Electronics of Early 20 th Century

          Electronics in the early 20th century started thriving at a greater speed unlike the pre-20th century developments. From the starting itself the electronics got its special recognition. The radio invented by the Italian genius Marconi and the work of Henry Hertz opened the road to further discoveries and inventions. In the first decade the new thing that was welcomed to the technical world was the vacuum tube. The vacuum tubes at that time worked as a miraculous component for the radio devices. Marconi’s radio needs some good detectors for the receiving of the incoming radio waves. For that reason a good rectifier was needed which can convert the AC into DC. There were already many AC generating stations and AC was getting very popular. So, the engineers were planning to change the AC into DC instead of producing the expensive DC. The duo of Tesla and Westinghouse brought many exciting features to the AC at that time. The invention of the induction motor by Tesla was a revolution in the use of AC. Someone brings the breakthrough when all the great minds are in need. That happened again. The then famous English physicist Fleming found an alternative to the DC production. He invented the first vacuum tube using the principle known as “Edison Effect”. According to the Edison Effect when there is a small separation in between the two conductors connected to a source of electricity and are heated then there can be a current in the conductor. That means the vacuum in between the conductors becomes a good carrier. That idea was actually in the brain of Sir Ambrose Fleming. So, he tried to do something which can demonstrate the Edison Effect. But when he tested his newly invented device he was happy to find that it can work as a rectifier, means which can change the AC into DC. History was created. This was the real birth of electronics.

          Here starts a new chapter in the history of human being. At that time Marconi’s radio was badly needing some good detectors. This vacuum tube filled that need. It has two electrodes and that’s why it was named as diode. It was the first diode and the main motivation behind the solid state devices which after some decades take control of the whole world economics. Just after two years of Fleming’s diode DeFrost in the US invented another similar device which was named as triode, because it had three electrodes. Besides the anode and cathode there was an extra electrode known as grid. The grid was controlling the flow of charges from the anode to the cathode. It was wonderful that triode had the characteristics of an amplifier. So it helped a lot in the growth of the communication at that time. Because the amplifier was an important component in the radio and other communication devices to strengthen the weak radio signals. A revolution in the whole science came when Einstein proposed his historic theory of relativity. But no one was ready to accept his theory at that time. But the work of J J Thomson and Rutherford opened the secrets of the atoms and its sub-particles. Max Plank and Niels Bohr provide the further explanation to the atomic theory. Einstein himself came with his big version known as the general theory of relativity. He was not bothered about the critics. He himself saved the corpuscular theory of light from death and opened the road to the quantum theory. It was not far to bring the quantum theory into light after Einstein’s Nobel winning photo-electric effect. Louis De Broglie, Heisenberg, Schrödinger and Dirac proved the reality of the quantum theory. So the research in the scientific community got a great speed. 9 The computers were another main attraction at that time. Due to the world wars there was a big need of computers for war related tasks like code breaking. During the first and second world war some computers were made for this purpose. But they were not that efficient as many of them were using decimal systems and all the prime components were made up of vacuum tubes.

          The invention of the television was a miraculous thing for the mankind. It was revolution in both communication technology and also for the world media. The distances between the continents did not seem to be far enough. People were able to watch the distant things from there home. The entertainment industry got new life. The popular artists through out the world become well known and got a huge recognition. The credit goes to the British engineer John Logie Baird who followed the foot prints of Marconi and tried to send the images in the same way as the speech. After a long experiment he found that a series of static pictures if sent within a small interval of time in between them, seem to be moving. This move was successful after a number of trails. Then came the Second World War and the scientists were busy in war related research and the attention from the general research was withdrawn. But the war technology also helped a lot in the future.