Har nogen kigget på denne nye fundamentale elektronikkomponent - memristoren:
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maj 2008, Fjerde byggesten i elektronik fundet med nanoteknologi:
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New Basic Element For Electronic Circuits: 'Memristor' Could Give Computers Memories That Don't Forget:
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Citat: "... This scientific advancement could make it possible to develop computer systems that have memories that do not forget, do not need to be booted up, consume far less power and associate information in a manner similar to that of the human brain. ... Chua argued that the memristor was the fourth fundamental circuit element, along with the resistor, capacitor and inductor, and that it had properties that could not be duplicated by any combination of the other three elements. ... ?To find something new and yet so fundamental in the mature field of electrical engineering is a big surprise, and one that has significant implications for the future of computer science,? said Williams. ..."
April 2008, Demystifying the memristor: Proof of fourth basic circuit element could transform computing
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Citat: "... As for the human brain-like characteristics, memristor technology could one day lead to computer systems that can remember and associate patterns in a way similar to how people do..."
( indlægssvar sendes til nntp://dk.teknik.elektronik )
De tre andre "fundamentalkomponenter" er lineære: En fordobling af spændingsamplituden for et harmonisk signal medfører en fordobling af strømmens amplitude.
Men Chua komponent er ikke lineær. Derfor synes jeg ikke helt at man kan sammenligne dem.
Citat: "... This observation provides a wonderfully simple explanation for several puzzling phenomena in nanoscale electronics: current?voltage anomalies in switching; hysteretic conductance; multiple-state conductances (as opposed to the normal instance of just two conductance states, ON and OFF); the often mischaracterized 'negative differential resistance', in which current decreases as voltage increases in certain nanoscale two-terminal devices; and metal?oxide?semiconductor memory structures, in which switching is caused by the formation and breakdown of metal filaments owing to the movement of metal atoms under applied bias. ... signal gain is not possible with a memristor ..."
Så det hjælper åbenbart på vores forståelse af visse underlige fysik/elektronik-observationer.
... signal gain is not possible with a memristor ..."
Her menes nok type-S negativ differentiel modstand?:
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Det må være dette:
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Citat: "...The element named "resistor" is really a resistor while the "negative resistor" is actually a voltage source, whose voltage is proportional to the current passing through it..."
?
Mon en model, der indbefatter memristorer, kan forklare hvorfor nogle hifi-folk kan høre forskel på forstærkere - selvom man hidtil ikke har kunnet måle betydende forskel med traditionel frekvensanalyse/Fourieranalyse?
Det kunne være interessant at undersøge?
Hvad med:
*keramiske kondensatorer eller elektrolyt kontra hifi-kondensatorer?
*lysnetsledninger kontra hifi-ledninger?
*"Gode" hifi-operationsforstærkere (f.eks. NE5534A) kontra LM741...?
*Transistorer kontra fets kontra elektronrør?
September 14, 1972, Tubes Vs. Transistors Is There An Audible Difference?
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Citat: "... Engineers and musicians have long debated the question of tube sound versus transistor sound. ... Over a period of several years we continued this rather informal investigation of the electronic sound problem. In the past, we have heard many widely varied theories that explain the problem, but no one, however, could actually measure it in meaningful terms. ... It is the listener's job to sort out the facts from the fiction. Electrical engineers, especially the ones who design recording equipment, can prove that there is no difference in tube or transistor sound. ... They do this by showing the latest specification sheets and quoting electronic figures which are visually quite impressive. It is true, according to the parameters being measured, that there is only a marginal difference in the signal quality. But are there some important parameters which are not being measured? ..."
The Vacuum Tube & the Human Ear By Keith Herron:
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Citat: "... To me, as an engineer, it seems inconceivable that a tube amplifier with a big old transformer at the output could sound better than a solid-state amplifier with no transformer. ... Much of the solid-state audio gear that I have heard, particularly the stuff that employs BJTs in the signal path, tends to sound more aggressive and harsh though the midrange and high frequencies. The sound stage generally has less depth, width, and height than that of its vacuum-tube counterpart. I have encountered a few designs that are exceptions to this and that makes me wonder if the sonic differences I have heard have more to do with proper or improper implementation of the various amplifying devices than with any guaranteed certain results of their use.
The worst thing an audio engineer can do is to assume that he or she knows much about the nature of human hearing. After all, the engineer who designed our hearing knows a few things we never will. ..."
Why Tubes?:
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Citat: "... Seems in 2003 vacuum tubes or electron valves are still best choice ... The negative feedback help to reduce the THD on paper at the same harming the dynamic range and adding upper level harmonics - very unpleasant coloration of the sound. ... but two or more stages feedback makes the system behave like a pound of soft dough - you pull one end but unpredictable getting thinner on the other end or in the middle and getting sticky. NF may create also unpredictable intermodulation and transient distortions, which is worse than simple reduced dynamic range. Music reproduced from such "all stages" deep NF amp sound machined and mechanical no matter tube or transistor /transistor is worse thou/. ... Some "new" tube designs, I've only heard about may use a some sort of magnetic field for extra regulation or "improvement"...but I haven't seen one yet. ..."
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Citat: "... The audible significance of measurable effects on signals is a continuing debate among audiophiles ... However, other audible differences in sound have proven difficult to define or measure, and it is difficult to explain these sound differences in words as the vocabulary available to describe sound is rather limited -even though the underlying sonic effects may be real. Audiophiles often use words like 'warm', 'liquid', 'smooth' and 'midrange magic' to describe the sound from tube amplifiers ... There has been considerable debate over the characteristics of tubes versus bipolar junction transistors. Some audiophiles have argued that the quadratic transconductance of tubes compared with the exponential transconductance of transistors is an important factor. This has not been proven ... Some high end tube amplifier designs also include vacuum tube rectifier circuits instead of modern silicon diode or bridge rectifier circuits. A cheap solid state rectifier does introduce audible noise into the circuit.[4] Audibility of the effects is disputed by many ... Audiophiles who prefer SET-amplifiers state that measured sound performance is a poor indicator of real world sound performance and distortion level is not the only criterion for good sound reproduction. ..."
Consumer and Designer Prejudices in High-End Audio: A New Way to Examine Them:
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Citat: "... It should also be noted that audio--high-end audio in particular--appears to be the only technological discipline suffering from the peculiar attitudinal syndrome analyzed above. You will not find automotive engineers, for example, claiming that one brand of spark plug (or ignition wiring or distributor) with exactly the same specifications and measured performance as another ?feels better? when driving, and certainly not that it makes the car go faster!
We are faced with so many real problems in audio design. It is time for the designers of audio electronics, when they are not accomplishing anything, to recognize it and move on to the solution of those real problems. ..."
Det er simpelthen imponerende at du kan svare dig selv 4 gange.....
Klaus
--
Modelbane Europas hjemmeside: http://www.modelbaneeuropa.hadsten.dk
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Men det kunne være interessant at måle, hvor meget memristans andre spoler, modstande, kondensatorer, mosfet og transistorer har.
Da det er en fundamental komponent, har alle komponenter memristans virkning - ligesom en kondensator har modstandsvirkning og spolevirkning (og memristorvirkning).
Alle kredsløb skal derfor modelleres med memristorer!
Noget af det der tilskrives (hystereseagtig) ulinearitet i en transistor kunne memristans?
Hvad med hysteresen i spoler og transformatorer med laminerede jernkerner - er noget af det memristans? En "ren" spole har ikke hysteresevirkning?
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