty simple in concept! There are some very interest variables there to play with too! Or.....are you doing all of your suggested sequence/cycle time during one cycle and not allowing the inductor/core to Osc. during the resonating part of the sequence and just discharge into Res. Cap.?
Respectfully,
Ben
Good Day K4,
I chose resonant charging for efficiency but of course you could charge directly. In that case obtaining the quantity of energy actually supplied to the inductor involves an accurate measure of the voltage and the current and an integration, whereas with the capacitor method you merely need to know the voltage and the capacitor value.
You can't disconnect from the power supply without first having the discharge capacitor connected, else there will be an almighty ring into stray capacity at the disconnect time. If the intention is to create something useful I would not go for a multi-cycle burst of output frequency as that will lose energy, a quarter cycle charge is the best. But if you only want to prove the concept then the peak voltage reached on the output capacitor tells you everything.
Smudge
Smudge
I found an unknown ferroxcube core in my box, i have done some tests on it this afternoon like we did some time ago during the simulation negative resistance tests, i have switched capacitors across a 10 turn coil on the core and recorded the results and calculated inductance versus frequency, any chance you could pass the data through your permeability spread sheet to produce a graph to see if it's suitable for this experiment when you get a chance.
Note my cap box has a variable cap inside which read 220pf and is in parallel with the switched caps so i had to add 220pf to all the switched in cap values in the spread sheet.
PS i worked out i can use Zeners as voltage controlled vari caps to change the capacitance, not yet sure if it fast enough though to do it on a cycle basis.
Cheers
Peter
Quote from: Smudge on 2016.10.01, 13:40:20
Good Day K4,
I chose resonant charging for efficiency but of course you could charge directly. In that case obtaining the quantity of energy actually supplied to the inductor involves an accurate measure of the voltage and the current and an integration, whereas with the capacitor method you merely need to know the voltage and the capacitor value.
You can't disconnect from the power supply without first having the discharge capacitor connected, else there will be an almighty ring into stray capacity at the disconnect time. If the intention is to create something useful I would not go for a multi-cycle burst of output frequency as that will lose energy, a quarter cycle charge is the best. But if you only want to prove the concept then the peak voltage reached on the output capacitor tells you everything.
Smudge
Excellent, a good explanation of what you would be doing. Some mighty fast precise switching there but nothing that can't be done!
Ben
Quote from: Peterae on 2016.10.01, 15:19:41
Smudge
I found an unknown ferroxcube core in my box, i have done some tests on it this afternoon like we did some time ago during the simulation negative resistance tests, i have switched capacitors across a 10 turn coil on the core and recorded the results and calculated inductance versus frequency, any chance you could pass the data through your permeability spread sheet to produce a graph to see if it's suitable for this experiment when you get a chance.
Note my cap box has a variable cap inside which read 220pf and is in parallel with the switched caps so i had to add 220pf to all the switched in cap values in the spread sheet.
PS i worked out i can use Zeners as voltage controlled vari caps to change the capacitance, not yet sure if it fast enough though to do it on a cycle basis.
Cheers
Peter
Can't get permeability without core size but plot of L against frequency will have same shape as plot of mu against frequency. No signs of a resonance there
Smudge
OK thanks Smudge was worth a try.
If i can work out a circuit to do what we need then i will order a core O0
Anyone else got any ideas on how to circuit this up would be appreciated.
Here is a spread sheet that takes in core dimensions, complex permeability data at the two different frequencies, number of turns, input voltage to the first capacitor then calculates the inductances, the capacitor values, the peak current when the first cap is fully discharged and the peak voltage on the second cap at the end of its charging period. Also energy in, energy out and the COP.
Smudge
Quote from: Peterae on 2016.10.01, 19:18:58
OK thanks Smudge was worth a try.
If i can work out a circuit to do what we need then i will order a core O0
Anyone else got any ideas on how to circuit this up would be appreciated.
Peterae,
Attached is a simple circuit to test for permeability resonance as Smudge describes.
M1 is basically "on" for most of the period which allows a desired constant current to be generated in L1 by means of V1, a variable dc supply. M1 is then switched "off" allowing the energy in L1 to be dumped into the parallel combo of the fet's drain to source capacitance Cdss and C2 thus generating a 1/2 sine across the total output capacitance.
The peak of the 1/2 cycle resonant voltage can easily be measured to calculate the output energy as compared to the input energy calculated from the constant current thru L1. No integration is necessary on the input.
There is a problem that must be considered however and that is even though both the dcr of L1 and the Rdson of M1 are low, there will still be a small amount of dc voltage required to produce the inductor current needed. The energy produced by this voltage and the decaying current ramp during the charging of the resonant output capacitance must be considered in the overall COP calculation.
pm
I think the problem is getting the value of L1 to use in the calculation. If there is a resonance in the core then L1 will vary with the frequency used to measure it. So if you are just looking for the resonance to check that it is there you might as well just look for that change of inductance.
If you are going for COP measurement then you must measure L1 at a low frequency, but are you then sure that your Li2/2 calculation of energy is good enough? My feeling is that you won't be sure you have got COP>1 without a cross check on energy going in and coming out, which is why I suggested resonant charging of L1. Putting energy into L1 direct from a DC supply doesn't allow you to get a good handle on the energy flow.
Smudge
Quote from: Smudge on 2016.10.02, 14:54:48
I think the problem is getting the value of L1 to use in the calculation. If there is a resonance in the core then L1 will vary with the frequency used to measure it. So if you are just looking for the resonance to check that it is there you might as well just look for that change of inductance.
If you are going for COP measurement then you must measure L1 at a low frequency, but are you then sure that your Li2/2 calculation of energy is good enough? My feeling is that you won't be sure you have got COP>1 without a cross check on energy going in and coming out, which is why I suggested resonant charging of L1. Putting energy into L1 direct from a DC supply doesn't allow you to get a good handle on the energy flow.
Smudge
OK, here is a circuit which does include both input and output resonance and is still reasonably simple. The only caveat is that C2 is also charges thru Rchg and L1 along with C1 but it will be rapidly discharged by M1 and should have no material effect on the charging of L1 by C1.
Basic operation is as follows- M1 and M2 are off for a period of time allowing C1 or Clow to be charged to a peak voltage as determined by the dc supply V1. Rchg should be at least several magnitudes larger than the impedance of the the L/C circuit. M1 is then switched on with Vpulse1 starting at T0 and turned off at T1 when C1 is fully discharged and the current in L1 is at it's peak. The time period from T0 to T1 should be 1/4 of the period of the low resonance frequency desired.
