How to calculate R thevenin (Circuits)

In summary, Rth (Thevenin equivalent resistance) is calculated by visualizing the path of current and finding the equivalent resistance of the resistors that the current travels through. In the given scenario, the current does not travel through branches containing R2 or R2k due to a short circuit. This means those resistances can be omitted and the remaining circuit can be analyzed using mesh or nodal analysis to find the Thevenin equivalent resistance.
  • #1
Miike012
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I am not understanding how Rth is calculated..

What I've been doing is visualizing the path that the current would make. Rth is then the equivalent resistance of those resistors that current travels through.

Is that how it's suppose to be done?

Anyways... if you look at my pictures... the current can take the paths:
Left picture: Current does not travel through branch containing R2 or R2k due to short circuit.

Right Picture: Current travels up to point a where the current is divided through branch containing R1 and branch containing R2.Can someone help me with a general approach for finding Rth?

Would it help if I labeled the node voltages and then proceeded on finding Rth? Because I can see that current would not go through R2 because the potential through that branch is zero.
 

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  • #2
Can you do mesh or nodal analysis to solve those circuits cause I can do that for you but forget R thevenin.
 
  • #3
You have the right idea.

Miike012 said:
Left picture: Current does not travel through branch containing R2 or R2k due to short circuit.
There is no current through R2 or R2k because the voltage across each is zero due to the short circuit.

So you can redraw the circuit omitting those two paths (replace the resistances by open circuits), and examine what this leaves you with.

There is not much remaining of the circuit in this particular case.
 

What is the purpose of calculating R thevenin in circuits?

The purpose of calculating R thevenin is to simplify a complex circuit into an equivalent circuit that is easier to analyze and design. This equivalent circuit can also be used to determine the maximum power transfer in the original circuit.

How do I find the value of R thevenin?

To find R thevenin, you need to first remove all voltage and current sources in the circuit except for the one you want to find the equivalent resistance for. Then, you calculate the resistance across the terminals where the voltage or current source was removed. This value is the R thevenin.

Can R thevenin be calculated for any type of circuit?

Yes, R thevenin can be calculated for any type of circuit, including linear and non-linear circuits. However, the calculation method may differ depending on the circuit's complexity.

What are the limitations of using R thevenin in circuit analysis?

One limitation of using R thevenin is that it assumes the circuit is linear, which means the relationship between voltage and current remains constant. If the circuit is non-linear, the equivalent circuit may not accurately represent the original circuit's behavior.

Can R thevenin be calculated for AC circuits?

Yes, R thevenin can be calculated for AC circuits using the same method as for DC circuits. However, the values of the components may vary due to the frequency of the AC signal, which may affect the accuracy of the equivalent circuit.

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