Looking for a sheet that resists

crashsite said:

There's no limit to posts or requirement to explain your technical skills. There is, however, an expectation that if a person is asking a question, they will make some effort to understand the answer. Even this latest post is merely a ploy to get some more attention. I am replying, not for you but, in the hopes that others here can see the shift of gears and the new direction you are trying to take your cry for attention.

Sorry, bud but, there's nothing new or useful in this new slant in your efforts.

If you truly do think this is an unfair characterization, you can easily show it by going back over some of your own questions and the answers and suggestions given and at least make some hints that you've taken the info given and tried to apply it to some semi-related problem.

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The only substantiation that is apparent to me of the claims that you say that you are making for others is one that might be a result of reviewing my own questions and the answers to them. There were three types of specific materials that were presented - and you don't know if, or why, or how much I researched any one of them. I'm interested in what a list of common natural - and artificial, materials describing the amount of energy required to move electrons to conduction bands might reveal about any type of natural occurring stratification of resistances in materials. I might also be able to use such a list to develop my game according to one design. It is not apparent to me how information about this list might detract from this site - or why any visitor to this site would be compelled to defend themselves as I have.

This thread feels like it's little more than a Turing test.

Triode said:

The answer to all of these questions is yes. But I still don't see why you are trying to make a device as complex as a MRI machine when you could just use some electronic pieces that take turns activating their position on a wire grid as found in a digital drawing tablet.

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I suppose I'm just interested in models. To answer the second part of your question, I started to make a wire grid. I ran into a couple of problems. First, it was really sloppy to make. The only way that I could neatly do the project was to space the wire far apart, which didn't offer much precision. Then there was the problem of how to make the game pieces connect to both perpendicur wires composing the grid. This led to mechanical difficulties that would have made the game difficult to opertate. I couldn't think of an algorithm that would allow me to use more than four wires indicating positions - and that might have been for wires that were parallel to one another in addition to perpendicular - I don't remember. I suppose that if I researched resistors more I might have come up with a solution - because the problem with the algorithm that I was using was that the tolerance of all of the reisistor that I had checked was too much. I thought about using potentiometers, but those seemed too complex for the project. Then I got interested in resistive properties of materials. An advantage of the grid, however, is that I planned on making it on top of a flat hinged transparent surface under which a map could be placed. I'd like to find a sheet that had an acceptable resistance and that was transparent. Maybe I could by expanding the list that I mentioned in a recent post.

jasonbe said:

I'd still like to see a model of what the resulting wave pattern might look like. This design does not have to be used for the game:

What would be the result of connecting a wire that had a length of some integer value times a wavelength to two points on a conducting cylinder, sheet, and sphere - having point and concentric circular sources of AC with the same wavelength, be in terms of wave patterns if the connections were not made a wavelength apart?

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Seriously...how do you not know this? Just look at a wave pool. THere's no difference between the two scenarios. It's just a travelling wave through the wire. THe red and blue waves, not the black standing wave.
https://en.wikipedia.org/wiki/File:Standing_wave_2.gif

The grid would not use actual contact with the part, it would use electromagnetic induction. Here's a wikipedia article on how current graphics tablets work. I usually study similar technologies if I am trying to create a new one, It's good to think outside the box, but you should atleast know what's inside the box. I would also look up "optical glyph tracking" there is existing source code for it that could help. Its what sony used in "Eye of judgement" which is very similar to what you say you would like to do.

blueroomelectronics said:

This thread feels like it's little more than a Turing test.

