What is Engineering?

The application of mathematics, science, economics, empirical evidence, social knowledge, and practical knowledge, to invent, innovate, design, build, maintain, research, and improve structures, machines, tools, systems, components, materials, processes, solutions, and organizations

The creative application of scientific principles to design or develop structures, machines, apparatus, or manufacturing processes, or works utilizing them singly or in combination; or to construct or operate the same with full cognizance of their design; or to forecast their behaviour under specific operating conditions; all as respects an intended function, economics of operation and safety to life and property

The art or science of making practical application of the knowledge of pure sciences, as physics or chemistry, as in the construction of engines, bridges, buildings, mines, ships, and chemical plants

The application of science and mathematics by which the properties of matter and the sources of energy in nature are made useful to people

The activities or function of an engineer

What is Electronic Engineering ?

Electronic engineering is an electrical engineering discipline which utilizes nonlinear and active electrical components (such as semiconductor devices, especially transistors, diodes and integrated circuits) to design electronic circuits, devices, microprocessors, micro-controllers and their systems.

Electronic engineering is a discipline that utilizes the behaviour and effects of electrons for the production of electronic devices (such as electron tubes and transistors), systems, or equipment.

     

Electronic engineering is the child of Electrical Engineering and father of Computer Engineering. Electrical Engineering deals with the generation of electrical power (from Thermal, Hydroelectric, Solar, Wind or other sources ), their transmission, distribution and most importantly direct utilization in electric machines like electric motor etc. The direct utilization means that the electric current (flow of electrons) is used as it flows through conductors. On the contrary Electronics Engineering makes the same electric current to flow through a manipulated medium, causing different behaviour. The manipulated medium is semiconductor based devices. The manipulation is done by manufacturing semiconductors of specific concentration and also by creating different shape,size and structure. Semiconductor is used to make many basic devices. More complex devices are made by abstracting these basic devices. Complex devices are used to make electronics devices including the hardware of modern digital computers and smartphones. Computer Science and Engineering focuses on developing algorithms and methods to create the application layer on top of this hardware.

Electronic in Daily Life

We hardly think the way the world would be without electronics. Electronics have become an integral part of human life. Everything from cooking to connecting with our love ones uses electronics or electronic components in some way. Electronics technology in cameras has increased dramatically. A digital camera that can capture still pictures or even video pictures and store them or transfer them to a computer where they can be saved, shared digitally with family or friends or printed out in hard form with a photo printer device. Pictures obtained through a camera or by means of a scanner can be edited, cropped, enhanced or enlarged easily through the marvel of electronics. Electronics devices are being used in the health field, not only to assist in diagnosis and determination of medical problems, but to assist in the research that is providing treatment and cures for illnesses and even genetic anomalies. Equipment such as MRI, CAT and the older X-rays, tests for diabetes, cholesterol and other blood component tests all rely on electronics in order to do their work quickly and accurately.

SubFields

Electronic Engineering has many subfields. This section describes some of the most popular subfields in electronic engineering.

• Signal processing
• Telecommunications Engineering
• Control Engineering
• Instrumentation Engineering
• Computer Engineering
• VLSI design Engineering 

Electronic Circuit

What is Circuit

A combination of passages, components and devices that form a working set of logic for a particular application.

A circuit is a path between two or more points along which an electrical current can be carried.

What is an Electronic Circuit

An electric circuit having at least one component that manipulates the voltage or current in the circuit.

An electronic circuit is composed of individual electronic components, such as resistors, transistors, capacitors, inductors and diodes, and at least one voltage or current source connected by conductive wires or traces through which electric current can flow.

Figure 1 Electronic Circuit

The circuit shown in Figure 1 is a simple electronic circuit, which consist of a voltage source, a resistor, light emitting diode and wire for connecting all these components.

.

An electronic circuit can usually be categorized as an analog circuit, a digital circuit, or a mixed-signal circuit (a combination of analog circuits and digital circuits).

