SEMP AI Smart Electromagnetic Generator (AISEG)

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2025-05-19, 06:40:39
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Author Topic: SEMP AI Smart Electromagnetic Generator (AISEG) (Read 27283 times)

Smudge	Re: SEMP AI Smart Electromagnetic Generator (AISEG) « Reply #100 on: 2025-05-05, 19:34:17 »
Group: Professor Hero Member Posts: 1996	This bench has been silent for over a year, it ceased four days after my last post there. In my personal life I have had problems that prevented me from continuing but now I am in a position for further deliberations. I start with a basic formula the everyone here should recognise, relating the magnetic field B within a transformer core to the current creating that field, B = u₀u_RH. (1) H is the ampere-turns divided by the length around the transformer core closed magnetic path, u₀ is free space permeability and u_R is the dimensionless relative permeability. The presence of the core allows us to produce large B using minimum current that enables our power transformers to be highly efficient. The high values of u_R come from what goes on inside the core where the initial application of low current causes some atomic dipoles to align or flip, that then increases the field which causes more dipoles to react and so on; that cumulative action is very much like positive feedback in an electronic circuit. The core material very quickly reaches the B values given by (1). When we look at the enormous number of atomic dipoles that are producing this cumulative action we can’t treat them individually, we use a number density M which is dipole-moment per unit volume. We then find B = u₀H + u₀M. (2) Here the core material characteristic u_R has disappeared. We have two field contributions, the current producing one B field (via H) as though the core was not present, and the atomic dipoles creating the other B field. This is all sensible as we know that the solid looking core volume is mostly free space, the atomic particles occupying very little volume. This feature, as though the core was not present, is used in one other part of EM theory dealing with permanent magnet load-lines where it is referred to as the air space occupied by the core. And it is important here on this bench as it influences how we deal with remanent magnetism decay. The thing to plant in your minds is that in any soft ferromagnetic core the air space occupied by the core has two fields planted there, one from coil currents and the other from the atomic dipoles. We can resurrect the core material permeability if we introduce the core susceptibility X where X tells you how much M you get for a given coil ampere-turns/m (H), M = XH. (3) Then since u_R = 1 + X we get from (2) back to (1). I can’t stress enough the importance of (2) in dealing with remanent magnetism decay where the driving current creating the magnetism is no longer present. Initially in the magnetizing pulse we do have a driving current producing H and also producing M via (3), giving us B for very little current. At the end of the pulse we have B_REM = u₀M_REM and it is M_REM that then decays. During that decay the H that is present from the load current created by the decaying B tries to negate that decay. But it is the M that is decaying, we don’t have M=XH available to us to deduce the effect of the load current on B and obtain the B waveform. That waveform leads to the current waveform hence also the energy. So, deducing the load current is equivalent to having transformer coils wound on an air core (a Rowland ring in many EM texts) with a primary ampere-turns starting at a value equal to M_REM then decaying at the known exponential time constant, and with the secondary resistively loaded. Solving this in the magnetic domain is a trivial task involving a first order differential equation. The susceptibility X plays its part in establishing the small values of H_SAT and input energy needed to magnetize the core but plays no part in the M_REM decay. To give an example a ring core reaching a B_SAT of 0.5T needs a pulse of 75mA peak into 100 turns with an input energy of 170μJ. The resulting M_REM is equivalent to a current of 600A in a primary coil on the core considered as air. That 600A decaying at a 2mS time constant creates an open circuit secondary pulse voltage of 2.5 volts. When loaded with 1 Ohm that drops slightly and the pulse output energy is over 6 mJ. You might ask why does SEMP not declare such enormous OU COPs? To start with they don’t use closed magnetic circuits. Their quoted decay of milliseconds does not occur at ambient temperatures, they have their equipment in an insulated container which IMO has to be heated to the correct temperature and held there. The passage of air through their cores is not for cooling, it is to keep them at the correct temperature. After the initial heating up from an external power source, some of the OU electrical output is used to maintain the temperature and that energy is not included in their COPs. SEMP also extract energy during the magnetizing pulse so they cannot achieve the enormous COPs that I have quoted here. Now some quotes from other people’s posts on this bench with my comments. It's not a Maxwell demon. It would have to provide useful power and be maintained without depletion. But that is what it does!! A device that draws its energy from a single thermal bath, such as the environment, is a Maxwell demon. Although the temperature is the driving effect, this may not be drawing energy from the environment. It may be tapping into the dipole spins acting as quantum dynamos. A more plausible theory would be that temperature has nothing to do with the effect. A high temperature is needed to get the decay. You are talking about slowing down the demagnetization process and demagnetizing it spontaneously. How is slowing down spontaneous? However, the magnetization energy also depends on the heat; it must be greater when the magnetic dipoles are thermally agitated, since more effort is required to align them. Not true. At high temperatures B_SAT reduces and so does the H needed to reach it. But magnetization decay by itself is not enough to induce any serious amps on coils. Oh really? Have you evidence for this? Smudge

