What is a Capacitor and why it is important in Electronic Circuit?
Hi guys you all know that capacitor is an electronic component which can store energy. But here in this article you will other important information about capacitor.
Related Article: What is a Resistor and why it is important in electronic circuit?
So what is a capacitor?
A capacitor is an electrical component with two terminals. It is a basic component. By nature it is a Passive component. In all electronic PCB you can easily find a capacitor which means it is an essential part of electronic circuit.
Capacitor Symbols and Units
Capacitor has two terminals as shown in schematic. Don’t confuse with Battery symbol because it is similar with capacitor.
Capacitor is denoted by “C”. If in a electronic circuit it will be C1, C2…
Unit of capacitors is in Farad. It denoted by “F” but Farad is a very large unit but actually we don’t use such a large size capacitor. In electronic circuit we required very small capacitor. So generally we use prefix with Farad. A table is given with prefix.
|Prefix Name||Abbreviation||Weight||Equivalent Farads|
How a capacitor constructed & how it works?
Construction of a capacitor is very easy. For construction of a capacitor we required 2 metal plates and a dielectric material. Here dielectric material sandwich between those metal plates and finally metal plates connected with terminals. The gap between metal plates should be very small (in mm) but ensure that both plates should be electrically isolated with each other. Usually a dielectric material is made from paper, glass, rubber or plastic etc. Generally metal plates are made from Aluminum.
The capacity of a capacitor is depend on given equation. As shown in figure capacity of capacitor increases if metal plate’s cross-section area increases & distance or gap between two metal plates decreases.
Here in equation εr is the dielectric’s relative permittivity, A is area of metal Plates, and d is the gap between plates.
Working of a capacitor
As shown in above picture when capacitor is connected with a power source it store some amount of charge in its metal plate. This phase is called charging of capacitor. Here positive and negative charges stored on the capacitor plates; an electric field is developed inside capacitor. This electric field – hold this charge. When capacitor stored charge`s electric field power is equivalent to battery`s electric field power, at that moment charging of capacitor goes complete. After it there is no current flow in capacitor terminal & capacitor is fully charged.
After it when capacitor terminal is connected with a resistance or any load it provide a path to flow electron. This is called discharging of a capacitor.
Available Capacitors for electronic project
Types of Capacitors
In market generally there are two type of capacitors are available.
Ceramic capacitor is small in size and also it has very small capacitance. Maximum size of ceramic capacitor is 10µF. It is a small yellow solid bulb shaped with two metal terminals.
It is a cylindrical shaped capacitor with two metal terminals. It has Positive & negative terminal. As compared to ceramic capacitor it has high capacitance and suitable to high voltage application.
In market a lot of capacitor available, you can choose as per your application. Here in upcoming article you will get details about application of capacitors.