With C1 at zero volts and M1 turning off, M2 is now switched on at T1 which will produce a reverse conduction mode that will clamp L1 at ground with very little loss. C2 or Chi will now charge at the high resonance frequency desired from the energy stored in L1. M2 must remain on from T1 to T2 lnog enough to allow a peak voltage to be produced in C2. The starting voltage on C1 and the ending peak voltage on C2 along with their values provide an easy means to calculate the COP.
This operation may be periodic as long as the circuit conditions are met.
pm
Hi partzman
Thanks looks good, and easy as well
Very ingenious O0
Regards
Peter
Partzman,
if M2 is turned on C1 is still parallell to L1 and the desired high frequency will be shorted by C1.
Solution could be another MOSFET which seperates C1 and Rchg from L1 at the instant you turn on M2.
But even then I will suspect that the Miller-Capacity will be a hf-bypass disturbing the build-up of the hf-resonance
So this problem is not so easy to be solved. The capacity of the supply may be another problem but could be neglegted if Rchg is large enough.
At the present I also have no idea how to solve this, have to think about it...
Mike
Hi
I think you make things too complicated using electronic knowledge in part when it is not useful.
Here is my idea for consideration: use ordinary push-pull circuit first with a proper HF choke on input with a additional electronic snubber to suppress any high frequency oscillations. Second circuit is a disruptive discharge on the same ferrite core which push-pull operates on (or on secondary core as you wish if you direct output of push-pull there) - with a almost non-inductive winding at 90 degrees (i non-inductive relation) to the push-pull windings . The output of push-pull must have hf diode bridge.
The essence of non-inductive winding and disruptive discharge circuit in non-inductive relation to the original power source winding (push-pull winding) is to create very fast pulses at push-pull winding by a special mode of operation. This winding should create big magnetic field in one direction followed by equal opposite big magnetic field in counter direction , with nanoseconds delay between. This will cause saturation of core for nanoseconds - breaking push-pull magnetic induction action for this period. Along with normal push-pull output will be also HF oscillation of additional energy - it will be on secondary and primary also - so here is the trouble.
I believe all the Akula, Ruslan, Dally,SR913 devices with ferrite core work that way (or trying to do so).
Electrons are valves to the cosmic energy from external magnetic field (Earth field), every generator in reality condense the external field, input energy is just wasted. When magnetic flux is passed through material using electrons momentum it cannot flow in two directions at the same time.So if you saturate core in 90 degrees then the original flux is broken too O0
Quote from: Smudge on 2016.09.28, 15:58:50
Here is something to think about regarding soft materials.
I enjoyed your take on soft magnetic materials and I mostly agree with it.
However I make an exception for this passage:
Quote from: Smudge on 2016.09.28, 15:58:50
And magnets swinging about inside coils induce voltage. Thus charging a coil with current at low frequency
creates a small voltage to "load" the current generator, while discharging itat the resonant frequency creates a greater output voltage, hence greater power out than power in.
First of all, voltage is not power nor energy, so it would be wrong to imply, that more induced voltage means more electric energy coming out of a coil.
It is almost as if you are saying, that the electric energy output of an ideal coil is proportional to dΦ/dt, where Φ is the instantaneous magnetic flux penetrating the inside of the coil (caused by these swinging magnets).
Quote from: Kator01 on 2016.10.03, 01:53:52
Partzman,
if M2 is turned on C1 is still parallell to L1 and the desired high frequency will be shorted by C1.
Solution could be another MOSFET which seperates C1 and Rchg from L1 at the instant you turn on M2.
But even then I will suspect that the Miller-Capacity will be a hf-bypass disturbing the build-up of the hf-resonance
So this problem is not so easy to be solved. The capacity of the supply may be another problem but could be neglegted if Rchg is large enough.
At the present I also have no idea how to solve this, have to think about it...
Mike
Mike,
I've attached a general equivalent circuit showing the conduction periods of M1 and M2.
During the conduction of M1, C2 is grounded through the Rdson of M1 and the energy in C1 is transferred to L1.
During the conduction of M2, C1 is grounded through the Rdson of M2 (reverse conduction) and the energy in L1 is transferred to C2.
It is desirable that the on resistance of M1 and M2 be as low as possible to reduce any effect on the COP calculation.
pm
edit-
Quote from: Smudge on 2016.09.29, 07:49:58
The attached pdf could help in turning published complex permeability data into the frequency variations of chi.
I appreciate your paper on the basics of complex permeability but I can't help to notice that you did not even mention, that the contribution of domain walls is strongly dependent on the ratio of magnetization, since for total magnetization these domain walls disappear.
This domain wall behavior is nicely illustrated in the attached paper.
Quote from: verpies on 2016.10.03, 13:23:38
I appreciate your paper on the basics of complex permeability but I can't help to notice that you did not even mention, that the contribution of domain walls is strongly dependent on the ratio of magnetization, since for total magnetization these domain walls disappear.
And of course the permeability also disappears (or rather drops down to unity) so there is no resonance to be seen. This will affect the power you can get from a given size of ferrite but it doesn't alter the principle.
Smudge
Here is another paper I wrote in 2007. This offers a slightly different approach in that the coil is charged with current quickly (at the resonant frequency), then held at that current while the core permeability relaxes down to its low frequency (or DC) value, then discharged slowly. The loop is again traversed CW indicating an energy gain. So you circuit gurus now have an alternative to consider.
Smudge
So here's a circuit to drive partsman's circuit.
Zener Diode 1 starts conducting at a pre determined voltage, pulling up the voltage divider R3/R4, the voltage when above 1.5V will cause the positive triggering Schmitt input of monostable IC1 to trigger, mono ICI output Q goes high for a determined amount of time set by R1/C3, thus turning the logic fet on M1.
After Mono 1C1 has timed out the output Q will go low triggering IC2's active low trigger pin causing IC2's output pin Q to go high which in turn drives logic fet M2 on.
when IC2 times out both fets are off and the power supply starts charging again until we get a trigger again on the Zener diode and the cycle completes again.
Here is a circuit that will allow one to find the resonance of any unknown junk box ferrite core in relatively quick fashion. The magnitude can be calculated from the results if the reference coil and measuring tools are accurate.
Basically, a differential measurement is taken between the output of a sine signal generator (CH1) and an output voltage (CH2) created by an inductive divider made up of an air coil reference and the inductor to be measured as seen in the attached schematic. Since XL = 𝜔L, the divider voltage will remain in a constant ratio to the input thru a given frequency range until the inductance of L2 begins to change. If the inductance in L2 increases, the difference (that is CH1-CH2) will decrease and reach a peak dip at some frequency. This can be measured on a scope or with two wideband AC voltmeters that would preferably be identical.
