Mosfet Heating Circuits

[Harvey]

Hi Wayne,

Originally, the goal was to replicate the claimed 1700% gain and give support to that camp. Glen's apparatus was his best guess at reverse engineering the original so we could get as close to those parameters as possible. Part of that process was to use the same or nearly the same ratings in the battery capacity. Much discussion exists on this forum with regards to the interdependency of the battery with the inductive resistor with regards to the apparent power in the system. There is well over 30W in play in each cycle, but the best we ever dissipated was around 7W, so that gives you an idea of how much apparent power there is.

Eventually, if the real source of the energy is identified precisely, the batteries would be removed completely. It is very undesirable to make a device that is supply dependent in this way.

The theory on which the device is premised which alleges these gains, is completely independent of any power supply, frequency mode or material. In simple terms it simply states that vibrating an atomic lattice with the right energy level will knock electromagnetic particles loose from the structure that are forced to slow down and heat up. It is alleged that these particles trade superluminal speed for temperature. Supposedly, when the material lattice is disturbed in this way it decomposes at an atomic level. The ratio of atoms to degrees is claimed to be sufficient to allow an inductive resistor to act as a fuel source for many years with the goal of producing heat.

As far as I know, out of all the experimenters involved in this research, Glen has produced the closest thing to a genuine replication to date. It is unfortunate that the original data was riddled with inaccuracy that made it nearly impossible to get any solid results based on those figures. This is one case where the empirical process completely superceded the academic. However, the end result clearly impresses on us all the extreme need for accuracy in the scientific process if we ever expect a publication to be taken seriously by mainstream - there can be no loose ends.

One loose end with this circuit is the interjection of current via the Mosfet gate. Glen performed a very short test to help tie up this loose end, but in my opinion it was not quite enough to convince the skeptics. Two microseconds stacked up against hours is not a good ratio. Personally, I would like to see the auxiliary battery used to pump this current removed from the equation and I have stated this forcefully with no acceptance. The circuit must be self contained if we ever expect to get anywhere with it. Using pulse generators only trades the problem to another supply source, it does not alleviate it.

I was very encouraged by one experimenter, Groundloop if I recall correctly, who used a resonant feedback winding to feed his oscillator. This was a definite step in the right direction because it pulled the power from the same source and was nearly 99% reactive (little or no dissipation in the drive components). But his work was set aside as it deviated from the goal of replicating the original. Here is the problem, the original was rejected by mainstream - why would we want to repeat that process?

We need a new system that produces the same results using the same technology and that new system needs to eliminate all of the pitfalls previously encountered. Only then will this ever be taken seriously.

The simple truth is, the batteries Glen used depleted to less than 6V each in a 13 hour test of continuous heat output greater than 120° F (I don't recall the exact figure) and we could not equate a gain from that. But he stopped that test prematurely because of time constraints that demanded he recharge the batteries. The system was still putting out heat even at that low power input and so was considered robust in that regard as it could maintain a relatively constant heat output with a wide range of voltage.

You may want to look at an HHO heating system. The goal in this case is to allow thermolysis to occur. Water splits at above 2,000° C. Using an HHO flame to heat a material that will glow at that temperature will introduce an exothermic reaction which will self sustain. See this video: YouTube - HHO Welder by Aquygen (Part 2 of 3)
If I were going to design a new heating system it would be based on this technology.

The exothermic nature of orthohydrogen directly related to the magnetic orientation of the protons. Perhaps there is something to this superluminal magnetic speed transformation after all

Cheers,

[wayne.ct]

Hi Wayne,

... the heating elements of these resistors contain Nickle ... waste product is copper ... the scientists are seeking IP control ...

I understand your response and thank-you.

Ni + H yields CU + heat, etc. but what are the possible catalysts and triggers? I think the explanation will ultimately involve chemistry and physics. It seems a sufficiently fast rising potential of sufficient magnitude must be involved. Hopefully the necessary conditions are reasonably attainable, i.e. in my budget.

