Norton equivalent circuits norton s theorem statement. Nortons theorem for linear electrical networks, known in europe as the mayernorton 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. Aug 05, 2016 video lecture on norton s theorem from chapter dc circuits of subject basic electrical engineering for firstyear engineering students. Just as with thevenins theorem, the qualification of linear is identical to that found in the superposition theorem. 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. Any twoterminal network consisting of resistors, fixed voltagecurrent sources and linear dependent sources is externally equivalent to a circuit. Nortons theorem for linear electrical networks, known in europe as the mayernorton theorem, states that any collection of voltage sources, current sources, and resistors with two terminals is electrically equivalent to an. 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. Thevenin s vo lta ge is the algebraic sum of vol tages across the loa d te rmina ls, due to each of the independ ent sources in the circuit, acting alone. 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. Like the thevenin equivalent, the norton equivalent does not take into account the resistance of. Thevenins theorem states that any two output terminals. The importance of thevenin s and norton s theorems when dealing with special cases of electric circuits is demonstrated.
It is a method for the reduction of a portion of a complex circuit into a simple one. Circuit analysis superposition thevenins and norton. 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. Create the actual circuit and measure the current across the load points. The norton equivalent circuit contains a current source with a resistance in parallel with it, which can be calculated as stated below. Thevenins theorem can be applied to linear networks only. It consists of the equivalent current source instead of an equivalent voltage source as in thevenins theorem. Nortons theorem states that any two terminals of network can be replaced by an equivalent parallel resistance.
Use nortons theorem for analysis of dc circuits and study the advantage of this. Thevenins theorem introduction thevenins theorem is a very important and useful theorem. Kirchho s laws 4 a v v 6 v 3 2 i 5 v 0 v i 0 5 r i 4 6 3 i 3 v 4 i 2 2 r 1 v 1 i 1 a b c e d kirchho s current law kcl. Like the thevenin equivalent, the norton equivalent does not take into account the resistance of the load the output the circuit is powering. Nortons theorem tutorial for dc circuits electronicstutorials. The parallel resistance is the resistance of the network when viewed from these open circuited terminals after all voltage and current sources have been. Thevenins theorem and its application electrical concepts. 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. Thevenins theorem states that any complicated network across its load terminals can be substituted by a voltage source with one resistance in series. 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. Circuit analysis superposition thevenins and norton theorem.
Nortons theorem dc circuits basic electrical engineering first year. A linear network consisting of a number of voltage sources and resistances can be replaced by an equivalent network having a single voltage source called thevenins voltage v. Thevenins theorem states that any linear circuit containing several voltages and resistances can be replaced by just one single voltage in series with a single resistance or impedance connected across the load. In schematic form, nortons theorem looks like this. 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. Norton s theorem is the converse of thevenins theorem. Read the current shown by the ammeter between terminals a and d. R n is the input or equivalent resistance at the terminals when. Thevenins nortons theorem and maximum power transfer. In the end, nortons theorem produces a single current source with a single resistance in parallel, along with the load.
As with thevenins theorem, everything in the original circuit except the load resistance has been reduced to an equivalent circuit that is simpler to analyze. If the circuit is linear, the superposition theorem holds and, thus, any circuit voltage or current can be expressed as a sum of terms, each term involving one source and equal to the circuit voltage or current due to that source alone, i. 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. Thevenins and nortons equivalent circuits and superposition. Thevenins and nortons theorems in the context of dc voltage. For understanding in depth regarding norton theory, let us consider norton s theorem examples as follows.
In the end, norton s theorem produces a single current source with a single resistance in parallel, along with the load. Superposition states that the voltage across or current through. The constant current is equal to the current which would flow in a short circuit placed across the terminals. Nortons theorem numerical problem example duration. Thevenin equivalent circuit any twoterminal linear network, composed of. Difference between thevenin and norton compare the.
Video lecture on nortons theorem from chapter dc circuits of subject basic electrical engineering for firstyear engineering students. Norton source current inorton and norton resistance rnorton. 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. It reduces the need for repeated solutions of the same sets of equations. Find the thevenin equivalent circuit of the circuit. The main difference between thevenins theorem and nortons theorem is that, thevenins theorem provides an equivalent voltage source and.
The main difference between thevenins theorem and norton s theorem is that, thevenins theorem provides an equivalent voltage source and an equivalent series resistance, while norton s theorem provides an equivalent current source and an equivalent parallel resistance. 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. Nortons theorem is a companion to thevenins, nortons theorem a circuit with any combination of resistors and sources can be replaced by a single current source in parallel with a single resistor. Nov 26, 2011 norton s theorem numerical problem example duration. Norton on the other hand reduces his circuit down to a single resistance in parallel with a constant current source. Nortons theorem maximum power transfer theorem supernode circuit analysis. A linear active network consisting of independent andor dependent voltage and current sources and linear bilateral network elements can be replaced by an equivalent circuit consisting of current sources in parallel with the resistance, the current source being the short circuited current across the load terminal and resistance being the internal. Norton s theorem, thus, greatly reduces and simplifies a circuit. 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. Thevenin and norton equivalents imperial college london.
