ELECTRICAL ENGINEERINGTechnological World

What is electrical engineering?Designing and developing objects which use

electricity, electronics and electrical circuits is the work of electrical engineers.

Electrical engineering covers two main areas:ElectricityElectronics

Electricity & ElectronicsAll electrical appliances and electronic

devices depend on electrical circuits.The main difference between electricity &

electronics lies in the design of these electrical circuit components.

ElectricityMaterials used for electrical components are:

metals & alloys (especially copper) – these are known as conductors.

Electrical components have potentially powerful currents.

Electrical components have circuits of normal size.

ElectronicsMaterials used for electronic components

are: materials such as silicon – these are known as

semiconductors.Electronic components have low-intensity

currents.Electronic components have miniaturized

circuits.

Circuit DiagramsCircuit diagrams are symbolic

representations showing how different electrical components fit together to form a whole.

Circuit DiagramsConventional symbols are used to represent

the components which make up a circuit diagram.

Electrical/Electronic CircuitsAll circuits carry an electric current.The conventional current direction flows

from the POSITIVE terminal of the power supply to the NEGATIVE terminal.

Electrical/Electronic CircuitsOn the other hand, the electron flow occurs

in the opposite direction from the NEGATIVE terminal to the POSITIVE terminal.

Direct & Alternating CurrentElectric current can be described as direct or

alternating depending on the way electrons flow through the circuit.

Direct CurrentDirect current (DC) is an electrical current

in which the electrons move continuously in the SAME direction.Electrons move in only ONE direction.

A battery is one example of a source of direct current.

Alternating CurrentAlternating current is an electric current in

which the electrons move BACK AND FORTH in a regular pattern.Electrons move in BOTH directions.

Power plants are examples of sources of alternating current.