# Capacitor Basics in Electronics

Understand Capacitor Basics in Electronics – Types of Capacitor and their Uses, Function in Circuit, Unit, Formula Explained with Diagram, Images, Video.

Here we understand Capacitor Basics in Electronics – Types of Capacitor and their Uses, Function in a Circuit, Unit and Formula Explained with Diagram, Images and Video. ## What is Capacitor?

A capacitor is an electronic component to store electric charge. It is a passive electronic component that can store energy in the electric field between a pair of conductors called “Plates”.

In simple words, we can say that a capacitor is a component to store and release electricity, generally as the result of a chemical action. The Leyden Jar was an early example of a capacitor.

Capacitors consist of two conducting surfaces separated by an insulator; a wire lead is connected to each surface.

## Capacitor Units and Symbol

### Capacitor Symbol

There are two capacitor symbols generally used in electronics. One symbol is for polarized capacitors, and the other symbol is for non-polarized capacitors.

In the diagram  below, the symbol with one curved plate represents a Polarized Capacitor. The curved plate represents the cathode (– ve) of the capacitor, and the other plate is anode (+ ve). Sometimes a plus sign is also added to the +ve side. Capacitor Symbol of Polarized and Non-Polarized Capacitors

### Capacitor Unit

The SI unit of capacitance is farad (Symbol: F). The unit is named after the Great English Physicist. Michael Faraday.

A 1 farad capacitor, when charged with 1 coulomb of electrical charge, has a potential difference of 1 volt between its plates.

## Different Types of Capacitors

There are several types of capacitors for different application and function. Following are the Most Common Types of Capacitors:

### 1. Ceramic Capacitor

These are non-polarized capacitors made out of two or more alternating layers of ceramic and metal. The ceramic acts as the dielectric and the metal acts as the electrodes.

Ceramic Capacitors are also called “Disc Capacitors.” Thru-Hole and SMD Type Ceramic Capacitor

### 2. Electrolytic Capacitor

Electrolytic capacitors are polarized. This means that the positive lead of the capacitor must be connected with positive terminal and negative lead to the negative terminal. Not doing so will damage the capacitor.

These types of capacitor are generally used where large capacitance is needed. Thru-Hole and SMD Type Electrolytic Capacitor

### 3. Film Capacitor

Film capacitors or plastic film capacitors are the most common type of capacitor used in most electronic circuit. There are are non-polarized.

They are highly reliable, have long life and have less tolerances. They also function well in high temperature environment. Thru-Hole and SMD Type Film Capacitor

### 4. Variable Capacitor

These are non-polarized capacitor. They have moving and fixed plates to determine the capacitance and are generally used in circuit of Transmitters and Receivers, Transistor Radios etc. Thru-Hole and SMD Type Variable Capacitor

## Diagram to Explain How Capacitor Works A simple capacitor connected to a battery through a resistor Time dependence of current in the circuit

## Capacitor uses and function

The main function of a capacitor is to store electric energy in an electric field and release this energy to the circuit as and when required. It also allows to pass only AC Current and NOT DC Current.

## Formula to Calculate Capacitance of a Capacitor?

• The formula for total capacitance in a parallel circuit is: CT=C1+C2…+Cn.
• The formula for total capacitance in a series circuit is : CT={1{1C1}+{1C2}…+{1Cn}}.

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