Published by:
Renji Elsa Jacob, M-Tech in Electrical & Electronics Engineering
Let us go through the evolution of electronics. In simple words, we can say that Electronics is the study of how to control the flow of electrons. In this current century, we are using electronic circuits and devices in any form every day because of gadgets like cell phones, TV, cameras, computers, home appliances, etc. Even electronics have improved their growth in areas like medical diagnosis, industries, automobiles, etc. So, we can say that it is impossible to work without electronics.
So, let's travel through some history of electronics and get to know the discoveries made by our inventors which we are enjoying now.
What is Electronics?
The branch of science and engineering which deals with the controlled flow of electrons through vacuum, gases, or semiconductors is called electronics. In 1897, Sir J J Thomson discovered electrons, and the word “Electronics” was taken from electrons. All the electronic gadgets have many components in it like inductors, resistors, capacitors, diodes, transistors, ICs, etc. These components are made up of semiconductor materials and the working of the components is based on the amount and direction of current flowing through them.
A device in which current flows through a vacuum or gas or semiconductor is called as an electronic device. All electronic system used in our daily life is a type of system. The working of the systems depends upon electronic variables like power or voltage or current and hence it is known as an electronic system. The electronic system is operated by electricity and it processes information/ data taken from the input and converts it into the desired output for the next level of usage.
Most of the electronic system is divided into 2 categories:
- Processing and distribution of information (Communication systems)
- Conversion and distribution of energy (Control systems)
An electronic system is to separate it into three parts:
- Inputs - Signals from the physical world (in the form of temperature, pressure, etc) are taken through electrical or mechanical sensors, which are converted to electric current and voltage signals.
- Signal Processing Circuits - The information contained in the signals are manipulated, interpreted, and transformed by the electronic components connected in these circuits.
- Outputs - When the current and voltage signals are transformed by other devices, we get the human-readable information.
For example, in a television set,
- Inputs - Broadcast signal received from an antenna or through cable for cable television.
- Signal processing circuits- These circuits inside the set uses the brightness, sound, and color information present in the received signal to control the output devices.
- Outputs - The processed sound information are converted into sounds that can be heard by listeners. The audio output device can be a speaker. The display output devices ((LED / a plasma/liquid crystal display (LCD) screen)) converts brightness and color into visible images.
History of Electronics and its Development
The three main components of the history of electronics are the vacuum tube, the transistor, and the integrated circuits. The birth history of electronics began in 1897 with the invention of the vacuum diode by J.A. Fleming then followed by a vacuum triode that was used to amplify electrical signals that were implemented by Lee De Forest in 1906. This again led to the introduction of tetrode and pentode tubes in 1925.
| Vacuum Tubes A device controlling electric current through a vacuum in a sealed container is called a vacuum tube. It is used as amplifier, or display screen (CRT) and also as on/off switches. The diode is the simplest vacuum tube which is similar to a light bulb with an extra electrode in it. These devices can be used for many other applications as the electrodes get increased. Tubes with three electrodes are called triodes and that with four electrodes are known as tetrodes. |
In 1948, the junction transistor was invented which began the era of the transistor. The major limitation of the vacuum tube was that the power consumed even if it is not used and the filaments burn out. Hence the transistor replaced the bulky vacuum tube. At first, the transistor was made of germanium but nowadays we use silicon more to fabricate all semiconductor devices.
Transistors
A three terminal semiconductor device that regulates current or voltage flow and acts as a switch or gate for signals is called as a transistor. Wherever the signal strength has to be increased, amplification is needed. This is done by a transistor. A transistor also acts as a switch to choose between available options. It also regulates the incoming current and voltage of the signals.
In 1958, Jack Kilby formulated the concept of constructing an entire electronic circuit on a single semiconductor chip. This invention of the integrated circuits (ICs) created an outstanding change in the electronic circuits as the whole circuit, which includes all active and passive components and its interconnections got integrated on a single chip which reduced the size, cost, and weight of electronic devices.
Integrated circuit (IC)
An Integrated circuit is a unique component that is built with thousands of transistors, resistors, diodes, and other electronic components on a tiny silicon chip. These are the building blocks of current electronic devices like cell phones, computers, etc. An integrated circuit, or IC, is a small chip that can function as an amplifier, oscillator, timer, microprocessor, or even computer memory. These extremely small electronics can perform calculations and store data using either digital or analog technology.
The ICs with enlarged capabilities of numerous thousand components on a single chip were introduced in the following years such as small-scale integration (SSI), medium-scale integration (MSI), large-scale integration (LSI), very-large-scale integration (VLSI) ICs.
In the following years, we developed JFETs and MOSFETs by improving the designing process which made more powerful transistors. Another great progress was the digital integrated circuits that changed the overall architecture of computers. All these essential changes led to the starter of microprocessors in 1969 by Intel. Later on, the analog integrated circuits were developed that introduced an operational amplifier for analog processing.
That’s all about the fundamental understanding of electronic history and we should not fail to recall the investment of time, hard work, and talents of the real heroes whose efforts we are enjoying now.
Application of Electronics
Electronics plays a vital role in almost all domains of our life. It has entered in every field from an ordinary timepiece to supercomputers, from the bedroom to office, from mobile to camcorders, from cooking to music, everywhere electronic items can be seen.
1. Medical field
Electronics devices are being used in the health field, not only to assist in the analysis and determination of medical difficulties but to contribute to the research that is providing treatment and cures for illnesses. All tests rely on electronic devices to do their work quickly and accurately.
Some of the medical devices and equipment used are:
- Stethoscope - To listen to inner sounds happening inside the human body
- Glucose meter for measuring sugar levels in the blood.
- PaceMaker for reducing and increasing the count of the heartbeat
2. Industry
Day by day the use of automatic control systems in different industries is increasing. The thickness, quality, and weight of a material can be easily controlled by electronic circuits. The operations of automatic door openers, lighting systems, power systems, safety devices, etc are controlled by electronic circuits. Even the power stations, which produce thousands of megawatts of electricity, are controlled by electronic circuits.
3. Automobiles
The automobile industry is one of the fastest-growing areas in the world. The most important application is electronic ignition, which provides improved timing of the ignition spark, particularly at high speeds. Numerous electronic types of equipment are used in cars for charging the battery, enabling power assisting functions, and monitoring and controlling the engine performance. Parking sensors, auto wipers, auto lights, safety (eg. Airbags), security, anti-theft systems, etc are the other areas of application in an automobile.
4. Defence and Aerospace
Defence and Aeronautical applications include: Missile Launching systems, Rocket Launchers for space, Aircraft systems, Military Radars, Boom barrier for military applications
5. Consumer Electronics
Consumer Electronics are devices and equipment meant for everyday use. This industry is most appropriate to the common people. Some of the categories are Office Gadgets (calculators, Personal computers, Scanners, and Printers, etc ), Home appliances such as Washing Machine, Refrigerator, Air Conditioner, Microwave Oven, etc. Audio and Video Systems such as headphones, VCRs, DVD players, Color TVs, etc, and Innovative Consumer Devices such as Setup Box, ATM, Smart Phones, etc. Storage Devices for optical playback and taping. Examples are DVDs, Portable MP3 player.
Conclusion
Electronics is having a great opportunity and our daily lives cannot happen without electronic appliances. Technology is progressing quickly in the field of semiconductors and advanced electronic applications will shape the world.
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