Thevenin theorem, thevenins theorem solution example. Thevenin norton equivalents and maximum power transfer. For understanding in depth regarding norton theory, let us consider nortons theorem examples as follows. The circuit on the left can be replaced with the thevenin equivalent voltage source having the equivalent opencircuit voltage vth 32 v and equivalent resistance r th 8 ohm if the load resistance r l connected to the terminals a and b is to be optimized for the maximum power dissipated in it, then rlopt r th. Norton equivalent is simply the source transformation of the. Nortons thereom is identical to thevenins theorem except that no compromise keith green pdf the. Like thevenins theorem, it simplifies the circuit one needs to study and dramatically reduces potential calculation errors nortons theorem states that networks with voltage and current sources, as well as resistors are electrically equivalent to one single current source and one single resistor in parallel with the. Simplifying any network by converting the active part of that network to an equivalent current source with an impedance connected in parallel is called norton theorem. The norton equivalent circuit contains a current source with a resistance in parallel with it, which can be calculated as stated below. For the circuit shown, find the thevenin and norton. Identify the differences and similarities between thevenin and norton equivalent circuits. Nortons theorem dc network analysis electronics textbook. Norton theorem norton equivalent current and resistance.
Construct the circuit show in figure 6 and measure the voltage across points a. Health care nami handbook of the streets ramsey county mental health ramsey county chemical dependency intergroup st paul st paul police department united way 211 bridging alley shop. Norton s theorem for linear electrical networks, known in europe as the mayer norton theorem, states that any collection of voltage sources, current sources, and resistors with two terminals is electrically equivalent to an ideal current source, i, in parallel with a single resistor, r. Thevenin equivalent circuits are discussed in section 5. Thevenin and norton equivalent circuits looking into and out of each active device port. Thevenin and norton equivalents this tutorial is intended to show how thevenin and norton equivalent circuits can be calculated. Aug 09, 2018 norton theoremany active network can be represented as an equivalent current source with an impedance connected in parallel across it. A and b of the black box for example, a resistor, we might be interested in the voltage.
I dont know how to calculate the norton resistance, since the dependent source 2u cannot be. Thevenins and nortons equivalent circuits solved problems. Any twoterminal network consisting of resistors, fixed voltagecurrent sources and linear dependent sources is externally equivalent to a circuit. Using the thevenins equivalent circuit, compute the value of vab with the 8. The main difference between thevenins theorem and nortons theorem is that, thevenins theorem provides an equivalent voltage source and. Circuit analysis using superposition principle duration. Nortons theorem is a powerful tool for solving electrical circuits. A brief introduction to nortons theorem electronics hub. Reconnect the original load to the thevenin voltage circuit as shown in. Thevenins and nortons theorems in the context of dc voltage.
Thevenins, nortons, and maximum power transfer theorems. If r th takes a negative value, it means the circuit is supplying power to the terminals. For alternating current ac systems the theorem can be applied to. Converting the circuit with is and r2 into an equivalent form voltage source in series with a resistance, we get the circuit shown in fig.
In directcurrent circuit theory, nortons theorem aka mayernorton theorem is a simplification that can be applied to networks made of linear timeinvariant resistances, voltage sources, and current sources. Nortons theorem states that networks with voltage and current sources, as well as resistors are electrically equivalent to one single current source and one single resistor in parallel with the. Replace the load with a short circuit and find the shortcircuit current. For understanding in depth regarding norton theory, let us consider nortons. The equivalent resistance then becomes a simple ohms law calculation, seen in equation 1. A few examples clarify how sources are removed and total solutions obtained. Calculate the voltage, v, at the output from the original sources. We obtain the short circuit current isc by shorting nodes ab and finding the current through. Now replace voltage sources with shorts and current sources with open circuits. Any collection of batteries and resistances with two terminals is electrically equivalent to an ideal current source i in parallel with a single resistor r. Calculate the output current, i ab, with a short circuit as the load. Place in series with to form the thevenins equivalent circuit replacing the imaginary fencing portion or fixed part of the circuit with an equivalent practical voltage source as shown in fig. Thevenin and norton equivalents university of houston. When using a voltage source, it can be assumed to be 1v for simple calculations.
