A closer look at a simulated Negative resistance coil.

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Author Topic: A closer look at a simulated Negative resistance coil. (Read 79946 times)

Smudge	Re: A closer look at a simulated Negative resistance coil. « Reply #25 on: 2015-02-03, 16:02:54 »
Group: Moderator Hero Member Posts: 1940	That looks like a large ferrite cylinder being used as a core. Putting coils on a common ferrite rod is one way of making a delay line. What it does demonstrate is that we have ways and means to increase the delay between our coils if we need to, since those voltage waveforms indicate the flux so there is a magnetic propagation delay along the rod (or cylinder in this case). But one thing at a time. Smudge

Peterae	Re: A closer look at a simulated Negative resistance coil. « Reply #26 on: 2015-02-03, 17:34:39 »
Group: Administrator Hero Member Posts: 3960	Shall, i wind 1 coil Anti Clockwise and the other Clockwise, or both the same direction and use the connections to buck them.? Not too much time tonight, we will see how it goes.

verpies	Re: A closer look at a simulated Negative resistance coil. « Reply #27 on: 2015-02-03, 17:41:50 »
Group: Professor Hero Member Posts: 3499	Quote from: EMdevices on 2015-02-03, 16:24:53 Here's a simpler circuit to implement time delay, a coax cable connecting 2 pulse transformers. i think the whole point Smudge's comparison between EM transmission lines and magnetic delay lines, is that they re not equivalent energetically and unit wise.

Smudge	Re: A closer look at a simulated Negative resistance coil. « Reply #28 on: 2015-02-03, 19:04:45 »
Group: Moderator Hero Member Posts: 1940	Quote from: Peterae on 2015-02-03, 17:34:39 Shall, i wind 1 coil Anti Clockwise and the other Clockwise, or both the same direction and use the connections to buck them.? Not too much time tonight, we will see how it goes. I don't think it matters which way you do it but Chris seems to think it does. Whatever you do make a note of it so that it can be looked into as a change later on. Cyril

Orthofield	Re: A closer look at a simulated Negative resistance coil. « Reply #29 on: 2015-02-03, 19:07:10 »
Sr. Member Posts: 331	Hi all, Let me introduce myself briefly. I've worked with Smudge on several projects in the past, and was happy to run across him doing research on bucking coils somewhat similar to what we have been doing. I've read this new thread but not all of the 'partnered coils' thread that came before, so forgive me if I repeat something that has already been covered. Something similar was done by Greg Watson in 1997: http://www.nanoworld.org.ru/data/01/data/club/overuni/pmod.htm where he claims a self-powering PMOD unit generating 78 mW. He says: PMOD. If we have a coil and ferrite core, it is possible to time separate the current applied to the coil by an external Emf source and the resultant back Emf generated as the ferrites domains align. I have found that there is a time delay of approx 20-30ns from the application of the coils H field and the domains starting to rotate into alignment and producing a back Emf. If the coil is driven for only 20-30ns, only a small amount of self induced back Emf is generated (the coil acts like the ferrite is not there). After the 20-30ns wide drive pulse, the coils H field is gone but the domains are still moving (they have inertia) and will generate quite a large back Emf which can be tapped. He used an old radio antenna ferrite about 150 mm long. He appears to have used the 3C80 material, with a LF mu of around 4000. He has some interesting tips. Even before that a lot of this research was done in the study of 'bubble memories'. Orthofield

Smudge	Re: A closer look at a simulated Negative resistance coil. « Reply #30 on: 2015-02-03, 19:25:17 »
Group: Moderator Hero Member Posts: 1940	Quote from: EMdevices on 2015-02-03, 16:24:53 Here's a simpler circuit to implement time delay, a coax cable connecting 2 pulse transformers. Think of the primary coils of the transformers as the coils of interest. The secondaries just transduce the flux change to voltage and back at the other end of the transmission line with time delay. So bend the coax and bring the transformers close together so that you can wire up the primaries in series. This should be an equivalent circuit to test the effect of time delay in flux. But remember, don't blame me if you don't get free energy. I think there is something special about magnetic propagation through a ferromagnetic medium that you won't get with delay through coax. Even if the coax has a dielectric the E field moving along that dielectric is transverse. In magnetic cores the mag field is longitudinal. And there is something special about longitudinal waves or near-field waves. I have yet to see evidence that core loss due to magnetic viscosity actually all goes as heat, it is just assumed that it does. The math says that the delay can both cause a loss (coils aiding) or a gain (coils opposing). Where does the energy go to or come from in those two cases? In both cases you can construct an elliptic flux v current loop where the deviation from a straight line is due to the phase shift caused by that delay. In one case the loop it traversed CCW (loss) and in the other CW (gain). If the loss goes as heat, the gain must come from cooling. It will be interesting to find out. Smudge

