Name: norton equivalent circuit in dc analysis
Uploaded: 2024-04-11T12:48:31.000Z
Duration: 1 min 14 s
Channel: JoVE

诺顿定理指出，任何一个线性双端网络都可以被等效为一个由单个电流源与一个电阻并联组成的电路。
为了应用诺顿定理，需从两个负载端子处移除负载电阻器：其余网络将被从这两个端子看进去的诺顿等效电路所替代。
诺顿电阻可通过将所有独立电源置零来确定。端口之间的等效电阻或输入电阻即为诺顿电阻。
为了求诺顿电流，将所有电源恢复至原始位置，然后通过计算标记端子间的短路电流来求得诺顿电流。
最后，用诺顿等效电路替换原网络，并重新连接负载电阻。
源变换技术可用于在诺顿等效电路和戴维南等效电路之间进行转换。
为了确定戴维南或诺顿等效电路，必须已知开路电压、短路电流以及输入电阻或等效电阻。
诺顿定理与戴维南定理和欧姆定律之间的紧密关系有助于求解复杂的电路。

诺顿定理

诺顿定理是一个基本原理，以此来指出线性二端电路可以用等效电路来进行代替，该等效电路包括了与电阻器（RN）并联的电流源（IN）。其中，IN代表了流经端子的短路电流，RN则代表了所有独立源均关闭时端子上的输入或等效电阻。这意味着图（a）所表示的电路可以与图（b）所示的电路进行互换。 <img alt="Figure1" src="/files/ftp_upload/15054/15054_PT_Figure_1.svg" style="text-align: center; height: 132px;"> 图（a） <img alt="Figure1" src="/files/ftp_upload/15054/15054_PT_Figure_2.svg" style="text-align: center; height: 132px;"> 图（b） 诺顿电阻的确定涉及到将电路内的所有独立源设置为零的过程。由此得出的得值代表了诺顿的阻力，这对于诺顿定理的应用是至关重要的。要计算诺顿电流，必须将所有的源恢复到其原始状态，然后确定标记端子之间的短路电流。如果要完成改造，还需要用诺顿等效电路来替换网络并重新连接其中的负载电阻。为了能够建立起戴维宁等效电路或诺顿等效电路，则必须了解其中的开路电压、短路电流以及输入或等效电阻。这些参数是电路转换过程中的关键要素。诺顿定理和戴维南定理之间的密切联系能够由以下关系得出： <img alt="Equation1" src="/files/ftp_upload/15054/15054_PT_Equation_1.svg" style="text-align: center; height: 14px;"> <img alt="Equation1" src="/files/ftp_upload/15054/15054_PT_Equation_2.svg" style="text-align: center; height: 34px;"> 同时将其与欧姆定律进行结合，从而为解决电路中的复杂问题提供了宝贵的工具。

诺顿定理指出，任何一个线性二端电路都可以被等效为一个由单个电流源与...

Education

教育

JoVE Core

Electrical Engineering

电气工程

Unit 1

第一单元

DC Circuit Analysis

直流电路分析

KEY TERMS AND CONCEPTS

关键术语与概念

Norton's Theorem

norton equivalent circuit in dc analysis

Norton equivalent circuit in DC analysis shows how a linear two-terminal circuit can be replaced by a simpler network. The replacement uses a current source, called I_N, in parallel with a resistor, called R_N. I_N is the short-circuit current through the terminals, and R_N is the input or equivalent resistance seen at the terminals when the independent sources are turned off.

To find Norton's resistance, all independent sources in the circuit are set to zero. The resistance measured at the marked terminals is then taken as R_N. To find Norton's current, the sources are restored to their original values and the short-circuit current between the terminals is found.

After the Norton equivalent is built, the load resistor is connected again to complete the transformation. This method gives a compact way to study how the circuit behaves at its terminals. It is closely linked to Thevenin's theorem, since both use the open-circuit voltage, short-circuit current, and equivalent resistance.

These relationships, together with Ohm's law, help solve more complex electrical circuits. By converting a network into its Norton form, students can compare terminal behavior more easily. The theorem is a useful tool for circuit analysis when a two-terminal linear network must be simplified.

Norton Equivalent Circuit in DC Analysis

nodal analysis

Using Node Voltages in Circuit Analysis

Nodal analysis uses node voltages to simplify circuit analysis. In this method, the voltage at each node becomes the main variable. Once those voltages are known, they can be used to find other values, such as the current through specific circuit parts. The process begins by choosing a reference node, also called a datum node. This node is selected for convenience and assigned a voltage of zero. The other nodes, called non-reference nodes, are then measured relative to that point. In the...

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Current Sources in Mesh Circuit Analysis

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superposition theorem

Analyzing Circuits with Superposition

Superposition is a circuit analysis method for linear circuits with more than one independent source. It lets you find the voltage across or current through an element by adding the separate effects of each source acting alone. To use superposition, keep one independent source active and turn off the others. A voltage source is replaced by a short circuit, and a current source is replaced by an open circuit. Then calculate the output from the single active source. Repeat the process for each...

thevinin's theorem

Thevenin Circuit Equivalents

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norton's theorem

Norton equivalent circuit in DC analysis shows how a linear two-terminal circuit can be replaced by a simpler network. The replacement uses a current source, called I_N, in parallel with a resistor, called R_N. I_N is the short-circuit current through the terminals, and R_N is the input or equivalent resistance seen at the terminals when the independent sources are turned off. To find Norton's resistance, all independent sources in the circuit are set to zero. The resistance measured at the...

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key terms and concepts

Learn how Norton equivalent circuits simplify a linear two-terminal network using a current source, parallel resistance, and short-circuit current.

Norton Equivalent Circuit in DC Analysis | JoVE K12

JoVE Core Electrical Engineering offers easy-to-understand animated videos that cover fundamental concepts of electric circuits along with circuit analysis techniques. It incorporates first-order and second-order circuits using operational amplifiers and circuit transformation concepts. The inclusion of practical design examples and real-world applications through scientist-in-action videos adds significant educational value, making complex concepts accessible.

electrical engineering

Norton Equivalent Circuit in DC Analysis

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