Have you tried isolating DC supply from the AC side of your apparatus with a "large" choke to gain accuracy with regards to input power? Or, is it your understanding that battery capacity effects are part of the system under test?

Let me expand on my question. I suppose it is really Glen's apparatus that I am talking about. What I am suggesting is to substitute a capacitor (electrolytic or other) for the battery supply and charge the capacitor in real time with the battery and choke configuration. In this way try to isolate the chemical effects, etc... Is that a bit more precise?

[Harvey]

Hi Wayne,

Thanks for the kind words

There is a difference between power (Watts) and energy (Joules) and that difference is time. 1 W x 1 s = 1 J.

When we look at these waveforms on the scope, we are looking at voltage. In order to get watts we need to convert the current in the circuit to voltage as well. These two voltage waveforms, one of which is the converted current, are then stored digitally by taking a snapshot of it. Any events that happen between snapshots are entirely lost.

Glen had access to a high resolution scope that divided the screen into 100,000 snapshots. Those were tests 21 and 22. Excel 2002 and earlier could not work with more than 64,000 snapshots of data. So I wrote that program in Access to specifically allow the evaluation of that data. It was then that we found some of these high power transitions as you mention. And we realized, that even with this high resolution, there could be others that we are missing in between snapshots.

It was hoped to get a real time analyzer arrangement with overlapping data logging so that smooth runs could be had to catch any and all of these interesting transitions, but it never transpired.

Once we have the voltage and current in our program, then the product of the two can be taken to get an idea of the supply power. That power averaged over time provides us with the approximation of input energy. The simple average as supplied by Excel was verified using the Simpson's Rule and the discrepancies were well below the margin of error for the system so we have a strong confidence that the analysis is correct, provided the voltage and current are correct.

So when we find a 300W peak in our power data it definitely raises some eyebrows. But at the same time it is quickly noted that the duration of that event must be factored to understand the energy contained within that envelope. These are very narrow events, but they are there and we do not know if they are averaged out, cumulative positive or cumulative negative because we simply did not catch them all to know. Had the test equipment not been recalled early due to unfortunate intervention, we may have been able to get more conclusive evidence in support of this circuit. However, the evidence seems to lean toward normal energy exchanges when factored over time. The simple truth is that current is flowing into the readings via the gate of the Mosfet and we also have battery drain. These two things need to be eliminated if we are to prove OU.

Because the heating elements of these resistors contain Nickle, I cannot help but wonder if this simple circuit is involved in the same process at some atomic level as that of Rossi's work:

Italian Scientists Claim (Dubious) Cold Fusion Breakthrough - FoxNews.com

You may want to look at his results as a viable direction for your goals. It is claimed that 15kW units are commercially available with an OU ratio of 800W:15,000W conservative. The waste product is copper. The cost to build one is unknown, and the scientists are seeking IP control.

If the electromagnetic fields are able to coerce electron capture within the metals of Glen's resistor and transmutation is happening, then this could be an answer as to how extra energy is found in the system. But there would need to be some electrolysis of water in the air to provide the needed Protons for the reaction, I would think. It is too bad we don't have the original resistors from the SA tests to do an analysis on - they may have stumbled on cold fusion without even realizing it It does make you wonder though, how much copper was in those resistors after they were run for a while

Glen may be able to help you with the setup if you want to try and replicate his results. Gad tried a different resistor of his own design and the calorimetry tests showed no OU. This may be a clue that ionic hydrogen is needed to precipitate the reaction and it may have been too difficult to get at it under water.

Cheers,

[wayne.ct]

You are not alone.

Hey Harvey,

I just wanted to let you know how much I appreciate what you are doing on this thread. I very much appreciated the video you posted at the beginning of last year, the one about Glen's test results. I just watched the whole hour of your commentary and then read and scanned through the rest of the thread. It was time well spent.