Smudge	Re: SEMP AI Smart Electromagnetic Generator (AISEG) « Reply #101 on: 2025-05-07, 09:20:37 »
Group: Professor Hero Member Posts: 1996	I should mention that there is one other reason that SEMP are not achieving the high COPs that I am quoting. IMO square loop material is the best candidate for this feature and that is what I assumed. The SEMP Fe cores will certainly not be square loop. I am convinced that the SEMP device works at some high temperature well above ambient. And having now studied how the decay of any PM material’s field is reduced from many years down to milliseconds as the temperature is increased, any square loop material can be made to exhibit millisecond decays at some temperature near the Curie point. MnZn ferrite has a Tc of 230C so it is possible to do experiments with a domestic oven. Smudge

F6FLT	Re: SEMP AI Smart Electromagnetic Generator (AISEG) « Reply #102 on: 2025-05-07, 15:20:02 »
Group: Experimentalist Hero Member Posts: 2174	Quote from: Smudge on 2025-05-05, 19:34:17 ...We then find B = u₀H + u₀M. (2) Here the core material characteristic u_R has disappeared. We have two field contributions, the current producing one B field (via H) as though the core was not present, and the atomic dipoles creating the other B field. ... I can’t stress enough the importance of (2) in dealing with remanent magnetism decay where the driving current creating the magnetism is no longer present. Initially in the magnetizing pulse we do have a driving current producing H and also producing M via (3), giving us B for very little current. At the end of the pulse we have B_REM = u₀M_REM and it is M_REM that then decays. During that decay the H that is present from the load current created by the decaying B tries to negate that decay. But it is the M that is decaying, we don’t have M=XH available to us to deduce the effect of the load current on B and obtain the B waveform. ... When we apply direct current to a coil, the field created by the electric current reorients the material's magnetic dipoles, and the electrical energy used to work on the dipoles is stored in the B field. The B field models this re-orientation of the dipoles. The electric current then serves only to overcome Joule effect losses. It's the extra energy needed at the start to reach the final current, i.e. the energy required in addition to that needed to overcome the Joule effect, that represents the magnetizing energy. When we supply an alternating current to a coil, the alternation corresponding to the current rise is equivalent to the previous case, until we reach the sinusoidal maximum, at which point the additional energy compared to the joule losses will have been stored in the B field. At the alternation corresponding to the fall in current, the collapsing energy of B is returned to the current, so less energy is required from the source. This explains why an LC resonant circuit is able to maintain an oscillation, and all the better if the circuit resistance remains low. Over a whole number of periods, losses aside, we have an energy balance of zero. The idea that demagnetization is linked to a natural phenomenon, for example because we're working near the curie point, or that magnetization/demagnetization takes place slowly or quickly, or that it involves a delay that would allow it to take place after the source current has been cut off, doesn't change the issue at all. Magnetic energy can be recovered in any case. But the collapse of the B field can't provide more than the initial energy, because there's no reason why the work involved in reorienting the dipoles to the rest position should be greater than that involved in orienting them when B is at its maximum. --------------------------- "Open your mind, but not like a trash bin"