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That's an interesting comment. I could interpret in many ways. I can only think of two possible scenarios. One, you are the human. In this case you might be complementing me because I learn like a machine - or computer, or insulting me because I learn like a machine. I don't know. I suppose it depends on your view of machines. The other possibilty, that you are the machine, might lead to a total of four conclusions about both of us - at least that I can think of. What does your comment mean to me? Its puzzling, actually. First, I haven't thought much about how machines work. Second, in addition to being interested in learning, I am also working on a project. I would like to think that I would be able to be evaluated by criteria that could be used after the project was complete. Then again, if one considered work a project - and this project is just an instance of me working, then one question might be how to evaluate what determines what machines and humans work on - and then consider if and how they work on different things differently. I suppose a tool is a machine - but people determine how they are used. Do you think that computers have a will? Do you think that all people do, stated or not stated? Can a person attribute a will to another person. Can peoples' wills be characterized - like electron densities? I think of Heisenberg - and if so, perhaps these lyrics can be related:

Well let me tell you 'bout the way she looked
The way she'd act and the colour of her hair
Her voice was soft and cool
Her eyes were clear and bright
But she's not there.

Navigation is easier when you have a compass...

jasonbe said:

I suppose I'm just interested in models. To answer the second part of your question, I started to make a wire grid. I ran into a couple of problems.

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See, that's the sort of thing that helps a lot. It gives us some sort of mental reference about what you are trying to do and what you have done.

If you look at even a cheap LCD digital watch closely, you'll see a pattern that's bee printed onto the glass (the segments for the digits, the alarm icon, the AM and PM used when setting, etc.). You'll also notice that the pattern is transparent. It's essentially resistive and conducts the voltages to the liquid crystal material to twist it. Sorry, don't recall the material...some kind of oxide, I think.

In such tiny amounts, it's pretty high resistance but, since the crystal twists with voltage and not current, that's okay. In larger amounts, the material can be relatively low resistance. The same basic technology is used to laminate resistive heating elements inside the windshields of aircraft while keeping the windshield transparent.

Of course, the material is too delicate to be directly contacted by something like a game piece. But, it could be used as a grid in a transparent layer. I'm rather doubting the utility of that since it would likely make more sense to put a wire grid under the game board for the position sensing and just put a clear overlay of glass or plastic over the top.

The fact that digitizing tablets and LCD/LED/Plasma TVs and monitors and other X-Y oriented devices exist and are mass produced conclusively tells us that dealing with large, high resolution matrixes is not an unsurmountable feat. That's not to say that it's practical to do it in a home workshop, however.

As far as a "table" of resistive materials for sheets, I don't think you'll find one. Any attempt to make sucha a table would result in a table that's so large and cumbersome as to be unusable. You'd need to not only address every element and compound and mixture of every material with resistive properties, you'd need to include the method of application.

For example, gold. Is the gold evaporated on in a vacuum, atoms thick? Is it plated on electrically, microns thick? Is it applied as gold leaf? Is is rubbed on or silkscreened or printed or dipped or dusted? Is it pure gold or an alloy and if an alloy, how many table entries for the different alloying percentages (keep in mind that several other materials may be alloyed at the same time to the gold). Is the gold mechanically mixed with other materials and if so, how many table entries do you make for the different mixtures?

There are so many variables that the usual (and really the only practical) way to do the resistive properties thing is to give the basic properties of just the basic materials, and some of the more common variations. Then you have to take the information and "construct" the resistive properties for your specific materials, applications and methods. It sucks but, until somebody makes a pretty super duper computer program that can address every possible permutation of every combination of materials and come up with an accurate result, the table you seek wont exist. But, they did map the human genome so, maybe somebody's working on this one, too...

I've thought about the picture at File:Standing wave 2.gif - Wikipedia, the free encyclopedia. Would the model apply the same to AC and water waves - because it seems to me that the formation of AC waves have to do with electron repulsion that might be most at the center of the wave - and the formation of water waves has to do with expansion starting at the surface of the wave which later effects the interior.

Triode said:

The grid would not use actual contact with the part, it would use electromagnetic induction. Here's a wikipedia article on how current graphics tablets work. I usually study similar technologies if I am trying to create a new one, It's good to think outside the box, but you should atleast know what's inside the box. I would also look up "optical glyph tracking" there is existing source code for it that could help. Its what sony used in "Eye of judgement" which is very similar to what you say you would like to do.

