Solving circuit with Thevenin's theorem

In summary, the conversation is about solving for voltage and current on R4 using Thevenin's theorem. The values given are U = 100V, R1 = 310, R2 = 610, R3 = 220, R4 = 570, and R5 = 200. The procedure for finding Rth and Vth is to put the circuit into simulation and determine that the voltage on R3 is equal to the voltage on R4, which is then used as the Vth. The theorem for current on R4 is IR4 = Vth / (Rth + R4), but the simulation showed an unrealistic value for Rth. The discussion also mentions the need to find Rth and V
  • #1
Simonkaa
2
0
Member advised to use the homework template for posts in the homework sections of PF.
Hey guys, I am supposed to solve for voltage and current on R4 using Thevenin's theorem here. Values are following:
U = 100V
R1 = 310
R2 = 610
R3 = 220
R4 = 570
R5 = 200

upload_2016-12-21_23-10-52.png

Now, I know I need to solve for Rth and Vth, so I put the circuit into simulation and figured out voltage on R3 is equal to voltage on R4, therefore that's my Vth. Although the theorem for current on R4 is
IR4 = Vth / (Rth + R4)
The simulation also showed current on R4 as 0.03 and pretty much my Rth would need to be as low as 12 to be suitable for this equation, which isn't possible given the current values for all resistors. Can anyone point me to the right direction? Thanks.
 
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  • #2
What have you learned about finding Thevenin equivalents? What is the procedure?
 
  • #3
gneill said:
What have you learned about finding Thevenin equivalents? What is the procedure?
That I need to find Rth and Vth first in order to calculate current and voltage on certain resistor
 
  • #4
Simonkaa said:
That I need to find Rth and Vth first in order to calculate current and voltage on certain resistor
Okay, but what is the procedure for finding Rth and Vth for a circuit?
 
  • #5
Simonkaa said:
That I need to find Rth and Vth first in order to calculate current and voltage on certain resistor
If you scroll down to the very foot of threads in these forums you will see links to older threads related to the current topic. Sometimes you will find help in posts in these earlier threads, but no promises.

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1. What is Thevenin's theorem?

Thevenin's theorem is a method used in circuit analysis to simplify complex circuits into an equivalent circuit with a single voltage source and a single resistance. This makes it easier to analyze and solve the circuit.

2. How do you find the Thevenin equivalent voltage?

To find the Thevenin equivalent voltage, you need to remove all the load resistors from the circuit and calculate the voltage at the open terminals. This voltage is the Thevenin equivalent voltage.

3. How do you find the Thevenin equivalent resistance?

To find the Thevenin equivalent resistance, you need to remove all the voltage sources from the circuit and calculate the total resistance between the open terminals. This resistance is the Thevenin equivalent resistance.

4. What are the advantages of using Thevenin's theorem?

Thevenin's theorem simplifies complex circuits, making them easier to analyze and solve. It also allows for the use of different load resistances without changing the original circuit. This makes it a useful tool for circuit design and troubleshooting.

5. Can Thevenin's theorem be used for circuits with dependent sources?

Yes, Thevenin's theorem can be used for circuits with dependent sources. The equivalent voltage and resistance are calculated using the same method as for circuits with independent sources, but the values may be different depending on the dependent source's characteristics.

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