# Help needed, equivalent resistance of this circuit

Discussion in 'General Electronics Discussion' started by jrios, Jan 2, 2014.

1. ### jrios

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Jan 2, 2014
Need to know which is the equivalent resistance of this scheme between the points A and B and and how do you know it. Thanks in advance, I'm not able to solve this problem myself...

2. ### Laplace

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Apr 4, 2010
The given resistor network contains an unbalanced Wheatstone Bridge which cannot be solved by simple series/parallel analysis. The following web page, http://www.allaboutcircuits.com/vol_1/chpt_10/3.html, recommends solving the unbalanced bridge using mesh currents and provides an example. As an alternative there is a solution using node voltages for the general case shown in the pdf attachment. Note that the equivalent resistance is calculated as Req= V0/I0 = V0/(I1+I2).

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3. ### jrios

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Jan 2, 2014
Many thanks, Laplace! I didn't know about Wheatstone Bridges, so I had no idea how to solve it. Now i'll study the method in the pdf and will try to do it with mesh currents too. It's a tricky circuit I'm so glad I find a solution for this. Thanks again man.

4. ### eem2am

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Aug 3, 2009
you can shovel it into the free ltspice simulator and put a voltage across it and see what current flows from the voltage source...V/I will give you the resistance