My goal is 10 to 100 watts output, no moving parts, OU watts-in vs. watts-out and under $100 in cost of parts. It looks like your MOSFET heater approach has a lot of possibilities.

I was particularly curious about the power rise of 30/300 units in 4 nanoseconds. Have you had any further thoughts on this? Perhaps you know that Don L. Smith claimed that better results were to be expected at higher frequencies, other things being similar?

It looks like you were at the limits of your 500 MHz scope. If 4 ns represents a 1/4 wave you would be in the +- 125 MHz region, I suppose? Perhaps you can relate this to the switching time of the MOSFET?

My name is Wayne. Thank-you for your consideration.

[Harvey]

Hi Harvey last time I used an AC transformer to the circuit. It gave greater heat to the resistor but after a while the tranformer burned out .
Experiments are expensive sometimes

You are not alone - that's why the manufacturers started stamping them with Volt-Amp (VA) ratings because people were burning them up

Have you ever wondered why a transformer uses VA but Resistive devices use Watts? All of the energy put into a pure inductor is returned to the circuit, none is consumed. The opposite is true of a resistive device where all of the energy is consumed. For more on these types of power see AC power - Wikipedia, the free encyclopedia

A transformer is a dual inductor and has the ability to transfer the energy to a resistive load. But there are two things that you don't want to exceed. The maximum voltage rating and the maximum current rating. If the voltage is too high, arcing can occur between the windings when the dielectric coating on the wires breaks down and begins conducting, gets hot and vaporizes. This leaves a hole where the arc jumps to the next wire (which is only spaced by the thickness of the coating on each wire) and the combination of heat from the arc and the high voltage will eventually short out many windings that way leading to destruction of the transformer. A similar thing happens when too much current is pushed through the wire and causes it to get hot. This leads decomposition of the dielectric coating and again arcing can happen if the spacing is too small for the voltages being used. More often though, the wires become soft and melt together (weld) under the extreme heat. The over current situation occurs because wire acts like a resistor, so we don't really have a true inductor unless it is made from a super conductor and even then there is still some resistance in the material but it would be extremely small.

I have a transformer here I'm looking at and it has numbers all over it. On the bottom it has 3 taps that say 0V, 100V, 110V followed by HT165 then across the top it has 6 taps labeled 0V, 8V, 10V, 12V, 14V, 16V and below that series a really big bold 5A. Then off to the left in a little box it says p110V s16V 80VA. Now I may want to run this at 240V but I don't know it can be run that high without breaking down. The HT165 is the part number, but it could also be a Hipot test number. If it was a Hipot number then for a certainty we could not exceed 165V. It is possible that Toyoden used the Hipot values as part numbers, but in this case it is not. Instead we find a relationship between the maximum secondary voltage (16) and current (5) and these two are placed together to get the HT165 part number. But if we click on the manufacturers PDF we discover that the transformer has an "inter-layer pressure" of 1.5kV. So rather than make assumptions regarding the (HT) label, it is always a good idea to check the manufacturers specifications.

Do you see how they determined the 80VA above? 16V x 5A = 80VA.

So since the breakdown voltage has been tested up to 1.5kV, I could use this at 240V as long as I observe the 80VA without fear of a dielectric breakdown. However, there is a real danger that the increased voltage will cause more heat in the winding that cannot get out. We can determine the primary current by taking 80VA / 110V = 0.727A. That is the normal rating and we expect the transformer to not get hot running at that. A quick look at my wire chart which is based on 700 circular mils per amp reveals that a 23 AWG wire will support that current and has a 20.4 ohms resistive load per thousand feet. It is clear that this transformer does not have seven thousand feet of wire in it (110V / .727A = 151.31 ohms) and 151.31 / 20.4 = 7,400 feet. That is all DC stuff. It is obvious that something else is dropping the voltage, and in this case it is the inductive reactance of the primary winding. So we cannot calculate the winding resistance unless we absolutely know the inductive reactance. So in this case, I measure the winding resistance and find it to be 3.7 ohms. This tells me that the real power dissipation of the primary winding is 1.955W (using the I²R formula) and I don't want to exceed that if I bump my voltage up to 240V because that is heat that can't readily dissipate from the device if it is more.

