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2019-11-14, 21:46:38
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Author Topic: Magnetic Compression Study" by Cyril Smith  (Read 23646 times)

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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 :(
   
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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!
   

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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.

   

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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
   

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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.
   
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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.

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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!

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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.

   
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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.

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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.
   

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Why one PIC MCU wasn't enough?
   

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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
   
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It's turtles all the way down
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


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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
   
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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
   

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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
   
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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
   

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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.
   

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@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.


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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.
   

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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.


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"As far as the laws of mathematics refer to reality, they are not certain; as far as they are certain, they do not refer to reality." - Einstein

"What we observe is not nature itself, but nature exposed to our method of questioning." - Werner Heisenberg
   
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