Thevenin and norton theorem solved problems pdf

Where V TH is the open-circuit voltage between the terminals of the network and R TH is the impedance measured between the terminals with all the energy sources replaced by their internal impedances. Thevenin's equivalent circuit. To show Thevenin's equivalent circuit we consider a circuit with a complicated passive network driven by an energy source V s. This circuit will be replaced by an equivalent circuit with a voltage source V TH called Thevenin's voltage and impedance R TH called Thevenin's impedance.

To calculate Thevenin's voltage at first remove the load. When the load has removed the voltage across AB is equal to the voltage across the resistor R 2. So the Thevenin's voltage is. Now to calculate Thevenin's impedance at first replace the energy sources with their internal impedance and the load R L also disconnected. STEP 1. STEP 2. Fig 3. We have already removed the load resistor in figure 1, so the circuit became an open circuit as shown in fig 2.

So the same voltage i. Therefore 12V will appear across the AB terminals. STEP 3. Open current sources and short voltage sources as shown below. Fig 4. STEP 4. We have removed the 48V DC source to zero as equivalent i. STEP 5. This is shown in fig 6 i. Thevenin circuit with load resistor. STEP 6. Now apply the last step i. Calculate the total load current and load voltage as shown in fig 6. Now compare this simple circuit with the original circuit shown in figure 1. From this circuit, The current flowing through path AB, i.

The circuit can be redrawn as,. Your email address will not be published. Save my name, email, and website in this browser for the next time I comment. Enter your Email Address to get all our updates about new articles to your inbox. Table of Contents. Facebook Twitter Linkedin.

Post navigation Previous Previous. Now, we should find an equivalent circuit that contains only an independent voltage source in series with a resistor, as shown in Fig. Unknowns are and. It is trivial that the current of resistor is equal to the current of the current source, i.

Please note that it is not saying that is the voltage across the load in the original circuit Fig. To find the other unknown, , we turn off independent sources and find the equivalent resistance seen from the port, as this is an easy way to find for circuits without dependent sources.

Recall that in turning independent sources off, voltage sources should be replace with short circuits and current sources with open circuits. By turning sources off, we reach at the circuit shown in Fig. The resistor is short circuited and the one is open.

Therefore, their currents are zero and. Now that we have found and , we can calculate in the original circuit shown in Fig. It is trivial that. A much more easier way to find here is to use the current devision rule. The current of the current source is divided between and resistors. Therefore, Now, replace the current source with a voltage source as shown below and solve the problem. The answers are , and. Yaz is here. I am passionate about learning and teaching.

I try to explain every detail simultaneously with examples to ensure that students will remember them later too. View more posts. Please let me know if you need more explanation. Since the 5 ohm resistance is open circuited why would the current would go in 5 ohm resistance, the current will only flow through 2 ohm resistance, hence the Rth will be 2ohm. I also think that the Rth is 2 ohm because all the other resistances goes into short circuit.

You have replaced -1A current source to -1V voltage source that is why values you got are mismatched. Have you checked out this example?