Name: capacitor charge and discharge
Uploaded: 2024-04-11T12:48:38.000Z
Duration: 1 min 15 s
Channel: JoVE

K12 Standards

Texas Essential Knowledge and Skills

High School

Chemistry and Physics

IPC.6

IPC.6.A

Capacitors

Car radios utilize capacitors to filter frequencies for clear signal reception.
Capacitors consist of two parallel conducting plates separated by a dielectric and store energy in their electric field.
Upon connecting a voltage source, positive and negative charges accumulate on opposite plates, generating a potential difference that equals the product of the electric field and the distance between the plates until it reaches the source voltage.
The electric field is proportional to the charge density, given by the total charge divided by the area of the plates.
The stored charge is directly proportional to the applied voltage, and the proportionality constant, known as capacitance, indicates the amount of charge stored to create a given potential difference. It is measured in farads.
For capacitors with a dielectric, the capacitance is directly proportional to the plate area and dielectric permittivity but inversely proportional to the distance between the plates.
Differentiating the charge-voltage equation of a capacitor with respect to time gives the current.
Charged capacitors discharge when connected to a load, and electrons flow in a reverse direction until the potential reaches zero.

capacitors

Capacitors play a crucial role in car radios, where they filter and store frequencies to ensure clear signal reception. Essentially serving as energy storage devices, capacitors store energy within their electric field and are composed of two parallel conducting plates separated by a dielectric.
When a voltage source is connected to a capacitor, positive and negative charges accumulate on the opposite plates. This accumulation generates a potential difference that equals the product of the electric field and the distance between the plates. This process continues until the potential difference reaches the source voltage.
The electric field within a capacitor is proportional to the charge stored on the plates and the area of the plates. The stored charge is directly proportional to the applied voltage. The proportionality constant in this relationship is known as capacitance, which indicates the amount of charge needed to create a given potential difference. The unit used to measure capacitance is the farad.
For parallel plate capacitors, the capacitance is directly proportional to the plate area and the permittivity of the dielectric, which is the material&#39;s ability to store electrical energy. Meanwhile, the capacitance is inversely proportional to the distance between the plates; the closer the plates, the higher the capacitance.
By differentiating the charge-voltage equation of a capacitor with respect to time, one can derive the current flowing through the capacitor. This is particularly important when considering how capacitors behave in circuit designs.
Furthermore, when a charged capacitor is connected to a load, it discharges. During this discharge process, electrons flow in the reverse direction until the potential difference across the plates reaches zero. This ability to store and release electrical energy makes capacitors invaluable components in many electronic devices. By understanding how they work, engineers can design more effective and efficient electronic systems.

Car radios utilize capacitors to filter frequencies for clear signal reception.
Capacitors consist of two parallel conducting plates separated by a ...

Education

JoVE Core

Electrical Engineering

Unit 1

Energy Storage Elements

KEY TERMS AND CONCEPTS

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 depends on the charge on the plates and the plate area.

The amount of charge stored is directly proportional to the applied voltage. The constant that links charge and voltage is called capacitance, and it is measured in farads. For a parallel plate capacitor, capacitance increases with larger plate area and with higher permittivity of the dielectric. Permittivity describes how well a material stores electrical energy. Capacitance also decreases when the plates are farther apart, so closer plates give a higher capacitance.

Capacitors also affect current in circuits. If the charge-voltage equation is differentiated with respect to time, it gives the current through the capacitor. When a charged capacitor is connected to a load, it discharges. Electrons then flow in the reverse direction until the potential difference drops to zero. This ability to store and release energy makes capacitors important in many electronic systems.

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

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 capacitors store charge, build potential difference, and discharge in circuits. See how plate area, distance, and dielectric affect capacitance.

Capacitor Charge and Discharge | 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

Resistors In Series

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Resistors In Parallel

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Combination Of Resistors

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Energy Transfer in Chemical Reactions

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Energy Stored in Capacitors

A parallel plate capacitor connected to a battery develops a potential difference across its plates.
By integrating the equation relating voltage and ...

Series and Parallel Capacitors

Capacitors can be connected in series and/or parallel configurations within a circuit.
Consider the capacitors connected in series to a battery; the plate ...

Equivalent Capacitance

Consider a complex capacitor network with three groups of capacitors connected in parallel, and these groups are then connected in series with each other. ...

Inductors

Inductors, often referred to as coils or chokes, play a crucial role in various electronics and power systems.
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Energy Stored in Inductors

An inductor is designed to store energy in its magnetic field, which is generated by the current flowing through its coils.
When the current is constant, ...

Series and Parallel Inductors

Inductors connected in series and/or parallel configurations can be simplified to an equivalent single inductor.
Consider a series connection of inductors ...

Design Example: Automobile Ignition System

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Design and construct series and parallel circuits that model real-world circuits such as in-home wiring, automobile wiring, and simple electrical devices to evaluate the transfer of electrical energy

Magnetism

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Magnetic Fields

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Design, evaluate, and refine a device that generates electrical energy through the interaction of electric charges and magnetic fields

IPC.6.B

Energy

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Conservation of Energy

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Conservation of Energy: Application

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Simple Harmonic Motion

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Plan and conduct an investigation to provide evidence that energy is conserved within a closed system.

IPC.6.C

Mechanisms of Heat Transfer I

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Mechanisms of Heat Transfer II

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Conduction, Convection and Radiation: Problem Solving

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Investigate and demonstrate the movement of thermal energy through solids, liquids, and gases by convection, conduction, and radiation such as weather, living, and mechanical systems.

IPC.6.D

Travelling Waves

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Wave Parameters

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Electromagnetic Waves

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Propagation Speed of Electromagnetic Waves

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Energy Carried By Electromagnetic Waves

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Intensity Of Electromagnetic Waves

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Plan and conduct an investigation to evaluate the transfer of energy or information through different materials by different types of waves such as wireless signals, ultraviolet radiation, and microwaves.

IPC.6.E

Interference and Superposition of Waves

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Reflection of Waves

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Reflection and Refraction

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Interference and Diffraction

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Construct and communicate an evidence-based explanation for how wave interference, reflection, and refraction are used in technology such as medicine, communication, and scientific research.

IPC.6.F

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Global Climate Change

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Evaluate evidence from multiple sources to critique the advantages and disadvantages of various renewable and nonrenewable energy sources and their impact on society and the environment.

IPC.6.G

Science concepts. The student knows the impact of energy transfer and energy conservation in everyday life. The student is expected to:

Capacitor Charge and Discharge

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