Name: circuit elements: passive, active, and linear
Uploaded: 2024-04-11T12:48:28.000Z
Duration: 1 min 21 s
Channel: JoVE

回路要素は、電気回路の基本的な構成要素です。それらは、能動的要素と受動的要素に分類できます。
能動要素はエネルギーを生成することができますが、受動要素はエネルギーを吸収します。
能動素子の例としては、電圧源や電流源などがありますが、抵抗器、コンデンサ、インダクタなどは受動素子の例です。
回路要素は、線形または非線形のいずれかにさらに分類できます。
回路または要素は、要素の励起と応答が重ね合わせと均質性の原理に従う場合、線形と見なされます。
電圧 v1 が応答 i1 につながり、電圧 v2 が応答 i2 につながるとします。要素が電圧の合計に応答し、応答の合計が応答する場合、重ね合わせの原理を満たします。
さらに、線形デバイスの入力に任意の定数を乗算すると、出力が等価に乗算される場合、均質性特性が満たされます。
抵抗器、コンデンサ、インダクタなどの線形要素は、線形特性を示します。
サーミスタのような要素は、これらの原理に準拠していないため、非線形です。

電気回路要素

回路要素は、電気回路の基本的な構成要素です。基本的に、電気回路はこれらの要素を相互接続したものです。電気回路内には、パッシブとアクティブの 2 種類の要素があります。能動素子は能動素子は外部からのエネルギーを電気信号に変換する能力を持っていますが、受動素子はエネルギーを生成しません。受動素子には抵抗、コンデンサ、インダクタなどのコンポーネントが含まれますが、能動素子には通常、発電機、バッテリー、オペアンプが含まれます。

最も重要なアクティブ要素は電圧源または電流源であり、通常、接続された回路に電力を供給します。回路要素を分類する方法は数多くあります。たとえば、完全に線形回路要素で構成された回路は、一部の非線形要素を含む回路よりも解析が簡単であるため、線形モデルと非線形モデルを区別することが重要です。

要素の励起と応答が特定の条件を満たしている場合、要素または回路は線形であるとみなされます。重ね合わせ特性と均一性特性の両方が線形要素によって満たされます。励起が電流 (i) であり、応答が電圧 (v) であるシナリオを考えてみましょう。要素が電流 (i1) を受けると、応答 (v1) が返されます。同様に、要素が別の電流 (i2) にさらされると、応答 (v2) が引き起こされます。

重ね合わせの理と均一性の原理のいずれかを満たさない回路要素は、非線形として分類されます。サーミスタはそのような非線形素子の例です。

回路要素は、電気回路の基本的な構成要素です。それらは、能動的要素と受動的要素に分類できます。
アクティブエレメントは...

Education

JoVE Core

Electrical Engineering

電気工学

Unit 1

ユニット1

Basics of Electric Circuits

電気回路の基礎

KEY TERMS AND CONCEPTS

主要用語および概念

Electric Circuit Elements

circuit elements: passive, active, and linear

Circuit elements are the building blocks of an electric circuit. An electric circuit is the connection of these elements. In this context, circuit elements are often grouped by how they behave and whether they supply energy.

One major group is passive elements. These elements do not generate energy. Common passive elements include resistors, capacitors, and inductors. The other group is active elements, which can generate energy. Generators, batteries, and operational amplifiers are typical active elements, and voltage or current sources are especially important because they usually provide power to the connected circuit.

Circuit elements can also be sorted as linear or nonlinear. This distinction matters because circuits made only of linear elements are easier to analyze than circuits that include nonlinear parts. A linear element follows both superposition and homogeneity. If the input is current, then one current level produces one voltage response, and another current level produces another response in a predictable way.

An element is nonlinear if it does not satisfy superposition or homogeneity. Thermistors are examples of nonlinear circuit elements. These categories help describe how circuit parts behave and how a circuit responds to electrical signals.

Circuit Elements: Passive, Active, and Linear

circuit-elements-passive-active-and-linear

charge and current

Electric Charge in Circuits

Electric charge in circuits explains how charged particles behave in matter and how current is produced. Everyday static effects, like a wool sweater sticking to the body or a shock from a carpet, show charge in action. Charge is an inherent property of atomic particles and is measured in coulombs (C). Matter is made of atoms with electrons, protons, and neutrons. Electrons carry a negative charge (-e), and protons carry a positive charge (+e). These two charges have the same magnitude. An...

voltage

Voltage in Electric Circuits

Voltage in electric circuits is the energy needed to move electric charge between two points. It is also called electromotive force, or EMF. In most circuits, an external force such as a battery provides this energy for electron movement in a conductor. The voltage between points a and b is written as v_ab. It is defined as the work, or energy, needed to move a unit charge from point a to point b. In the equation, w is the energy in joules and q is the charge in coulombs. Voltage is measured...

