This website uses cookies to ensure you have the best experience. Learn more

The Capacitor Essay

4985 words - 20 pages

The Capacitor
A typical electrolytic capacitor

A capacitor (originally known as a condenser) is a passive two-terminal electrical component used to store energy electrostatically in an electric field. In its basic form, a Capacitor consists of two or more parallel conductive (metal) plates which are not connected or touching each other, but is electrically separated either by air or by some form of a good insulating material such as waxed paper, mica, ceramic, plastic or some form of a liquid gel as used in electrolytic capacitors. The insulating layer between a capacitors plate is commonly called the Dielectric. The forms of practical capacitors vary widely, but all contain at ...view middle of the document...

However, when a capacitor is connected to an alternating current or AC circuit, the flow of the current appears to pass straight through the capacitor with little or no resistance.
There are two types of electrical charge, positive charge in the form of Protons and negative charge in the form of Electrons. When a DC voltage is placed across a capacitor, the positive (+ve) charge quickly accumulates on one plate while a corresponding negative (-ve) charge accumulates on the other plate. For every particle of +ve charge that arrives at one plate a charge of the same sign will depart from the -ve plate. Then the plates remain charge neutral and a potential difference due to this charge is established between the two plates. Once the capacitor reaches its steady state condition an electrical current is unable to flow through the capacitor itself and around the circuit due to the insulating properties of the dielectric used to separate the plates. The flow of electrons onto the plates is known as the capacitors Charging Current which continues to flow until the voltage across both plates (and hence the capacitor) is equal to the applied voltage VC. At this point the capacitor is said to be “fully charged” with electrons. The strength or rate of this charging current is at its maximum value when the plates are fully discharged (initial condition) and slowly reduces in value to zero as the plates charge up to a potential difference across the capacitors plates equal to the source voltage. The amount of potential difference present across the capacitor depends upon how much charge was deposited onto the plates by the work being done by the source voltage and also by how much capacitance the capacitor has and this is illustrated below.

Capacitor Construction
The parallel plate capacitor is the simplest form of capacitor. It can be constructed using two metal or metallised foil plates at a distance parallel to each other, with its capacitance value in Farads, being fixed by the surface area of the conductive plates and the distance of separation between them. Altering any two of these values alters the value of its capacitance and this forms the basis of operation of the variable capacitors.
Also, because capacitors store the energy of the electrons in the form of an electrical charge on the plates the larger the plates and/or smaller their separation the greater will be the charge that the capacitor holds for any given voltage across its plates. In other words, larger plates plus smaller distance equals more capacitance. By applying a voltage to a capacitor and measuring the charge on the plates, the ratio of the charge Q to the voltage V will give the capacitance value of the capacitor and is therefore given as: C = Q/V this equation can also be re-arranged to give the more familiar formula for the quantity of charge on the plates as: Q = C x V
Although we have said that the charge is stored on the plates of a capacitor, it is...

Other Essays Like The capacitor

Static Charge Essay

603 words - 3 pages was used to store charge in a Leiden Jar capacitor. The charged conductor was touched to the outside metal of theNeon bulbs were used to show the direction of electron flow and prove the Leiden Jar acted as a capacitor by storing the charge and not creating a circuit. The apparatuses used were plexi-glass, a Styrofoam plate, a neon bulb and a metal pan for the first part of the experiment. In the second part, a Leiden Jar was made by wrapping

Amplitude Demodulation Essay

677 words - 3 pages of LC1. Since the diode only conducts only during the half cycles and gives the result. Although the average input voltage is zero, the average output voltage across R always varies above zero. The low pass filter, made up of capacitor C2 and resistor R, removes the RF (carrier frequency) which so as far as the rest of the receiver is concerned serves no useful purpose. Capacitor C2 charges rapidly to the peak voltage through the small resistance

Electri Sequence

592 words - 3 pages meaning it’s all wired in parallel. Except that the defrost termination stat and defrost stat are wired in series together. The neutral wire comes from the plug or junction box and branches off where one wire goes to the capacitor and then to the contactor of the current relay and finally connected to the start winding of the compressor. And the other neutral wire that is brought down is then connected to the top of the current relay, at the coil

Electronic Engenier

1933 words - 8 pages obtain the greatest steady power dissipation? D 25. Which circuit will retain stored energy if the battery is connected to it and then disconnected? B because the capacitor can not discharge 26. A parallel-plate capacitor is charged by connection to a battery. If the battery is disconnected and the separation between the plates is increased, what will happen to the charge on the capacitor and the voltage across it? A) Both remain

The Unijunction Transistor

1300 words - 6 pages resistance. The simplest application of a UJT is as a relaxation oscillator, which is defined as one in which a capacitor is charged gradually and then discharged rapidly. The basic circuit is shown in Fig.7; in the practical circuit of Fig.8 R3 limits the emitter current and provides a voltage pulse, while R2 provides a measure of temperature compensation. Fig. 9 shows the waveforms occurring at the emitter and base 1; the first is an