Peterae	Re: A closer look at a simulated Negative resistance coil. « Reply #31 on: 2015-02-03, 19:32:29 »
Group: Administrator Hero Member Posts: 3960	Welcome orthofield Sounds good chaps I am also working on my digital monostable with fet driver output, this maybe capable of a 4-6 amp pulse with a very short width, not yet sure how small but i have certainly done 17nS but with a fet attached it ended up much wider at about 100nS. I tested that by setting the pulse width to 17nS and i would get a pulse from the fet with that low setting, things should be much better with just the fet driver. I use a MCP1406/1407 driver chip http://ww1.microchip.com/downloads/en/DeviceDoc/22019B.pdf

Peterae	Re: A closer look at a simulated Negative resistance coil. « Reply #32 on: 2015-02-03, 21:09:58 »
Group: Administrator Hero Member Posts: 3960	OK Wound second coil inductance was a bit higher at 3.6mH not sure why, i could try taking 1 turn off and see if that balances it. Anyway no chance of seeing a phase difference at 10KHz I have 2 scope shots 1st is across both coils, green sig gen coil, yellow second coil ww2 2nd is with a 19.958 Ohm measured non inductive resistance in series with the sig gen and green trace. yellow across second coil. ------------------------ A closer look at a simulated Negative resistance coil. ww2 copy.jpg (123.02 kB, 1024x600 - viewed 684 times.) A closer look at a simulated Negative resistance coil. currentvssecv copy.jpg (143.79 kB, 1024x600 - viewed 647 times.)

Orthofield	Re: A closer look at a simulated Negative resistance coil. « Reply #33 on: 2015-02-04, 13:34:11 »
Sr. Member Posts: 331	Hi Smudge, I agree that there is something special about the domain delay vs. transmission line delay. You can think of of a wave of rotating domains in a ferrite rod (for instance) as a transfer of mechanical energy down the rod. The changing domains generate energy when they pass through the distant coil, and in turn this coil can reflect back to the first with a second wave of domains. In a transmission line any energy that is reflected from the far end of the line is subtracted from the load at that end, but this doesn't seem to be the case with the magnetic domains. The very act of tapping off the energy at the far end should causes the domain wave back to the start. I do think the domain movement losses should show up as heat, and are equivalent to hysteresis losses, but there are cases where the domain movement is not lossy. Bubble domains in the old memories could be created and destroyed, but didn't lose mechanical energy in progress. It's possible that electric delays in a Tesla/Avramenko one wire system could be used similarly to magnetic lines. Peterae, nice work, not a snap getting sharp 17 nS pulses. This is comparable to what Greg Watson was using and should see results. Note Greg's use of a very thin gap to 'reset' the core for another pulse. If the core is continually subjected to pulses in the same direction, it will tend to magnetize and the effect will be lost over some cycles. Ideally you want back and forth motion of the domains, like in the Sweet VTA.

verpies	Re: A closer look at a simulated Negative resistance coil. « Reply #34 on: 2015-02-04, 14:05:16 »
Group: Professor Hero Member Posts: 3499	What happened to Greg Watson, anyway?

Peterae	Re: A closer look at a simulated Negative resistance coil. « Reply #35 on: 2015-02-04, 19:32:37 »
Group: Administrator Hero Member Posts: 3960	Hi EM Yes i had seen this but seen as it's the current flowing in the Inductor i thought it would be 90 Degrees. Peter

Smudge	Re: A closer look at a simulated Negative resistance coil. « Reply #36 on: 2015-02-04, 19:43:33 »
Group: Moderator Hero Member Posts: 1940	Quote from: Peterae on 2015-02-04, 19:32:37 Hi EM Yes i had seen this but seen as it's the current flowing in the Inductor i thought it would be 90 Degrees. Peter I think EM missed the fact that you measured the voltage across the resistor, he assumed it was across inductor and resistor in series. Not surprised you didn't measure any phase shift, it calculates out at a fraction of a degree. But nevertheless it must be there and it will induce a small negative resistance for the bucking mode. So worth going further methinks. But to answer Chet's question in another thread, moving to a higher frequency ferrite where you could work at say 10MHz instead of 10 KHz should give a 10^6 improvement in negative resistor value, so well worth purchasing those toroidal cores. Smudge