The reference coil L1 ideally should be linear and with low self capacitance and away from any material that would alter it's u=1. The reference coil should be equal or close to the inductance of the coil/core to be tested but is not necessary but would provide the best sensitivity.
I have used an Agilent 33120A generator set with 50 ohm output and prefer to do a manual sweep for finding the peak rise in inductance. For most ferrites, the frequency range seems to be from 100kHz to 1.5mHz or thereabout.
pm
Quote from: Smudge on 2016.10.03, 14:17:48
Here is another paper I wrote in 2007. This offers a slightly different approach in that the coil is charged with current quickly (at the resonant frequency), then held at that current while the core permeability relaxes down to its low frequency (or DC) value, then discharged slowly. The loop is again traversed CW indicating an energy gain. So you circuit gurus now have an alternative to consider.
Smudge
If I understand this paper correctly, the previous circuit I proposed for your low to high permeability change would work for the high to low with a change in timing and cap values.
The attached schematic shows the required changes. C1 is now the high frequency resonating cap with inductor L1 and is brought to a predetermined energy level by V1 and R1. Then, Vpulse1 is applied to M1 at T0 and held until T2. When the energy in C1 has completely transferred to L1, Vpulse2 is applied to M2 at T1 thus clamping and holding the current in L1. The time interval from T1 to T2 is the relaxation period for the core permeability to settle.
M1 is then switched off at T2 dumping the energy in L1 into C2 at a lower determined frequency rate. M2 must remain on long enough for this energy transfer to occur. The output energy calculated from the peak voltage in C2 as compared to the starting input energy in C1 determines the COP.
pm
Thanks for the circuits partsman, i can adapt my circuit also for circuit 2 by adding another mono.
I think one of the most important things now would be to try and find a core that would give at least 50% gain that is possible to purchase, unless we can find a source of the military spec core that was in Smudges list, i dont think this thing will be loop-able without that sort of figure.
The 4E2 core from Ferroxcube may not be military, but is a special used in large scale experiments such as particle accelerators. It is available on special order but likely to be expensive. Searching Google Images for mu v. temperature to look for other possibilities I came across the use of meta-materials. The "swiss-roll" material used in the imaging experiment described in the attached pdf could be interesting. Its complex permeability curve is given and although the mu's are low the ratio from peak mu to low mu is quite high, like 8:1. Making your own resonant core could offer possibilities.
Smudge
Using the circuit of post #47, I have the following results from testing an Arnold TSF7070 ferrite toroid core. I have attached the data sheet below.
The core is wound with 7 turns evenly spread over the surface of the toroid. The linear reference coil is an air coil with 101 turns of 25ga wound on a 4.84cm/1.90" pvc tube with no spacing between turns. The measured inductance using a current ramp method is 362uh and the self resonant frequency SRF=2.6MHz.
The test results are shown below and if the numbers are correct, this core appears to have a Hi/Lo permeability change of 5153/2736 = 1.88.
I have purchased these on Ebay and they are still available but before purchasing any, let's be sure these test results are reasonably correct!
I plan to test this core in the circuit I previously posted and will post the results when finished.
pm
Edit: Please note that the ur's are reversed on the original schematic posted. This post is now correct.
Hi Partsman
I just tried your circuit and a large unknown core, there seems to be a constant difference in amplitude between the air core and the 7 turn coil on the core to test, then when i get up to about 780khz the core under test's amplitude increases to match my input amplitude and starts going out of phase.
Yellow chan is across 50 Ohm sig gen source, cyan chan is across coil under test.
Air coil is on a 20cm tube not sure of turns but they are bifilar wound but i am only using 1 winding of the bifilar Inductance measures 164uH
The large core under test has 7 turns wound evenly around the circumference and measures 161uH which by coincidence is very close to the air core inductance.
I measured the SRF of the air core coil at 2.64MHz by scoping and using a grid dip meter to excite it.
I suspect this core has a flat resonance frequency, previous inductance tests did not show much, i will try to did those tests out when i get back from a short trip tonight.
Quote from: Peterae on 2016.10.04, 18:42:17Hi Peterae,
OK, look forward to your results. In the meantime I've had a chance to test the TSF7070 core using the high/low and low/high circuits and here is the problem I've found. The required value of capacitance to resonate with 452uH at 810kHz is 85pfd which is less than the drain to source capacitance of nearly all mosfets making any measurement attempts totally inaccurate IMO. The high/low test for example yielded a COP ~.5 which I really don't have any confidence is accurate. One thing to note is that there was a slight increase in the clamped inductor current which would indicate that the permeability was decreasing over time.
Hi Partsman
I just tried your circuit and a large unknown core, there seems to be a constant difference in amplitude between the air core and the 7 turn coil on the core to test, then when i get up to about 780khz the core under test's amplitude increases to match my input amplitude and starts going out of phase.
Yellow chan is across 50 Ohm sig gen source, cyan chan is across coil under test.
Air coil is on a 20cm tube not sure of turns but they are bifilar wound but i am only using 1 winding of the bifilar Inductance measures 164uH
The large core under test has 7 turns wound evenly around the circumference and measures 161uH which by coincidence is very close to the air core inductance.
I measured the SRF of the air core coil at 2.64MHz by scoping and using a grid dip meter to excite it.
I suspect this core has a flat resonance frequency, previous inductance tests did not show much, i will try to did those tests out when i get back from a short trip tonight.
Hi Peterae,
OK, look forward to your results. In the meantime I've had a chance to test the TSF7070 core using the high/low and low/high circuits and here is the problem I've found. The required value of capacitance to resonate with 452uH at 810kHz is 85pfd which is less than the drain to source capacitance of nearly all mosfets making any measurement attempts totally inaccurate IMO. The high/low test for example yielded a COP ~.5 which I really don't have any confidence is accurate. One thing to note is that there was a slight increase in the clamped inductor current which would indicate that the permeability was decreasing over time.
pm
Quote from: Smudge on 2016.09.29, 15:15:13
Just found this paper hidden among my files. It may help in understanding just what complex permeability means and how it effects circuits. It
You should make an appendix to this paper instructing how to measure it with VNAs.
VNA is a standard lab instrument that provides phase vs. frequency information as well as S parameters in arbitrary 2-port networks.
