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

Элементы цепи являются основными строительными блоками электрической цепи. Их можно разделить на активные и пассивные элементы.
Активные элементы могут генерировать энергию, в то время как пассивные элементы поглощают энергию.
Примерами активных элементов являются источники напряжения или тока, в то время как примерами пассивных элементов являются резисторы, конденсаторы и катушки индуктивности.
Элементы схемы могут быть дополнительно классифицированы как линейные и нелинейные.
Цепь или элемент считается линейным, если возбуждение и реакция элемента подчиняются принципам суперпозиции и однородности.
Предположим, что напряжение v1 приводит к ответу i1, а напряжение v2 приводит к ответу i2. Если элемент реагирует на сумму напряжений суммой откликов, то он удовлетворяет принципу суперпозиции.
Кроме того, удовлетворяется свойство однородности, когда умножение входного сигнала линейного устройства на любую константу приводит к эквивалентному умножению выходного сигнала.
Линейные элементы, такие как резисторы, конденсаторы и катушки индуктивности, обладают линейными характеристиками.
Такие элементы, как термисторы, являются нелинейными, так как не соответствуют этим принципам.

Элементы электрических цепей

Элементы контура являются основными строительными блоками электрической цепи. По сути, электрическая цепь – это взаимосвязь этих элементов. В электрических цепях можно встретить два типа элементов: пассивные и активные. Активные элементы обладают способностью генерировать энергию, а пассивные - нет. Пассивные элементы включают в себя такие компоненты, как резисторы, конденсаторы и катушки индуктивности, тогда как активные элементы обычно включают генераторы, батареи и операционные усилители.

Наиболее важными активными элементами являются источники напряжения или тока, которые обычно обеспечивают питание подключенной цепи. Существует множество способов классифицировать элементы схемы. Например, отличие линейных моделей от нелинейных имеет решающее значение, поскольку схемы, состоящие полностью из линейных элементов, легче анализировать, чем схемы с некоторыми нелинейными элементами.

Элемент или цепь считаются линейными, если возбуждение и реакция элемента соответствуют определенным условиям. Линейный элемент удовлетворяет как свойствам суперпозиции, так и однородности. Рассмотрим сценарий, в котором возбуждением является ток (i), а откликом — напряжение (v). Если элемент подвергается воздействию тока (i1), он выдает отклик (v1). Аналогично, когда элемент подвергается воздействию другого тока (i2), он вызывает отклик (v2).

Любой элемент схемы, который не соответствует ни принципу суперпозиции, ни принципу однородности, классифицируется как нелинейный. Терморезисторы являются примерами таких нелинейных элементов.

Элементы цепи являются основными строительными блоками электрической цепи. Их можно разделить на активные и пассивные элементы.
Активные элементы могут ...

Education

JoVE Core

Electrical Engineering

Электротехника

Unit 1

Раздел 1

Basics of Electric Circuits

Основы электрических цепей

KEY TERMS AND CONCEPTS

ОСНОВНЫЕ ТЕРМИНЫ И ПОНЯТИЯ

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 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 Elements: Passive, Active, and Linear

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