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

Un condensateur à plaques parallèles connecté à une batterie développe une différence de potentiel à travers ses plaques.
En intégrant l’équation reliant la tension et le courant, une équation pour la tension aux bornes du condensateur à un moment donné est déterminée.
Les condensateurs possèdent une mémoire, ce qui signifie que leur tension dépend du flux de courant passé.
La puissance instantanée délivrée à un condensateur est intégrée dans le temps pour déterminer l’énergie stockée dans le condensateur.
Un condensateur non chargé a une tension nulle. Ainsi, l’énergie stockée dans le condensateur est déterminée en termes de charge et de capacité, ce qui représente l’énergie présente dans le champ électrique entre les plaques.
Cette énergie peut être récupérée car un condensateur idéal ne dissipe pas d’énergie.
Un condensateur non idéal a une résistance aux fuites sur un modèle parallèle, généralement suffisamment élevée pour être négligée dans la plupart des applications pratiques.
Un condensateur peut se charger lorsqu’il est connecté à une batterie, mais agit comme un circuit ouvert vers la tension continue.
La tension aux bornes d’un condensateur est toujours continue et ne peut pas changer brusquement.

Énergie stockée dans des condensateurs

Un condensateur à plaques parallèles, lorsqu'il est connecté à une batterie, développe une différence de potentiel entre ses plaques. Cette différence de potentiel est essentielle au fonctionnement du condensateur, car elle détermine la quantité d’énergie électrique que le condensateur peut stocker. En intégrant l'équation qui relie la tension et le courant dans un condensateur, on peut dériver une équation pour la tension aux bornes du condensateur à un moment donné. Cette équation est cruciale pour comprendre et prédire le comportement des condensateurs dans les circuits électroniques. Une propriété intéressante des condensateurs est qu’ils possèdent une sorte de mémoire. La tension aux bornes d’un condensateur dépend à tout moment du flux de courant passé qui le traverse. Cela signifie que les condensateurs peuvent « mémoriser » leur historique de charge et de décharge, ce qui peut être utile dans diverses applications telles que le stockage en mémoire dans les ordinateurs. La puissance instantanée délivrée à un condensateur peut être utilisée pour déterminer la quantité d'énergie stockée dans le condensateur. Si l’on considère un condensateur non chargé au temps égal à moins l’infini, sa tension est nulle. Cela signifie que l'énergie stockée dans le condensateur peut être déterminée en termes de charge et de capacité. Cela représente l'énergie présente dans le champ électrique entre les plaques. Cette énergie stockée peut être récupérée en termes de puissance puisqu’un condensateur idéal ne dissipe pas d’énergie. Cependant, les condensateurs du monde réel ne sont pas idéaux. Un condensateur non idéal a une résistance de fuite de modèle parallèle, mais celle-ci est généralement suffisamment élevée pour être négligée dans la plupart des applications pratiques. Une caractéristique unique des condensateurs est qu’ils agissent comme un circuit ouvert à la tension continue (CC), mais peuvent se charger lorsqu’ils sont connectés à une batterie. Cette propriété permet aux condensateurs de bloquer le courant continu tout en laissant passer le courant alternatif (AC). Une autre caractéristique importante des condensateurs est que la tension à leurs bornes est toujours continue et ne peut pas changer brusquement. Ce comportement est essentiel dans de nombreuses applications, telles que le lissage de la tension dans les alimentations électriques et le filtrage du bruit dans le traitement du signal. En conclusion, comprendre les condensateurs, leurs propriétés et leur comportement dans les circuits est un aspect fondamental de l’électronique. Il permet aux ingénieurs de concevoir et de construire des systèmes électroniques complexes qui font partie intégrante de la vie moderne.

Un condensateur à plaques parallèles connecté à une batterie développe une différence de potentiel à travers ses plaques.
En intégrant l’équation reliant la tension et ...

Education

Enseignement

JoVE Core

Electrical Engineering

Génie électrique

Unit 1

Unité 1

Energy Storage Elements

Éléments de stockage d'énergie

KEY TERMS AND CONCEPTS

TERMES ET CONCEPTS CLÉS

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...

inductors

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...

energy stored in inductors

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...

series and parallel inductors

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

design-example-automobile-ignition-system

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

south-carolina-college-and-career-ready-science-standards

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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HS-PS3-1

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Clarification statement: Examples of phenomena at the macroscopic scale could include the conversion of kinetic energy to thermal energy, the energy stored due to position of an object above the earth, and the energy stored between two electrically-charged plates. Examples of models could include diagrams, drawings, descriptions, and computer simulations.

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Clarification statement: Emphasis is on both qualitative and quantitative evaluations of devices. Examples of devices could include Rube Goldberg devices, wind turbines, solar cells, solar ovens, and generators. Examples of constraints could include use of renewable energy forms and efficiency. 

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HS-PS3-3

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Plan and conduct an investigation to provide evidence that the transfer of thermal energy when two components of different temperature are combined within a closed system results in a more uniform energy distribution among the components in the system (second law of thermodynamics). 

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

Maxwell's Equation Of Electromagnetism

James Clerk Maxwell (1831&#x2013;1879) was one of the major contributors to physics in the nineteenth century. Although he died young, he made major ...

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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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