So how do I know if the transformer will draw more than 0.727A when I put the 240V on it with no load? I don't. It is reasonable to conclude that if 110V is causing a flow of 0.727A then it will increase when I put 240V on it but those are maximum load situations. Our concern is the no-load condition because if that will work, then all we need to do is adjust our load to keep things within range. A simple test is to put a 0.7A fuse in the primary circuit and test it no-load. We call this a smoke test (the smoke in this case is inside the fuse glass ). If the fuse doesn't blow and all seems good under no load, then we can put our meter in there and see how much power the primary consumes at 240V in a no load condition and whatever is left over (for the 80VA) can be applied to our load.

In the example transformer above we find a ratio of 6.875 : 1 on the 16V tap. How much voltage will that have if I use 240V on the primary instead of 110V? 240 / 6.875 = 34.91V. So how much current could I take out of the secondary? Let's say our smoke test showed that no-load was using 0.1A on the primary. That leaves us 80VA - (240V x 0.1A) = 56VA. I can now take 56VA / 34.91V = 1.6A This also tells me that I could put a 56W load on the secondary.

That's how a hobbyist or experimenter can re-purpose a transformer and minimize the possibility of burning it up.

Let's say we are working with some exotic switching circuit that produces wild and crazy spikes of unknown proportions and we don't want to blow our transformer that is rated at 1.5kV breakdown - what can we do to protect it? First, a fuse is a good idea. Secondly, we can use a 1.2kV MOV to clamp any spikes that exceed that rating. This will keep things safely 0.3 kV below our maximum rating. (See MOV-07D751K http://www.bourns.com/data/global/pdfs/MOV07D.pdf) So that is another way to keep things safe.

Unfortunately, sometimes our safety measures add extra levels of complexity to our designs that interact with or interfere with the desired function of the circuit. For example, the part referenced above has a 70 pico Farad capacitance and at certain frequencies can look like a short circuit even though the voltage is nowhere near the ratings. So everything needs to be considered when designing something from scratch.

[Guruji]

AC transformer

Hi Harvey last time I used an AC transformer to the circuit. It gave greater heat to the resistor but after a while the tranformer burned out .
Experiments are expensive sometimes

[Harvey]

Hi Harvey I did a heater as a hair dryer too to see if it gives more heat but not that difference I found.
I noticed that when using less resistance in ohms the resistor becomes hotter though maybe this contradicts what you've already told me but try it yourself with a 8ohm instead of 10ohm.
Yes I should use thinner gauge as you've said too.
Thanks.

It can be easy to miss some details in my writing when I don't emphasize them, sorry for that:

". . .smaller gauge wire will get hotter with the same amount of current flow."

In order to get the same current flow in a higher resistance wire we must increase the voltage. I suppose that in your test your voltage was constant and so the greater resistance caused a lower current flow.

In essence, what you proved empirically and what I stated are exactly the same thing but are expressed in different terms where your voltage is constant and my current is constant.

Try and get your current to be constant in both cases and compare the heat. Then using I²R determine the power in each case and plot the temperature to watt ratios. I think you will find that the smaller wire produces more heat for less power.

[Guruji]

Heater

Hi Harvey I did a heater as a hair dryer too to see if it gives more heat but not that difference I found.
I noticed that when using less resistance in ohms the resistor becomes hotter though maybe this contradicts what you've already told me but try it yourself with a 8ohm instead of 10ohm.
Yes I should use thinner gauge as you've said too.
Thanks.

