I want to check solutions to various resistance calculation problems, by making a large, but not infinite model to see how close my answer is.

Stuff like the infinite lattice of 1 ohm resistors.

http://bwrc.eecs.berkeley.edu/Classes/icbook/SPICE/

the infinite lattice should be precisely solvable right? so you're just trying to do a check of you answer.

there should be a simple enough way of generating an answer to most questions like that, maybe with a simple script...

There's spice, which I found to be horribly unusable, and Xirinx, which was usable but *horribly* buggy. If there's a decent one out there I don't know of it

The infinite lattice of 1 ohm resisitors problem is something I think you'll only figure out with math, I doubt a practical electronic simulation toolkit has the ability to similate infinite numbers of components

Also its a hard problem, we spent half a semester studying the various laws of resistors and whatnot but I coudln't figure it out after quite a bit of puzzling, and I think that's because the solution is more math related than related to physical laws, quite unlike the practical sorts of problems you encounter in real life

I'm studying electrical engineering and we use PSPICE (a version of SPICE) for all our circuits modeling. It's a very powerful program once you get used to it. As far as I know, you can't use it to solve the infinite resistors problem; you'll probably need to rely on your own math skills for that.

http://www.electronics-lab.com/downloads/schematic/013/

it should be able to simulate a larg number of resistors, << infinite but large enough to get an answer.

i still think i'd write a script to figure out the answer, with a single recursive function call.

I was going to just make a fairly big lattice, to see if my answer was nearly right, at least.

If that's your plan, you should be able to do it very easily in PSPICE.

You came up with an answer? I'm quite impressed. What did you do?

a little bit of maths i imagine.

0─□─┬─□─┬...
□ □
0─□─┴─□─┴...

say you have a repeating set of resistors like this(each □ of resistance R, say), and you want to find out the total resistance Rt between the two '0's
you know that the resistance at any set of junctions is the same as the total (because it's infinite)

0─□─┬─¦─□─┬...
□ ¦ □
0─□─┴─¦─□─┴...
so the resistance after the dashed line is Rt, and then you just have to solve the maths in the usual way...

damn forum messed up my white space :(
the boxes on the second line are supposed to be connected to vertical lines.

is this for physics class?

haha i am so bad at that stuff

No, I was just amusing myself messing about with these things.

I've done a ladder of resistors
_
l-l
l-l
l-l
l-l
ad infinitum

And the same sort of thing
ad infinitum
l-l
l-l
l-l
l-l
Ad infinitum

I've also done those with rather than being one wide, n wide.

I have an answer for the full grid (like squared paper), but that one I think is wrong in some way that I cannot work out. If I can straighten out the Physics or Maths (not sure which) I'll try it with a cube lattice in 3 space, then try the n dimensional result.

Then there's also adding diagonals in, and other tessellations to play with.

"You came up with an answer? I'm quite impressed. What did you do?"

Power dissipated over whole component= Sigma (Power dissipated at each resistor)
Putting across a voltage of 1.
V^2/R=Sigma(v^2/r)
1/R=Sigma(v^2)

And then play about with the diagram to get the various potential differences across the resistors (in any loop the potential differences sum to 0)

once you have it generalised to an NxN square it should be easy to add the extra dimensions...


your way seems to have an extra power dissipation equation that i've never needed.
unless the extra dimension adds an extra variable... but i think you can do it in parts...

what was your answer for NxN 2-d infinite series

□--□--□--□--...
|.....|....|....|
□--□--□--□--...
|.....|....|....|
□--□--□--□--...
|.....|....|....|
....
actually in this (with □s as resistors and ignoring the .s )
what two points are you trying to measure the resistance between?

i love the 3 thing.

"There are 3 main points I'd like to cover: Immigration, healthcare, and social security."
lmao

I'm trying to measure between two adjacent points (ie along an edge).

The answer I had I have since disproved.

Ugh... spice (computer engineer, here)... I remember it well and the hours put into it in the wee hours of the twilight for labs that I care not to remember ;)

As I said... I'm a computer engineer who focused on software and AI... circuits were never much fun for me ;)