series parallel circuit calculation

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The website given before didn't help me because all it show is simple series and parallel circuits. I have a parallel circuit with a jumper of 1 ohm from one side to onother and i don't know how to deal with it.
 
This circuit is neither a series circuit nor a parallel circuit. There is no simple formula that can solve it. If you click on the link provided by 480sparky just above, you will see that their "figure 2" is an exact match for your circuit, if you only set the value of the second voltage source "E2" to zero (i.e., replace it with a wire). I did not follow the subsequent links, so I do not know whether they showed a solution method. But perhaps that is a good starting place.

I know how I would go about it: by using the "Loop Current Method." That is how I would, if I would, but I won't (with apologies to "The Little Engine that Could").
 
Yes, its a wheatstone bridge.

Draw the center 1 ohm resistor as (2) 2 ohm resistors in parallel. Then it is divided into two delta circuits.

Then do a search for delta to wye conversions. Once you convert both delta's to wye's, you have a series parallel circuit that can be solved with simple combinations of resistors.

Steve
 
Steve -
never thought of that - interesting

Alex -
You have four equations and four unknowns. It's solveable. The four equations are the three nodes and the battery voltage.

It's just an algebra problem. Four simultaneous equations are a mess, but its just a grind. There are some matrix math techniques that make it a little easier.

Take a look at the setup.

carl
 
Steve -
Perhaps you could give me a resource for the Y - D transformation method for circuit analysis.

Alex -
Wikipedia is not an authoritive source. However, I suspect you knew that:cool:

carl
 
I found the conversions in my engineering reference manual. And as a bonus, there was an example of a wheatstone bridge. I guess thats where I learned that trick about splitting the resistor from.

http://i49.photobucket.com/albums/f252/Sragan/DeltatoWye.jpg

This is the easy way to solve it, for those of us who don't like doing similtaneous equatitons - I can't even spell that :)

My mistake. They don't split the center resistor. They just use it to make a single delta. Then the other two resistors just wind up in series. Even less work.

Steve
 
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If you know how to do a delta to wye conversion the circuit is very simple.
See attached file parallel ckts. Enlarge for clarity. Z1 = 0.22 Z2 = 0.55 and Z3 = 0.55. Ckt total of 1.23.
 
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Thanks, but I was looking for the derivation, not just the formula.

Good thing you guys found that, I had an error in my posting. Since you found the formulas, i won't repost.

Just curious, what did you get for the resistance?

I got 1.44 ohms. I've only got about 15 minutes in it (didn't use the D-Y conversion), so who knows how many errors.

carl
 
Alex electrical student said:
View attachment 963
I have this circuit where i know the voltage of 100 V DC and the resistance of the resistors. Is it possible to find the total resistance of the circuit and the amperage?
Click to expand...

I get 1.65 Ohms. Give me a dollar and I will tell you how I did it.

BTW, two equations, not four, and no conversions.

Nemmine, my answer can't be right!
 
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