Name: circuit source equivalents
Uploaded: 2025-05-22T09:06:14.000Z
Duration: 1 min 15 s
Channel: JoVE

소스 변환 기술을 사용하면 저항과 직렬로 연결된 전압 소스를 저항과 병렬로 등가 전류 소스로 또는 그 반대로 변환할 수 있습니다.
변환하는 동안 회로의 저항 값은 동일하게 유지됩니다. 옴의 법칙을 사용하여 전압 또는 전류 값을 결정할 수 있습니다.
전류 소스의 화살표는 항상 전압 소스의 양극 단자를 가리킵니다.
이 기술은 내부 저항 특성으로 인해 이상적인 전압 및 전류 소스에 적용할 수 없습니다.
전압 소스, 전류 소스 및 일부 저항으로 구성된 회로를 고려하십시오. 소스 변환을 사용하여 중앙 저항을 통과하는 전압 강하를 결정할 수 있습니다.
처음에는 감소된 회로를 얻기 위해 두 소스 모두에 소스 변환을 적용합니다.
이제 왼쪽 전압 소스를 다시 전류 소스로 변환합니다. 회로는 단일 전류 소스 구성으로 더욱 단순화됩니다.
전류 분배 공식을 사용하여 저항을 통과하는 전류를 얻습니다. 옴의 법칙으로 대체하면 저항기 양단의 전압 강하가 얻어집니다.

소스 변환

소스 변환은 회로 분석에 사용되는 기본 기술로, 복잡한 전기 회로를 단순화하는 데 유용한 도구를 제공합니다. 이 기술에는 저항과 직렬인 전압 소스를 저항과 병렬인 전류 소스로 교체하거나 그 반대로 교체하는 작업이 포함됩니다. 여기서 핵심 개념은 원래 소스가 비활성화(꺼짐)될 때 회로 끝 단자의 등가 저항이 동일하게 유지된다는 것입니다.

소스 변환을 수행할 때 전류 소스 화살표의 방향은 항상 전압 소스의 양극 단자를 향한다는 점에 유의해야 합니다. 이 규칙은 일관성을 보장하고 적절한 회로 방향을 유지하는 데 도움이 됩니다.

그러나 내부 저항이 0이기 때문에 이상적인 전압 소스에는 소스 변환이 적용되지 않는다는 점을 언급할 가치가 있습니다. 이와 대조적으로 비이상적인 전압 소스는 내부 저항이 0이 아니므로 소스 변환이 가능합니다. 마찬가지로, 내부 저항이 무한한 이상적인 전류원은 유한한 전압원으로 대체될 수 없습니다.

소스 변환의 실제 적용을 설명하기 위해 비이상적인 전압 소스(Figure 1)와 비이상적인 전류 소스(Figure 2)에 개별적으로 연결된 회로를 고려해 보세요. 직렬 저항이 병렬 저항과 동일하고 전압 소스의 전압이 옴의 법칙을 준수하는 경우 이러한 비이상적인 소스는 서로 동일해집니다.

<img alt="Figure1" src="/files/ftp_upload/15051/15051_PT_Figure_1.svg" style="text-align: center; height: 128px;">
Figure 1: 비이상적인 전압 소스가 있는 회로

<img alt="Figure2" src="/files/ftp_upload/15051/15051_PT_Figure_2.svg" style="text-align: center; height: 128px;">
 Figure 2: 비이상적인 전류 소스가 있는 회로

비이상적인 전압 소스를 등가의 비이상적인 전류 소스로 교체해도 회로 내 요소의 전압이나 전류 특성은 변경되지 않습니다. 이는 전체 회로 동작에 영향을 주지 않고 회로 분석을 단순화하는 소스 변환의 힘을 보여줍니다.

소스 변환 기술을 사용하면 저항과 직렬로 연결된 전압 소스를 병렬로 등가 전류 소스로 변환 할 수 있습니다.

Education

교육

JoVE Core

Electrical Engineering

전기공학

Unit 1

제1단원

DC Circuit Analysis

DC 회로 분석

KEY TERMS AND CONCEPTS

주요 용어 및 개념

Source Transformation

circuit source equivalents

Circuit source equivalents make it easier to simplify electrical circuits in circuit analysis. A source transformation replaces a voltage source in series with a resistor by a current source in parallel with a resistor, or it replaces a current source in parallel with a resistor by a voltage source in series with a resistor.

