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Uses of Capacitor

Last updated date: 01st Mar 2024
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Overview of Capacitor

The majority of electronic equipment uses capacitors as essential parts. They are extensively utilised in electrical loads, power supply units, and electronic circuits. Along with resistors and inductors, capacitors are one of the "Big Three" passive components that make up fundamental electronic circuits.

In order to filter out erroneous electric impulses and stop harm from electric surges to delicate parts and circuits, capacitors play another more crucial function. We will read about the uses of capacitors in detail in this article. So, let's get started learning about this fascinating topic. Read ahead!

What is a Capacitor?

A capacitor is a device that stores energy in the form of electric charge. A capacitor's energy storage capacity is around 10,000 times smaller than that of a battery of the same size, yet it is still useful for a wide variety of circuit designs.

A capacitor is made from two metal plates that are separated by a substance called the dielectric. The dielectric can be constructed of any type of insulating material, such as paper, glass, ceramic, or anything that prevents the flow of current, whereas the plates are conductive and typically made of aluminium, tantalum, or other metals.

Different Types of Capacitors

Different Types of Capacitors

Uses of Capacitors

A capacitor is a device used to store electrical energy. It is an electrical component which has two terminals. There are many applications of capacitors, how about reading them one by one? Let’s have a look!

  • Bypass (Decoupling) Capacitors

Bypass or decoupling capacitors are typical examples. They are frequently used with electronic components and positioned between the IC's power source and the ground.

  • Converter from AC to DC

DC adapters are another common application for capacitors. Diode rectifiers are frequently used to convert AC voltage to DC voltage, however, they are ineffective without the aid of capacitors.

  • Filtering of Signals

A different use for capacitors is in signal filtering. They can block low-frequency sounds while enabling high frequencies to flow through due to their precise response time.

  • As Sensors

Capacitors are employed as sensors to measure a wide range of things, such as fuel levels, mechanical strain, and atmospheric humidity. The structure of a gadget affects its capacitance.

  • Relays for Power Conditioning 

The conditioning power supply is a crucial application for capacitors. When charged, capacitors block DC signals but let through AC signals.

Applications of Capacitor in a Fan

When you turn off the ceiling fan, you might have noticed that it doesn’t stop immediately; this is because the capacitor inside the fan will be discharging the energy. An average ceiling fan motor has two capacitors. The "start" capacitor is the first, and the "run" capacitor is the second.

For an AC motor to turn the motor shaft, there must be a revolving magnetic field (fan blades). This is accomplished by providing voltage with various phase combinations to various windings. There will be only a voltage phase in a single phase, such as the one in your home where a ceiling fan would be used. The capacitor is employed to give the motor's windings a phase shift, or a temporal offset between currents, creating the illusion that the motor is working in a multiphase system.

Role of Capacitor in a Fan

Role of Capacitor in a Fan

What does Capacitor do?

  • A capacitor is a device used to store the charge. It stores the charge between the two plates it consists of. It suppresses DC voltages.

  • It transmits AC voltages or signals; the greater the frequency permitted for transmission, the smaller the capacitance. The frequency that can pass depends on how big the capacitor is;

  • Unlike a battery, which can almost appear to be a battery for tiny current discharges, a supercapacitor keeps a charge but does not have a huge energy storage capacity;

  • You could add a few more suggestions to the list above by utilising multiples and connecting them to resistors, inductors, and other components, such as doing things like only allowing a specific frequency (or band) to go through or removing noise, as mentioned in previous articles. Our technology would be far more fundamental and constrained without capacitors.


In this article, we learned various important facts about capacitors. We learned that The purpose of a capacitor is to store electrical energy. Additionally, the capacitor serves as a filter, allowing alternating current (AC) while obstructing direct current (DC). In a circuit schematic, a capacitor is represented by this symbol. Two electrode plates facing each other but separated by an insulator make up the capacitor's construction. 

We also learned that each electrode on the capacitor stores an electric charge when a DC voltage is applied. Current flows as the capacitor are charged. When the capacitor is fully charged, the current will stop. Isn’t this article an answer to why use capacitors? We think it was since you have learnt the uses of capacitors above. 

FAQs on Uses of Capacitor

1. A capacitor is a battery?

An electronic device called a battery transforms chemical fuel into electrical energy to produce a static electric charge that serves as a power source. On the other hand, a capacitor is a part of an electrical device that stores electrostatic power inside an electric field.

2. Is a resistor necessary for a capacitor?

The majority of start capacitors lack a resistor. However, you will also need to use a resistor on the new capacitors if you need to replace a start capacitor that does have one.

3. Could a capacitor charge quickly?

Up to 63% of a supplied voltage can be charged into a capacitor in a single time constant. The capacitor would be charged to 99 per cent of the source voltage after 5-time constants.