History Of Capacitors

As the name suggests, capacitors are electronic devices that store electrical energy within a magnetic field. It’s a passive electronic part with two terminals. These components are designed to add capacitance and are known as capacitors, while capacitance can be found between any two conductors in close proximity in just electrical circuits. The original names for capacitors included ‘condenser’ and ‘condensator’. One notable exception is the condenser microphone, which is also known as a capacitor mic. 

History Of Capacitor

During the year 1745, things began to change when German scientist Ewald Georg von Kleist discovered that a charge could be stored by connecting an electrical generator to a glass container of water. He even conducted an experiment in which he took his own hand and water and made both of them, act as a conductor, along with that a jar as a dielectric. The same year similar capacitor was invented by Pieter van Musschenbroek, a Dutch scientist who dubbed the Leyden jar and named it after his workplace Leiden University. When wireless (radio) made standard capacitors more popular, they were eventually replaced by more powerful devices using flat glass plates alternately with foil conductors, which had a lower inductance but higher capacitance, which were only used in Leyden jars up until around 1900. After him, many scientists developed different capacitors, which included, Daniel Gralath, Benjamin Franklin, etc. 

Smaller packages, such as a flexible dielectric sheet (similar to oiled paper) sandwiched between sheets of metal foil, became more commonplace. Many high-power applications, such as automotive systems, still use the term “condenser” to refer to early capacitance. In 1782, Alessandro Volta coined the term to describe a device that could store a greater density of electric charge than an isolated conductor. As a result of the condenser’s ambiguity, the term “capacitor” has been preferred since 1926.

Glass, porcelain, paper, and mica have all been used as insulators in electrical engineering for a very long time. These dielectric materials were ideal for capacitor dielectrics when they were first invented. Ceramic capacitors were used in the early Marconi wireless transmitters for high-voltage and high-frequency transmissions of high voltage and high frequency. When William Dubilier first invented the mica capacitor in 1909, the world was forever changed. Pre-war, the majority of capacitor dielectrics in the United States were made with mica as the main component.

A patent for an “electric liquid capacitor with aluminum electrodes” was granted to him in 1896 by the US Patent and Trademark Office. When organic chemists developed plastic materials during World War II, the capacitor industry began to use thinner polymer films instead of paper. British Patent 587,953 was one of the earliest examples of film capacitors.

As the first of its kind, a “low voltage electrolytic capacitor with porous carbon electrodes” was developed in 1957 by H. Becker. Electrolytic capacitors’ etched foils contain carbon pores, which were thought to hold a charge that could be used to charge a capacitor that he had built for himself. It’s unclear, he wrote in his patent, “exactly what is taking place in the component if it is used for storage of energy.

Measurement Unit

The Farad is the SI unit for electrical capacitance and is represented by the letter F. An English physicist is the inspiration for the name of this unit: Faraday. For example, the ability of an object or body to hold an electrical charge is known as a farad. SI base units, such as s4A2m-2kg-1, are used to express this value.

Types of capacitors:

Ceramic Capacitors

A ceramic capacitor is a kind of fixed value capacitor, which is the most common type and has 2 or more layers of metal and ceramics that act as electrodes. These capacitors are non-polar and can be used in any direction of the circuits. The composition of the capacitor as the ceramic content defines its electrical behavior along with the applications. They also come in different shapes and styles and are particularly used for RFI/EMI suppression.

Film Capacitors

Film dielectrics, polymer films, and plastic films are all other terms for film capacitors. It is advantageous to use film capacitors because of their low cost and long shelf life. The dielectric material used on the other side of the film capacitor is metalized and extremely thin. Each application calls for a specific thickness of film capacitors. These capacitors typically have a voltage range of 50 volts to 2 kilovolts in them.

Electrolytic Capacitors

It is a kind of a polarized capacitor which have two different plates of anodes or positive place and is made of metal. These capacitors are also capable of passing or bypassing low-frequency signals. Apart from this, an oxidized layer is applied to the metal anode to serve as a dielectric in electrolytic capacitors. 

Paper Capacitor

One of the more common names for a paper capacitor is a “fixed capacitor.” Paper capacitors have a fixed capacity for storing electric charge. Paper is placed between two metallic plates to act as a conductor and they are used for capturing medium capacitance values 1nF to 1uF.

 Power Film Capacitors

Power film capacitors are constructed in the same way as ordinary film capacitors. Plastic polypropylene film is used as a dielectric in the construction of this type of capacitor.