Name: capacitor voltage and charge behavior
Uploaded: 2024-04-11T12:48:38.000Z
Duration: 1 min 10 s
Channel: JoVE

K12 Standards

new-jersey-student-learning-standards-for-science

New Jersey Student Learning Standards for Science

High School

Physical Science

Energy

HS-PS3-2

Energy Stored in Capacitors

Um capacitor de placa paralela conectado a uma bateria desenvolve uma diferença de potencial entre suas placas.
Ao integrar a equação que relaciona tensão e corrente, uma equação para a tensão no capacitor em um determinado momento é determinada.
Os capacitores possuem memória, o que significa que sua tensão depende do fluxo de corrente passado.
A energia instantânea fornecida a um capacitor é integrada ao longo do tempo para determinar a energia armazenada no capacitor.
Um capacitor não carregado tem uma tensão zero. Assim, a energia armazenada no capacitor é determinada em termos de carga e capacitância, que representa a energia presente no campo elétrico entre as placas.
Essa energia pode ser recuperada, pois um capacitor ideal não dissipa energia.
Um capacitor não ideal tem uma resistência a vazamentos de modelo paralelo, geralmente alta o suficiente para ser negligenciada na maioria das aplicações práticas.
Um capacitor pode ser carregado quando conectado a uma bateria, mas atua como um circuito aberto para tensão CC.
A tensão em um capacitor é sempre contínua e não pode mudar abruptamente.

energia armazenada em capacitores

Um capacitor de placas paralelas, quando conectado a uma bateria, desenvolve uma diferença de potencial entre suas placas. Essa diferença de potencial é fundamental para o funcionamento do capacitor, pois determina quanta energia elétrica o capacitor pode armazenar.

Ao integrar a equação que relaciona tensão e corrente em um capacitor, pode-se derivar uma equação para a tensão através do capacitor a qualquer momento. Esta equação é crucial para compreender e prever o comportamento de capacitores em circuitos eletrônicos.

Uma propriedade interessante dos capacitores é que eles possuem uma espécie de memória. A tensão através de um capacitor em qualquer momento depende do fluxo passado de corrente através dele. Isso significa que os capacitores podem “lembrar” seu histórico de carga e descarga, o que pode ser útil em diversas aplicações, como armazenamento de memória em computadores.

A potência instantânea fornecida a um capacitor pode ser usada para determinar a quantidade de energia armazenada no capacitor. Se considerarmos um capacitor descarregado no tempo igual a menos infinito, ele terá tensão zero. Isto significa que a energia armazenada no capacitor pode ser determinada em termos de carga e capacitância. Isso representa a energia presente no campo elétrico entre as placas.

Esta energia armazenada pode ser recuperada em termos de potência, uma vez que um capacitor ideal não dissipa energia. No entanto, os capacitores do mundo real não são ideais. Um capacitor não ideal tem uma resistência de vazamento de modelo paralelo, mas geralmente é alta o suficiente para ser negligenciada na maioria das aplicações práticas.

Uma característica única dos capacitores é que eles atuam como um circuito aberto à tensão de corrente contínua (DC), mas podem ser carregados quando conectados a uma bateria. Esta propriedade permite que os capacitores bloqueiem a DC enquanto permitem a passagem da corrente alternada (AC).

Outra característica importante dos capacitores é que a tensão entre eles é sempre contínua e não pode mudar abruptamente. Esse comportamento é essencial em muitas aplicações, como suavização de tensão em fontes de alimentação e filtragem de ruído no processamento de sinais.

Concluindo, compreender os capacitores, suas propriedades e seu comportamento em circuitos é um aspecto fundamental da eletrônica. Ele permite que os engenheiros projetem e construam sistemas eletrônicos complexos que são essenciais para a vida moderna.

Energia Armazenada em Capacitores

Um capacitor de placa paralela conectado a uma bateria desenvolve uma diferença de potencial entre suas placas.
Ao integrar a equação que relaciona tensão e ...

Education

JoVE Core

Electrical Engineering

Engenharia Elétrica

Unit 1

Unidade 1

Energy Storage Elements

Elementos de Armazenamento de Energia

KEY TERMS AND CONCEPTS

TERMOS-CHAVE E CONCEITOS

capacitor voltage and charge behavior

Capacitor voltage and charge behavior depend on how a parallel plate capacitor connects to a battery. When the battery is attached, a potential difference forms across the plates. That voltage determines how much electrical energy the capacitor can store.

The voltage across a capacitor can be found by integrating the equation that links voltage and current. That relationship lets students predict the voltage at any moment during charging or discharging. It also shows why a capacitor keeps a record of its past current flow. In that sense, the capacitor has a kind of memory.

This memory effect means the voltage at one moment depends on what happened earlier in the circuit. That idea is useful in applications such as memory storage in computers. The instantaneous power delivered to the capacitor can then be used to calculate the energy stored in it.

If the capacitor starts uncharged at time equals minus infinity, its initial voltage is zero. From there, the stored energy can be written in terms of charge and capacitance. That energy is the energy in the electric field between the plates. An ideal capacitor can give that energy back because it does not dissipate energy.