I have never seen complex permeability graphed on a Smith chart, did you? (Cole-Cole chart notwithstanding)
Hi Folks,
I went through the 'in stock' offer of some core distributors on ferrite cores they sell that may have a "promising" complex permeability peak change vs frequency as Smudge explained in his paper. I found two core materials, N87 and N97 from Epcos/TDK, these are available in toroidal shape (for the N87 material) and in not toroidal but various core shapes (for the N97 material).
Here are the choices for the N87 ring cores with prices:
http://www.mouser.co.uk/Passive-Components/EMI-RFI-Components/EMI-RFI-Suppressors-Ferrites/Ferrite-Toroids-Ferrite-Rings/_/N-bw7t9Zscv7?Keyword=b64290+n87&FS=True&Ns=Pricing|1 (http://www.mouser.co.uk/Passive-Components/EMI-RFI-Components/EMI-RFI-Suppressors-Ferrites/Ferrite-Toroids-Ferrite-Rings/_/N-bw7t9Zscv7?Keyword=b64290+n87&FS=True&Ns=Pricing%7C1)
Here are the choices for the N97 material for various core shapes with prices:
http://www.digikey.com/product-search/en/magnetics-transformer-inductor-components/ferrite-cores/5113149?k=&pkeyword=&pv70=744&FV=fff4004e%2Cfff8053d&mnonly=0&newproducts=0&ColumnSort=0&page=1&stock=1&quantity=0&ptm=0&fid=0&pageSize=25 (http://www.digikey.com/product-search/en/magnetics-transformer-inductor-components/ferrite-cores/5113149?k=&pkeyword=&pv70=744&FV=fff4004e%2Cfff8053d&mnonly=0&newproducts=0&ColumnSort=0&page=1&stock=1&quantity=0&ptm=0&fid=0&pageSize=25)
Here are the choices for the PE22 material, core shapes are EC and EE:
http://www.mouser.co.uk/Passive-Components/EMI-RFI-Components/EMI-RFI-Suppressors-Ferrites/Ferrite-Toroids-Ferrite-Rings/_/N-bw7t9Zscv7?Keyword=pe22&Ns=Pricing%7c1&FS=True (http://www.mouser.co.uk/Passive-Components/EMI-RFI-Components/EMI-RFI-Suppressors-Ferrites/Ferrite-Toroids-Ferrite-Rings/_/N-bw7t9Zscv7?Keyword=pe22&Ns=Pricing%7c1&FS=True)
I included the curves of complex permeability change vs frequency for the N87 and N97 core materials, for the N87 I estimated 40% gain and for the N97 I estimated 52% gain if I am not mistaken.
Gyula
Quote from: verpies on 2016.10.04, 22:07:43
You should make an appendix to this paper instructing how to measure it with VNAs.
VNA is a standard lab instrument that provides phase vs. frequency information as well as S parameters in arbitrary 2-port networks.
I've used network analyzers in the past (HP and Rhode & Schwartz) for L band measurements. But that was a lifetime ago, I'll leave it to the younger generation to do what you suggest.
QuoteI have never seen complex permeability graphed on a Smith chart, did you?
No, and I can't claim any connection to the Smith who invented it. Used the Smith chart a lot to impedance match antenna over a wide frequency band (again at L band).
Quote(Cole-Cole chart notwithstanding)
WTH is a Cole-Cole chart?
Smudge
It is a 2D chart, on which the real part of complex permittivity is graphed on the X axis and the imaginary part is graphed on the Y axis. ( see here (http://cp.literature.agilent.com/litweb/pdf/5989-2589EN.pdf) )
Thanks gyula hopefully that will give us some more to look at.
partsman
unfortunately i am not ready to test this yet, i will need to order some bits and build the drive electronics.
Is the Drain Source capacitance going to be a problem?.
For an IRF840 for instance it looks to be CDS = COSS−CRSS or 200pf which is not so bad
but a logic level fet IRLZ44 for instance is 1200-200 or 1nF :o
i need to do some more research on this i think O0
EDIT
Added logic fet IRLB8743PBF = 300-105 = 195pf
IRFI530NPBF = 160-88=72pf
IRLI530NPBF= 160-90=70pf
trouble is that when Vds is low 0v then COSS is larger
Quote from: Peterae on 2016.10.05, 19:42:10
Thanks gyula hopefully that will give us some more to look at.
partsman
unfortunately i am not ready to test this yet, i will need to order some bits and build the drive electronics.
Is the Drain Source capacitance going to be a problem?.
For an IRF840 for instance it looks to be CDS = COSS−CRSS or 200pf which is not so bad
but a logic level fet IRLZ44 for instance is 1200-200 or 1nF :o
i need to do some more research on this i think O0
Peterae,
Yes, in my tests using the IRF636 with a Cds~130pfd it is a problem as I require an 83pfd cap for the high frequency storage. IOW, i can't reach the 810kHz peak permeability frequency. The other problem with the mosfet Cds is non linearity of C0ss. It is greater than the spec sheet data at low voltages and decreases with drain voltage increase. As I see it, we need a core material like Smudge spec'd that has a low overall permeability and a reasonable high frequency permeability peak. This would allow the use of higher capacitance values for the high frequency peak.
There are possible solutions with certain mosfets. I have some IRF5802 with a Cds ~20pfd but it is smd and a bugger to handle, at least for me!
So, all things considered, I'm now focusing on altering core permeability with PM biasing which is where this is all headed anyway IMO. Nothing to report at the moment however.
pm
Quote from: partzman on 2016.10.05, 20:40:38
....
There are possible solutions with certain mosfets. I have some IRF5802 with a Cds ~20pfd but it is smd and a bugger to handle, at least for me!
...
Hi partzman,
You could make or buy a simple adapter that would host the smd MOSFET and "convert" it to a bigger size. It would still make you use a lupe to mount the TSOP-6 package but it needs to do once... and then you can handle it easier any time.
Perhaps it could be plugged into a TSOP socket or mount onto such board like this link shows (ebay also has many smd adapters):
http://www.newark.com/capital-advanced/33206/smd-adapter-6-sc-59-6-sot-23-6/dp/10M5369 (http://www.newark.com/capital-advanced/33206/smd-adapter-6-sc-59-6-sot-23-6/dp/10M5369)
or you could make such from a small pcb piece.
Gyula
Quote from: gyula on 2016.10.05, 22:59:43
Hi partzman,
You could make or buy a simple adapter that would host the smd MOSFET and "convert" it to a bigger size. It would still make you use a lupe to mount the TSOP-6 package but it needs to do once... and then you can handle it easier any time.
