Electronics is the branch of science and technology which makes use of the controlled motion of electrons through different media and vacuum. The ability to control electron flow is usually applied to information handling or device control. Electronics is distinct from electrical science and technology, which deals with the generation, distribution, control and application of electrical power. This distinction started around 1906 with the invention by Lee De Forest of the triode, which made electrical amplification possible with a non-mechanical device. Until 1950 this field was called "radio technology" because its principal application was the design and theory of radio transmitters, receivers and vacuum tubes.
Most electronic devices today use semiconductor components to perform electron control. The study of semiconductor devices and related technology is considered a branch of physics, whereas the design and construction of electronic circuits to solve practical problems come under electronics engineering. This article focuses on engineering aspects of electronics.
Electronic devices and components
An electronic component is any physical entity in an electronic system used to affect the electrons or their associated fields in a desired manner consistent with the intended function of the electronic system. Components are generally intended to be connected together, usually by being soldered to a printed circuit board (PCB), to create an electronic circuit with a particular function (for example an amplifier, radio receiver, or oscillator). Components may be packaged singly or in more complex groups as integrated circuits. Some common electronic components are capacitors, resistors, diodes, transistors, etc. Components are often categorized as active (e.g. transistors and thyristors) or passive (e.g. resistors and capacitors).
Analog circuits
.Most analog electronic appliances, such as radio receivers, are constructed from combinations of a few types of basic circuits. Analog circuits use a continuous range of voltage as opposed to discrete levels as in digital circuits.
The number of different analog circuits so far devised is huge, especially because a 'circuit' can be defined as anything from a single component, to systems containing thousands of components.
Analog circuits are sometimes called linear circuits although many non-linear effects are used in analog circuits such as mixers, modulators, etc. Good examples of analog circuits include vacuum tube and transistor amplifiers, operational amplifiers and oscillators.
One rarely finds modern circuits that are entirely analog. These days analog circuitry may use digital or even microprocessor techniques to improve performance. This type of circuit is usually called "mixed signal" rather than analog or digital.
Sometimes it may be difficult to differentiate between analog and digital circuits as they have elements of both linear and non-linear operation. An example is the comparator which takes in a continuous range of voltage but only outputs one of two levels as in a digital circuit. Similarly, an overdriven transistor amplifier can take on the characteristics of a controlled switch having essentially two levels of output.
Digital circuits
Digital circuits are electric circuits based on a number of discrete voltage levels. Digital circuits are the most common physical representation of Boolean algebra and are the basis of all digital computers. To most engineers, the terms "digital circuit", "digital system" and "logic" are interchangeable in the context of digital circuits. Most digital circuits use two voltage levels labeled "Low"(0) and "High"(1). Often "Low" will be near zero volts and "High" will be at a higher level depending on the supply voltage in use. Ternary (with three states) logic has been studied, and some prototype computers made.
Computers, electronic clocks, and programmable logic controllers (used to control industrial processes) are constructed of digital circuits. Digital Signal Processors are another example.
Eligibility & Course Areas
Educational : To become an electronics engineer one needs to have a degree in electronics engineering (BE / B.Tech) or must have passed the AMIE (Associate Membership Examination of the Institute of Engineers) in electronics or Graduate membership Examination of the Institution of Electronics and Telecommunication Engineers or at least a diploma in Electronics Engineering. A post graduate degree is required for most research or teaching posts and management positions. An additional degree in business administration is desirable for those seeking administrative or management positions.
The basic eligibility criteria for a BE / B.Tech is 10+2 or equivalent examination, with Physics, Chemistry and Mathematics. Admission to these courses is highly competitive and only those with high academic performance in the board of examination i.e the marks secured in the final exams of 10+2 and in the entrance test can expect admission. Entrance to the IIT's is through 'JEE' (Joint Entrance Exam) and for other major institutions through AIEEE (All India Engineering/Pharmacy/Architecture Entrance Examination) OR their own separate entrance exams and other state level and national level exams.
Duration :
The duration is 4 Years for BE / B.Tech courses. The diploma courses in polytechnics are of 3 years duration.
The focus in the study programme is on understanding electronic networks and devices, electromagnetic field theory, computer fundamentals, as also their protection, and communication
and control systems.
Personal Attributes : A creative and inventive mind and an interest in physics and mathematics is essential to take up this challenging career. They should have good analytical skills, an eye for detail, sustained attention and the ability to work as part of a team. They should also have good communication skills.
Job Prospects & Career Options
Job Prospectus
An electronics engineer can get a job in Central Government, State Governments and their sponsored corporations in public enterprises and the private organizations like All India Radio, Indian Telephone Industries, MTNL, National Physical Laboratories, AIR, Civil Aviation Department; Post and Telegraph Department; Co-ordination Department, National Physical Laboratory, Bharat Electronics Limited, Development Centers in various States etc. dealing in manufacture, sales and services of electronics consumer goods and appliances. Electronics engineers are also absorbed into the entertainment transmission industry, research establishments, and defense. They can also take up teaching and research in one of the many engineering colleges in India or abroad.
Career Options
As an Electronic Engineer, entry for junior posts in the Government departments is by direct recruitment through advertisements in newspapers. Selection to Gazetted posts is through the competitive examinations conducted by Union and State Public Service Commission. UPSC conducts an Engineering Service Examination (Telecommunication and Electronics Engineering group) annually for vacancies in Central Engineering Services and various State Public Service commissions conduct their own competitive Exams for vacancies in State engineering services.
In the Defence Services, young engineers start as Second Lieutenants. For selection into the Defence Services- Indian Army, Indian Air Force, Indian Navy, applications are invited through National dailies and Employment News.
Similarly vacancies in the private and public sector are advertised through leading daily newspapers of the country and the Employment News. Mostly the candidates are interviewed after thorough scrutiny of their basic inputs and the selections are made on merit. Central Electronics Ltd., Indian Railways, Atomic Energy Commission, Hindustan Aeronautics Limited, Ministry of Civil Aviation, Directorate General Posts and Telegraphs Departments etc are some of the prospective employers in the field.
Electronic Engineers can start their own business by manufacture electronic parts, goods and components. He can also start a repair or assembly shop for television receivers, amplifirers.Electronic Engineers, recording equipment etc. Since electronics is a labour intensive and talent -oriented field, it gives high returns for a given initial investment. Loan facilities are offered by banks and Small Scale Industries Development Corporations for starting a business.
