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Looking for a sheet that resists

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jasonbe

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Are there thin sheets of material on the market that have resistance levels - comparable to resistors, which vary in a well defined relation to units of distance?
 
Are there thin sheets of material on the market that have resistance levels - comparable to resistors, which vary in a well defined relation to units of distance?

"telo deltos" paper?

Carbon paper?

The resistance is spec'ed in ohms per square, believe it or not.
 
Well hell, that makes sence. Never thunked of that :)
 
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Black anti-static polythene bags.
 
Could you help me find some "telo deltos" paper? I tried to find an internet translation - and did an internet search, and couldn’t find any. I’ve used carbon paper before and never thought of its electrical properties. However, the carbon paper would be exposed to rubbing and I’m afraid that this might change the carbon paper's electrical properties. The black anti-static polythene bags might work, but something more rigid would be better. Something transparent would be the best.
 
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Could you help me find some "telo deltos" paper? I tried to find an internet translation - and did an internet search, and couldn’t find any. I’ve used carbon paper before and never thought of its electrical properties. However, the carbon paper would be exposed to rubbing and I’m afraid that this might change the carbon paper's electrical properties. The black anti-static polythene bags might work, but something more rigid would be better. Something transparent would be the best.

Back in the 70s we needed to find the characteristic impedance of various shaped conductors. With this paper you paint the conductor shape on the paper with conductive ink and measure it with an ohmmeter. Using a scale factor gives you the impedance.
BDM (Braddock, Dunn & McDonald) corp. knew where to get this paper, and the correct spelling. With computers this kind of thing is probably obsolete unless it has other uses.
I hope this helps.
 
Back in the 70s we needed to find the characteristic impedance of various shaped conductors. With this paper you paint the conductor shape on the paper with conductive ink and measure it with an ohmmeter. Using a scale factor gives you the impedance.
BDM (Braddock, Dunn & McDonald) corp. knew where to get this paper, and the correct spelling. With computers this kind of thing is probably obsolete unless it has other uses.
I hope this helps.

It does. I’m going to check with BDM, if they are still in business. It might also be helpful if you could check the spelling or give me any other names that the paper might go by.
 
Can anyone help me out with some engineering terms that might help me search the internet for rigid sheets – preferably transparent, or paint that has a well defined rate of resistance per unit distance?
 
Can anyone help me out with some engineering terms that might help me search the internet for rigid sheets – preferably transparent, or paint that has a well defined rate of resistance per unit distance?

ohms per square
sheet resistivity
sheet conductivity
carbon
conductive coating
resistive coating
flexible
silvery
 
Graphite Rub

Are there thin sheets of material on the market that have resistance levels - comparable to resistors, which vary in a well defined relation to units of distance?

A "poor man's" solution is to grind up some graphite (or buy some graphite powder) and rub it into the surface of some paper. Depending on your application (precision positioning or just needing some varying resistance), it may or may not give consistent enough results.

At one time, I had experimented with this but, the results weren't great. I didn't really try to refine the technique.
 
Hi there,


Just to note, i tried some "Wire Glue" a while back and although it was pretty neat
stuff it did not have a well defined resistance as i think you are looking for.
It was resistive alright, but it varied quite a bit with temperature and bending
of the base insulator and stuff like that.

Perhaps you can tell us what you are trying to do or build or whatever so that
we might know of something else that would work...
 
Still hung up on that game board idea are we?
https://www.electro-tech-online.com/threads/structure-of-resistor-question.86145/
https://www.electro-tech-online.com...s-that-gives-them-resistive-properties.86422/

Are you just going to keep asking the same question over and over until someone tells you what you want to hear? Normally, when people run into problems like this in a project it's one of two things:

-It's impossible with current technology
-They are going about it the wrong way

There was oodles of respones with very in-depth discussion about why your implementation would not work the last few times you asked this question, as well as many alternatives.

To summarize what he is asking for people who aren't up to speed: He wants a resistive playing board with multiple conductive/resistive playing pieces. Placing the playing pieces on the board is supposed to change the resistance in that particular area of the board, and thus change the resistance seen by 3 contacts connected to the edges of the board. By measuring the change in resistance (or current flow) between these 3 contacts, he wants to monitor the position of all playing pieces on the board. Furthermore, he wants it to be transparent so he can overlay a "graphical map" of sorts onto the board.
 
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Still hung up on that game board idea are we?
https://www.electro-tech-online.com/threads/structure-of-resistor-question.86145/
https://www.electro-tech-online.com...s-that-gives-them-resistive-properties.86422/

Are you just going to keep asking the same question over and over until someone tells you what you want to hear? Normally, when people run into problems like this in a project it's one of two things:

-It's impossible with current technology
-They are going about it the wrong way

There was oodles of respones with very in-depth discussion about why your implementation would not work the last few times you asked this question, as well as many alternatives.