Perhaps it could be plugged into a TSOP socket or mount onto such board like this link shows (ebay also has many smd adapters):
http://www.newark.com/capital-advanced/33206/smd-adapter-6-sc-59-6-sot-23-6/dp/10M5369 (http://www.newark.com/capital-advanced/33206/smd-adapter-6-sc-59-6-sot-23-6/dp/10M5369)
or you could make such from a small pcb piece.
Gyula
Hi Gyula,
Thanks for the suggestions. I have some adapters that I used to mount the TSOP-6 devices but they aren't an exact fit as they are SOT-6 as I recall. After soldering a few, I'm a bit cross-eyed for a while! :o
pm
I managed to get the fet drive electronics built today, i used a pcb i made some time ago that has a 18V supply on board to drive a dual fet driver, originally built to be driven from 2 onboard pic micros, having found i had some 74HC123 monostable chips in my box i used this dual mono and built the mono circuit on vero to plug into the fet driver board.
Just need to order some FETs now and i will be ready to test partsmans circuit.
the scope shot shows
mono 1 output yellow
mono 2 output cyan
fet driver output 1 purple
fet driver output 2 blue
The fet driver is a dual TC4427
I was amazed how good these monostables are i could get under 100ns pulse set using the pot.
PS the soldering looks bloody terrible on the pcb LOL, looked all right with my glasses on but looks like i need to resolder it using a magnifying glass. Oh the joy of getting old.
OK i have managed to order some cores
2 of these http://uk.farnell.com/ferroxcube/e80-38-20-3c91/ferrite-e-core-e80-38-20-3c91/dp/2103347
2 of these http://uk.farnell.com/epcos/b65811jr87/ferrite-core-rm-n87/dp/1422720
2 of these http://uk.farnell.com/ferroxcube/rm8-i-3c95/ferrite-core-rm-i-3c95/dp/2103462
and a selection of fets with low coss
Just testing the 3C95 or N95 core, i wound 6 turns on the core and measured 121uH, my air core is the same as before at 165uH
loose coupled oscillator shows SRF at 1.94MHz
Using Partzman's circuit i tested at 100KHz and the found the frequency at which the Ch1-CH2 difference was smallest, strangely this appears to be above the SRF at 2.744MHz see scope shots.
I am setup as per post 37
So core is N95 or in this case equivalent 3C95 as per previous post
i used a 120pf cap for my high cap silver mica and a 20nf for my low cap.
I used 2 x IRF640NLPBF Fets
First scope shot is to show overall picture of whats happening and triggered from CH1 yellow trace
Second scope shot is triggered of CH2 cyan and zoomed in.
Third scope shot zoomed in on time-base more
Fourth scope shot is on the gates
Quote from: Peterae on 2016.10.16, 10:33:39
I am setup as per post 37
So core is N95 or in this case equivalent 3C95 as per previous post
i used a 120pf cap for my high cap silver mica and a 20nf for my low cap.
I used 2 x IRF640NLPBF Fets
First scope shot is to show overall picture of whats happening and triggered from CH1 yellow trace
Second scope shot is triggered of CH2 cyan and zoomed in.
Third scope shot zoomed in on time-base more
Fourth scope shot is on the gates
Hi Peterae,
Something doesn't look quite right to me but perhaps I don't understand your scope probe connections so it would help if you identify where your probes are attached in the schematic.
In looking at the 3C95 data sheet, I see the permeability resonance peak is at ~750kHz and this is approximately the frequency the CH1-CH2 minimum test should have indicated.
I also can't justify your value of 120pfd for high frequency resonance at 2.744MHz with 121uH if I understand correctly. Chigh should be ~28pfd in this case.
The problem I experienced in this Hi to Lo test is that the capacitance of L1 seemed to create a divider with Chigh that made the high frequency half sine impossible to evaluate with my setup.
pm
Hi partzman
Sorry i was really short of time this weekend so it was a fast setup before going out, each scope probe is across each capacitor, so the yellow trace is across the higher value (19.56nF) cap and the Cyan across the lower value cap (120pf)
yes you are right about the 120pf, problem i have is that i have no decent lower value caps that are rated over 100V, i was hoping that from the above test i could get an idea of what the fet capacitance is and see what value i needed to aim for and then buy some caps, i had not realized the value would be so low though, only just started looking at the test results myself, now i need to try and understand what's going on.
The high voltage peak base looks to be about 800ns is this my high frequency tuned period 1/800ns = 1.25MHz half cycle so my resonant frequency is = 625KHz, if thats correct for my 121uH then that equates to a capacitance of 535pf, which means my fet is having a massive effect.
EDIT
QuoteIn looking at the 3C95 data sheet, I see the permeability resonance peak is at ~750kHz and this is approximately the frequency the CH1-CH2 minimum test should have indicated.
I cannot explain my result either.
I just found some blue 3kv ceramic caps in a box with varying values, would they be any good for my high frequency capacitance, i believe that silver mica are probably best but maybe i can give a 47pf 3kv ceramic cap a go and see what the difference is on the pulse.
Could we use 2 fets in series to half our fet capacitance as per a bidirectional fet switch.
(http://i.stack.imgur.com/oHpNV.jpg)
http://electronics.stackexchange.com/questions/79028/understanding-two-mosfet-with-sources-connected
ah i knew Matt whats built one of these, here is his link
http://www.overunityresearch.com/index.php?topic=2594.msg41116#msg41116
(http://www.overunityresearch.com/index.php?action=dlattach;topic=2594.0;attach=14699)
Hi Peter,
Yes, for the bidirectional MOSFET switch the resulting drain-source capacitance may get lower than any of the single devices has. However, to be precise, they would not be halved because the capacitances involved are voltage dependent. The total voltage may be halved across each device but the device capacitances may not, due to the lower (halved) voltages across each. We know that this capacitance increases as the drain-source voltage is lowered, and the dependence is nonlinear.
Would like to show a simpler circuit than what Matt used. His circuit is enhanced with the fast diodes in parallel with the body diodes and also with the fast driver ICs. Of course, these are application specific, I uploaded this schematic to Doug Konzen at the EVGray yahoo group years ago, when he tinkered with coil shorting in motors if I recall correctly, this is why the reed switch with the series 10k (or lower) was included at the driver chip input. A function generator may also give the input there instead, and of course other circuit variations are possible.