So norton s theorem allows you to take any circuit with any number of power sources and reduce it to a single current source in parallel with a single resistance, along with the load. Norton theorem any two terminal linear circuit can be replaced by an equivalent circuit consisting of a current source and a parallel resistor. If we applied some sort of load across the terminals. Then to find v th, use mesh analysis with all independentdependent sources included and solve for the open circuit voltage. Equivalence let us define equivalence in the most general form, and then modify this definition as needed. S is then the equivalent resistance r eq seen across the output terminals with the voltage source turned off. These are a few of the community resources available to assist with everything from food and clothing to mental health and chemical dependency. Use equivalent circuits to analyze the effect of changing load resistances. Oct 09, 20 find thevenins and norton s equivalent circuits. Verification of nortons theorem using the simulator, step1.
Thevenins theorem can be applied when analyzing a circuit with dependent sources. In these cases, we need to find open circuit voltage and short circuit current to determine norton s and also thevenins equivalent circuits. Create the nortons equivalent circuit by first creating a current source of required equivalent current in amperes 2 a in this case, and then measure the current across the load using an ammeter. What is the norton equivalent circuit for the circuit below.
Equivalent circuits are simplified versions of complex circuits that yield the same values and can, therefore, be used to simplify calculations about those circuits. The value of r is the same as that in the thevenin equivalent and the current i can be found by dividing the open circuit voltage by r. Another useful application is the noise analysis of devices. The circuit shown in figure 1b is the thevenin equivalent circuit of the. If there is not any independent source then both voc0 and isc0 so skip step 2. Jun 03, 2019 in contrast to the thevenins theorem, nortons theorem replaces the part of the circuit with an equivalent circuit that constitute a current source and a parallel resistance. Ee40 lec04 mesh analysis th itheveninandn t e i l td. Using the nortons equivalent circuit, compute the value of vab with the 8. Because the t model for the jfet is the same as the t model for the mosfet for the case where the body is connected to the source, the. Nov 09, 2012 thevenins equivalent with dependent and independent sources problem 5.
The aim of this paper is to identify these methods and introduce them in a simple, general, comprehensive, and efficient way. You have determined both the open circuit voltage vth and the short. Find the norton source current by removing the load resistor from the original circuit and calculating the current through a short wire jumping across the. At a pair of terminals of the network, it can be replaced by a current source and a single resistor in parallel. Discuss the purpose of equivalent circuits and provide examples of use scenarios. Nortons theorem nortons theorem states that a linear active network consisting of independent or dependent voltage source and current sources and the various circuit elements can be substituted by an equivalent circuit consisting of a current source in parallel with a resistance.
Determine the thevenin and norton equivalent circuits for various circuit configurations. Nortons theorem states that it is possible to simplify any linear circuit, no matter how complex, to an equivalent circuit with just a single current source and parallel resistance connected to a load. Nortons thereom is identical to thevenins theorem except that the equivalent circuit is an independent current source in parallel with an impedance resistor. For both thevenin equivalent circuits and norton equivalent circuits, students will confirm the founding theorems of equivalent circuits through a.
Nortons equivalent or norton equivalent circuit is a reduced version of or equivalent circuit of a complex electrical network circuit, derived in accordance with the nortons theorem. V th r th nortons theorem to a single current source in. Thevenins theorem this theorem says that any circuit with a voltage source and a network of resistors can be transformed into one voltage source and one resistor. Easy step by step procedure with example pictorial views this is another useful theorem to analyze electric circuits like thevenins theorem, which reduces linear, active circuits and complex networks into a simple equivalent circuit. Online tutorial on creating a norton equivalent circuit. Therefore, through norton s equivalent, a current divider circuit is formed, which we can easily calculate currents through various branches of the circuit. Therefore, through nortons equivalent, a current divider circuit is formed, which we can easily calculate currents through various branches of the circuit. In this lab, students will learn about thevenin and norton equivalent circuits. Thevenin and norton equivalent circuits national instruments. Once this is done, the circuit solutions can usually be written by inspection. Thevenins and nortons equivalent circuit theorems any combination of voltage sources, current sources and resistors with two terminals is electrically equivalent thevenins theorem to a single voltage source vth and a single series resistor rth connected in series.