Smudge	Re: SEMP AI Smart Electromagnetic Generator (AISEG) « Reply #103 on: 2025-05-09, 16:37:42 »
Group: Professor Hero Member Posts: 1996	Quote from: F6FLT on 2025-05-07, 15:20:02 But the collapse of the B field can't provide more than the initial energy, because there's no reason why the work involved in reorienting the dipoles to the rest position should be greater than that involved in orienting them when B is at its maximum Maybe you did not mean this, but what you have written implies that the energy supplied to magnetize the core occurs after B has reached its maximum value, and that is not the case. The energy is drawn from the source while B is rising due to the dipoles coming into alignment, and the value of B finally reached comes predominantly from the aligned dipoles; the applied current only produces a small contribution to B . Your statement seems to admit that work is involved (energy is consumed) for both the magnetization and the demagnetization phases. You only have to look at the first and second quadrant of a typical BH curve to see that the two energies are not the same, the demagnifying energy consumed in the second quadrant is less than the magnetizing energy in the first quadrant. The SEMP system does not supply energy to demagnetize, there is some external source doing that. Energy appears in the load resistor as the B field decays. I see no reason why that work output from reorienting the dipoles to the rest position should be linked to that involved in orienting them into alignment when that reorienting field is simply the carrier of energy from the external force to the load resistor. Yes, that external force must supply the extra energy over and above the realignment value. Quote It's the extra energy needed at the start to reach the final current, i.e. the energy required in addition to that needed to overcome the Joule effect, that represents the magnetizing energy. You seem to divorce the Joule heating from the magnetizing energy, but the Joule heating of the core is inextricably linked to the BH loop area and the loop only has area if remanent magnetism plays its part, which is very much the case here. Quote When we apply direct current to a coil, the field created by the electric current reorients the material's magnetic dipoles, and the electrical energy used to work on the dipoles is stored in the B field. The B field models this re-orientation of the dipoles. That is true only for linear material where there is no remanence. Then the energy stored in the B field is recoverable. In the SEMP system the remanent B field does not directly model the reorientation, it is the time history of the B field that models that energy. The integral of B wrt time yields the voltage that loads the current source, and very conveniently that energy is mapped by the area within the BH loop. Quote The electric current then serves only to overcome Joule effect losses. If by Joule losses you mean i2R losses then certainly that is directly linked to the current. But the current is essential for driving the dipole alignment and delivering the energy needed to do that. Quote When we supply an alternating current to a coil, the alternation corresponding to the current rise is equivalent to the previous case, until we reach the sinusoidal maximum, at which point the additional energy compared to the joule losses will have been stored in the B field. At the alternation corresponding to the fall in current, the collapsing energy of B is returned to the current, so less energy is required from the source. This explains why an LC resonant circuit is able to maintain an oscillation, and all the better if the circuit resistance remains low. Over a whole number of periods, losses aside, we have an energy balance of zero. Again you are considering a core that has negligible remanence where energy is stored then retrieved, where the quantity of energy stored relates to the B field via the uR of the core material. The small remanence determining the area of the BH loop you have dismissed as Joule losses. This does not apply to the SEMP system. Quote The idea that demagnetization is linked to a natural phenomenon, for example because we're working near the curie point, or that magnetization/demagnetization takes place slowly or quickly, or that it involves a delay that would allow it to take place after the source current has been cut off, doesn't change the issue at all. Magnetic energy can be recovered in any case. And what is the quantity of energy to be recovered? In my consideration of a square-loop material, when magnetized the core u_R has dropped to unity when the current is switched off. At that instant the energy stored in the B field with u_R = 1 is far greater than the energy used to magnetize. We have a core that acts like air if we ignore eddy currents. This is already known in magnetic theory where the air space occupied by the core is used to determine the load line applied to the BH curve of permanent magnets. I stick by my view that when some external force is driving the dipole reorientation it is driving the change in M so we can’t then claim M is available to get u_R>>1, we must consider an air core. That yields an output energy that can exceed the original input by quite a margin. The source of that energy is the external force. Smudge

verpies	Re: SEMP AI Smart Electromagnetic Generator (AISEG) « Reply #104 on: 2025-05-09, 18:26:46 »
Group: Professor Hero Member Posts: 3713	Quote from: Smudge on 2025-05-09, 16:37:42 You only have to look at the first and second quadrant of a typical BH curve to see that the two energies are not the same, the demagnifying energy consumed in the second quadrant is less than the magnetizing energy in the first quadrant. Yes, it follows Quote from: Smudge on 2025-05-09, 16:37:42 You seem to divorce the Joule heating from the magnetizing energy, but the Joule heating of the core is inextricably linked to the BH loop area and the loop only has area if remanent magnetism plays its part, which is very much the case here. Well, he is right on this one. The energy of the Joule heating is equal to the integral of i²R over time, so in the absence of resistance (as with ideal coils) the Joule heating energy is zero.

