OK, I thought people were thinking of 'normal' volume controls, not DC-driven versions.SY said:sub 20 Hz
What is 1/f noise like with these? Even a 'DC' control could hit problems if the control voltage is unstable.
SY,
This is the old COHERER argument (Coherer - Wikipedia, the free encyclopedia). Lots of interesting stuff occurs with small conductive particles sort of touching. The observations are quite old, the explanations have changed over time, but all the results are still pretty much OPINIONs.
The rubber matrix does a nice job of replacing the shaker!
ES
This is the old COHERER argument (Coherer - Wikipedia, the free encyclopedia). Lots of interesting stuff occurs with small conductive particles sort of touching. The observations are quite old, the explanations have changed over time, but all the results are still pretty much OPINIONs.
The rubber matrix does a nice job of replacing the shaker!
ES
SY
The interesting thing about the coherer is that the RF from the antenna would cause it to conduct enough to allow a static DC voltage across it to also conduct.
The issue that I think is still relevant is the actual start of conduction mechanism.
I also suspect you could produce an elastomer that has a tiny modulus of compression.
But I think we agree the dominant mechanism of changes in resistance of conductive rubber is as stated.
ES
PS I am still waiting for the samples found at Roswell.... !!!
The interesting thing about the coherer is that the RF from the antenna would cause it to conduct enough to allow a static DC voltage across it to also conduct.
The issue that I think is still relevant is the actual start of conduction mechanism.
I also suspect you could produce an elastomer that has a tiny modulus of compression.
But I think we agree the dominant mechanism of changes in resistance of conductive rubber is as stated.
ES
PS I am still waiting for the samples found at Roswell.... !!!
They may be, but the input from a musician or player is analog. The units I designed would translate pressure into a digital signal output to determine the loudness of a note (or drum strike) or to detect aftertouch. For video games, one often wants to translate pressure into a character attribute (like speed or tilt). If you've used the pressure buttons in an Xbox or played a DrumKat, you'll know what I mean. Aftertouch in electronic pianos is almost universally done with conductive rubber strips.
Practically speaking, aftertouch (mono or poly) isn't used for piano patches/programs since pressing on a standard piano isn't part of the design.
However, digital piano programs sometimes use other layers (sounds) such as strings or others, to come to life or fade in when pressure is applied to the keyboard.
Velocity or how hard/fast you strike the keyboard is the single most used/important controller for piano. Also, velocity is often used to bring in other voices- as explained above using velocity instead.
My guess at the coherer (and it is a guess) is that the voltage produced by the radio frequency is much higher than the DC placed across the device. I think it is just a very low current dielectric breakdown between the metal particles. Perhaps like a sintering action.
Tunneling in no way degrades the barrier does it?
Tunneling in no way degrades the barrier does it?
My guess at the coherer (and it is a guess) is that the voltage produced by the radio frequency is much higher than the DC placed across the device. I think it is just a very low current dielectric breakdown between the metal particles. Perhaps like a sintering action.
Tunneling in no way degrades the barrier does it?
The RF is lower voltage and current!
simon7000, I couldn't find mention of the voltage in that wiki article. I know spark gaps were used in early RF experiments. Those certainly were of a high voltage.
Yeah, but by the time the signals crossed the Atlantic Ocean they dropped a bit! The wiki article is a bit sparse.
The issue is that coherers worked and there still is not a complete explanation. As they are long obsolete there probably never will be, just folks claiming to know the answer.
Of course I have seen quite a few folks insist the effect can't happen, but that is a different issue.
Magic makes better movies than brain fodder :C
Anyhoo, I think quantum mechanics could be brought to bear on any activity if it is true that the universe is quantum mechanical in nature. (which is a prevalent consensus) The falling of an apple is of a "quantum" nature. What precisely determines the time and mechanism of the stem releasing? The "quantum tunneling" of an electron from one location in one cellulose molecule to another probable location?
My guess is that quantum tunneling does say something about the fundamental mechanism of electric flow through a conductive powder loaded insulator, but as a macroscopic effect it's just a buzzword description.
SY, how strongly does the loading fraction affect the resistance of the matrix? Is it something you need to have extreme control over?
Anyhoo, I think quantum mechanics could be brought to bear on any activity if it is true that the universe is quantum mechanical in nature. (which is a prevalent consensus) The falling of an apple is of a "quantum" nature. What precisely determines the time and mechanism of the stem releasing? The "quantum tunneling" of an electron from one location in one cellulose molecule to another probable location?
My guess is that quantum tunneling does say something about the fundamental mechanism of electric flow through a conductive powder loaded insulator, but as a macroscopic effect it's just a buzzword description.
SY, how strongly does the loading fraction affect the resistance of the matrix? Is it something you need to have extreme control over?
double prism evanescent wave coupled attenuator.
Ercol immediately withdrew all guarantees on my kitchen table's legs!
Tade
soot is a beautiful black.I think QM should be taught first.
Ian
I fear I have become a persistent existentialist,with a pragmatic approach to patents.
Simon
A QTC pill will conduct Dab radio antenna voltage.
DF96
sounds good to me,I've come to think QT is ubiquitous.
regards Max.
Ercol immediately withdrew all guarantees on my kitchen table's legs!
Tade
soot is a beautiful black.I think QM should be taught first.
Ian
I fear I have become a persistent existentialist,with a pragmatic approach to patents.
Simon
A QTC pill will conduct Dab radio antenna voltage.
DF96
sounds good to me,I've come to think QT is ubiquitous.
regards Max.
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SY, how strongly does the loading fraction affect the resistance of the matrix? Is it something you need to have extreme control over?
Very strongly; the means of dispersion of the conductors within the dielectric is also highly critical. If you look at conductivity versus loading, the curve resembles a sigmoid. You can reduce the slope of the transition point a bit by choosing the right mix of conductors (some high structure stuff can be efficacious) or doing something really oddball by loading in high percentages of a semiconductor- this will kill the volumetric resistance changes, but if you use the surface effect, you can get great repeatability and dynamic range. This trick was the basis for a few hundred million isometric joysticks and signature pads.
Ahhh...I see, so we can expect a QT amplifier schematic soon for this thread?....I fear I have become a persistent existentialist,with a pragmatic approach to patents......
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