power and energy

Circuit Power, Absorption, and Supply

Circuit power, absorption, and supply explain how much energy an element uses or delivers in an electric circuit. These ideas matter in electrical engineering because power and energy calculations help describe circuit behavior. A 100-watt light bulb, for example, emits more light than a 60-watt bulb, so wattage is a useful measure in real devices. Power is the time rate of expending or absorbing energy. It is measured in watts, written as W. The relation between power and energy uses the...

electric circuit elements

Circuit elements are the building blocks of an electric circuit. An electric circuit is the connection of these elements. In this context, circuit elements are often grouped by how they behave and whether they supply energy. One major group is passive elements. These elements do not generate energy. Common passive elements include resistors, capacitors, and inductors. The other group is active elements, which can generate energy. Generators, batteries, and operational amplifiers are typical...

circuit terminology

Circuit Parts: Branches, Nodes, and Loops

Circuit parts like branches, nodes, loops, and meshes help describe how electrical networks work. An electrical network is a system of connected elements, such as resistors, capacitors, inductors, and voltage or current sources. Unlike a circuit, a network does not have to form a closed path. A circuit is also made of connected electrical elements, but it must include one or more closed paths. These loops let current flow continuously, which is what makes the circuit operate. Because of this,...

independent and dependent sources

Circuit Source Symbols and Controls

Circuit sources in electrical circuits can be independent or dependent. They provide the power a circuit needs to operate. Independent voltage sources supply a fixed voltage, and independent current sources supply a fixed current. Their output does not change because of other parts in the circuit. These sources use standard symbols in circuit diagrams. An independent voltage source is shown with + and - signs to mark the potential difference. An independent current source is shown with an...

ohm's law

Resistance and Conductance in Circuits

Resistance and conductance help explain how electric current moves through a circuit. Resistors are basic circuit parts made from metallic alloys or carbon compounds. They are used to model how a material resists current and to control and regulate electrical power in a circuit. Ohm's law describes the link between voltage and current across a resistor. The voltage across a resistor is directly proportional to the current through it. The constant that sets this relationship is resistance.

kirchhoff's current law

Kirchhoff's Current Law at Circuit Nodes

Kirchhoff's Current Law explains how current behaves at a circuit node. A node is the point where two or more circuit elements meet. The law says the current entering a node equals the current leaving it. That balance follows the rule of charge conservation, which means electric charge is not lost at the junction. When applying KCL, currents entering the node are treated as positive and currents leaving the node are treated as negative. The currents can be added algebraically at the node, and...

kirchhoff's voltage law

Voltage Balance in Closed Circuit Loops

Kirchhoff's Voltage Law explains how voltage is balanced in a closed circuit loop. It is a basic rule in electrical engineering and comes from the idea of energy conservation. Energy can change form, but it cannot be created or destroyed. KVL states that the algebraic sum of all voltages around a closed path, or loop, is zero. In other words, the total voltage supplied in a loop equals the total voltage drop across the components in that loop. A loop can be traced clockwise or anticlockwise,...

voltage dividers

Series Resistors and Voltage Split

Series resistors split voltage across a circuit. In a series setup, resistors are linked one after another. The same current flows through each resistor in the chain. To analyze this behavior, Ohm's law is used to relate voltage, current, and resistance. Kirchhoff's voltage law says the voltages around a series loop add up to the source voltage. That means the current in the circuit equals the source voltage divided by the total resistance in series. The current value can then be used in Ohm's...

current dividers

Parallel Resistors and Current Division

Parallel resistors share the same two nodes, so each resistor has the same voltage across it. In this circuit setup, Kirchhoff's current law applies. The source current equals the sum of the currents through each branch. Ohm's law helps find the branch currents from the source voltage and the resistor values. The source current is equal to the source voltage times the sum of the reciprocals of the resistances. This makes it easier to calculate how current divides in the circuit. The current...

equivalent resistance

Delta-Wye Network Conversion

Delta-wye network conversion helps analyze resistor circuits that are not arranged in simple series or parallel paths. These three-terminal equivalent networks use the wye (Y), also called tee (T), and the delta (Δ), also called pi (π), as practical circuit models. These networks are useful in many circuit settings. They appear in three-phase electrical systems, electrical filters, and matching networks. They can also be used on their own or combined with more complex circuits. A delta...

design example: resistive touchscreen

Resistive Touchscreen Voltage Mapping

A resistive touchscreen uses voltage mapping to locate a finger touch on a mobile device. It is built from two metallic layers. The top layer is flexible, and the bottom layer is rigid. A narrow gap separates them, and the high resistance between the layers is an important part of the design. When a user touches the screen, the two layers meet at one point. That contact point is called the touchpoint. The touch lowers the resistance between the layers at that spot and changes the electrical...

key terms and concepts

Learn how circuit elements are grouped as passive or active, and how linear and nonlinear behavior affects circuit analysis. Includes examples like batteries and thermistors.

Circuit Elements: Passive, Active, and Linear | 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 Elements: Passive, Active, and Linear

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