Real capacitors are not perfect. A non-ideal capacitor has a parallel-model leakage resistance, but this resistance is usually high enough to ignore in most practical cases. Capacitors also act as an open circuit for direct current, yet they can still charge when connected to a battery. This is why they block DC while allowing alternating current to pass.

Another key feature is that capacitor voltage changes continuously. It cannot jump suddenly. This property is important in power supplies, where capacitors smooth voltage, and in signal processing, where they help filter out noise. Understanding these behaviors is a basic part of electronics and helps engineers build modern electronic systems.

Capacitor Voltage and Charge Behavior

capacitors

Capacitor Charge and Discharge

Capacitors store electric energy and help control signals in devices like car radios. They work by holding charge on two parallel conducting plates with a dielectric, which is the insulating material between the plates. When a voltage source is connected, positive charge builds up on one plate and negative charge builds up on the other. This charge separation creates a potential difference, and it keeps increasing until it matches the source voltage. The electric field inside the capacitor...

energy stored in capacitors

Capacitor voltage and charge behavior depend on how a parallel plate capacitor connects to a battery. When the battery is attached, a potential difference forms across the plates. That voltage determines how much electrical energy the capacitor can store. The voltage across a capacitor can be found by integrating the equation that links voltage and current. That relationship lets students predict the voltage at any moment during charging or discharging. It also shows why a capacitor keeps a...

series and parallel capacitors

Capacitance in Series and Parallel

Capacitors in series and parallel affect a circuit in different ways. These arrangements change the total capacitance, which is the circuit's overall ability to store charge. Knowing the difference helps explain how a circuit responds to signals. When capacitors are connected in series to a battery, the plate tied to the battery's positive terminal becomes positively charged. The plate connected to the negative terminal becomes negatively charged. The other plates develop equal and opposite...

equivalent capacitance

Capacitors in Series and Parallel

Capacitors in series and parallel can be simplified by replacing the group with one equivalent capacitor. This equivalent capacitor stores the same charge as the original network when the same potential difference is applied. The idea helps make complex capacitor circuits easier to analyze. In a parallel connection, capacitors share the same voltage across each branch. The equivalent capacitance of N capacitors in parallel is the sum of their individual capacitances. This type of connection...

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Inductors in Electric Circuits

Inductors are passive components used in electric circuits to store energy in a magnetic field. They are often made by coiling a wire around a magnetic core. This structure gives the component its inductive behavior and its ability to respond to changing current. When current flows through an inductor, the voltage across it is proportional to how quickly the current changes with time. This relationship is written using the passive sign convention, and the constant of proportionality is called...

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How Inductor Current Stores Magnetic Energy

An inductor stores energy in its magnetic field. That field is created by the current flowing through the coil. When the current stays steady, there is no measurable voltage across the inductor, so it behaves like a short circuit for direct current. The energy stored in an inductor is the total power delivered over time. It can be written as a function of inductance, L, and current, i, where the stored energy increases with the current in the coil. This relationship helps explain how much...

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Equivalent Inductance in Circuit Networks

Equivalent inductance in circuit networks helps simplify circuits with multiple inductors. When inductors are combined, the circuit can often be replaced by one inductor with the same effect on the current and voltage. For inductors in series, the same current flows through each component. Applying Kirchhoff's voltage law shows that the total voltage is the sum of the inductor voltages. As a result, the equivalent inductance of a series group is the sum of the individual inductances. This is...

design example: automobile ignition system

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Car Spark Coil Voltage Design Example

An automobile ignition system uses a spark plug and a spark coil to create the high voltage needed to ignite the fuel-air mixture in each cylinder. The spark plug has two electrodes with an air gap between them. When enough voltage appears across that gap, a spark forms and starts combustion. A 12-volt car battery does not create that spark by itself. The system uses an inductor, which is a component that resists rapid changes in current, to build a much larger voltage. In this ignition setup,...

key terms and concepts

Learn how capacitor voltage builds, how charge stores energy, and why capacitors block DC, pass AC, and smooth voltage in circuits.

Capacitor Voltage and Charge Behavior | 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

Texas Essential Knowledge and Skills

Chemistry and Physics

IPC.6

IPC.6.A

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South Carolina College and Career Ready Science Standards

Physics

motion-and-stability-forces-and-interactions

Motion and Stability: Forces and Interactions

P-PS2-5

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Clarification statement: Emphasis is on explaining the meaning of mathematical expressions used in the model. 

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Clarification statement: Emphasis is on analyzing data from student investigations and using mathematical thinking to describe the energy changes both quantitatively and conceptually. Examples of investigations could include mixing liquids at different initial temperatures or adding objects at different temperatures to water. 

Assessment Boundary: Assessment is limited to investigations based on materials and tools provided to students.

HS-PS3-4

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Magnetic Fields

Source: Yong P. Chen, PhD, Department of Physics &#38; Astronomy, College of Science, Purdue University, West Lafayette, IN
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Assessment Boundary: Assessment is limited to systems containing two objects.

HS-PS3-5

Capacitor Voltage and Charge Behavior

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