on video What is the purpose of capacitor?

What is the purpose of capacitor?

What is the Role of Capacitor in AC and DC Circuit?

Role of Capacitor in AC Circuits:

In an AC circuit, capacitor reverses its charges as the current alternates and produces a lagging voltage (in other words, capacitor provides leading current in AC circuits and networks)

Role of Capacitor in DC Circuits:

In a DC Circuit, the capacitor once charged with the applied voltage acts as an open switch.

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What is a Capacitor?

The capacitor is a two terminal electrical device used to store electrical energy in the form of electric field between the two plates. It is also known as a condenser and the SI unit of its capacitance measure is Farad “F”, where Farad is a large unit of capacitance, so they are using microfarads (µF) or nanofarads (nF) nowadays.

A capacitor is similar to a battery, as both stores electrical energy. A capacitor is a much simpler device that can’t produce new electrons, but stores them. Inside the capacitor the terminals connected with the two metal plates separated by dielectric material (such as waxed paper, mica, and ceramic), that separate the plates and allows them to hold opposite electrical charges maintaining electrical field.

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Capacitors can be useful for storing charge and quickly discharging into the load. In a simple way, a capacitor also works as a small rechargeable battery. The electrical equivalent symbol of different types of capacitor is given below:

Now, we know the concept of the capacitor’s charging and its structure but, do you know what Capacitance is? The capacitance is the ability of a capacitor to store the charge into it. There are some factors which affect the capacitance.

Plate’s Area

Gap between the plates

Permittivity of the insulating material

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A capacitor has a wide range of applications in electronics, such as Energy Storage, Power Conditioning, Power factor correction, Oscillators and filtration.

In this tutorial we will explain to you, how you can use a capacitor in an electronic circuit. There are three ways to connect a capacitor in an electronic circuit,

Capacitor in Series

Capacitor in Parallel

Capacitor in AC Circuits

Capacitor in DC Circuits

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How Capacitor Works?

Working and Construction of a Capacitor

Whenever voltage is applied across its terminals, (Also known as charging of a capacitor) current start to flow and continue to travel until the voltage across both the negative and positive (Anode and Cathode) plates become equal to the voltage of the source (Applied voltage). These two plates are separated by a dielectric material (such as mica, paper, glass, etc. which are insulators), which is used to increase the capacitance of the capacitor.

When we connect a charged capacitor across a small load, it starts to supply the voltage (Stored energy) to that load until the capacitor fully discharges.

Capacitor comes in different shapes and their value is measured in farad (F). Capacitors are used in both AC and DC systems (We will discuss it below).

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Capacitance(C):

Capacitance is the amount of electric charge moved in the condenser (Capacitor), when one volt power source is attached across its terminal.

Mathematically,

Capacitance Equation:

C=Q/V

Where,

C = Capacitance in Farads (F)

Q = Electrical Charge in Coulombs

V = Voltage in Volts

We will not go in detail because our basic purpose of this discussion is to explain the role and application/uses of capacitors in AC and DC systems. To understand this basic concept, we have to understand the basic types of capacitor related to our topic (as there are many types of capacitor and we will discuss the latter capacitor types in another post because it is not related to the question).

Why AC Needs More Insulation Than DC at Same Voltage Level?

Capacitors in Series

How to Connect Capacitors in Series?

In series no capacitor is directly connected to the source. To connect them in series you need to join them end to end, as shown in the below image,

When you connect the capacitors in series the total capacitance is decreased. Hence, the connection is in series so the current through the capacitors will be equal. Also, the charge stored by plate of capacitor will be the same because it is coming from the adjacent capacitor’s plate.