Click to expand...

At this time I'd enjoy working on an inexpensive project that would therefore not involve the products that you have mentioned. Still, thank you for bringing them to my attention. Would you be able to tell me about what data structures the source code uses?

crashsite said:

See, that's the sort of thing that helps a lot. It gives us some sort of mental reference about what you are trying to do and what you have done.

If you look at even a cheap LCD digital watch closely, you'll see a pattern that's bee printed onto the glass (the segments for the digits, the alarm icon, the AM and PM used when setting, etc.). You'll also notice that the pattern is transparent. It's essentially resistive and conducts the voltages to the liquid crystal material to twist it. Sorry, don't recall the material...some kind of oxide, I think.

In such tiny amounts, it's pretty high resistance but, since the crystal twists with voltage and not current, that's okay. In larger amounts, the material can be relatively low resistance. The same basic technology is used to laminate resistive heating elements inside the windshields of aircraft while keeping the windshield transparent.

Of course, the material is too delicate to be directly contacted by something like a game piece. But, it could be used as a grid in a transparent layer. I'm rather doubting the utility of that since it would likely make more sense to put a wire grid under the game board for the position sensing and just put a clear overlay of glass or plastic over the top.

The fact that digitizing tablets and LCD/LED/Plasma TVs and monitors and other X-Y oriented devices exist and are mass produced conclusively tells us that dealing with large, high resolution matrixes is not an unsurmountable feat. That's not to say that it's practical to do it in a home workshop, however.

As far as a "table" of resistive materials for sheets, I don't think you'll find one. Any attempt to make sucha a table would result in a table that's so large and cumbersome as to be unusable. You'd need to not only address every element and compound and mixture of every material with resistive properties, you'd need to include the method of application.

For example, gold. Is the gold evaporated on in a vacuum, atoms thick? Is it plated on electrically, microns thick? Is it applied as gold leaf? Is is rubbed on or silkscreened or printed or dipped or dusted? Is it pure gold or an alloy and if an alloy, how many table entries for the different alloying percentages (keep in mind that several other materials may be alloyed at the same time to the gold). Is the gold mechanically mixed with other materials and if so, how many table entries do you make for the different mixtures?

There are so many variables that the usual (and really the only practical) way to do the resistive properties thing is to give the basic properties of just the basic materials, and some of the more common variations. Then you have to take the information and "construct" the resistive properties for your specific materials, applications and methods. It sucks but, until somebody makes a pretty super duper computer program that can address every possible permutation of every combination of materials and come up with an accurate result, the table you seek wont exist. But, they did map the human genome so, maybe somebody's working on this one, too...

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That's interesting. I was wondering about the laminate mentioned in a previous post. I know that they try to characterize substances by how light reacts to them. This may involve grinding up a substance, mixing it with a liquid, and characterizing the resulting wave map outside of the spectrum of the liquid part of the map. I don't know if it can be done with substances that are made of large compounds that wouldn't allow a lot of characteristic light to pass or substances that when disassembled would not react with light in a way that represented the unbroken bonds that were characteristic of the original substance. Its called spectroscopy. I was researching resistance - though I didn't get enough information to characterize the type of material that I need in this respect. And I don't remember any of the spectrum databases being able to be searched by conductivity - though there were many fields and I did not pay attention to all of their features. They did have chemical models, though. I would still rather learn about the resistance from structure - and I doubt that I would be able to infer a relationship involving resistance given many different models of compounds.

Someone mentioned earlier a linear relationship - though I'm not certain in which context. Does this type of relationship exist between resistance, distance, DC current, and a uniform medium? I've seen models of current diverging and converging at their sources - and I imagined that this had something to do with resistance. However, nothing to me suggested an obvious linear relationship.