Gyula
Quote from: Peterae on 2016.10.16, 18:03:27
Hi partzman
Sorry i was really short of time this weekend so it was a fast setup before going out, each scope probe is across each capacitor, so the yellow trace is across the higher value (19.56nF) cap and the Cyan across the lower value cap (120pf)
yes you are right about the 120pf, problem i have is that i have no decent lower value caps that are rated over 100V, i was hoping that from the above test i could get an idea of what the fet capacitance is and see what value i needed to aim for and then buy some caps, i had not realized the value would be so low though, only just started looking at the test results myself, now i need to try and understand what's going on.
The high voltage peak base looks to be about 800ns is this my high frequency tuned period 1/800ns = 1.25MHz half cycle so my resonant frequency is = 625KHz, if thats correct for my 121uH then that equates to a capacitance of 535pf, which means my fet is having a massive effect.
EDITI cannot explain my result either.
I just found some blue 3kv ceramic caps in a box with varying values, would they be any good for my high frequency capacitance, i believe that silver mica are probably best but maybe i can give a 47pf 3kv ceramic cap a go and see what the difference is on the pulse.
Hi Peterae,
I had responded to your post earlier but I see it didn't make it so I'll try again. You might try to remove your 120pfd cap which would reduce the actual capacitance to 415pfd. This should make your hi frequency resonance ~710kHz which is close to the 3C93 data sheet. If you have the device socketed, swap out the 640's and see if you can get closer to the 750kHz target.
However, let's look at your results of the numbers you have posted. It appears that the 19.56nfd cap has been charged to 17.9 volts from the dc supply so this equates to an energy of 3.13uJ. The output cap at 535pfd has reached a peak of 123 volts and this equates to 4.05uJ. If I read your scope traces correctly, this equates to a gain of 129%. To be at 100%, Chigh would be 414pfd.
pm
Thanks for your replies gyula and partzman.
ok so first then i can try to totally remove the 120pf and rely on the fet capacitance and see what happens.
Not sure why the post did not get posted, it can do that if someone posts while you posted and warns you that, the only other way is a timeout when the page does blank.
yes i can also try different fets at some point, it maybe interesting to try the fet switch as well.
I cut the high frequency cap out of circuit now so there is only the fet capacitance.
QuoteThe high voltage peak base looks to be about 800ns is this my high frequency tuned period 1/800ns = 1.25MHz half cycle so my resonant frequency is = 625KHz, if thats correct for my 121uH then that equates to a capacitance of 535pf, which means my fet is having a massive effect.
The above was based on the fact that the inductance of the coil under test was 121uH but having thought about that the whole idea is that the inductance will change, so i cannot see how we can do any calculations to work out the fet capacitance because at high frequency we have an unknown fet capacitance and an unknown inductor inductance.
EDIT
Its quiet interesting the capacitance changes when the pulse goes from rising to falling, when rising it takes 260ns and when falling it takes 340ns which corresponds to a frequency of 961KHz and 735KHz respectively.
So if the inductance was the same 121uH at 961KHz the we have a capacitance off 226pf when rising and 387pf when falling.
I suppose really what i need to do is now try caps to see what cap value i need to use to get resonance of 961KHz and then calculate the inductance from that and then we would also know for sure the fets capacitance which should give us a more accurate estimation of the energy in the fets capacitance.
So in the above experiment i have an initial voltage of 18v and a cap of 19.56nF = 3.17uJ
and the output voltage of 178V and a estimated cap value of 226pf = 3.58uJ or a gain of 113%
so if the theory that the inductance increases at resonance then we can say that the capacitance must be smaller than our above calculations, lets say that the inductance increases by 5% then we can assume we have a inductance of 127.05uH and therefore out fet's capacitance would calculate out to be 215.88pf and a total stored energy at 178v of 3.4199uJ so we are still > unity at 5% increase in inductance which is interesting.
How about a 30% increase in inductance, 157.3uH giving a capacitance of 174.37pf and energy at 2.762uJ, so now we are under unity.
So it looks like it really comes down to how much our inductance increases at resonance.
Quote from: Peterae on 2016.10.17, 17:06:51
I cut the high frequency cap out of circuit now so there is only the fet capacitance.
The above was based on the fact that the inductance of the coil under test was 121uH but having thought about that the whole idea is that the inductance will change, so i cannot see how we can do any calculations to work out the fet capacitance because at high frequency we have an unknown fet capacitance and an unknown inductor inductance.
EDIT
Its quiet interesting the capacitance changes when the pulse goes from rising to falling, when rising it takes 260ns and when falling it takes 340ns which corresponds to a frequency of 961KHz and 735KHz respectively.
So if the inductance was the same 121uH at 961KHz the we have a capacitance off 226pf when rising and 387pf when falling.
I suppose really what i need to do is now try caps to see what cap value i need to use to get resonance of 961KHz and then calculate the inductance from that and then we would also know for sure the fets capacitance which should give us a more accurate estimation of the energy in the fets capacitance.
So in the above experiment i have an initial voltage of 18v and a cap of 19.56nF = 3.17uJ
and the output voltage of 178V and a estimated cap value of 226pf = 3.58uJ or a gain of 113%
so if the theory that the inductance increases at resonance then we can say that the capacitance must be smaller than our above calculations, lets say that the inductance increases by 5% then we can assume we have a inductance of 127.05uH and therefore out fet's capacitance would calculate out to be 215.88pf and a total stored energy at 178v of 3.4199uJ so we are still > unity at 5% increase in inductance which is interesting.
How about a 30% increase in inductance, 157.3uH giving a capacitance of 174.37pf and energy at 2.762uJ, so now we are under unity.
So it looks like it really comes down to how much our inductance increases at resonance.
Peterae,
A suggestion, it appears that your on time for Vpulse2 might be a little short and if so, it won't hurt your measurements to increase it some. This might be creating the apparent difference in the parametric capacitance of the fet from rising to falling edge but then again maybe not.
pm
Not had a chance to try increasing the time period for M2 yet but definitely worth trying.
So tonight i have measured the cap value required to resonate at 961KHz & 100KHz to see what the inductance calculates out to
for 961KHz i had to dial a cap value of 156pf and for 100KHz 17.7nf, the inductance calculates to 175.82uH for 961KHz & 143.12uH for 100KHz
So at 961KHz we have a fet capacitance value of 156pf which was at 178V so our energy calculates to 2.471u Joules
and using the same process to work out our start energy we have a cap value of 17.7nf at 18V which calculates out at 2.867u Joules
so unless i have something wrong i calculate an efficiency of 86.2%
anyone agree or disagree with my findings?
It is interesting that the efficiency seemed higher with the 120pf cap, it will be interesting to try another core type, i ordered a high frequency type which looked good on the permeability chart i think it was 4C65 and will try this at the weekend.