Nortons theorem is a way to reduce a network to an equivalent circuit composed of a single current source, parallel resistance, and parallel load. This is not a new way or approach rather its the same conventional way what we use to solve electrical networks but in an organized manner. Proof of thevenin and norton theorem physics stack exchange. Ill excerpt and paraphrase this proof found in the appendix a. Illustration of thevenins theorem formal presentation of thevenins theorem proof of thevenins theorem worked example 2 worked example 3 worked example 4 summary introduction thevenins theorem is a popular theorem, used often for analysis of electronic circuits. 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. With a resistor, while nortons theorem replaces the linear circuit with a. A linear network consisting of a number of voltage sources and resistances can be replaced by an equivalent network having a single voltage source called thevenins voltage v th. Thevenins theorem and its application by g r sinha 9 th june, 2017 thevenins theorem thev enins theorem stat es that a linear an d bilater al netwo rk can be. Verification of nortons theorem using the simulator, step1. In directcurrent circuit theory, nortons theorem aka mayernorton theorem is a simplification. The importance of thevenins and nortons theorems when dealing with special cases of electric circuits is demonstrated. Jul 03, 2018 thevenins theorem is the most used and useful approach to solve electrical networks.
Norton s theorem can be thought as an alternative of thevenins theorem in the sense that the thevenins theorem reduces a complex network into a voltage source and a series resistance. To verify the validity of my arguments above, i found a formal proof of thevenins theorem in one of my undergrad textbooks. Easy step by step procedure with example pictorial views nortons theorem may be stated under. Norton s theorem dc circuits basic electrical engineering first year. Nortons theorem dc network analysis electronics textbook. Also similar to thevenins theorem are the steps used in norton s theorem to calculate the. The nortons theorem also explains about the constant current that is equal to the current of the short circuit placed across the terminals. Thevenins and nortons equivalent circuits and superposition theorem thevenins and nortons theorems thevenins theorem as far as its appearance from outside is concerned, any two terminal network of resistors and energy s ources can be replaced by a series combination of an ideal voltage source voc and a resistor r, where. Nortons theorem explained learning about electronics.
Just as with thevenins theorem, the qualification of linear is identical to that found in. Fundamentals of circuits, electronics, and signal analysis by kendall l. Thevenins and nortons theorems illinois institute of. Its theoretical value is due to the insight it offers about the circuit. We have followed the convention that current leaving a node is positive. The current source being the shortcircuited current across the load terminal and the resistance being the.
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 open connection points where the load resistor used to be. Learn vocabulary, terms, and more with flashcards, games, and other study tools. Norton s theorem is a way to reduce a network to an equivalent circuit composed of a single current source, parallel resistance, and parallel load. A complex twoterminal circuit can be replaced by an equivalent circuit consisting of a voltage source. Norton s theorem states that any linear complex electrical circuit can be reduced into a simple electric circuit with one current and resistance connected in parallel. The parallel resistance of the network can be viewed from the open circuit terminals when all the voltage and current sources are. Nortons theorem, thus, greatly reduces and simplifies a circuit. Rl is selected as the resistor where it is proposed to determine the current value. Nortons theorem and its dual, thevenins theorem, are widely used for circuit analysis simplification and to study circuits initialcondition and steadystate response. In circuit theory, thevenins theorem for linear electrical networks states that any combination of voltage sources, current sources, and resistors. Consider the following example of a linear circuit with two sources. This theorem helps in the study of the variation of current in a particular branch when the resistance of the branch is varied while the remaining network remains the same for example.
Superposition, thevenin norton equivalent circuits. These cases have typically been dealt with in difficult and non systematic. A complex twoterminal circuit can be replaced by an equivalent circuit consisting of a. It states that any two terminal linear network or circuit can be represented with an equivalent network or circuit, which consists of a current source in parallel with a resistor. It can be see n that thevenins theorem is an outcome of superposition theorem. Thevenins theorem can be used as a circuit analysis method and is particularly useful if the load is to take a series of different values. This theorem helps in the study of the variation of current in a particular branch when the resistance of the branch is varied while the remaining network remains the same for example designing of electronics circuits. The nortons theorem states that any number of voltage sources, current sources and resistors having two open ends can be simplified into an ideal current source and a resistor connected in parallel with the source.
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