F6FLT	Re: SEMP AI Smart Electromagnetic Generator (AISEG) « Reply #105 on: 2025-05-09, 21:49:43 »
Group: Experimentalist Hero Member Posts: 2174	Quote from: Smudge on 2025-05-09, 16:37:42 ... The energy is drawn from the source while B is rising due to the dipoles coming into alignment, and the value of B finally reached comes predominantly from the aligned dipoles This is what I say. What I said was that the final B was obtained at the cost of electrical energy during the current's rise, so obviously not after B is maximum (By ‘When we apply direct current to a coil’, I mean that it's at the moment when we make contact and the current starts to flow, that it supplies the energy, and until B is maximum, or stable in the case of a DC current). Quote You seem to divorce the Joule heating from the magnetizing energy, but the Joule heating of the core is inextricably linked to the BH loop area and the loop only has area if remanent magnetism plays its part, which is very much the case here.That is true only for linear material where there is no remanence. Then the energy stored in the B field is recoverable. In the SEMP system the remanent B field does not directly model the reorientation, it is the time history of the B field that models that energy. The integral of B wrt time yields the voltage that loads the current source, and very conveniently that energy is mapped by the area within the BH loop. The fact that the B/H relationship is not linear does not change the problem because it is a macroscopic view, but the validity of the instantaneous relationship of B or dB/dt with the current is always verified. There is only a step-by-step influence in both time and space of the dipoles on each other, each being seen by the other as a current creating a field. At each step between each dipole, the usual relationships apply. The potential energy of a magnetic dipole is Ep=-µ.B where µ is the magnetic dipole moment (not the permeability here). If B does not vary linearly, neither does the potential energy, so the energy taken from the current to reorientate the dipoles will not be the same as in the linear case, but for each dipole it will always satisfy the same linear equation at a given instant. To obtain the balance over a cycle, an integration has to be performed. But whatever the way in which the dipoles re-orientate themselves, whether their potential energy varies in one way or another, and whether the constraints linked to the material cause a non-linear macroscopic effect to appear, their final situation being the same as the initial situation, the energy balance will be zero because the potential energy does not depend on the path followed. To justify an excess of energy over a cycle, we can envisage work being done somewhere by thermal effects, but certainly not by the laws of electromagnetism or mechanics, and even less by engineering equations. Quote the applied current only produces a small contribution to B . ... And what is the quantity of energy to be recovered? In my consideration of a square-loop material, when magnetized the core u_R has dropped to unity when the current is switched off. At that instant the energy stored in the B field with u_R = 1 is far greater than the energy used to magnetize. ... The intensity of the B field says nothing about the energy supplied. We do not have simple superimposed fields, the one linked to the current and the one linked to the dipoles of the material, but forces that oppose the current supplied as it rises, which requires more energy from the current source to maintain it. The regime is not static. This is why it takes enormous energies to magnetise neodymium magnets, supplied in impulse form. Much more than is left in the field of the magnet. --------------------------- "Open your mind, but not like a trash bin"

verpies	Re: SEMP AI Smart Electromagnetic Generator (AISEG) « Reply #106 on: 2025-05-10, 00:02:56 »
Group: Professor Hero Member Posts: 3713	Quote from: F6FLT on 2025-05-09, 21:49:43 ...the validity of the instantaneous relationship of B or dB/dt with the current is always verified An instantaneous relationship of B and current (i) requires an infinitely quick response of core's magnetization (M). What do you mean by the relationship of the dB/dt and current (i) ? The monotonicity of the BH curve in one direction ? The derivative of the BH curve certainly is not monotonic ... « Last Edit: 2025-05-10, 10:55:45 by verpies »

verpies	Re: SEMP AI Smart Electromagnetic Generator (AISEG) « Reply #107 on: 2025-05-10, 01:35:15 »
Group: Professor Hero Member Posts: 3713	Quote from: Smudge on 2025-05-09, 16:37:42 At that instant the energy stored in the B field with u_R = 1 is far greater than the energy used to magnetize. We have a core that acts like air if we ignore eddy currents. Just because the dµ_R /di = 1 does not mean that µ_R = 1 at this point.

