Calculating total resistance?

[tomix]

Hi,

I am looking for an algorithm for calculating total resistance of a
circuit.

The circuit is repersneted using a graph where every edge represent a
resistor.


Thanks in advance

 

[John Larkin]

On Sat, 7 Jun 2008 03:27:25 -0700 (PDT), tomix <tomerdr@hotmail.com>
wrote:

Hi,

I am looking for an algorithm for calculating total resistance of a
circuit.

The circuit is repersneted using a graph where every edge represent a
resistor.


Thanks in advance

Google "circuit mesh analysis" or "circuit node analysis." The general
method is to write a heap of loop equations and solve; it's
essentially a matrix analysis thing.

http://en.wikipedia.org/wiki/Mesh_analysis

Real engineers seldom or never do this. Relatively simple circuits can
be solved by ad-hoc techniques, reducing series and parallel branches.
Anything more complex, it's easier to just crank up LT Spice.

There are simple iterative numerical methods to solve a general
resistor network, but they are compute-intensive, so you may as well
use Spice.

I prefer to design things that are easy to analyze. One often has that
option. With opamps being so cheap these days, it's easy to
orthogonalize things instead of making a minimal-components hairball.

John