To summarize what he is asking for people who aren't up to speed: He wants a resistive playing board with multiple conductive/resistive playing pieces. Placing the playing pieces on the board is supposed to change the resistance in that particular area of the board, and thus change the resistance seen by 3 contacts connected to the edges of the board. By measuring the change in resistance (or current flow) between these 3 contacts, he wants to monitor the position of all playing pieces on the board. Furthermore, he wants it to be transparent so he can overlay a "graphical map" of sorts onto the board.

I might not try to delete the post until someone comes up with an idea or has specialized knowledge relating to the question that makes completion of this project a priority, and then even then I probably won't delete the post. I found the last two responses interesting. I think that the way that this site is indexed, some posts could belong in more than one forum.
 
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A "poor man's" solution is to grind up some graphite (or buy some graphite powder) and rub it into the surface of some paper. Depending on your application (precision positioning or just needing some varying resistance), it may or may not give consistent enough results.

At one time, I had experimented with this but, the results weren't great. I didn't really try to refine the technique.

Did you learn about graphite from a list?
 
Hi there,


Just to note, i tried some "Wire Glue" a while back and although it was pretty neat
stuff it did not have a well defined resistance as i think you are looking for.
It was resistive alright, but it varied quite a bit with temperature and bending
of the base insulator and stuff like that.

Perhaps you can tell us what you are trying to do or build or whatever so that
we might know of something else that would work...

I'm looking for a thin sheet of material that has a resistance level that varies as a function of distance up to a foot or so comparable to the resistance offered by a variable resistor.
 
Yes but you want it in two dimensions. X-Y

Are you suggesting that some sheets might have a thickness or other characteristic that will make it so that for some reason or another resistance in two dimensions might not consistently vary as a function of distance? I can't say that such sheets are not popular because I am not familiar with the market. However, I am also aware of no natural phenomenon that excludes material from having a certain resistance levels - including the ones that I'm interested in. Hopefully, someone will be able to direct me to something premade - or some things that are readily available and easily assembled.
 
You're still ignoring the fact that you can't keep track of more than one piece. Keeping track of one piece is already hard enough due to the minimal changes in resistance (and may not be implementable if you can't find a sheet of material with the tolerances you need).

But keeping track of multiple pieces is impossibile, even theoretically. Each set of resistances measured does not correspond to a unique set of positions on the board. It only works with one piece per board.
 
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You're still ignoring the fact that you can't keep track of more than one piece. Keeping track of one piece is hard enough due to the minimal changes in resistance already (and may not be implementable if you can't find a sheet of material with the tolerances you need). But keeping track of multiple pieces is a theoretically impossibility. You just have too many variables and not enough equations to solve them with.

I was thinking about how many possible locations might be identifiable for a given number of game pieces, and how this number of locations could be reduced if how pieces were drug rather than disconnectedly relocated was analyzed - or if the signals communicating locations were timed. I think that a part resembling a sheet could make this project worthwhile, however the resistive properties do not have to be inherent in the sheet – these properties could be an attribute of something else such as the coatings that were suggested earlier.
 
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I was thinking about how many possible locations might be identifiable for a given number of game pieces, and how this number of locations could be reduced if how pieces were drug rather than disconnectedly relocated was analyzed - or if the signals communicating locations were timed.

Varying the way you measure resistance between the contacts still doesn't resolve the fact that multiple pieces can be positioned multiple ways to get the same resistance reading becayse all playing pieces still influence each measurement all at once.

Neither does recording the resistance and position of playing pieces in various combinations because all playing pieces still influence each measurement all at once. By the way, there's no difference between dragging a piece across the board while taking measurements or placing it on the board at a slightly different location each time. You can only take discrete measurements at discrete locations, whether or not the playing pieces are moving continuously across the board. Besides, you wouldn't be able to drag it anyways since you would need to let the piece sit still to get an measurement of it's position before measuring the resistance. It's still going to produce a discrete reading either way. The only difference is how far apart on the board each measurement is being taken, and making the distance very small or very large does not solve the core problem:

All playing pieces still influence each measurement all at once. If you can't find a way around this, it's not going to work.

Might I also point out that if you did try to record all position-resistances for just 2 playing pieces and you divided the board up in a measly 10x10 grid or 100 locations, there would be 9900 possible combinations all of which you would have to move through? Increase the number of playing pieces or sectors by any amount and that combination will sky rocket even more. Of course, none of this would change the fact that more than one position is going to give you the same resistance readings.
 
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