[Harvey]

Hi guys did I read rightly in the past of this forum thread that if thinner wire is used for heater resistor it gets more hot?
Thanks

Yes, the experimental evidence by the resistor wire manufacturer shows that smaller gauge wire will get hotter with the same amount of current flow. The reason for this is that the smaller gauge wire has more resistance.

However, it should be noted that there is a surface area factor that relates to the ability of the material to dissipate that heat.

What I have not seen is some test that shows how the smaller wire will heat up the volume of a box compared to a large wire with the same surface temperature.

But there is a reason why bread toasters and hair dryers use small gauge wire. However, I have noticed that a large material does not cool down as fast when air moves across it. Instead of transferring the heat to the air, it is protected at the core of the material. This may mean that hollow heating elements could be better than solid ones. That way we get the greater surface area without the core conservancy.

[Guruji]

Heater

Hi guys did I read rightly in the past of this forum thread that if thinner wire is used for heater resistor it gets more hot?
Thanks

[Harvey]

Hi Harvey interesting about the modification you've made on the circuit I will try it. The 0.0047uf should be removed even the junction wire from 1n4148 to negative side I mean?
Thanks

The wire is actually being moved to the other side of the 1K resistor. This action allows us to remove the 1.5K resistor on the left and replace it with a straight wire.

The 0.047µF capacitor is completely erroneous to the operation of the 555 and if it were larger could actually lead to early failure of the chip when the full measure of its energy is discharged directly through discharge path internally. It serves no purpose in the timing. I suspect that the early technician either confused this with the .0033 µF or was attempting (incorrectly) to filter some noise. Another possibility is that the published schematic was purposely altered in an attempt to prevent actual replication thereby ensuring that any interested parties would come to the source for clarification. Whatever the reason, it's presence in the circuit is useless and apart from heating up the chip it has no impact on the operation.

Checking the original parts lists against the schematics reveals such discrepancies.

The reason for the proposed changes was to reduce the heat in the NE555 and lower the timer power consumption while eliminating two unnecessary components and offering a greater range of adjustment. Higher resistance in the timing circuit means less current.

NOTE:
There may be some slight differences between the calculated frequency values and the simulated or actual values due to the exclusion of the voltage drops in the diodes in the calculations. So as a disclaimer: Actual results may vary

But that's part of the fun of experimenting, comparing the reality to the expected and documenting the results.

[Harvey]

Hi Gad,

The timing is approximately 0.693 * R * C:
T in seconds
R in Ohms
C in Farads


So for for the time the waveform is high T(H), we have a maximum of 0.693 * (50,000 + 1,000) * (.0033 * 10^-6)

Then the time the waveform is low T(L), we have maximum of 0.693 * (50,000 + 100,000) * (.0033 * 10^-6)

For the minimums simply remove the 50,000 ohm pots from the two above calculations as if they were each adjusted to zero.

So we get the following ranges:
T(H) = 2.29 µs to 116.63 µs
T(L) = 330 µs to 495 µs

The frequency period is T(H) + T(L) and therefore the frequency in Hertz is 1/(T(H) + T(L)). Comparing the two extremes of Minimums and Maximums we get ((2.29 * 10^-6) + (330 * 10^-6))^-1 = 3,009 Hz or 3.0094 kHz for the fast end and ((116.63 * 10^-6) + (495 * 10^-6))^-1 = 1,634.98 Hz or 1.635 kHz for the slow end. Therefore the frequency range is 1.635 to 3.009 kilo-Hertz, which places the target of 2.4 kHz well within its adjustment range.

The (+) duty cycle is essentially a ratio of the period (T(H) + T(L)) = 100% to how long the output is high, T(H). So (T(H) / ((T(H) + T(L))) * 100 will give you your duty cycle in percent.