Just as with thevenins theorem, the qualification of linear is identical to that found in the superposition theorem. Use nortons theorem for analysis of dc circuits and study the advantage of this. As the circuit to the left of xy in figure 6a does not have any independent source hence i s. The circuit shown in figure 1b is the thevenin equivalent circuit of the circuit shown in figure 1a. The current source being the shortcircuited current across the load terminal and the resistance being the. The circuit has both independent and dependent sources. Vth v ab opencircuit voltage rth v th i ab where i ab is the shortcircuit current or rth rab with all the voltage and current sources zeroed. This will we the thevenin equivalent resistance rth. To find the equivalent, the norton current i no is calculated as the current flowing at the terminals into a short circuit zero resistance between a and b. This theorem is an extension of the thevenins theorem, proposed by e.
Application of thevenin and norton equivalent circuits 887 1 fig. To illustrate the procedure, several examples are given. Thevenin equivalent of a voltage source a rl b vth rth according to the thevenin theorem, the equivalent voltage source and internal resistance of any linear circuit are. Norton equivalent with dependent source electrical. Jan 11, 2014 thevenins theorem nortons theorem posted on january 11, 2014 by sheniel04 in electrical circuit theory, thevenins theorem for linear electrical networks states that any combination of voltage sources, current sources and resistors with two terminals is electrically equivalent to a single voltage source v and a single series resistor r. Electronicstheveninnorton equivalents wikibooks, open. The figure above illustrates a circuit with vcvs and its norton equivalent model as seen from port b. Mustafa kemal uyguroglu thevenins theorem zany circuit with sources dependent andor independent and resistors can be replaced by an equivalent circuit containing a single voltage source and a single resistor. Norton equivalent circuits are discussed in section 5. Both method1 and method2 determine v oc exactly the same. Thevenin and norton equivalents equivalent networks thevenin equivalent thevenin properties determining thevenin complicated circuits norton equivalent power transfer source transformation source rearrangement series rearrangement summary e1. Nortons theorem states that any linear complex electrical circuit can be reduced into a simple electric circuit with one current and resistance connected in parallel. Those sources mentioned above can also either be dependent or independent sources. Learn vocabulary, terms, and more with flashcards, games, and other study tools.
In this case, all independent sources are turned off and the r th is calculated by applying a current source or voltage source at the open terminal. On the application of thevenin and norton equivalent. Et304a laboratory 5 thevenins and nortons theorem and. Nortons theorem is a network reduction electrical network analysis technique which can be used to analyse the current through a branch in complex network of linear electronic components. Equivalent circuit concept a network of voltage sources, current sources, and resistors can be replaced by an equil ti itivalent circuit whi h h id ti l t i lhich has identical terminal properties iv characteristics without affecting the operation of the rest of the circuitthe operation of the rest of the circuit. Supplementary worked examples 165 the thevenin equivalent circuit is shown below. In your lecture class, you will cover these topics in more detail, but the information here is enough to perform the ece 2100 lab iii exercise. Calculate the equivalent resistance across the open ends. Suppose the following circuit has its load identified and removed, so that we can determine the thevenin equivalent between points ab. Easy step by step procedure with example pictorial views nortons theorem may be stated under. Thevenins theorem states that we can replace entire network by an equivalent circuit that. So nortons theorem allows you to take any circuit with any number of power sources and reduce it to a single current source in parallel with a single resistance, along with the load. Learn about thevenin theorem and dependent source circuits.
Thevenins theorem greatly simplifies analysis of complex circuits by allowing us to replace all of the elements with a combination of just one voltage source and one resistor. On the application of thevenin and norton equivalent circuits. Hence, we start by finding the open circuit voltage voc vab. Thevenins and nortons theorems illinois institute of. Thevenins theorem 2 any linear, twoterminal network with dependent and independent sources can be represented by an equivalent circuit consisting of a single voltage.
Pick a good breaking point in the circuit cannot split a dependent source and its control variable. Any two terminal linear circuit can be replaced by an equivalent circuit consisting of voltage source in series with a single equivalent resistance. Thevenins theorem nortons theorem shennode sheercuits. Norton equivalent circuits nortons theorem statement. A complex twoterminal circuit can be replaced by an equivalent circuit consisting of a voltage source. Create the actual circuit and measure the current across the load points. Nortons theorem is a way to reduce a network to an equivalent circuit composed of a single current source, parallel resistance, and parallel load. Nortons theorem example with solution electronics tutorials. Any linear electric network or 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. Find norton s equivalent circuit to the left of terminal xy in figure 6. Like thevenins theorem, it simplifies the circuit one needs to study and dramatically reduces potential calculation errors. For the circuit shown, find the thevenin and norton equivalent circuits.
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