Smudge	Re: SEMP AI Smart Electromagnetic Generator (AISEG) « Reply #108 on: 2025-05-10, 09:26:24 »
Group: Professor Hero Member Posts: 1996	Quote from: F6FLT on 2025-05-09, 21:49:43 .......The potential energy of a magnetic dipole is Ep=-µ.B where µ is the magnetic dipole moment (not the permeability here). If I may correct you here, Ep=-µ.B.sin(a) where a is the angle between the dipole axis and B. This brings the orientation of the dipole into consideration. Quote To justify an excess of energy over a cycle, we can envisage work being done somewhere by thermal effects Which is exactly my point. Quote but certainly not by the laws of electromagnetism or mechanics, and even less by engineering equations. That's a brutal dismissal of our laws and equations. If OU is possible (and your above remark suggests it is) surely it is a worthwhile exercise to have engineering equations that allow us to design systems that do this. I will proceed with producing a more detailed paper showing my equations. Quote We do not have simple superimposed fields, the one linked to the current and the one linked to the dipoles of the material With respect I disagree. B=µ₀(H+M) clearly defines a field that is the sum of two components, one from the current (H) and one from the dipoles (M) Quote but forces that oppose the current supplied as it rises, which requires more energy from the current source to maintain it. Now you have jumped to force opposing a current as an argument for fields not superimposing which is inconsistant. The force opposing the current is a voltage that is proportional to dB/dt hence proportional to both dH/dt (hence di/dt) and dM/dt. That is during the magnetization phase. Under demagnetization the same applies but now dM/dt is the driver and the force supports the load current. Smudge

Smudge	Re: SEMP AI Smart Electromagnetic Generator (AISEG) « Reply #109 on: 2025-05-10, 09:55:18 »
Group: Professor Hero Member Posts: 1996	Quote from: verpies on 2025-05-10, 01:35:15 Just because the dµ_R /di = 1 does not mean that µ_R = 1 at this point. Forgive me but I don't see where dµ_R /di = 1 comes from, but maybe that is not what you meant to say. My guess is you are saying that the slope of the BH curve at B = B_R and H = 0 may not mean that µ_R = 1 at that point. For the SEMP Fe cores I agree, but I am considering square-loop material with idealised characteritics and µ_R = 1 does apply at that point.

Smudge	Re: SEMP AI Smart Electromagnetic Generator (AISEG) « Reply #110 on: 2025-05-10, 10:01:30 »
Group: Professor Hero Member Posts: 1996	Quote from: verpies on 2025-05-09, 18:26:46 Well, he is right on this one. The energy of the Joule heating is equal to the integral of i²R over time, so in the absence of resistance (as with ideal coils) the Joule heating energy is zero. I am taking Joule heating as being heating of both the core and the coil. Traversing around a complete BH loop takes energy that is either dissipated in the core or mysteriously disappears into some other dimension.

verpies	Re: SEMP AI Smart Electromagnetic Generator (AISEG) « Reply #111 on: 2025-05-10, 10:37:06 »
Group: Professor Hero Member Posts: 3713	Quote from: Smudge on 2025-05-10, 09:26:24 B=µ₀(H+M) clearly defines a field that is the sum of two components, one from the current (H) and one from the dipoles (M) Could you draw the MH curve for posterity ? The slope of its ends will be horizontal on the graph, won't it ?

tak22	Re: SEMP AI Smart Electromagnetic Generator (AISEG) « Reply #112 on: 2025-05-10, 16:21:35 »
Newbie Posts: 21	Quote from: Smudge on 2025-05-07, 09:20:37 I am convinced that the SEMP device works at some high temperature well above ambient. And having now studied how the decay of any PM material’s field is reduced from many years down to milliseconds as the temperature is increased, any square loop material can be made to exhibit millisecond decays at some temperature near the Curie point. MnZn ferrite has a Tc of 230C so it is possible to do experiments with a domestic oven. I happen to have 4 Ferroxocube TN36/23/15-3R1 square loop toroids: https://elnamagnetics.com/wp-content/uploads/library/Ferroxcube-Materials/3R1_Material_Specification.pdf If there were a suggested POC experiment I'd be interested in trying it. A source for square loop info: http://qrp.gr/squareloop/index.htm tak

Smudge	Re: SEMP AI Smart Electromagnetic Generator (AISEG) « Reply #113 on: 2025-05-10, 16:33:47 »
Group: Professor Hero Member Posts: 1996	Quote from: verpies on 2025-05-10, 10:37:06 Could you draw the MH curve for posterity ? The slope of its ends will be horizontal on the graph, won't it ? Yes and here is an idealised square-loop. ------------------------ SEMP AI Smart Electromagnetic Generator (AISEG) M v H loop.jpg (22.33 kB, 501x476 - viewed 159 times.)

