But hey Mr. Rasmussen - we are all of course really interested and looking forward to the final, peer reviewed incl. measurements, report.
Really!
//
Really!
//
Well said, and as you know very well, only some of the electroacoustic transducer nonlinearities are just a function of the current and only those that are just a function of the current may be cured by a current drive. There are other nonlinearities that depend on a cone displacement, temperature etc. and these types of nonlinearities take place in the resulting distortion even under a pure current drive. So, the statement made here before by another member, that distortion measured at acoustical side is a copy of distortion in current, is simply incorrect. There are many distortion mechanism remaining even under the cleanest current drive. Wolfgang Klippel is the one who knows and who should be studied.
How about a diaphragm under complete control of the coil? There'd probably need to be two, one in the centre conventionally, and one at the edge instead of the surround. I seem to recall seeing something similar, unless I dreamt it. Like a dome speaker I suppose.
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I'll get you one for Christmas! Just look up in the sky on Christmas morning, you will see it there!
(You do know how to share, don't you?)
Sheesh, I figured antimatter would be the want..I guess it's old hat now..
With the co-wound vc's, the coil being used as the sense, when subtracted from the first will give only the real component of the driven coil's voltage. If you connect the two coils at the hot side (and out), the low side of the sense coil will float off ground by the exact amount of the real part of the drive signal. The subtraction will remove all inductance, all energy storage, all velocity, and will present only the current times the resistive losses in the speaker. The losses are the coil resistance, eddy losses, acoustic energy transferred to the air. with DSP, you can derive the pure in phase component of the losses, the remainder should be the non linear stuff.
What I like about this is it is a real time instantaneous value for the non linearities. It's not a measure of the acoustic distortion, but the magnetic system.
jn
With the co-wound vc's, the coil being used as the sense, when subtracted from the first will give only the real component of the driven coil's voltage. If you connect the two coils at the hot side (and out), the low side of the sense coil will float off ground by the exact amount of the real part of the drive signal. The subtraction will remove all inductance, all energy storage, all velocity, and will present only the current times the resistive losses in the speaker. The losses are the coil resistance, eddy losses, acoustic energy transferred to the air. with DSP, you can derive the pure in phase component of the losses, the remainder should be the non linear stuff.
What I like about this is it is a real time instantaneous value for the non linearities. It's not a measure of the acoustic distortion, but the magnetic system.
jn
Might already have it. Can't tell of course.
I forgot, we worked on the design of one of those liquid argon detectors. Major voltages there, hundreds of kv, the ladder multipliers were also immersed in the liquid argon. Some wacky stuff I tell ya.
I used to love the parody of Doc Emmit Brown.. Until it became evident that it was not parody, many of them are really really like that..well except for the Mr Fusion..
One guy actually had a Delorean. One day, he went to go home, but put his stainless thermal coffee travel cup on the top of the car. Forgot it, drove off with it balanced precariously on top.
I almost wet my pants...If only I had my cell phone ready to video.
jn
I have met many people so clever I can't work out how clever they really are who do things like forget to take their PJs off before putting their trousers on or should not be left with sharp objects. Others can fit into normal society without anyone even noticing...
If you understand German, a classic from the 70s:
< YouTube >
The children's play "We build a nuclear power plant".
Contains lots of cites that have made it into everyday language.
"Früher war mehr Lametta"
Gerhard
some people have way too much time on their hands. Now where is that recording of 'smoke on the water' played on a dot matrix printer 🙂
Not sure, exactly, but we mortals have to well, at least possess some humour. And there is a U in humour, no matter how much the us pidgin tries to ignore it.
found this, this 'morn.. it's relevant to many who peruse this thread. re copyright law and circuitry, and decisions handed down.
Reading now I see it is not in the US, but it may be that the logic process falls in similar ways. Finding actual cases that have gone forth and rendered decisions re circuits/drawings/etc, in the US, is a pretty tall order. Oddly enough.
What it seems to be saying, at first glance, is that a creative person might be able to find a different way to lay out a notably custom/novel circuit that is only covered by copyright.... and side step infringement cases.
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Did you read the decision? It let me once and then I couldn't go back. It read to me as exactly what the US code says. The infringement can only be of the layout as if it was photographically (or similarly) reproduced exactly, the same holds for IC masks. Nothing contained in copyrighted drawings or layouts protects any circuit or device ideas.
The decision was in favor of the defendant, the one held as being in infringement. Taiwanese law in this seems to be similar to the USA's versions, in scope and decisions. It all looks kinda Chiang Kai-shek-ish to me. (that US alignment-buddy thing)
Move some parts around, use a different 3-d arrangement when laying out the board, etc. I mention this as some are possibly in error in their understanding of exactly how much of a circuit is protected if they copyright but don't patent. I myself wanted to be more clear on this, than I was....
good discussion on the complex parameters and interactions
This stems from my cruising the audio side of ebay this morn. That shitstorm of Asian copies out there.
Move some parts around, use a different 3-d arrangement when laying out the board, etc. I mention this as some are possibly in error in their understanding of exactly how much of a circuit is protected if they copyright but don't patent. I myself wanted to be more clear on this, than I was....
good discussion on the complex parameters and interactions
This stems from my cruising the audio side of ebay this morn. That shitstorm of Asian copies out there.
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In general none, though you can patent things like strip line antennas (unlikely to not find prior art). Most of the laws are agreed upon via treaties and as opposed to what some here believe I would be surprised to find dramatic differences in these very basic issues from country to country. Don't confuse this issue with trademarks and fraud.
List of parties to international copyright agreements - Wikipedia
Yes, Scott is correct. US Copyright law protects a schematic diagram or a board layout only in its graphical sense, like a photo or painting. It does not protect the idea behind the schematic. Thus a photocopy of the schematic could violate the creator's copyright, but building the circuit and selling it as your own would not. To protect the idea of the circuit you need a patent. The internal layout of an IC is protected under a separate law, which is neither copyright nor patent, but borrows notions from both of those areas of the law.
George
George
What about when you make modifications to a PCB like cutting a trace. Normally you would need to get permission from the author before doing so in other copyright works.
Mark, I believe you're talking about droit moral, a civil law notion, which does not have a ready analog in US law. Droit moral protects the integrity of the artist's work and, as you mention, can be construed to prevent the owner of the work from materially altering the work. US copyright law would not prevent a person from cutting a trace on a PCB. Droit moral certainly might prevent the owner from, say, cutting up a piece of sculpture.
Erm... No! Why should it matter that one defaces their own purchased property?
Beyond that; Copyright law is (from experience) Largely unenforceable.
All moral indignations aside.
Only when Large/ V large sums of $$ are involved is it even remotely cost effective to attempt enforcement and even then it's a crap shoot.
Beyond that; Copyright law is (from experience) Largely unenforceable.
All moral indignations aside.
Only when Large/ V large sums of $$ are involved is it even remotely cost effective to attempt enforcement and even then it's a crap shoot.
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