So let us set up a hypothetical situation where we have adjusted our T(H) to be 15 µs and our T(L) to be 405 µs. What is our frequency and what is our duty cycle? The frequency would be ((15 * 10^-6) + (405 * 10^-6))^-1 = 2,380.95 Hz or 2.4 kHz. Our duty cycle would be ((15 * 10^-6)) / ((15 * 10^-6) + (405 * 10^-6))) * 100 = 3.57% You don't actually have to convert the units for a ratio as long as all the units are the same (in this case microseconds) so 15/(15+405)*100 provides the same answer of 3.57%

That is why the discharge leg has a 100K resistor in it and the charge leg only has a 1K resistor in it. It was done specifically to keep the duty cycle down around 4%

Now that you understand how it works, can you determine what the duty cycle range is? Can you determine which components to alter to change the center frequency? How about to change the duty cycle range?

Changing the .0033 µF capacitor will shift the center frequency while keeping the same duty cycle spread.

Bringing the 100k resistor (discharge resistor - dR) closer to the 1K resistor (charge resistor Cr) will change the duty cycle spread closer and closer to 50%. If dR < Cr then the (+) duty cycle will be less than 50% if dR > Cr then the (+) duty cycle will be greater than 50%.

It is important to realize that when you change the duty cycle, you may be changing the frequency period as well. These are inexorably linked. Because these adjustments do in fact impact frequency, a common misconception is that they are frequency adjustments - they are not. Their primary function is to provide independent adjustment of the duty cycle, one is for the on time and the other is for the off time. Theoretically, if one is adjusted one way, the other should be adjusted the other way to keep the overall period the same.

[Guruji]

modified circuit

Hi Harvey interesting about the modification you've made on the circuit I will try it. The 0.0047uf should be removed even the junction wire from 1n4148 to negative side I mean?
Thanks

[gadh]

Hi Harvey
First, many thanks on the thorough explanation...
However i do not intend to start investigating the resonance ranges (no Mhz ranges for now) but my only goal is to prove COP>1 in the current circuit, a thing we discussed alot in the past posts.

i use now your modified circuit as you posted here:

http://www.energeticforum.com/64217-post1908.html

Also i want to know whether the freq. range of the following circuit version (the old one i used) is the same as your modified one and if not - what is the freq. range of it : (if you can give an easy equation how to calc. it it would be great)

http://www.energeticforum.com/64174-post1902.html

Many thanks,
Gad

[Harvey]

Hello Harvey.
i finally got my hands on a professional RCL meter , and measured my load resistor's RCL values. The device allows measuring at max. 100khz so that's what i've used:
R = 11.2 Ohms (I assuse its resistance, not impedance)
L = 23.36 uH
(at 1khz, L = 23.5 uH so we can assume that in 200-300khz the L would not change much as well)

parasitic capacitance between windings:
1 binding = 0.93pF
between 2 bindings = 0.83pF
between 3 bindings = 0.80pF

My question:
Since the load resistor in the first reported test was measured as 8.64uH, and mine is 3x greater , should i change the 555 frequency range acordingly (in order to seek properly for the right resonance freq.) ?
which values should i change in the 555 circuit ?

Thanks in advance,
Gad

Hi Gad,

I'm not sure what you mean by 'binding', but if your capacitance values are the values between turns on the resistor and you have 48 turns then I would expect the total capacitance to be 1/ ((1/c1) + (1/c2) . . .) up to 48. Thus if all of the turns have the same capacitance per turn (ct) between their nearest neighbors, we can use 1/ (47*(1/ct)) to arrive at the total capacitance of the coil because they are all in series with each other. So your measurements are a little confusing if the 'binding' means turns. I would expect 0.31 pF for 3 turns if any and all single turns were 0.93 pF between a nearest neighbor and an overall of 0.01979 pF for the entire coil. We use 47 instead of 48 because the capacitance is in the gap between the turns and their are only 47 gaps.