Smudge	Re: SEMP AI Smart Electromagnetic Generator (AISEG) « Reply #114 on: 2025-05-10, 16:39:29 »
Group: Professor Hero Member Posts: 1996	Quote from: tak22 on 2025-05-10, 16:21:35 I happen to have 4 Ferroxocube TN36/23/15-3R1 square loop toroids: https://elnamagnetics.com/wp-content/uploads/library/Ferroxcube-Materials/3R1_Material_Specification.pdf If there were a suggested POC experiment I'd be interested in trying it. A source for square loop info: http://qrp.gr/squareloop/index.htm tak That is great news, your MnZn ring cores will be ideal as you can get them close to Tc in a domestic oven. I will write up my ideas for an experiment for your consideration.

Smudge	Re: SEMP AI Smart Electromagnetic Generator (AISEG) « Reply #115 on: 2025-05-11, 10:17:56 »
Group: Professor Hero Member Posts: 1996	@tak, Are your cores coated with polyamide (nylon) 11? If they are its melting point is 180-190C and we want to get to near 230C. How difficult is it to remove?

F6FLT	Re: SEMP AI Smart Electromagnetic Generator (AISEG) « Reply #116 on: 2025-05-11, 16:52:14 »
Group: Experimentalist Hero Member Posts: 2174	Quote from: Smudge on 2025-05-10, 09:26:24 ... If OU is possible (and your above remark suggests it is) surely it is a worthwhile exercise to have engineering equations that allow us to design systems that do this. I will proceed with producing a more detailed paper showing my equations. With respect I disagree. B=µ₀(H+M) clearly defines a field that is the sum of two components, one from the current (H) and one from the dipoles (M) ... Quote from: verpies on 2025-05-10, 00:02:56 An instantaneous relationship of B and current (i) requires an infinitely quick response of core's magnetization (M). What do you mean by the relationship of the dB/dt and current (i) ? The monotonicity of the BH curve in one direction ? The derivative of the BH curve certainly is not monotonic ... By ‘instantaneous’, I mean a direct interaction between two entities, such as two magnetic dipoles like electrons, when we consider a single instant, not a duration, and in a context where the propagation time of the effect vector can be legitimately neglected. The B field models a macroscopic average, or resultant, of all the dipole fields. This does not invalidate the model which describes each interaction between dipoles by a linear equation. The B/H non-linearity is not in fact due to an electromagnetic phenomenon, but due to the material, the constraints I suppose of the crystalline lattice on the electrons which mean that the force to orientate the magnetic dipoles will have to be different according to their instantaneous orientation and the history of the overall magnetisation already achieved. Modelling by the B=µ₀(H+M) field is a translation into the electromagnetic domain of ‘mechanical’ effects in the material that disturb the orientation of the dipoles, resulting in non-linearity. This is practical in engineering, but in physics it does not allow us to draw direct conclusions about energy by overlooking the way energy is stored in the material. The only conclusions we can draw from physics is that the energy in the field is at most equal to the magnetisation energy. --------------------------- "Open your mind, but not like a trash bin"

tak22	Re: SEMP AI Smart Electromagnetic Generator (AISEG) « Reply #117 on: 2025-05-11, 17:02:18 »
Newbie Posts: 21	Cores are uncoated

lfarrand	Re: SEMP AI Smart Electromagnetic Generator (AISEG) « Reply #118 on: 2025-05-11, 21:57:21 »
Sr. Member Posts: 281	I also have a bunch of Ferroxcube TN36/23/15-3R1 ferrite cores, about 60 of them in fact. I thought the square BH curve looked interesting so I bought some when the opportunity presented itself a couple of years ago. They were becoming increasingly hard to buy since Ferroxcube stopped manufacturing them. I'd also be interested in trying out anything you have to suggest Smudge.

