How our Gadgets Evolved? | History of Electronics

In this modern time, every now and then we are dealing with different kinds of electronics. Our gadgets, appliances, laptops, smartphones, cameras and smart-TVs, all have electronics circuits boards with chips and integrated circuits. Electronics have been integrated in different aspects of our lives like in healthcare, transportation, manufacturing automation, power grids, weather forecast and in our very own homes. In this era of modern technology, without electronics we will surely be living differently.

In order for us to move forward we have to know our past and the milestone of our pioneers as they discover and unravel the mystery of science behind each of the building blocks of modern technology that we all know now.

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Electronics covers a wide range of technology. This term was originally applied to the study of electron’s behavior and movement which were first observed in the first electron tubes or popularly known as vacuum tubes which composed of a sealed glass or metal ceramic enclosure and electrodes. Electronics came to be used in a wider purpose as the advancement in knowledge in the fundamental nature of electrons and the way in which the motion of these particles are developed. Today several scientific and technical discipline deals with various aspects of electronics. This led to the development of key building blocks of electronics which are transistors, integrated circuits, lasers and fiber optics. These brought us to infinite arrays in manufacturing consumer electronics, industrial electronics and military technologies. Truly, we can say that we are in an electronic revolution a keystone in the 21st century.

Reign of Vacuum Tubes

During the 18th and 19th century, theoretical and experimental studies of electricity led to the development of the first electrical machineries and began the widespread use of electricity. The history of electronics began to evolve independently from electricity during the late 19th century with the identification of the electron by Sir Joseph John Thomson and the measurement of the its electric charge by Sir Robert A. Millikan in the year 1909.

As Thomson works out his discovery, at the same timeline, Thomas A. Edison observed a bluish glow in some of his early lightbulbs under certain conditions and later found out that a current would flow from one electrode in the lamp to another if the second one, called an anode, is made positively charged with respect to the first, which is now called cathode. Thomson and by Sir John Ambrose Fleming, later revealed that Edison’s observation was a result of emission of electrons from the cathode, which is the hot filament in the lightbulb. The motion of the electrons to the anode, which is a metal plate, created an electric current that would not exist if the anode were negatively charged.

This discovery paved the way to the development of electron tubes, including an improved X-ray tube invented by William D. Collidge and Fleming’s thermionic valve which were used in radio receivers. Fleming’s valve revolutionized the detection radio signal, which are very high-frequency alternating current. This radio signal requires that the signal should be rectified precisely. Before, radio signals were detected by various devices such as the “cat whisker” detector. This is composed of a fine wire, hence the whisker name, in delicate contact with the surface of a natural crystal of lead sulfide (called galena) or some other semiconductor material. These devices were undependable, has insufficient sensitivity, and required constant adjustment of the whisker-to-crystal contact to produce a desired result. On the other hand, the cat-whisker were the pioneers of today’s solid-state devices. Arguably, crystal rectifiers worked at all even from its disadvantages. This encourage scientists to thrive and continue studying them and steadily obtain the fundamental understanding of the electrical properties of semiconductor materials which are essential in the invention of transistors.

Lee De Forest, an American engineer, developed a type of vacuum tube which is capable of amplifying radio signals. De Forest incorporated a grid of fine wire in Fleming’s original valve between the cathode and anode. The device was patented in 1907 and dubbed as the “Audion” which is a three-electrode vacuum tube. The vacuum tube permitted the development of radio broadcasting, long distance telephony, television and the first electronic digital computers. These early versions of electronic computers were the largest vacuum tube systems ever built. One of which is the popular ENIAC (Electronic Numerical Integrator and Computer), which is constructed in 1946.

From the many different requirements of vacuum tubes led to various improvements, enabling them to handle more power, operate at a higher frequency, greater reliability, and more compact to the size of a thimble.

The cathode-ray tube which are once used in our home tv, were originally developed for displaying electrical waveforms on a screen for engineering measurements. This can be seen from old oscilloscopes and later on evolved in various use like in our old tv screens and monitors. Images are formed by deflecting electron beam through the use of electric fields in horizontal and vertical plane.

Vacuum tubes are fragile and later on wear out in service. Failure occurs in normal usage either from the effect of repeated heating and cooling which entails thermal stress to the electrodes. This brings to physical failure in some part of the internal structure of the tube. Vacuum tubes also take time to be warmed up in its operating temperature, which is a big gap work efficiency. These limitations encourage scientist at Bell Laboratories to find an alternative to the vacuum tube which led to the development of the semiconductor transistor.

Age of Semiconductors