Now let us divide the history of electronics into two broad categories. That can be done on the basis of development of the electronic technology and its use in the in the day to day life. Before the 20th century there was a little or almost no electronics in the day to day life of a common man. So, the time before 20th century can be taken as the pre-developmental era in the growth of electronic technology. So, we should start from the very beginning of electrical engineering, which is regarded as the parent of electronics. The formal beginning of electrical engineering goes back to 18th century when Franklin gave the explanation to the cause of thunder and lighting. It was a big mystery at that time. But, the lucid explanation of Franklin gave the first idea of charge flow and its consequence. Though the concept of charge was there before Coulomb there was no formal mathematical theory to explain the concept. So Coulomb’s theory was regarded as the first mathematical expression that defined the electrical charge in a well defined manner. He also invented the torsion balance and that helped him to calculate the force of interaction between the electrical charges, which is today known as Coulomb force after his name. There after the next big name was Luigi Galvani who discovered the so called bioelectricity from his famous experiment using the frog leg. He thought that electricity as one of the sources of life. That created some ideas that electricity is related to life at that time. But, anyway his famous frog leg experiment gave some solid basis to the future researchers to develop the concept of potential difference.
The mystery of the frog-leg experiment was disclosed by Alessandro Volta. He repeated Galvani’s frog leg experiment using various types of electrodes. There after he concluded that the spark in the frog-leg experiment is not due to the frog rather it has a different reason. He told that when the copper and zinc electrodes are kept in the acid there arises some potential difference between the electrodes and the charges flow from one electrode to the there if there is any physical connection between them through some conducting wire. That was the first electric cell mad by Volta. After his name the potential difference is also known as Voltage. The strangest and the most effective thing in the history of electrical engineering is the merging of magnetism with the electricity which gives rise to the one of the most fundamental interactions of nature known as the electromagnetic interaction. But it happened quite late in 1820 when Oersted found that the needle of a compass is deflected when kept near a current carrying conductor. So from that observation he concluded that the magnetism of a compass is affected by current. There after magnetism is considered as an aspect of electromagnetism, not as a different entity. Ampere proved the relationship using algebra. Gauss also gave the alternative forms of mathematical equations to explain electricity and magnetism. Those works of Gauss are known as Gauss theorems. But it was not known why some energy in the form of potential difference is required to make the charges flow from one end to the other. The explanation came from the German scholar George Simon Ohm. He for the first time introduced the concept of resistance and conductance. In almost all the conductors there is some 6resistance that opposes the flow of current through them. That’s why the charges cannot flow in the conductors without the presence of any energy source in the form of potential difference. Then it was proved that potential difference is very important to keep the charges moving from one end to the other in a conductor. Potential differences can be created in various ways. At that time the chemical cells were the main sources of electricity. In the next phase started the real victory of the electrical engineering under the leadership Michel Faraday. He not only gave birth to some interesting theories, but himself invented some fundamental electrical machines like the transformer and electric motors. Faraday was a poor child who had always aims to do something big in the scientific research. He got the opportunity from the then big name Humphrey Davy. After that Faraday had never looked back. He gave many fundamental theories which are like the back bone to the electrical sciences. His concept of lines of forces was not accepted by the then scientific community, but was later found to be the fundamental fact of electromagnetism. He first gave the knowledge of electrical power generation and made the first transformer of the world. But it was a bit strange that he himself did not have the idea that his discoveries will some day change the science of the world. Faraday’s laws of electrolysis were beneficial to both the chemists and physicists of that time. That also was a fundamental tool to prove that the electric charges are quantised. He also gave the concept of inductance, which was also developed by another great of that time, Joseph Henry. Lenz was there to modify faraday’s second law of induction. So the electrical engineering was unstoppable and running really fast to be the most attractive science at that time. Faraday’s law was not accepted by many of his contemporaries because the nature of the lines of forces he described did not sound satisfactory to many at that time, but there was another genius to understand and explain it quite lucidly. He supported Faraday and combined all the mathematical equations available at that time to systematise the electrical science. Not only that, he also gave some other stunning theories that changed the science there after. He was none other than Maxwell. Maxwell’s equation is today fundamental to all theory of electrical machinery and communication sciences. It has used in every field more or less. His theories are one or the best scientific achievements of the world for ever. He unified the optics as a part of the whole electromagnetism. After Maxwell it was just the matter of time to invent the electrical machines and communication devices to deliver the service to the mankind and to take the civilisation in the road of science and technology.
The first achievement after Maxwell’s theory was the invention of the electric bulbs by another genius Thomas Edison. The lighted the world by his electric bulbs. He invented numerous electrical devices and contributed the most to the consumer electrics. He was mainly using DC and was the greatest advocate of the use of DC. But one of his contemporaries Nicola Tesla had something different in his mind. He used his brain to make AC popular. He invented the induction motor and proved that AC can be used more efficiently than DC. After some years with the help of Westinghouse he took the tender of the Niagara Project and started generating AC. Another big thing had happened at the same time while Edison was trying to light an electric bulb. That was the “Edison effect” or the thermoionic effect. Edison found that in a closed environment even without the physical contact of wires there exist a small current through them when they are heated to a sufficiently high temperature. 7By the same time there was a great need to reduce the distance of the various parts of the world by means of some communication technology. Alexandra Graham Bell opened the account by inventing the telephone. At around the same time the telegraphic communication using the Morse code was very popular. That was even used for the transatlantic communications. But the main breakthrough, which mesmerised the communication science, came when the German physicist Henry Hertz discovered the radio waves and also gave the methods to transmit and detect them. Then started a new chapter in the communication technology area. Not far than a decade after that the Russian scientist Popov and the Italian electrical engineer Marconi invented the radio and used antennas for radio communications. The electronics had its identity in the world, but without the presence of its principal components.
No comments:
Post a Comment