As far as the inductance goes, we cannot believe anything we have read unless it has been properly validated. The inductance of a coil is very specific to the geometry and the published geometries are simply incorrect and even impossible to achieve as stated, this has been openly admitted to. IIRC, the inductance was based on a calculation, not a measurement. So it is very good that you have actually done the measurement. I'd have to check my calculations, but I think your measurement is quite close to the calculation I arrived at for Glen's resistor.

Let us consider the self resonance of your resistor (the ringing frequency). This is the frequency that we would expect the coil to 'ring' at if it were solely connected to a battery source, raised to full current and then both ends of the coil were disconnected abruptly and simultaneously. The energy stored in the field would rush back into the coil causing an EMF to form on one terminal, and then that would setup a secondary event of causing current to flow through the coil in the other direction which creates a new reversed polarity field that when the current stops flowing would collapse and cause EMF to form on the other terminal. This process would continue back and forth until all of the energy is fully dissipated and that is what we call a decayed ringing or a damped sinusoid (See Laplace Time Domain f(t) damped sine equation here: http://people.seas.harvard.edu/~jones/es154/Laplace/Table_pairs.html and here:http://highered.mcgraw-hill.com/site...z80377_apb.pdf)

To calculate the expected frequency of that waveform we can use the resonance formula f = 1/2π√LC where L is Henries and C is Farads and f is Hz. Using your values, we have 1 / (6.2832 * (√(0.0000235 * 0.00000000000001979))) = 233,379,821.5 Hz (or 233.4 MHz). That's what we would expect if all other interactions were removed from the inductor.

However, in the MOSFET Heater preferred mode of oscillation we do not see a primary damped wave or inductive ringing pattern nor do we see primary frequency anywhere near 240 MHz. Even though we have seen frequencies displayed as high as 900 MHz, these have been secondary lower amplitude effects that are not considered to be part of the primary retriggering frequencies that are typically between 140 - 250 KHz. So obviously, we have something else happening here that is only partially dependent on the inductance of the resistor. A careful observation of Glen's waveforms will reveal that the energy contained in the magnetic field does not reverberate in the decayed ringing waveform mentioned above but rather it is fully dissipated within the first half cycle so that even the internal body diode does not get a chance to activate on the negative half of the cycle because the energy is already spent before it reaches the negative transition. This means that the energy to dissipation ratio is well matched in Glen's precise configuration. If the inductor were too large, then the energy stored in the field would be too great and negative ringing would ensue. If the inductance were too little then not much energy would be dissipated and the heat would suffer. When the ratio is well matched, all of the energy goes to heat.

We have already discussed the rise time of the current curve and the disadvantage of pumping current through the resistor after it has reached 99% of its peak value. At that point the inductor is fully charged, meaning that the field cannot take on any more energy and there is no longer any inductive reaction because the flux becomes static at that point. So once the curve levels off (or just before) it is time to turn off the MOSFET. At that instant, the resistance of the inductive resistor along with the capacitance of the MOSFET and the energy stored in the field all play a part in what is left to become the BEMF spike. The area of that spike is representative of the energy in it. If the MOSFET turns off fast, then the area is distributed as a high amplitude narrow spike. If the MOSFET turns off slow then the area is distributed as a low amplitude wide spike. Either way, the energy is the same. We do not want that energy to be passed through the MOSFET which at this point will look like a 2800 pF capacitor to ground. Instead, we want that energy to be reflected back through the resistor and fully dissipated in the coils so that no energy is left to form a reverse BEMF spike on the other end of the coil. I have noticed that in some of Glen's videos, the frequencies did shift enough that he lost that good match and some of the energy was wasted in the MOSFET diode.