At this point, I am reminded of all of the posts to this thread that criticized me for being motivated to receive attention. Now that I think more about it, perhaps they are right. I could just a easily have looked up this answer myself. But then, what is the purpose of this site - a place where people can turn when they have not found their answers in texts and offer their advanced knowledge? If that is the case, I may have been misusing this sight. However, I am still inclined to think of this site as a place where people can communicate ideas about electricity that does not have to be limited to specialized knowledge at any level.

jasonbe said:

I've thought about the picture at File:Standing wave 2.gif - Wikipedia, the free encyclopedia. Would the model apply the same to AC and water waves - because it seems to me that the formation of AC waves have to do with electron repulsion that might be most at the center of the wave - and the formation of water waves has to do with expansion starting at the surface of the wave which later effects the interior.

Click to expand...

You're thinking about it too much. THe basics of waves remain the same, regardless of what they are physically in the same way an oscillating RC circuit behaves similar to a vibrating spring and mass.

BTW, it's not electron repulsion that makes current flow. It's more to do with an electric field applying a force on the electrons.

jasonbe said:

At this point, I am reminded of all of the posts to this thread that criticized me for being motivated to receive attention. Now that I think more about it, perhaps they are right. I could just a easily have looked up this answer myself. But then, what is the purpose of this site - a place where people can turn when they have not found their answers in texts and offer their advanced knowledge? If that is the case, I may have been misusing this sight. However, I am still inclined to think of this site as a place where people can communicate ideas about electricity that does not have to be limited to specialized knowledge at any level.

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You are not these people. I can tell by some of the questions you are asking. If you did reading we would be explaining concepts to you, not walking through trivial details step-by-step. There's a difference between helping and teaching and both still require you to do your own thinking. Teaching quickly gets cumbersome on a forum, but not even that is happening here. What is happening is spoonfeeding- that's where you get an answer and take it exactly as is without attempting to expand on it in your OWN head.

Mechanical vs. Chemical

jasonbe said:

I know that they try to characterize substances by how light reacts to them. This may involve grinding up a substance, mixing it with a liquid, and characterizing the resulting wave map outside of the spectrum of the liquid part of the map. I don't know if it can be done with substances that are made of large compounds that wouldn't allow a lot of characteristic light to pass or substances that when disassembled would not react with light in a way that represented the unbroken bonds that were characteristic of the original substance. Its called spectroscopy.

Click to expand...

Liquid crystals don't actually react to light that way. It's truly a mechanical thing. The crystal is a polarizing filter. It physically twists under the influence of a voltage (piezoelectric effect) and, in doing so, changes its plane of polarization. The LCD display, incorporates a fixed, polarizing filter (at least in simpler displays) and the effect is the same as rotating two polarizing filters, one in front of the other. When the planes of polarization are the same, maximum light passes and when they are normal to each other, minimum light passes.

What you are referring to sounds more like the action found in self-darkening glasses that darken in the sun and then lighten up again in the shade. You;ll have to get another view on that action as I'm absolutely ignorant of how it works. But, I would be interested to see what others may write about it.

It may be nit picking but, isn't, "spectroscopy" the study of the different frequencies (wavelengths) of light and I suppose any other things that could be thought of as having a measurable "spectrum"?

Ebb and Flow

jasonbe said:

Someone mentioned earlier a linear relationship - though I'm not certain in which context. Does this type of relationship exist between resistance, distance, DC current, and a uniform medium? I've seen models of current diverging and converging at their sources - and I imagined that this had something to do with resistance. However, nothing to me suggested an obvious linear relationship.

Click to expand...

You may be referring to something like the way some people model operational amplifiers. I personally prefer to work out such circuits as voltage dividers but, a lot of people prefer to think of them in terms of current flowing into and out of nodes around the circuit.

Since the differential inputs respond to voltage differences and the output is usually a signal voltage that drives some current into a load, I've always felt that using the current model adds another step or layer to the solution. I'm sure there are some (perhaps many) that would rather violently disagree with me on this.

At this time I'd enjoy working on an inexpensive project that would therefore not involve the products that you have mentioned. Still, thank you for bringing them to my attention. Would you be able to tell me about what data structures the source code uses?