Analog Circuits

Analog electronic circuits are those in which current or voltage may vary continuously with time to correspond to the information being represented.

Analog circuitry is constructed from two fundamental building blocks: series and parallel circuits.

Series circuit

The same current passes through a series of components but the voltage divides across each component according to resistance.

Parallel circuit

                      
All the components are connected to the same voltage, and the current divides between the various components according to their resistance.

Basic Components

The basic components of analog circuits are wires, resistors, capacitors, inductors, diodes, and transistors.

Representation

                         
Analog circuits are very commonly represented in schematic diagrams, in which wires are shown as lines, and each component has a unique symbol.

Digital Circuit

In digital electronic circuits, electric signals take on discrete values, to represent logical and numeric values. These values represent the information that is being processed

Basic Components

                            
Digital circuits make extensive use of transistors, interconnected to create logic gates. Transistors interconnected so as to provide positive feedback are used as latches and flip flops.

Mixed Signal Circuit

Mixed-signal or hybrid circuits contain elements of both analog and digital circuits.

Examples

                
Comparators, timers, phase-locked loops, analog-to-digital converters, and digital-to-analog converters.

Most modern radio and communications circuitry uses mixed signal circuits.

For example

                  
In a receiver, analog circuitry is used to amplify and frequency-convert signals so that they reach a suitable state to be converted into digital values, after which further signal processing can be performed in the digital domain.

Control System

What is Control System?

When a number of devices or elements are combined together to produce a desired output then such a system is said to be control system. Each device or element has its own effect on the output. So we can define the Control System as;

Definition of Control System

A control system is a system of devices or set of devices, that manages, commands, directs or regulates the behavior of other device or system to achieve desire results.

Fig. 1

Use of Control Systems in daily life

In recent years, control system plays an important in automation of daily used products and things. For example a refrigerator, an air conditioner, a geezer, an automatic iron, an automobile all are control system.These systems are also used in industrial process for more output. We find control system in weapons system, power system, transportation systems,  space technology, robotics and many more. The principles of control theory is applicable to engineering and non engineering field both.

Feature of Control System

It is feature of control system that is has clear mathematical relation between its input and output. If the relation between input and output is represent by linear proportionality then the control system is called linear control system. When the relation between input and output is represent by non-linear proportionality then the control system is called non linear control system.

Control System Requirements

Good control system has following requirements;

1. Accuracy: High Accuracy
2. Sensitivity: Sensitive to input signals only
3. Noise: A good control system should be able to reduce the noise effect for better performance
4. Stability: It Should be stable
5. Bandwidth: Bandwidth should be large as possible for frequency response of good control system
6. Speed: A good control system possesses high speed
7. Oscillation: A small numbers of oscillation or constant oscillation of output tend to system to be stable

Types of Control System

There are basically two main types of control system i.e Open Loop control system and Closed Loop control system.

• Open Loop Control System : If the control action of the control system is independent of the output then the system is called open loop control system (see Fig.2a).

Fig.2a

     

    . Advantages of Open Loop Control System:       Following are the advantages of open loop control system;

1. Its construction is easy.
2. Its design is simple
3. It is economical as its price is low.
4. Easy to maintain.
5. Generally stable.

  . Disadvantages of Open Loop Control System:

     Following are the disadvantages of open loop control system;

1. These are inaccurate.
2. Reliability is less.
3. Output cannot be correct automatically.

• Closed Loop Control System : If the output of the control system has effect on its input quantity in such a way that input can adjust in accordance with that output is called closed loop control system (see Fig.2b).

Fig.2b

    . Advantages of Closed Loop Control System:       

                                                                                 Following are            the advantages of closed loop control system

1. More accurate.
2. Facilitates the automation.
3. Bandwidth is large
4. Less effected by noise.

   . Disadvantages of Open Loop Control System:

                                                                                  Following are          the disadvantages of open loop control system

1. Complex in design.
2. Cost is high.
3. Maintenance is difficult.