Capacitor | Working | Explanation | Calculations

Hey Guys, I’m back again with another interesting article on Basic Electronics. Today we are going to discuss about  CAPACITOR. Yes, most of you must be amazed by listening to this and wonder that is rather quite simple, but it isn’t as it seems to be. So to clear up Basic Concepts about capacitors and understanding how it works?. We are taking up this topic to give you all the clear picture of this. Let’s begin!!!

What is Capacitor 🙄🙄🙄?

Capacitors word first make our assumption to capacity or storage. Yes, it is a device which is used to store a small amount of charge. Charge is the very basic quantity of electricity. Everything in electricity which needs to do something require some amount of power, or we can say that it requires charge. There are various types of capacitors which are available in the market and for various purpose. But the most basic form can be called a parallel plate capacitor.

Capacitors are used for various purpose like purifying current, decoupling, signal processing, also as oscillators. Let’s discuss about these in detail later. The capacitors are very useful while making breadboard circuits or making some practice implementations in early stages as careful calculations need to be made at that time but in finished product we won’t be able to do sometimes.

Working of Capacitor:

Working of capacitors are rather very simple. Capacitors usually stores some charge in it at specific voltage to perform certain tasks. Like in DC or AC motors it is used as starters which provides some backup charge in it to soft start motors. Or in Rectifiers or Transformers circuits it is used as decoupling and purifying capacitors. Also in RF circuits it is used as signal processing and antenna purpose.

These all works to reduce the electric field which is developed due to high voltage and current flow in circuit. Like in amplifiers circuits it is very compulsory to use capacitors or there will be some type of noises. Or in Audio in circuits, To connect the microphone to the circuit a capacitor is used in series with the microphone to reduce the disturbances and noise developed.

Measuring Capacitance & Connections:

Capacitance can be measured by using measuring devices like multimeters or using formulas. As I have described earlier that the most basic Capacitor is PARALLEL PLATE CAPACITOR. Parallel plate capacitor is a simple arrangement of two conducting metal plates kept at a small distance apart. When these plates are connected with power supply, one plates accumulates positive charge while the other accumulates negative charge.

The distance in filled with some sort of dielectric material. This dielectric material is solely responsible for increase and decrease in capacitance. For this, we can either use a multimeter like images below or use this formula for calculating CAPACITANCE. CAPACITANCE is defined as the tendency of a component in a circuit to store some amount of energy in the form of charge at a specific voltage.

RICHMETERS R113D

UNITY DT-9205A

These are the two multimeters which I use personally for my all projects and demonstrations. These can easily be found on the net. RICHMETERS R113D, UNITY DT-9205A. Frankly, I say that I have purchased Richmeters one from AliExpress at a cheaper price. But as in INDIA now AliExpress is banned, you may find it a bit costly.

Now if you want to measure capacitance using Formula then here it is

C=εoKA/d

Here εo is Permittivity of free space, K is dielectric constant, A is Area of the plate and d is the distance between the plates.  C is the capacitance of the capacitor its unit is Farad. Also, the relation between charge, voltage and capacitance is:

q=CV

Here is the table for calculation of the capacitance according to the code printed on it:

Parallel Combination:

If capacitors are connected in parallel in the circuit then it is opposite to the resistors means, capacitance is added like Cnet = C1 + C2 + C3 + ……………. + Cn. But keep in mind if you are using capacitance rated at different voltages then supply voltage with reference to the lowest rated one else capacitors will blast like firecrackers 🧨🧨 in the circuit, and it could be dangerous. Believe me it is not fun guys to play with electronics it is much dangerous than you see it while reading I had experienced it personally.

Series Combination:

If capacitors are connected in Series, then capacitance is added in reciprocal way like:

1/Cnet =1/C1 + 1/C2 + 1/C3 + ……………….. + 1/Cn or to simplify this it can be written as Cnet = C1 x C2 x C3 x …………….. x Cn/(C1 + C2 + C3 + …………………… + Cn).

Types of Capacitor:

On the basis of polarity:

Polar Capacitor:

These are capacitor which have specif pins for positive and negative terminals. These are advised to be connected as the pins are defined, if connected in the wrong way it may malfunction or behave improperly.

Non-polar Capacitors:

These are capacitors which are not defined for any polarity or terminals. It can be connected in any position, it does not affect the behavior or malfunction like polar capacitors.

On the basis of Material & Composition:

Parallel Plate Capacitor or Dielectric Capacitor

These capacitors are the most basic one, which are made of two simple conducting plates. These are mainly filled with air or left open so, that air act as dielectric. In this type, the capacitance can be changed by changing the dielectric or moving the plates away or near as needed.

Film Capacitors

These capacitors are made of films and enclosed in epoxy like substance. These are generally non-polar capacitors which can be connected in any position. But these come in a small range of values upto 100µF. The cap is mainly used in high voltage and current devices, somewhat like AC devices.

Radial & Axis Lead Capacitors

These capacitors are as the same as Film capacitors, but they are rolled into axis type or radial type with dielectric film sandwiched between them. These are also mainly non-polar, which can be connected in any way. Also, they come in small range. But they are used in more power and precise devices for stability and efficient working.

Ceramic Capacitors

These are capacitors to which we are most familiar. These are the most common, easily available and wide range of values available in the market. They are mainly non-polar and can be used only in low power devices. The can withhold small amount of power and at medium voltage. They are basically coded according to the chart mentioned above. They come in both SMD and DIP version.

Electrolytic Capacitors

This is the last type of capacitors we are discussing today. If you are a hobbyist and have craze to open destroyed appliances. Then you must have seen these type of capacitors a lot. They come in both SMD version and DIP version. They are basically polar capacitors which are advised to be connected in the correct polarity or may cause dangerous effects. Also, they blast which a great energy and sound is connected in overvoltage 😂😂😂.

So, At this point, we come to an end to this Basic Electronic article. Have fun reading it and if you get some doubt then you can comment below freely.

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