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I wasn't suggesting that you buy a tablet and modify it, I meant you should read about how they work and consider using those methods. They wouldn't be used if they weren't cost effective. You could actually get a busted one and use the parts from it, but I just meant to imitate the methods. The most common kind uses a grid of wires, and the pen has a magnet, as you may know when you move a magnet over a wire a current is induced. You can't get a piece to a location without moving it. Then you just detect like battle ship, if wire C and wire 5 had current induced then a piece moved over grid space C5. For the optical glyph tracking code, theres a lot of user created stuff out there, but what I looked at was a C++ 6.0 library. I don't recall the name but I found it pretty easily with a Google search, and if you want another format you can probably find it.

No Positrak differential here...

jasonbe said:

At this point, I am reminded of all of the posts to this thread that criticized me for being motivated to receive attention. Now that I think more about it, perhaps they are right. I could just a easily have looked up this answer myself. But then, what is the purpose of this site - a place where people can turn when they have not found their answers in texts and offer their advanced knowledge? If that is the case, I may have been misusing this sight. However, I am still inclined to think of this site as a place where people can communicate ideas about electricity that does not have to be limited to specialized knowledge at any level.

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Well, this does bring up a question (at least in my mind) of just what sort of "help" you are trying to get from it.

I wasn't going to mention this earlier but, I noticed fairly early on in this thread that you seem to have some lore of knowledge about different...how should I say...conceptual things but, no apparent desire to have them explained in detail. It all kept (keeps) leading back to the high-level conceptual stuff.

So, I'll just ask, point blank. Are we really pretty much "spinning our wheels" by trying to come up with practical info and scenarios based on fairly basic electrical and electronic theory and practice? The nuts 'n bolts of it, you might say.

dknguyen said:

You're thinking about it too much. THe basics of waves remain the same, regardless of what they are physically in the same way an oscillating RC circuit behaves similar to a vibrating spring and mass.

BTW, it's not electron repulsion that makes current flow. It's more to do with an electric field applying a force on the electrons.

Click to expand...

I can understand why it might not be appropriate to compare waves at a site whose focus is electronics. I have thought some about water waves and may take a risk of bringing them up later. I've been trying to understand the generation of AC from its source at a turbine. This might involve me looking for a thread that was specifically about AC. However, I haven't given up on using AC in the game. I'm not sure how many times a generator could reverse the direction of current per revolution of the turbine. However, would the electron flow be becoming more dense before the completion of a half rotation of the turbine if the number was twice? Or, is the spacing of the moving electons pretty much uniform in wide wires - and it is the electrons speeding up and slowind down that determines the cycle of AC? I had - and probably still do have, a lot of misconceptions about AC. However, if it is only during the maximum and minimum current flow - during the top and the bottom of the AC cycles, that the speed of electricity is near that of light, is it accurate that between these times the speed is zero? If so, would it be feasible to either increase the wavelength - to a distance of twice or more than the length of the game board, and decrease the amplitude of the wave enough so that changes in the speed of the electrons are slow enough so that they could be measured between points on the game board as an indicator of distance? Or would the speed of the electrons in this situation be too erratic?

crashsite said:

Liquid crystals don't actually react to light that way. It's truly a mechanical thing. The crystal is a polarizing filter. It physically twists under the influence of a voltage (piezoelectric effect) and, in doing so, changes its plane of polarization. The LCD display, incorporates a fixed, polarizing filter (at least in simpler displays) and the effect is the same as rotating two polarizing filters, one in front of the other. When the planes of polarization are the same, maximum light passes and when they are normal to each other, minimum light passes.

What you are referring to sounds more like the action found in self-darkening glasses that darken in the sun and then lighten up again in the shade. You;ll have to get another view on that action as I'm absolutely ignorant of how it works. But, I would be interested to see what others may write about it.