Orthofield	Re: A closer look at a simulated Negative resistance coil. « Reply #37 on: 2015-02-04, 20:07:57 »
Sr. Member Posts: 331	>What happened to Greg Watson, anyway? It's not a pretty picture, verpies. He was involved in a seeming solar power scam in 2008: http://revolution-green.com/sun-cube-sad-story-solar-going-wrong/ When I worked with him he seemed to be a sincere researcher, if a bit self aggrandizing-- not an unusual feature :-) orthofield

Peterae	Re: A closer look at a simulated Negative resistance coil. « Reply #38 on: 2015-02-04, 20:46:46 »
Group: Administrator Hero Member Posts: 3960	OK 2 main coil 32Turns each bucking config 100Hz L 360uH Q 1.475 R 0.1534 Ohm Z 0.2736 Ohm 1KHz L 360.4uH Q 14.592 R 0.1551 Ohm Z 2.2701 Ohm 10KHz L 360.2uH Q 98.07 R 0.2301 ohm Z 22.637 Ohm now to wind a primary on top, 5 turns each bucking mode. OK 5 turns each measuring 89uH Bucking @ 10KHz gives L 9.729uH R 0.0417 Ohm Z 0.6127 Q 14.664 Ohm that's all for tonight though $:-\$ So next then i need power measurements If i place 1 20 Ohm non inductive resistance in series with the primary bucking coils and driven by the sig gen and then use a second 20 Ohm as my load across the bucking 32Turn coils. I don't have the joy of a current probe. How do i setup for power measurements. « Last Edit: 2015-02-04, 22:24:44 by Peterae »

Orthofield	Re: A closer look at a simulated Negative resistance coil. « Reply #39 on: 2015-02-04, 22:49:26 »
Sr. Member Posts: 331	Hi Peterae, I just would like to make sure I understand your findings so far. I apologize if I'm going over old ground here... First you tested the reduced reactance effect with bucking coils. Bucking series L1 and L2 have a much lower net L than they would separately. As befits a ferrite core, the L values of the bucking config are pretty stable between 100 Hz and 10 Khz. Since there is a 90 degree V phase shift, as EMdevices said-- this must be a phase shift already, right?... as a transformer the voltage should be the same phase or 180 away. The addition of the bucking coil is similar to tests that partzman and I have been doing. I'll let him explain these in more detail when he wants. For myself, I've been collecting information that a delta/T or star connected set of three mutually inducting coils can have a negative resistance in one coil leg in steady state AC operation. If the leg with the negative resistance contains a resistive energy generator, then the internal resistance of this generator can be cancelled. The main reference to this is Tellegen's patent US2093665, "Star And Delta Connection Of Impedances" where he shows that the basic math of transforming a star into a delta indicates a net -R, or -L on one leg, as the result of a positive impedance on another leg. He describes a variety of interesting circuits in this totally forgotten patent, but the first couple paragraphs will suffice. Bode later claimed that in filters based on Bartlett's theorem, the actual resistance of the leg carrying the pass frequency would be nulled out by this -R in his T section filters. There are other examples of this. I know this seems to get off subject, but it seems as soon as you start putting a third coil on the bucking coils, then you may have some of these -R effects even in steady operation, and this would be an entirely separate effect from the domain-based phase shift. This use of a third coil is more like what partzman and I have been doing lately. orthofield ------------------------ StarAndDeltaConnectionOfImpedances.pdf (556.53 kB - downloaded 232 times.)

Peterae	Re: A closer look at a simulated Negative resistance coil. « Reply #40 on: 2015-02-05, 06:21:30 »
Group: Administrator Hero Member Posts: 3960	Hi orthofield Interesting patent, need a bit more time to look it over. Post 1 explains that Smudge was able to simulate a negative resistance. http://www.overunityresearch.com/index.php?topic=2773.msg45196#msg45196 We switched to toroidal ferrite as it calculates out a stronger effect. More description in Post 20 http://www.overunityresearch.com/index.php?topic=2773.msg45368#msg45368 I've not really tested that much so far, just been winding turns and testing these, the bucking tests will start tonight hopefully. Just to be clear when i post data like below then this is just my LCR meter measuring a coil at 100Hz, i can measure at 1KHz & 10KHz Also. 100Hz L 360uH Q 1.475 R 0.1534 Ohm Z 0.2736 Ohm Thanks Peter