This is why the retriggering (as described in other posts in this thread) seems to improve the function of the MOSFET heater, because it forces an early switching of the current and moves the duty cycle closer to 50%. There may be some clashing or collision of the energy in the coil due to the aperiodic operation as well. If a new trigger event begins before the BEMF has fully dissipated, then we end up with a current collision where the BEMF is moving conventional current back toward the battery (+) and the MOSFET turns on asking for current to be moved the other direction to the battery (-). The occurs because the inductor is acting as a separate energy source . Such clashes would create standing waves in the inductor which are well known to dissipate energy in antenna leads and load coils. The SWR (standing wave ratio) is typically kept as close to 1:1 as possible in those systems to prevent power loss. In the MOSFET heater we prefer just the opposite, we want the energy to dissipate in the heater coil and it is best suited to have it fully dissipated in a single half cycle.

If it's possible to disturb the vacuum and get energy to fall out of it, then I think these very narrow high amplitude BEMF spikes coupled with aperiodic magnetic confusion (SWR collisions) in the heater coil is a good way to shake it up and see what falls out.

Any actions above 10 MHz are also candidates for dielectric heating.

Plotting the curve of the MOSFET Ciss capacitive reactance (2800 pF) reveals that it becomes impedance matched with the vacuum (300 Ohms) at 189,470 Hz. Plotting the curve of the Heater Coil inductive reactance reveals that it does not match the vacuum impedance until it reaches 1.948836 MHz so it is unlikely that we are getting a resonant action there unless there is a slight shift in the values and we are aligning a subharmonic. Also, we find on the MOSFET capacitive reactance curve that it does not match the 11.2 Ohm resistance of the Heater Coil until it reaches 5.075093 MHz.

What all of these mismatched impedances tell us is that the MOSFET heater circuit is not a resonant system. If it were a resonant system it would have a near zero resonant impedance and an 11.2 ohm resistive impedance to the battery and would drain it with haste with a repetitive 2.14A draw at nearly a 50% cycle. That alone would dissipate 51 W of power in the 11.2 ohm resistor 50% of the time giving an average 25.5 W just sitting there resonating at a single frequency. This is not what we see happening in any of the recorded data available to us from 1998 onward. So the evidence is reasonably clear that this is not a resonant system - the specified parts just simply are not set up for any resonance. Not included here in these numbers is the wire and battery inductance and capacitance. Some of the high speed oscillations present in Glen's picture's could not be reproduced in the spice simulators until we added wire capacitance between the CSR and battery. So I was able to conclude that some of the interactions were related to the proximity of the positive and negative wires laying close to each other and having capacitance between them. However, those transitions were very small in comparison to the rest of the signal amplitudes and can probably be dismissed but I mention them here because those things can directly impact resonance.

Now, if by some arrangement you were able to reduce the effective capacitance of the MOSFET to 272 pF then it would be nearly impedance matched to both the vacuum and the Inductor for resonance 1.948836 MHz. You may want to try putting a 301 pF capacitor across a 1 Ohm resistor and place that assembly between the Heater coil and the MOSFET. The series capacitance of the 301 pF and the MOSFET 2800 pF Ciss would then be an effective 272 pF. The actual impedance of the entire system would be somewhere around 12.2 Ohms, but from a reactance perspective the inductor, the capacitor and the vacuum would be reasonably tuned and phase compensated. This last suggestion is purely experimental and deviates from the prior work done in this area. But is is a step toward a resonant system if that is what you want to experiment with.

The NE555 does not have a frequency range as high as 2 MHz and those parts that do have a range that high would need to be buffered to drive the MOSFET. So trying to push things up into that range could be problematic. However, you could use your existing 555 at a lower frequency multiple and try and strike the resonant system say 1/4 of the time (every fourth beat) and see if it syncs up. So if you set your NE555 for 487,209 Hz things could sync up on the 4th harmonic.

The frequency is a function of the charging and discharging of the timing capacitor. The pots and the series resistors control the RC constants involved. Diodes have been added to allow steering a separate charge and discharge timing. The capacitor charges from the supply line through that pot, resistor and diode and it discharges through pin 7 and the other diode pot and resistor. If you post a link here to the schematic you are using, I will specify the values and part numbers for your desired frequency range.