I suspect that Nelson, Charles and I are reasonably familiar with what works and what does not. I stopped with the 'patent' approach when several audio companies ran with my patented design, and gave me NOTHING, except that it was an 'obvious' approach to the problem it solved. (Yeah, sure!) It only took me almost 3 years to 'impress' its originality on one of them, in their own offices. Then, it became 'obvious'. Trust me, that is the way of things.
That's right. When you patent something you are effectively giving away your intellectual property especially if you are an individual or small company and your invention attracts a large company who will offer you crumbs or just steal it and dare you to sue them. They will bankrupt you in legal fees and exhaust you dragging out litigation for up to a decade or more. I've terminated preparation of seven additional patents on my ideas, I'm sorry I obtained even one patent on it already. I have a working prototype that's well disguised. If someone is interested they will get a demonstration and that's all until I see some money.
That has been quite different than my experience with the patent system. I pray to be ripped off by a big company- litigation attorneys drool at the prospect of going after someone with deep pockets, and juries tend to be sympathetic to the little guy in cases like that. It's getting ripped off by small players that causes the most grief.
Lawyers do not like taking on patent infringements cases on contingency. They are much too speculative. If you are going to sue, you'd better have plenty of cash ammo for your war. You'd better be prepared to wage a long battle too. Advice from two different attorneys when there was an infringement on part of my patent...don't sue. Estimated legal cost 20 years ago was $125,000 and up to a decade of litigation with delays and appeals. I'm glad I took their advice.
If the defendant has deep pockets, they love it. I talk from experience here.
$125k, if you have to pay, will get you through the first month. Figure $500k just to get to your first hearing in front of a judge.
depends on how good the advertising was...after all people won't buy unless they know a lot about the product...
Not in my own experience. I read neither reviews nor advertisements and often even not the technical specs before purchasing gear to my sound system.
How could you have overlooked the actual key point that Malcolm stated:
"Modulating the OL transfer function
means you modulate the circuit’s
closed-loop (CL) phase shift. What is
interesting is that it looks remarkably
similar to correlated jitter; they share
a family resemblance (Fig. 3). It also is
similar to what people have been talking
about as dynamic-phase modulation in
amplifiers."
Now maybe I am just dense, but when he speaks of "dynamic-phase modulation" it sounds to me like he is saying PIM in an erudite fashion.
So Malcolm is saying that adding feedback increases the PIM of a circuit. John has been saying the same thing for years, yet he is harassed, mocked, and treated with derision for it -- sometimes by you.[snip]."
You're apparently missing my and several other's point and seem to have so for some time. Feedback can generate PIM, but PIM is also present without feedback. Feedback can also decrease the PIM that is present without feedback, in open loop. So it depends on many factors whether rthge application of feedback actually results in more or less total PIM.
You misrepresent me and several others grandiosely. The discussion was whether degeneration was a form of nfb; the discussion was NOT whether nfb is the same as degeneration. I did not attack anyone, I did not 'demand' anything, although I agree that a discussion between Bruno and Nelson, both individuals which can discuss an issue straightforward and factually, would most probably give valuable insight. That is why I said I was 'eagerly awaiting an LTE'. Not the way you misrepresent and twist it around, for whatever reason.
jan
Ok as the guy whose has spent around 10^6 dollars on lawsuits, there are no winners. Lawyers may get money for their time, but getting to that point requires lots of work and time. Lawsuits are competitions, hard work wins. I find contingency fee lawyers are better at some types of suits.
But I really would rather have my money and time back.
Bose sues Harman every so often and wins big money on patents that were well written but probably not new!
Now right now I have two products that are worth a lot of money. One will replace the Corcom style filters with a lower cost and more effective product. The other will save insurance companies 20% of their payouts. Instead of developing these I will work on a third product well related to my field that should be quite profitable. It is a better choice as I know most of the ins and outs and the major players.
Charles,
Nice to hear from you, keep dropping the secrets, it is nice to actually see some progress!
ES
But I really would rather have my money and time back.
Bose sues Harman every so often and wins big money on patents that were well written but probably not new!
Now right now I have two products that are worth a lot of money. One will replace the Corcom style filters with a lower cost and more effective product. The other will save insurance companies 20% of their payouts. Instead of developing these I will work on a third product well related to my field that should be quite profitable. It is a better choice as I know most of the ins and outs and the major players.
