I accidently stumbled onto the Fractor page on Wikipedia.
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I have never heard of these components, but the description seems curious. Looks remarkably similar to a snubber, except of course they are not sold on the basis of phase. I know people used to bounce signals around in quartz to get a large delay, and thermistors have been used as integrators in the past, but this appears to be something different.
The only link appears to be dead, and googling the term just turned up the Wikipedia page plus an Answers.com entry which was cc Wikipedia.
Do they really exist? If so, where can I find more info?
It looks remarkably like a hoax to me. I've never seen them (but who has seen everything?). But the part about it supplying both the P and D functions, and the fact that the author seemed to be claiming that the integral term is there to supply phase shift (It isn't. It's the infinite DC gain you want; the phase shift is an unwanted side effect).
Oh Jerry, it's late in the day, and I can't handle anything resembling obscurity. I don't see anything to your response except for the one sentence above. Be kind, and clarify.
I did a whois on the URL. It exists, but the contact email is for an undergraduate at the University of North Dakota. URLs are cheap enough to get one just for a joke.
Unless you've seen something like this before, _I_ still think it's a hoax, or at best someone who's severely optimistic about the uniqueness and utility of what they've found.
I did look -- your edits hadn't made it to the page when I posted my reply. Your comment is much clearer, now.
Incidentally, I cannot legally call myself an "engineer", at least for business purposes. A PE license is a grand thing for folks who do different work than me, but I rarely work at the intersection of regulations and technology. Its lack doesn't bar me from very many things that I'd like to do, and from nothing that I consider my core business.
On Tue, 05 Jun 2007 19:56:26 -0400, Jerry Avins proclaimed to the world:
It does to me too. I thought that it might be describing something I have seen to correct power factor in power generation but after reading the whole thing and the mention of PID makes me think that this information is not accurate or a hoax.
If it IS a hoax (and the Wikipedia entry doesn't make any sense to me too), rather than just nonsense, then it also made it to here:
"12:00-13:00 Gary Bohannan. @Engr203?Introducing a New Class of Electronic Circuit Element: the Fractor? Invited Lecture for ECE6800 Electrical Engineering Colloquium
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"and here:
Perhaps someone should ask Dr. Gary Bohannan of Wavelength Electronics, Montana? (Resume on slide-29, here: )
Kelvin B. Hales Kelvin Hales Associates Limited Consulting Process Control Engineers Web:
On reflection I am beginning to wonder if the problem is in the classification "Electronic component". It maybe that from a mathematical viewpoint you could have a systems "building block" (such as a summing amplifier, multiplier etc) that has certain characteristics and could be considere from a systems viewpoint as a component.
So you could make a component that implements the function, but conventional terminology would make that a "module" or an "integrated circuit" rather than an "Electronic component".
Looking at the history of the article I note that the other contributions of the original author suggest that he is more orientated towards applied mathematics than pratical electronic engineering, so possible confusion is perhaps understandable.
Even so, it would be a bit of a grey area. For example, ready made snubbers are sold as individual components, allthougth in this case Wikipedia (and textbooks) treat them as electronic circuits.
It is not a component you can order from a catalog and solder into a circuit. It can not allow the designer to specify an arbitrary phase shift. The device described is either a hoax or a deranged fantasy.
On Wed, 06 Jun 2007 12:03:23 -0000, Roger proclaimed to the world:
I had thought something similar about this but had not looked at the guys history. His comment about it being mainly used by control engineers, something about the way it was worded, lead me to this. I think you might has the right idea.
Well, they certainly believe it's true. The one presentation I found looked quite opaque -- if it's truly useful stuff I sincerely hope someone makes it a bit more accessible! In the mean time, I think I'll stick with traditional methods.
Whatever they believe, "The continuous nature of the differintegral allows a control systems designer to select an arbitrary phase angle of the response of their systems" is nonsense.
Moreover, "Before the invention of the fractor, control systems designers were required to scale a 90 degree phase lag with a 90 degree phase lead, in what is commonly known as a PID controller. The fractor replaces the ID (integer/derivative) terms of the PID with a single F term of the desired phase" shows a complete lack of comprehension of what a PID is all about.
There seems to be an unfortunate tendency in western culture to seize upon alternative control strategies such as fuzzy logic, neural nets, and now this, then blow it out of proportion.
I remember when fuzzy logic was billed as the answer to _every_ control problem that you could possibly want to solve, at roughly the same time that neural networks were billed as the solution to every problem in both control _and_ signal processing. It was getting so you couldn't read an article on either of those subjects without getting virtual spittle on your face from the wild-eyed enthusiasm of the writer.
As a consequence a lot of people shut a big iron door in the face of anyone who mentions either of these two subjects -- in spite of the fact that for some applications, fuzzy logic is a very successful design strategy, and there are even a few people who not only make money with neural nets, but make money for their customers, too (really! I know one of them!).
I'm wondering if this subject isn't going to wend the same path, with people who know the subject but are completely ignorant of traditional control feeling proud of themselves for presenting lame solutions to well-known (and far better solved) problems of traditional control. Should it happen, they'll alienate their audience the same way the fuzzy logic & neural network guys did.
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