verpies	Re: SEMP AI Smart Electromagnetic Generator (AISEG) « Reply #119 on: 2025-05-12, 01:22:11 »
Group: Professor Hero Member Posts: 3713	Quote from: Smudge on 2025-05-10, 16:39:29 That is great news, your MnZn ring cores will be ideal as you can get them close to Tc in a domestic oven. An those who do not have such an oven can make-do with a halogen light bulb and some high-temp insulation (fiberglass, basalt wool, mineral wool, clay pot, fireclay brick, etc...) so the heat does not escape.... Hot air guns or hot air soldering stations are a viable source of controllable heat, but some thermal insulation is needed to maintain temperature uniformity. Resistive heaters that use coiled Constantan/Nichrome wire generate unwanted magnetic fields. A halogen incandescent light-bulb or a hot air-gun is cleaner EM-wise and easier to obtain. Gas flame is too hot and too hard to control. Also, it is chemically reducing or oxidizing (depending on the part of the flame) and it generates combustion fumes. Quote from: Smudge on 2025-05-11, 10:17:56 ...we want to get to near 230C. Normal winding wire will have its enamel coating thermolysed at 230°C and the adjacent turns will short-out if they touch. If the naked turns touch the hot core core, that might create some unwanted conduction. too. Polyimide/Polyamide-imide coated copper wire is able to withstand 265°C. There are high-temp specialty silicones that can withstand up to 530°C (~1000°F).

Smudge	Re: SEMP AI Smart Electromagnetic Generator (AISEG) « Reply #120 on: 2025-05-12, 07:28:36 »
Group: Professor Hero Member Posts: 1996	Thanks for that useful information Verpies. When I write up the experiment I already decided the wire needs that high temperature coating. At the moment I am cursing the Microsoft Word equation editor, the old version was much better. I will get there with persistence. I think temperature control will be the stumbling block in these experiments, it may be difficult to get a stable relaxation time but we'll see.

Smudge	Re: SEMP AI Smart Electromagnetic Generator (AISEG) « Reply #121 on: 2025-05-12, 09:13:00 »
Group: Professor Hero Member Posts: 1996	Here is my paper describing experiments using the MnZn ferrite ring cores. I am preparing another paper looking into the math. Enjoy! Smudge ------------------------ Experiments Exploring Remanent Magnetism Decay.pdf (440.18 kB - downloaded 24 times.)

verpies	Re: SEMP AI Smart Electromagnetic Generator (AISEG) « Reply #122 on: 2025-05-12, 12:43:48 »
Group: Professor Hero Member Posts: 3713	Quote from: Smudge on 2025-05-12, 07:28:36 I think temperature control will be the stumbling block in these experiments, Modern hot air soldering stations have pretty good closed-loop temperature controllers and some of us already have them on our workbenches. A pit or a channel surrounded by some thermal insulation is still necessary to keep the peripheral cooling at bay ...and the thermal gradients it creates. Drilling a hole in a white fireclay brick seems like the easiest way to accomplish this. No special drill bit is necessary - even wood drill bits work because the stuff is not dense and very crumbly. Once you have that insulated pit/channel, just put the core inside and blow the temp-stabilized hot air into it.

verpies	Re: SEMP AI Smart Electromagnetic Generator (AISEG) « Reply #123 on: 2025-05-12, 13:11:27 »
Group: Professor Hero Member Posts: 3713	Quote from: Smudge on 2025-05-12, 09:13:00 Here is my paper describing experiments using the MnZn ferrite ring cores. @Anyone: What is the maximum remanent B of these MnZn ferrite ring cores ? @Smudge: Why does the primary need to be supplied with a current source? What's wrong with a switched voltage source ? @Smudge: Wouldn't it be better to switch-in the load resistor only after the primary current falls to zero ? Would the typical fly-back converter topology be applicable here ? In such topology, the primary and secondary currents do not flow at the same time.

Smudge	Re: SEMP AI Smart Electromagnetic Generator (AISEG) « Reply #124 on: 2025-05-13, 07:39:47 »
Group: Professor Hero Member Posts: 1996	Quote from: verpies on 2025-05-12, 13:11:27 @Anyone: What is the maximum remanent B of these MnZn ferrite ring cores ? 410mT at 25C and 340mT at 100C. Applied H = 1200A/m Quote @Smudge: Why does the primary need to be supplied with a current source? What's wrong with a switched voltage source ? That was simply the way my brain works in the magnetic domain which is current driven. Yes a switched voltage source is what people will use so I will add more to include the likely waveforms. And as we know the core details I will go into the actual voltages and currents to be expected. Quote @Smudge: Wouldn't it be better to switch-in the load resistor only after the primary current falls to zero ? Would the typical fly-back converter topology be applicable here ? In such topology, the primary and secondary currents do not flow at the same time. Yes, and that would yield the greatest COP.

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