The key idea is that the equivalent resistance at the circuit terminals stays the same when the original sources are turned off. When making the change, the current source arrow must point toward the positive terminal of the voltage source. This keeps the circuit orientation consistent.

Source transformation does not work for ideal voltage sources because they have zero internal resistance. It also does not work for ideal current sources because they have infinite internal resistance. Nonideal voltage sources and nonideal current sources can be transformed because their internal resistance is not zero or infinite.

The transcript shows this idea with a nonideal voltage source and a nonideal current source. When the series resistance matches the parallel resistance, and the voltage across the voltage source follows Ohm's law, the two sources are equivalent. Replacing the nonideal voltage source with the matching nonideal current source does not change the voltage or current in any circuit element.

Circuit Source Equivalents

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...

nodal analysis with voltage sources

Supernode Equations in Nodal Analysis

Nodal analysis uses node voltages and Kirchhoff’s laws to solve circuits with voltage sources. It is a systematic method for breaking a complex circuit into smaller parts that are easier to analyze. In this example, the circuit includes four resistors and two voltage sources. One voltage source is connected between a non-reference node and the reference node. In that case, the non-reference node voltage can be written directly as the source voltage. This removes one unknown and makes the...

mesh analysis

Mesh Currents for Circuit Analysis

Mesh currents give students a simpler way to analyze planar circuits. In mesh analysis, the unknowns are currents, not voltages. The method uses Kirchhoff's voltage law, or KVL, to build the equations needed to solve the circuit. A mesh is a closed loop in a circuit that does not contain any smaller loops inside it. Each independent mesh is assigned a mesh current, and this current is usually drawn in the clockwise direction. These mesh currents are used as the main circuit variables during...

mesh analysis with current sources

Current Sources in Mesh Circuit Analysis

Current sources make mesh circuit analysis easier because they can reduce the number of equations needed. This applies to both independent and dependent current sources. The method depends on where the current source is placed in the circuit. When a current source appears in only one mesh, the setup is simple. Assign mesh currents as usual, but leave out the mesh that contains the current source from the equation process. Then apply Kirchhoff's voltage law, or KVL, to the remaining mesh to get...

source transformation

Circuit source equivalents make it easier to simplify electrical circuits in circuit analysis. A source transformation replaces a voltage source in series with a resistor by a current source in parallel with a resistor, or it replaces a current source in parallel with a resistor by a voltage source in series with a resistor. The key idea is that the equivalent resistance at the circuit terminals stays the same when the original sources are turned off. When making the change, the current source...

linear circuits

Circuit Linearity and Resistor Behavior

Circuit linearity describes how a circuit responds when its input changes. A linear circuit has an output that is directly proportional to its input. This behavior follows two rules: homogeneity and additivity. Homogeneity means that if the input, or excitation, is multiplied by a constant factor, the response is multiplied by the same factor. For example, if the current is increased by a constant k, the voltage also increases by k times. Additivity means that the response to a sum of inputs...

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

Thevenin circuit equivalents simplify linear two-terminal circuits by replacing the fixed part of a network with one equivalent source and one resistor. This method is useful when a circuit has a fixed section and a load that can change. A household electrical outlet is a familiar example, because different appliances can be plugged in or removed. Each change in load can require a new circuit analysis, so an equivalent circuit makes the work easier. Thevenin's theorem states that a linear...

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...

maximum power transfer

Load Matching in Thevenin Circuits

Load matching in Thevenin circuits helps a source deliver the most power to a connected load. This matters in engineering fields such as telecommunications, where power delivery must be optimized. Even then, internal losses can be significant and may equal or exceed the power sent to the load. The Thevenin equivalent circuit is a useful way to study this situation. It replaces the full linear circuit with a simpler source and resistance while keeping the load in place. In this setup, the load...

design example: strain gauge bridge or wheatstone bridge

design-example-strain-gauge-bridge-or-wheatstone-bridge

Wheatstone Bridge Output for Strain Gauge Design

A strain gauge and Wheatstone bridge work together to turn mechanical strain into an electrical signal. In engineering, this setup is often used to measure force or pressure. Each part of the bridge has a resistance that changes slightly when strain is applied. The main goal is to turn a very small voltage output into a larger, easier-to-read signal. A voltmeter can then measure that output more clearly. To do this, an engineer designs the strain gauge circuit and figures out how much...

key terms and concepts

Learn how source transformation replaces nonideal voltage and current sources while keeping terminal resistance the same in circuit analysis.

Circuit Source Equivalents | 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

Circuit Source Equivalents

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