EDIT
Actually in hindsight i should have used the measured value of the low capacitance for input energy and then this is as previously posted, i want to remeasure this value at some point just to confirm it measures 19.56nF
QuoteSo in the above experiment i have an initial voltage of 18v and a cap of 19.56nF = 3.17uJ
so with an input of 3.17uJ and an output of 2.471u Joules this is worse still at 78% efficiency.
Quote from: Peterae on 2016.10.18, 17:23:34
So at 961KHz we have a fet capacitance value of 156pf which was at 178V so our energy calculates to 2.471u Joules
...
and using the same process to work out our start energy we have a cap value of 17.7nf at 18V which calculates out at 2.867u Joules
so unless i have something wrong i calculate an efficiency of 86.2%
anyone agree or disagree with my findings?
The accuracy of this calculation is actually worse than that, because the MOSFET's D-S capacitance is not constant - it changes with the voltage :(
Hi guys :)
I just stumbled on this thread and after of quick PDF read about 2 materials used I would like to add some food for thought.
In akula 30W lantern 2 was materials used in the core. In RomeoUK Muller dynamo replica again 2 materials used also in the core. Sounds familar? ;)
From akula I had word he used partially magnetic material grinded with ferrite dust then used in home made baked cores(heated for demagnetisation). The amount of magnetic material (most likely Barium) was up to 30% of the core. This mix is adding interesting properties to the core and you might find something unusual about it in the state of ferro-resonance. In short from the akula explanation, the magnetic relaxation period takes longer than magnetization and this is where energy gain is.
In addition, akula used magnetostriction to power up quartz crystals mixed in core as well so the electricity was recycled from BEMF+quartz which netted power gain.
Cheers!
just to see what real power i had with the 120pf cap in the previous tests because now we have a good idea of the fet's capacitance
first just the 120pf @ 123V = 907nJ
and at 710KHz we dont know the fet's capacitance but at 961KHz we do know it was 156pf so if we add 120+156 = 276pf @ 123V = 2.088uJ with an input power of 3.13uJ giving a efficiency = 66.7%
The output cap at 535pfd has reached a peak of 123 volts and this equates to 4.05uJ
I don't think i am shorting the cap long enough and am still leaving energy stored, what's causing the ringing is that possibly energy that's still in the capacitor or is it to do with my DC input feed charging the system again? I mean if i have shorted the cap to 0V why would the cap start ringing again and there seems to be a fair delay after my fet switched off before the ringing starts, seems strange to me.
Another core type high frequency 4C65
9 turns giving me 7.955uH
low frequency cap 328nf
high frequency cap 53pf + fet capacitance.
Scope pictures as below yellow chan across low freq cap
Cyan across high freq cap
It lools like i was only able to get to a time period of 140ns or a high frequency of 3.57MHz which is probably not high enough.
So input energy 18.4V = 55.524u Joules
output energy without fet capacitance account for 1.354u Joules
if we were to guess the fet capacitance to be 150pf then we would have a total capacitance of 203pf = 5.184u Joules
Another core type N87 which is what gyula mentioned.
6 turns giving me 138uH so i used the 18.9nf cap for low freq.
and same high freq cap as before 53pf+ fet capacitance.
So input energy 18.4V = 3.199u Joules
output energy without fet capacitance accounted for 394.426n Joules
if we were to guess the fet capacitance to be 150pf then we would have a total capacitance of 203pf = 1.511u Joules
The results so far seem to be all over the place, IMHO the unknown fet capacitance is making life very hard to get reliable results.
maybe my next move is to try 2 fets in series config and see if the COP gets better.
Here is a lo to hi resonance test using a P7070 2"OD core with 7 turns measuring 337uH at 36mT. The data sheet shows a ui resonance peak at 700kHz. The M1 mosfet is an IRF5802 with Ciss=88pf typical and Coss=26pf typical. The M2 mosfet is a BUK553.
CH1(yel) is the gate drive to M1, CH2(blu) is the voltage across Chi, CH3(pnk) is the voltage across Clow, and CH4(grn) is the current thru Lx.
Clow is a 6800pf metalized polyester cap that is charged to 10 vdc for an input energy of 340nJ. Chi is a 100pf silver mica in parallel with the net output capacitance of M1 and the 3.9pf scope probe. I chose to make the output frequency determination by measuring the period when Lx has completely discharged into Chi and then multiplying by 4. From the scope shot it can be seen this period is 341.3ns which equates to a frequency of 732.5kHz.
This means the net Chi is 140pf. The output voltage of Chi reaches a peak of 42.95v for an output energy of 129nJ resulting in an overall COP=.38 for this setup and material.
Note the step rise in the current in Lx which is a result of the capacitance of the winding IMO. Also the non-linearity of the mosfet capacitance on the falling edge plus the poor energy transfer to Lx and the odd negative current increase after the discharge of Chi.
pm
A follow up on my previous post with a delay added to the turn off of M1 which clamps the current in Lx for ~ 2us before releasing Lx to charge Chi.
There is no appreciable difference in the peak voltage reached on Chi but the high frequency has increased to 750kHz. Assuming the net output capacitance of M1 has remained unchanged at 140pf, then the inductance of Lx has decreased to 322uH due to a permeability change over the clamp time period.
What does not make sense is the calculation of the apparent energy in Lx prior to the dump to Chi. In the previous post, this would be ~388nJ and in this delayed example, ~400nJ. This would mean that a gain may be present but due to inefficiency in the energy shuttle from Lx to Chi it does not appear to be so!
pm
That is an amazing fet capacitance you have there partzman O0
Any idea why the ringing follows on after a time from releasing the short across chi as this maybe stored energy somehow manifesting back into the system, it seems to be quiet a high frequency not much less than chi but the fet is off at the point it appears.
I realize now that i fell of the permeability curve in my last test, was too high a frequency with my 53pf so will home that in when i get a chance and match the curve frequency, it's good i need to add capacitance for that.
The other thing that occurred to me is to try adjusting the M1 period for max peak voltage across the chi.
I'm stuck with the one type of fet at the moment as the others have been placed on back order.
I hope smudge is OK as he has not logged in since the 13th Oct, i know he goes away a lot so hopefully we will see him back soon, I would like him to clarify the gain for some of my cores.
Quote from: Peterae on 2016.10.24, 17:07:07
That is an amazing fet capacitance you have there partzman O0
Any idea why the ringing follows on after a time from releasing the short across chi as this maybe stored energy somehow manifesting back into the system, it seems to be quiet a high frequency not much less than chi but the fet is off at the point it appears.