It may be nit picking but, isn't, "spectroscopy" the study of the different frequencies (wavelengths) of light and I suppose any other things that could be thought of as having a measurable "spectrum"?

Click to expand...

We may be talking about differnt things. I was not talking about LCD or glasses, though I wouldn't have wanted to discourage you from making those interesting comments. Its been a while since I learned about spectroscopy, so it may be a good idea to look for a confirmation of anything that I write. Spectroscopy is, I think, the study of light and frequencies. I think - but am not certain, that for each wavelength or group of wavelength that are controlled to pass through a substance, a resulting map of the effects of the substance on these wavelengths is used as an indicator of what the substance is. These maps are characterstics of the structure of component parts of substances. However, I'm not sure if this technique would work for the type of sheet that I am looking for because - though I have very little experience, I am not familiar with any experiments that invovled a type of metal that I can imagine being ground up for the type of test preparation that I am familiar with. However, results and interpretations of experiments or tests that involve bombarding the types of materials that may be useful for me to use as a sheet in the game in different ways - with different types of particles - radiation perhaps, might be useful to learn about for the purpose of the game board. How these particles react to the board might somehow be indicative of the resistance of the board to electricity.

I should probably get back to what you said in an earlier post about LEDs. One thing that occurred to me while I was thinking about workable materials is that if there is a specific resistance that I am looking for then it is probably associated with an amount energy that has to be transformed into heat, light, or something else. I thought about heat producing products that might offer resistances that I am looking for. The parts of an LED - that you mentioned, was the second thing that I considered that might convert energy into light via resistance - after a light bulb. However, I don't know if I have the knowledge or tools to readily use these materials. For example, I can't imagine myself building a sheet out of LED material. Do you have any ideas? There was a laminate that was mentioned that converted electricity into heat - maybe the type used as a defroster on windshields. However, I haven't researched the laminate because I was sceptical - perhaps incorrectly, abount how evenly the sheet had to be applied - if it had to be applied in liquid form, in order to get consistent levels of resistance per unit distance on the surface of the game. I am still looking for a premade sheet - though I may have to make my own. Shims are appealing, but I have found that some of them are made to be electrically resistant because they are building materials. Maybe a database about the heat or light released per distance and units of electricity might be useful. Earlier I was thinking that a useful database might include electon orbital information. However, heat and light might be easier for me to interpret in terms of resistance - than orbitals. I wonder if the spacing of the molecules has something to do with resistance to light or heat ratios - in addition to orbital information. For example, as I am looking for levels of resistance that are measurable with inexpensive equipment, would the heat or light - or changes in the amount of heat or light that vary with resistance, have to be perceptable? I really don't want my game board to be a heater or a light, but it may have to be. What else besides heat and light could resistance convert electricity into - if I am saying that correctly. Is there some type of solid flat material that on a very small imperceivable level turns resistance into chemical movement - and not so much heat or light? Though this is not only what I am looking for, what would be invovled?

crashsite said:

You may be referring to something like the way some people model operational amplifiers. I personally prefer to work out such circuits as voltage dividers but, a lot of people prefer to think of them in terms of current flowing into and out of nodes around the circuit.

Since the differential inputs respond to voltage differences and the output is usually a signal voltage that drives some current into a load, I've always felt that using the current model adds another step or layer to the solution. I'm sure there are some (perhaps many) that would rather violently disagree with me on this.

Click to expand...

I can't think of how an amplifier would utilze a sheet that has particular resistive properties. I was under the impression that when electricity was introduced to a sheet, the electrons might not only travel in a direction that completes the circuit but also deviate as a result of resistance. Though I may be wrong, I did not intuit the resistance offered by the material to be measurable in linear terms as the distance between continuous locations on the material where the circuit was connected was changed - because if I was interpreting the model of a flat material correcly the paths seemed to curve outward. I don't understand how the workings of amplifiers might relate to the workings of a device used to electronically identify locations.

You forgot to mention easy to assemble and cheap.