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

ソース変換技術により、抵抗と直列の電圧源を抵抗と並列の等価電流源に、またはその逆に変換できます。
変換中、回路内の抵抗値は同じままです。オームの法則を使用して、電圧または電流の値を決定できます。
電流源の矢印は、常に電圧源の正端子を指しています。
この手法は、内部抵抗特性のため、理想的な電圧源や電流源には適用できません。
電圧源、電流源、およびいくつかの抵抗器で構成される回路を考えてみましょう。ソース変換を使用すると、中央の抵抗器の両端の電圧降下を決定できます。
最初に、両方のソースでソース変換を適用して、縮退回路を取得します。
次に、左側の電圧源を再び電流源に変換します。この回路は、1つの電流源構成にさらに簡素化されています。
電流分周式を使用して、抵抗器を流れる電流が得られます。これをオームの法則に代入すると、抵抗器の両端の電圧降下が得られます。

ソース変換

ソース変換は回路解析で使用される基本的な技術であり、複雑な電気回路を単純化するための貴重なツールを提供します。この技術には、抵抗器と直列の電圧源を抵抗器と並列の電流源に置き換えたり、その逆の置き換えが含まれます。ここで重要な概念は、ソースをオフにしたとしても、回路の終端端子の等価抵抗は同じままであるということです。

ソース変換を実行するときは、電流源の矢印の方向が常に電圧源の正端子を指すことに注意が必要です。この規則により一貫性が保証され、適切な回路の向きを維持するのに役立ちます。

ただし、理想的な電圧源は内部抵抗がゼロであるため、ソース変換は理想的な電圧源には適用できないことに注意してください。対照的に、非理想電圧源は内部抵抗がゼロではないため、ソース変換が容易になります。同様に、無限の内部抵抗を持つ理想的な電流源を有限の電圧源で置き換えることはできません。

ソース変換の実際の応用を説明するために、非理想的な電圧源 (Figure 1) と非理想的な電流源 (図 2) に接続された回路を個別に考えてみましょう。直列抵抗が並列抵抗と等しく、電圧源の両端の電圧がオームの法則に従う場合、これらの非理想的な電源は互いに等価になります。

<img alt="Figure1" src="/files/ftp_upload/15051/15051_PT_Figure_1.svg" style="text-align: center; height: 128px;">
Figure 1: 非理想的な電圧源を使用する回路 図

<img alt="Figure2" src="/files/ftp_upload/15051/15051_PT_Figure_2.svg" style="text-align: center; height: 128px;">
 2: 非理想的な電流源を使用する回路

非理想的な電圧源を同等の非理想的な電流源に置き換えても、回路内のどの要素の電圧特性や電流特性も変わりません。これは、回路全体の動作に影響を与えることなく回路解析を簡素化するソース変換の力を示しています。

ソース変換技術により、抵抗器と直列の電圧源を並列の等価電流源に変換できます。

Education

JoVE Core

Electrical Engineering

電気工学

Unit 1

ユニット1

DC Circuit Analysis

直流回路解析

KEY TERMS AND CONCEPTS

主要用語および概念

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

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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...

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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 電気工学 は、電気回路の基本概念と回路解析テクニックを網羅したアニメーションビデオシリーズです。オペアンプと回路変換および 1 次・ 2 次回路の概念を網羅しています。実験を撮影した実写動画では、設計例や現代社会での応用が含まれており、複雑な概念も分かりやすく学習いただけます。

electrical engineering

Circuit Source Equivalents

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