Thevenin equivalent (symbolic circuit calculation)

In summary: You will see that the current flowing through the circuit is equal to the voltage across the resistor at node A multiplied by the sum of the impedances in series and in parallel at node B.
  • #1
Casper Hansen
13
0

Homework Statement


I have trouble to find the right procedure to transform the circuit below to a thevenin equivalent.
I am looking for a symbolic solution a step by step guidance of where to start and how to add/locate all the impedance in series and parallel in order to calculate the sum of Z seen from point A and B
upload_2018-10-1_15-35-42.png

upload_2018-10-1_15-35-31.png

The Attempt at a Solution


[/B]
I have a hard time see which impedance are in series and parallel, as Z5, Z4 and Z3 forms a star connection to GND?

upload_2018-10-1_15-42-33.png


Would the solution be to make a form of star/delta transformation of the circuit in order to calculate the circuit?
 

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  • #2
You have to define the nodes between which you want the Thevenin equivalent. Without that your question has no answer.

Also, we don't DO "step by step" instructions. YOU do a step by step analysis and tell us when you get stuck.
 
  • #3
phinds said:
You have to define the nodes between which you want the Thevenin equivalent. Without that your question has no answer.

Also, we don't DO "step by step" instructions. YOU do a step by step analysis and tell us when you get stuck.

My post have been updated with nodes A and B
 
  • #4
Casper Hansen said:
My post have been updated with nodes A and B
Then a first step of getting the Thevenin Equivalent voltage should be REALLY easy. What is it?
 
  • #5
phinds said:
Then a first step of getting the Thevenin Equivalent voltage should be REALLY easy. What is it?
If i know the voltage but need to find the sum of impedances in order to calculate the current
 
  • #6
Casper Hansen said:
If i know the voltage but need to find the sum of impedances in order to calculate the current
You did not answer my question.
 
  • #7
Casper Hansen said:
If i know the voltage but need to find the sum of impedances in order to calculate the current
You can find the current by using standard circuit analysis methods: basic KVL & KCL, Nodal Analysis, Mesh analysis... Take your pick.

Edit: Or, as you've stated, you could use a star-delta transform to begin reduction of the resistor network.
 
  • #8
phinds said:
You did not answer my question.
Sorry I did not quite get what you are asking for?
 
  • #9
Casper Hansen said:
Sorry I did not quite get what you are asking for?
"Then a first step of getting the Thevenin Equivalent voltage should be REALLY easy. What is it?" is asking you for the Thevenin Equivalent voltage. I don't see how I could have asked it any more plainly. What is the Thevenin Equivalent voltage, given the circuit you have drawn with the nodes you have drawn? Just LOOK.
 

What is Thevenin equivalent?

Thevenin equivalent is a method used to simplify a complex circuit into a single voltage source and a single resistance. It is used to analyze and understand the behavior of a circuit by replacing it with a simpler equivalent circuit.

How is Thevenin equivalent calculated?

The Thevenin equivalent is calculated by removing the load resistance from the original circuit and finding the open circuit voltage at the load terminals. Then, the equivalent resistance is calculated by shorting all voltage sources and finding the resistance between the load terminals. The open circuit voltage and equivalent resistance are then used to create the Thevenin equivalent circuit.

What are the advantages of using Thevenin equivalent?

Thevenin equivalent simplifies complex circuits, making them easier to understand and analyze. It also allows for easier calculation of circuit parameters such as voltage, current, and power. The equivalent circuit can also be used to predict the behavior of the original circuit under different conditions.

What are the limitations of Thevenin equivalent?

Thevenin equivalent assumes that the circuit is linear and that the behavior of the circuit remains the same when the load is changed. It also does not take into account non-linear components such as diodes and transistors. The accuracy of the equivalent circuit depends on the accuracy of the measurements and assumptions made during calculation.

When is Thevenin equivalent most useful?

Thevenin equivalent is most useful when analyzing circuits with multiple elements and when predicting the behavior of a circuit under different conditions. It is also useful for circuit design and troubleshooting as it simplifies the circuit and makes it easier to understand the effects of different components.

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