|Date: Fri, 15 Feb 2002
As far as I am aware, Sweet never filed a patent (the work, I think, was also a take-off or derivative of Gabriel Kron's negative resistor, built at Stanford University on a GE contract in the late 1930s). Sweet later worked for GE, and Kron was his mentor and patron. Kron's real work was held and never released, although I cite some quotations from Kron's papers to show he tried to get through the censors the gist of what he had done, including the "open path" between any two points in a circuit, whether there is any physical connection or not. Again, Kron never fully revealed the secret of his open path. I take a crack at it in my forthcoming book, but it's my "best estimate". So I don't think the Sweet VTA was independently patentable, though I may be wrong on that.
For the actual status, one would have to consult a good attorney. Sweet signed several conflicting agreements with different backers, none of which were ever "cleaned up". So in my view it's an area to be avoided, because it's a legal nightmare. Who needs such at my age? One can take the energy from the vacuum in a hundred ways, not just one. Sweet's way was indeed a very good way. There are also a hundred other good ways.
So it's a matter of the patent law on how an inventor must pursue his invention, and all that, and the interpretations of the various rulings that have been made over the years. Only an attorney can advise on all that. Sweet also was married, and so he left a widow. Depending on wills, state laws, and such, what results for the patent rights is again a matter for lawyers to determine. Even the lawyers may disagree.
The Sweet device has been partially replicated by at least four experimenters. Each succeeded in activating the magnets into self-oscillation, and in getting power out more than the input. Today, self-oscillation in magnetic materials is well-known in thin film work, but to my knowledge they do not do it at ELF frequencies as Sweet did, nor do they do it nearly so powerfully as he did. But the self-oscillation itself is known, and you can even purchase books on it. A typical example is V. S. L'vov, Wave Turbulence Under Parametric Excitation: Applications to Magnets, Springer Series in Nonlinear Dynamics, Springer-Verlag, New York, 1994. This includes self-oscillation in permanent magnets. Professor L'vov is or was with the Department of Physics, Weizmann Institute of Science, Israel.
One part of the problem is that the magnets have to be (1) barium ferrite, and (2) specially conditioned so that the barium nucleus is in self-oscillation with the adjacent vacuum, which acts as a semiconductor. A paper showing that the vacuum can indeed act as a semiconductor in certain case is Richard E. Prange and Peter Strance, "The Semiconducting Vacuum," American Journal of Physics, 52(1), Jan. 1984, p. 19-21. The authors show that the vacuum may be regarded as a semiconductor. In particular, the vacuum in the region close to the nucleus of a superheavy element is analogous to the inversion layer in a field effect transistor. The authors introduce the idea of the inverted vacuum. Just as a semiconductor may be manipulated by subjecting it to external fields, doping etc., it appears that so can be the vacuum. It appears that Sweet used this effect and special triggering techniques to stimulate the barium nuclei into very powerful self-oscillation with the surrounding vacuum.
These days, ELF oscillation in nuclei is also known.
So the major problem is to get a strong, stable self-oscillation established in the magnets themselves, before building the unit. Once that is done, the Sweet unit can be replicated. His first unit produced only 6 watts, but his second unit produced 500 watts output for a 10 Volt, 33 milliampere input. So that's a COP (if I didn't drop a decimal somewhere!) of about 1,500,000.
None of the inventors I know of who replicated it, ever achieved such a COP. To my knowledge, the longest they achieved the activation was about 6 weeks. At least one did light a 100-watt bulb or so, but the output decayed. Often the activation (by the others) would last only a minute or two, then a few minutes as they got better at it, etc.
And in my view, yes, the unit could be replicated and developed, but only by a very competent team having several disciplines.
Remember there are more than 200 known effects in magnetics, and only about half of them are well-understood. The rest are understood from "fairly well" to "somewhat" to "not at all". The "very strong type of self-oscillation" that Sweet achieved is, in my opinion, among the "understood a little bit" category. The typical electrical engineer who thinks of magnets only in terms of north and south poles, etc. is doomed to failure. Magnetism is very much more complicated than that; simply check any modern university text in materials science or in the magnetics phenomena of materials science. Another thing is that Sweet carefully chose his magnets from many surplus ones. Only about one in 30 has sufficiently uniform field from point to adjacent point, to hold the self-oscillation. That's a matter of manufacture, and in theory that could be licked. But finding magnets made to a 10% local variation or less is difficult, with what is available off the shelf.
So when one looks at the duplication effort, it would be quite costly (from the individual viewpoint). It will require an experienced materials science team, with specialists in a couple different branches of magnetics. Such folks exist, but not a great number of them.
Anyway, for me that was just experiences along the way. These days I'm totally committed to our own MEG, and so am concentrating on that.