Lab Report

641 words - 3 pages electric field between two charges electrodes by finding lines of equal potential. Once these are found, we construct the field map using the knowledge that the electric field lines are orthogonal to the lines of equipotential. Ideally, we are supposed to place on the electrodes by a direct current source such as a battery. Then, the two electrodes would form a charged capacitor whose field line geometry we should like to determine; however, this

My Style of Management

3748 words - 15 pages capacitor (EC, also named as supercapacitor) is a novel type of energy storage device whose capacitance is 20–200 times higher than that of an electrolytic capacitor [1, 2]. The supercapacitor has several advantages of high power density, long cycle life, short charge time and safety over the battery and attracts great interests for energy storage devices [3]. Depending on charge-storage mechanism, they are basically classified into two types: electric

Ruskin Bond.Rar

2792 words - 12 pages AMPLIFIERS Output IP3 Second Harmonic dBm dBm dBm dBm dBm dBm dBc dBc dBc At 10MHz At 30MHz At 50MHz At 10MHz At 30MHz At 50MHz At 10MHz At 30MHz At 50MHz 3-4 Rev C2 010813 RF2312 Pin 1 Function RF IN Description RF input pin. This pin is NOT internally DC-blocked. A DC-blocking capacitor, suitable for the frequency of operation, should be used in all applications. The device has internal feedback, and not using a DCblocking

Eo Assignment Write Up

711 words - 3 pages applied voltage. L/d is called as geometric factor. The equivalent electronic circuit for the electro optic modulator system is given below. In this model, the modulator is modelled as a capacitor. Electro-Optic Intensity Modulation One suitable example for this Intensity modulator is LiNbO3. In this a phase modulator is inserted between cross polarizers. Polarization is varied by changing the phase modulator voltage V(t). In this the

Term Paper Philippine Literature

1416 words - 6 pages ” that contain the frequency of the input as the fundamental, plus higher frequency harmonics. The output may then be passed through an LC (inductor-capacitor) circuit tuned to the frequency of the input sinusoid. This tuned circuit acts as a bandpass filter and yields a sinusoid at the output that is approximately the same frequency as the input (the narrower the passband, the closer the approximation). Power amplifier circuits contain

Nt1210 Intro to Networking

1443 words - 6 pages | 00110100 | | 19 | 10011 | 50 | 110010 | | 172 | 10101100 | 170 | 10101010 | | 14 | 1110 | 6 | 110 (binary) | | 0 | 0000 | 10. Which of the following answers best describes how RAM (capacitor) physically writes a binary 0 or 1? a. Using an electrical charge 11. A single hexadecimal digit is equivalent to ____4____ binary digits. 12. Complete the following to Decimal to binary to hexadecimal chart. Decimal | Binary | Hex

Related Papers

Investigating The Capacitance Of A Parallel Plate Capacitor Using A Reed Switch

1821 words - 8 pages Title: Investigating The Capacitance of a Parallel-plate Capacitor Using a Reed Switch Objective : To investigate the factors affecting the capacitance of a parallel-plate capacitor using a reed switch. Apparatus : Reed switch 1 Signal generator 1 Capacitor plate 2 Polythene spacers 16 Polythene sheet 1 Bateery box with 6V 1 Voltmeter 0 – 5 V 1 Resistance substitution box 1 Light-beam galvanometer 1 Standard mass 0.1


2896 words - 12 pages 1.0 Super Capacitor Lab 2.0 Flywheel Lab 3.0 Introduction to Labview 1.0 SUPER CAPACITOR LAB The aim of this task is to observe charge and discharge characteristics of a super capacitor, after that to compare achieved and theoretical characteristics. 1. 1: Recording the Supercapacitors Charge Characteristic PANASONIC - EECHW0D306 - CAPACITOR, RADIAL, 30F, 2.3V Farnell 1305076 Using the battery discharge test PCB setup the

Cv And Transistors Essay

1595 words - 7 pages PHYSICS HOMEWORK Institution Student name Introduction The homework is composed of discussions of the capacitor - voltage relationship (C-V characteristics) in MOS capacitors. Transistors are also part of the homework. The capacitor-voltage analysis is a technique that is widely used to determine wide range parameters of MOS capacitors. These parameters involve flat-band voltage, threshold voltage, substrate doping concentration and the

Global Single Layers Capacitors Industry 2015 Market Research Report

1071 words - 5 pages and is a valuable source of guidance and direction for companies and individuals interested in the market. Ask a sample or any question, please email to: or Table of Contents 1 Industry Overview of Broadband Capacitor 2 Production Cost and Processes of Broadband Capacitor 3 Production Market Segmentation of Broadband Capacitor 4 Global Summarized Data (Capacity