Smudge	Re: A closer look at a simulated Negative resistance coil. « Reply #41 on: 2015-02-05, 09:52:18 »
Group: Moderator Hero Member Posts: 1940	Quote from: Peterae on 2015-02-04, 20:46:46 OK 2 main coil 32Turns each bucking config 100Hz L 360uH Q 1.475 R 0.1534 Ohm Z 0.2736 Ohm 1KHz L 360.4uH Q 14.592 R 0.1551 Ohm Z 2.2701 Ohm 10KHz L 360.2uH Q 98.07 R 0.2301 ohm Z 22.637 Ohm now to wind a primary on top, 5 turns each bucking mode. OK 5 turns each measuring 89uH Bucking @ 10KHz gives L 9.729uH R 0.0417 Ohm Z 0.6127 Q 14.664 Ohm that's all for tonight though $:-\$ So next then i need power measurements If i place 1 20 Ohm non inductive resistance in series with the primary bucking coils and driven by the sig gen and then use a second 20 Ohm as my load across the bucking 32Turn coils. I don't have the joy of a current probe. How do i setup for power measurements. OK as expected in bucking arrangement the inductance is very much smaller than that of an individual coil indicating almost complete cancellation. So in the formula L=L₁+L₂-2L₁₂ the mutual coupling term L₁₂ is almost equal to L₁ or L₂. Let's say 3mH for L₁₂. From your single coil inductance I calculate the core mu to be over 2000, let's say 2000. Using a ferrite dielectric constant of 6.7 (could be more) and v_p=c/sqrt(muK) I get the velocity as 2.6x10⁶. With a separation between coils of 0.135m the time delay is 52nS. At a frequency of 10KHz that is a phase shift phi of 3.3millirads. Hence sin(phi)=3.3x10^-3. The negative resistance formula R=-2omega)L₁₂sin(phi) yields a value of minus 0.062 ohms. That can be compared with your measurement of 0.231 ohms positive. So if you shorted your coils so that the power all got dissipated in their resistance and used the heat as an output you would have a COP>1. For a given current flow i the heat power would be i²0.231 while the input supplied input power would be i²(0.231-0.062), hence COP=1.37. But using a large value of load resistor you would reduce the COP so not worth doing. For maximum COP the load resistor should equal the negative one then COP is infinite. I think you can now see why going higher in frequency is desirable. All else being equal if you could operate at 100KHz the negative R would be 6.2 ohms, at 1MHz it would be 620 ohms, at 10Mhz it would be 62 Kohms. Smudge

Chet K	Re: A closer look at a simulated Negative resistance coil. « Reply #42 on: 2015-02-05, 10:03:43 »
Group: Ambassador Hero Member Posts: 4045	Smudge Working on getting what we need for higher frequencies Chet « Last Edit: 2015-02-05, 11:58:14 by Chet K »

verpies	Re: A closer look at a simulated Negative resistance coil. « Reply #43 on: 2015-02-05, 13:02:16 »
Group: Professor Hero Member Posts: 3499	Quote from: Chet K on 2015-02-05, 10:03:43 Working on getting what we need for higher frequencies I am afraid that even with a HF toroid we will soon run into the problem of not having an analog amplifier at these frequencies. A weak unamplified signal will be drowned out by the noise. A digital amplifier (for rect waves) can be made pretty easily but an analog one (e.g. for sine waves) is a difficult beast. I have one up to 200MHz @100W and it weighs 25kg (55lbs).

Grumage	Re: A closer look at a simulated Negative resistance coil. « Reply #44 on: 2015-02-05, 15:10:43 »
Group: Renaissance Man Hero Member Posts: 2765	Dear All. Is there a realativly simple method to determine the AL value of a Ferrite? Please be aware that I have not got anywhere near the test equipment that Peterae has got. Cheers Grum. --------------------------- Nanny state ? Left at the gate !!

verpies	Re: A closer look at a simulated Negative resistance coil. « Reply #45 on: 2015-02-05, 16:08:14 »
Group: Professor Hero Member Posts: 3499	If you have an inductance meter then just divide the inductance by the number of turns squared. If you don't then drive the inductor (like Itsu) from a signal generator, UCC driver and a MOSFET with a low duty rectangular wave and measure how quickly the current rises with a scope and a CSR.

