Thevenin equivalent example problems. Thevenin's Theorem with solved problem 2022-10-17

Thevenin equivalent example problems Rating: 8,2/10 1833 reviews

Thevenin's Theorem is a powerful tool for analyzing electrical circuits and determining the equivalent resistance and voltage of a circuit. It allows us to simplify a complex circuit by reducing it to a single equivalent resistance and voltage, making it easier to analyze and solve problems. In this essay, we will explore several example problems that demonstrate how to use Thevenin's Theorem to solve for the equivalent resistance and voltage of a circuit.

One common use of Thevenin's Theorem is to determine the equivalent resistance and voltage of a circuit when given a load resistance. For example, consider the following circuit:

[circuit diagram]

In this circuit, we have a voltage source V, a resistance R1, and a resistance R2. We also have a load resistance R3, which is the resistance we are trying to determine the equivalent resistance and voltage of. To solve this problem using Thevenin's Theorem, we must first find the equivalent resistance of the circuit with the load resistance removed. This can be done by replacing the load resistance with a short circuit, as shown in the following diagram:

[circuit diagram]

We can then use Ohm's Law to find the current through the circuit, and use this current to find the equivalent resistance. In this case, the current through the circuit is given by:

I = V / (R1 + R2)

The equivalent resistance of the circuit is then given by:

Req = V / I

= V / (V / (R1 + R2))

= R1 + R2

Once we have determined the equivalent resistance of the circuit, we can find the Thevenin voltage by shorting the voltage source and measuring the voltage across the short circuit. In this case, the Thevenin voltage is simply the voltage of the source, V.

With the equivalent resistance and voltage determined, we can now find the load resistance by replacing the short circuit with the load resistance and solving for the current through the load. In this case, the current through the load is given by:

I = V / (Req + R3)

Substituting in the values we found earlier, we get:

I = V / ((R1 + R2) + R3)

This gives us the current through the load, which we can then use to find the power dissipated by the load, or to solve for any other unknown quantities in the circuit.

Another example of using Thevenin's Theorem is to find the equivalent resistance and voltage of a circuit when given a load current. Consider the following circuit:

[circuit diagram]

In this case, we have a current source I, a resistance R1, and a resistance R2. We also have a load resistance R3, and we are trying to determine the equivalent resistance and voltage of the circuit when the load current is I. To solve this problem using Thevenin's Theorem, we must first find the equivalent resistance of the circuit with the load resistance removed. This can be done by replacing the load resistance with an open circuit, as shown in the following diagram:

[circuit diagram]

We can then use Ohm's Law to find the voltage across the circuit, and use this voltage to find the equivalent resistance. In this case, the voltage across the circuit is given by:

V = I * (R1 + R2)

The equivalent resistance of the circuit is then given by:

Req = V / I

= (I * (R1 + R2)) / I

= R1 +

thevenin equivalent example problem

So having a -ve sign with resistance doesn't make sense because it's directionless quantity. We required only the internal resistance of those active sources. Since an open circuit draws no current, there is no voltage drop across the 20-kV resistor. We also know that current is not flowing through the 8kâ„¦ resistor as it is an open circuit, but the 8kâ„¦ resistor is in parallel with 4k resistor. What is the open circuit voltage that appears across the two terminals? I hope you will find it for me after you read my answer.

Next

Thevenin equivalent circuit examples

. If the voltage increases on a positive resistor, its current increases as well. Again and in case the circuit is formed by a single loop that has two nodes only, solving it becomes rather simple. And the drop across the resistor is 6V. Thevenin theorem also known as the Helmholtzâ€”ThÃ©venin theorem states that any linear circuit containing only Th in series with a single resistance R Th connected across the load.

Next

Thevenin and Norton Theorem Circuits Conversion

The equations of the second and the third mesh should not include Ix. We will convert this circuit to Thevenin Equivalent Circuit. . Thevenin equivalent circuit has a single loop. Solution: Let r L be removed and the branch currents be named figure 9 a represents the circuit configuration. Hence, the open-circuit terminal voltage is the same as the voltage drop across the 100-kV resistor. Voltage dividers, branch currents, node voltage, superposition, and source transformations the last two will be covered soon are all legitimate methods for finding V th.

Next

Finding Thevenin's Equivalent

In fact, all that we can determine from measurements at the output terminals of any network containing one or more voltage sources is that the network is equivalent to a simple constant-voltage source with a single internal resistance in series with it. Any linear electric network or a complex circuit with current and voltage sources can be replaced by an equivalent circuit containing of a single independent voltage source VTH and a Series Resistance RTH. Resistors act to reduce current flow, and, at the same time, act to lower voltage levels within circuits. From this circuit we can calculate I L for different values of load resistance. Step 2 - Deactivate the constant sources for voltage source, remove it by internal resistance and for current source replace the source by open circuit and find the internal resistance R Th looking through the open circuited load terminals. What is the importance of an equivalent circuit? If it enters a voltage source from its positive terminal then +V is added otherwise it will be â€”V. Please help me with it.

Next

Thevenin's Theorem Example with Solution

Put these values in the below equation to find the Thevenin resistance. For nodal analysis: The sum of all current at a node equals zero. Please let me know. And find a value of equivalent resistance. This way, 12V 3mA x 4kâ„¦ will appear across the 4kâ„¦ resistor. Short out any voltage sources and open up any current sources â€” All sources must be deactivated to find the Thevenin equivalent resistance.

Next

Thevenin's Theorem with solved problem

The current source combined with the arrangement of resistors make voltage division all but impossible. Thus Also, or, Let us now deactivate the constant sources. Of the two Thevenin equivalent values, V th tends to be the harder one to find because there is no one best way to work all problems. Thank you very much for all your help and time. Once we have the equivalent circuit, the problem can be solved using three simple voltage dividers. .

Next

Thevenin's Theorem

From this circuit we can calculate I L for different values of load resistance. What is nonlinear electrical model? Next, a dc voltage supply v dc be applied across a-b such that the input current be I 1 at terminal a. But if the voltage source has an internal resistance, it needs to be added to the voltage source. Do you see the problem? It requires the deconstruction of the circuit into ideal simple circuit elements â€” e. How do you solve the Thevenin theorem examples? My idea is to tell you to remember this and others while your study in electricity and later in electronics deals with new circuits and devices. Solution Step 1 We select the unknown resistance passing the 20-mA current as the load, remove it from the original circuit in Figure 3 a , and place it in the Thevenin- equivalent circuit of Figure 3 b.

Next

Thevenin Equivalent Voltage & Resistance: What is it? (Theveninâ€™s Theorem)

I understand I have been told not to use Ix but let's play with it for some time. A linear circuit can have an independent source, dependent source, and register. Thevenin equivalent circuit consists of a single voltage source Thevenin voltage and Norton equivalent circuit consists of a current source Norton current. The value of e is the open circuit voltage at the terminals, and the value of r is e divided by the current with the terminals short circuited. And the voltage across the independent source is zero. The open-circuit voltage that appears across the two terminals is the Thevenin voltage. Do you see the problem? A direct current I T will flow in the circuit from the load terminals due to application of V T.

Next