I realize now that i fell of the permeability curve in my last test, was too high a frequency with my 53pf so will home that in when i get a chance and match the curve frequency, it's good i need to add capacitance for that.
The other thing that occurred to me is to try adjusting the M1 period for max peak voltage across the chi.
I'm stuck with the one type of fet at the moment as the others have been placed on back order.
I hope smudge is OK as he has not logged in since the 13th Oct, i know he goes away a lot so hopefully we will see him back soon, I would like him to clarify the gain for some of my cores.
Hi Peterae,
Yes, I had those fets for use in class E amplifiers operating in the MHz range and they worked quite well.
My guess on the ringing seen is a result of lead inductance resonating with the circuit capacitance. I did run relatively short leads but my layout could be better.
When using the higher capacitance fets, I found it was like trying to hit a moving target. The other problem I see is the very low levels of energy we're trying to resolve. The graphs of permeability change in the various core materials is shown relative to initial permeability which as you know is measured as H approaches zero, so we are committed to these low levels. This is what made the powdered iron cores appealing to me.
I agree in regards to Smudge because usually when he travels he still "connects" once in a while.
pm
I kept my fet connection wires for chi to under 1cm and seem to have the same ringing.
anyway if anyone would like a PCB i have 9 of these boards, they have onboard 5v or 8v supply 78l05 or 78l08 and also a lm317 supply for the fet driver which can be set to any voltage using resistors, any fets can be fitted as well, they were originally designed to be driven by 2 pics (8 pin dip sockets) which fire white noise at each fet stage but it is possible to breadboard any circuit and plug into these 8 pin dips. i will send these out free off charge and postage if interested.
Why one PIC MCU wasn't enough?
Quote from: verpies on 2016.10.24, 22:35:53
Why one PIC MCU wasn't enough?
Because it was the mixing of 2 white noise channels that creates the anomalous high power pulse in the copper ring, i was working on.
This board was going to be given out for people to study the bifilar crackling effect i studied, and as i have a pcb built up, when i have finished using it for this stuff i will indeed power it up with 2 white noise pic micros and a coil.
See thread starting at this post, there is a video in the next post that shows the results.
http://www.overunityresearch.com/index.php?topic=272.msg3740#msg3740
Peter
That is a nice little board to have around the shop. I have pics available but may also rework it for 555's so count me in for one. Thank you for your generous offer.
Regards, ION
Hi ION
No problem, i will send you 2 boards, can you PM me your full address as i tend to not keep records of such info.
Cheers
Peter
I am still around. I have a peek at this site almost every day but don't necessarily log on because of some peculiarity on my PC. It is getting old now, runs XP that is no longer supported by Google Chrome. I keep getting Chrome messages that the OUR site took too long to respond, and I just can't be bothered to keep reloading. Doesn't happen on my laptop running windows 7 (or is it 8?). Having said that, something I have done recently with Norton safe search has altered the way my machine works and it seems a lot better now.
I am not a circuit guy, haven't been since using vacuum tubes although I did build the first prototype transistor radio for Vidor-Burndept back in 1956! My only contribution to the fet capacitance problem is to keep the inductance low by using minimum turns so that you supply most of the capacitance needed. That may need thick wires, or parallel wires, to minimise resistive losses.
I do have some comments about the cores. The complex permeability charts are always derived using toroidal cores that have no air gaps. I think your experiments should also use ring cores. I know from experience using C cores that even with polished and lapped flat faces pressed together with considerable force there is always an effective "air gap" present. And that air gap will reduce the wanted effect you are looking for. With the effect being quite small in the first place, it could be completely obscured. So IMO using C cores, E cores or pot cores is a no no.
Smudge
Hi Smudge
Good to hear you are around O0
I better look for more cores as most of the ones i ordered were pot cores, i only have the one toroid and that is the high frequency one and i could not get high enough frequency on that one, it is interesting you mention less turns.
The core i have is type 4C65 and looking at the datasheet i need to get to about 20MHz :o
Any chance you could try a gain calculation on this core to see if it is even worth trying.
http://www.ferroxcube.com/FerroxcubeCorporateReception/datasheet/4c65.pdf
Thanks
Peter
You have a real mu of 160 and an imaginary mu of 15 at 22MHz, while at a low frequency such as 1MHz you have a real mu of 130 and an insignificant imaginary mu. Putting those values into equation 10 in my paper "On using Complex Permeability Resonance to get OU" I calculate the COP to be 1.06. My equation did not take account of circuit losses, only core losses, so you must expect something lower than that value. That 4C65 ferrite doesn't have a significant resonance so is not the best material to use. However it could give you a good grounding into getting the feel for this type of experiment where you could look for the resonance by plotting your measured COP against the high frequency value used in each measurement. You should observe maximum COP at around 22MHz, even if the COP is less than unity
Smudge
Hi Smudge
Thanks for looking at that core, i did have a play this morning, I've not had time to publish my results yet, but i will say that even with 1.5 turns and just my fet capacitance i do not reach 20MHz, and then the problem is that i don't know what the fet's capacitance is so i have no way to calculate my output power level from the voltage peak obtained.
We need another type of circuit to try this out one that does not involve the fet's capacitance.
I ran the circuit and let it constantly recharge the Clow so that it kept firing every time it charged through a complete M1 & M2 cycle, this allowed me to adjust the fet on/off time while running and i could easily find the highest peak across the Chi.
I am now thinking of trying a transistor switch to see how that performs.
@Peterae
Believe it or not, I do still keep tabs on this site..
I noticed familiar waveforms you've posted. These being the ones where you've shorted a capacitance with the results of a pulsing voltage increase when removing the short.
The familiarity I see is that of dielectric absorption or 'soakage'. I can't say that those waves are indeed soakage but they do appear to be in my eye.
Hi WW
good to see you are around still.
Yeah it's interesting, when i turn up the fet's delay so it stays on longer the humps move with it, so they wait for the fet to turn off and then appear.
Quote from: Peterae on 2016.11.02, 19:37:33
Hi WW
good to see you are around still.
Yeah it's interesting, when i turn up the fet's delay so it stays on longer the humps move with it, so they wait for the fet to turn off and then appear.
That would be consistent with capacitor soakage. You wouldn't believe how many times I thought I was producing solitons and found out is was just the dielectric in the capacitor trying to recover after being discharged.
Initial recovery was usually in what seemed to be pulses that generally smoothed out to a slightly elevated voltage level.
It appears to me that a lot of folks shorting caps and coils to obtain 'free energy' have been seeing this effect. Of course, this isn't free.