Charles,
Nice to hear from you, keep dropping the secrets, it is nice to actually see some progress!
ES
Jan,
Bruno P. I think has acknowledged the weakness in his presentation when he mention the distortion of distortion or something similar. He does not consider it to be a serious omission, others may disagree.
As to the discussion over degeneration vs. feedback, this is getting silly. It used to be ignored as not really being the type of feedback as in the original H. S. Black article. http://www.audioxpress.com/magsdirx/ax/addenda/media/Bell-Feedback.pdf
Many argued that since it does reduce gain it must be feedback. In Black's paper the cathodes of some of the circuitry shown do have cathode resistors and he does not refer to this as feedback. He clearly shows the "Global" feedback as THE feedback!
So if someone wants to argue it is feedback, that is correct and expands the definition. But to be clear I suspect I and others really need to call it (Black's version) global feedback. Local feedback I think today means global feedback around one of a series of amplifier stages, and the global is used to refer to the feedback around the whole mess.
ES
Bruno P. I think has acknowledged the weakness in his presentation when he mention the distortion of distortion or something similar. He does not consider it to be a serious omission, others may disagree.
As to the discussion over degeneration vs. feedback, this is getting silly. It used to be ignored as not really being the type of feedback as in the original H. S. Black article. http://www.audioxpress.com/magsdirx/ax/addenda/media/Bell-Feedback.pdf
Many argued that since it does reduce gain it must be feedback. In Black's paper the cathodes of some of the circuitry shown do have cathode resistors and he does not refer to this as feedback. He clearly shows the "Global" feedback as THE feedback!
So if someone wants to argue it is feedback, that is correct and expands the definition. But to be clear I suspect I and others really need to call it (Black's version) global feedback. Local feedback I think today means global feedback around one of a series of amplifier stages, and the global is used to refer to the feedback around the whole mess.
ES
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Ed, yes can look at it from different angles. What is important for me is that everything you can say about what we call feedback, the similarity of effects and equations, can also be said about degeneration, and for me jxc has shown that convincingly. So my opinion is that degeneration is a form of negative feedback but of course it is not identical to global feedback or local D-G or C-B feedback. It also, I must say, appeals to my view that at a higher level nature often re-uses the same concepts, although that is hardly a hard engineering datum
But yes, it looks different and maybe the effect on the stage performance is different (which doesn't contradict the fact that the equations etc are similar); I haven't followed that particular part of the discussion very closely.
The fact that Black didn't mention it as such doesn't make it not so - Black was the pioneer, the forerunner, and in fact had invented feedforward a decade before feedback! So it would only be natural if later, people who stood on Black's shoulders would have completed the picture.
jan
the "historical piroity" arg ...need I mention Phlogiston?
degeneration is a fine term, describes useful circuit topologies that did predate Black’s “invention” and subsequent development of negative feedback theory
but degeneration shouldn’t be distinguished as separate, unrelated, not described by "negative feedback" for the purpose of confusing the buying public with the "No Feedback amplifier" label
extending the audiophile Marketing "win" for the "No Feedback" categorization into actual circuit theory discussions, circularly claiming the superiority of "nfb" because the reviewers have been sold on the "story" is a disservice to people wanting to learn how to design, analyze circuits for DIY
degeneration is a fine term, describes useful circuit topologies that did predate Black’s “invention” and subsequent development of negative feedback theory
but degeneration shouldn’t be distinguished as separate, unrelated, not described by "negative feedback" for the purpose of confusing the buying public with the "No Feedback amplifier" label
extending the audiophile Marketing "win" for the "No Feedback" categorization into actual circuit theory discussions, circularly claiming the superiority of "nfb" because the reviewers have been sold on the "story" is a disservice to people wanting to learn how to design, analyze circuits for DIY
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As I said the argument is silly. Degeneration is a fine name for cathode resistor type issues. Global feedback is a more precise name for Black's version. Local feedback is stage feedback that is not degenerative.
A cathode resistor is providing feedback, but Black did not mean that when he wrote his papers so using a different name keeps the historical perspective, and is technically accurate.
Does that clear up what I wrote?
A cathode resistor is providing feedback, but Black did not mean that when he wrote his papers so using a different name keeps the historical perspective, and is technically accurate.
Does that clear up what I wrote?
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