Orthofield	Re: A closer look at a simulated Negative resistance coil. « Reply #46 on: 2015-02-05, 16:56:04 »
Sr. Member Posts: 331	Hi Peterae, Thanks for the breakdown. >Interesting patent, need a bit more time to look it over. The take away is that if three coils are centered tied, then in some cases a form of negative resistance will ensue even in the static AC condition. This type of -R can "only" reduce losses, but is easily confused with a power gain, which is a -R that is greater than the real R of the circuit. I agree with Cyril that a power gain can result from the time delay in bucking coils, although I come at it from another standpoint. Although greatly interested in negative resistance, I thought in terms of creating a pulse so short relative to the length of the core that it becomes a distinguishable domain wall moving through the core (which I imagined as a long ferrite stick). Then, the pulse is over by the time the moving domains reach the further coil, so no loading results. It takes little energy for the source to create the moving domain wall, and not only does it power the load at the far end, but the load reaction itself creates another domain wall moving back to the start. In this case, the source must become a sink after the initial pulse. Smudge may be referencing this possibility when he talks about the coils being suddenly connected to a low impedance. The situation is made more complicated by using two bucking coils. Then the timing must be such that the return pulse doesn't overlap the source pulse. It almost seems as if the Bloch walls would pass through each other as solitons. Although Smudge has suggested the effect can exist in continuous AC, I think a very short pulse is much more likely to get good results, initiated at one end of a decently long high mu ferrite rod, and measured at the other end. A few notes interspersed below: Post 1 explains that Smudge was able to simulate a negative resistance. http://www.overunityresearch.com/index.php?topic=2773.msg45196#msg45196 We switched to toroidal ferrite as it calculates out a stronger effect. --It's just a hunch that a ferrite rod will work better. Perhaps because the ends of the rod represent 100% reflection. More description in Post 20 http://www.overunityresearch.com/index.php?topic=2773.msg45368#msg45368 I've not really tested that much so far, just been winding turns and testing these, the bucking tests will start tonight hopefully. --OK, that's what I thought. When you started talking about a third coil, I thought I must have missed something. Just to be clear when i post data like below then this is just my LCR meter measuring a coil at 100Hz, i can measure at 1KHz & 10KHz Also. --Sure. Have to start with that. orthofield 100Hz L 360uH Q 1.475 R 0.1534 Ohm Z 0.2736 Ohm Thanks Peter [/quote]

Orthofield	Re: A closer look at a simulated Negative resistance coil. « Reply #47 on: 2015-02-05, 17:38:46 »
Sr. Member Posts: 331	Hi Cyril, On looking at a ferrite catalog, Peterae's test is probably being done with something like Fair-rite material 78 which has an initial mu of 2300 and a roll off at 1 Mhz: http://www.fair-rite.com/newfair/materials78.htm I assume that we want the initial mu to be as high as possible, since a higher mu will represent both a longer delay, and less loss. Unfortunately the HF ferrite materials have mus around 40-150. Do you think these tests will work with the typical low-mu HF pulse transformer materials? How important is having the mu high? orthofield

Peterae	Re: A closer look at a simulated Negative resistance coil. « Reply #48 on: 2015-02-05, 18:29:57 »
Group: Administrator Hero Member Posts: 3960	Fair enough so we want a large toroid using 3F4 ferroxcube material. Equivalent to 3F4 are the following Material 75G Epcos N92 MMG F49 TDK PC50 FDK 7H10 Magnetics K Nicera BM29 TDK have discontinued PC50 in favour of a newer PC95 material http://www.mhw-intl.com/news/2009/10/tdk-power-ferrite-pc95-verses-pc50/ PC95 is electrically conductive at 6 Ohm per metre and is mn-zn ferrite I've tried tracking down 3F4 made by other manufacturers and so far not found any big toroid's that are the same material, infact it's beginning to appear this type of ferrite is being discontinued. « Last Edit: 2015-02-05, 19:11:14 by Peterae »

Orthofield	Re: A closer look at a simulated Negative resistance coil. « Reply #49 on: 2015-02-05, 19:11:04 »
Sr. Member Posts: 331	Hi Peterae, The 3F4 has an initial mu of around 900. I wonder if this will cause a higher attenuation, or if it really matters? I guess we will see... orthofield

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