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Electrical Engineering. Electrical Engineering. Covers two main areas: - Electricity - Electronics All appliances and electrical devices depend on electrical circuits. Electrical component are made with a particular type of material: Semiconductor (silicon) Conductors (metals & alloys). - PowerPoint PPT Presentation
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Electrical Engineering
Electrical Engineering Covers two main areas: - Electricity - Electronics
All appliances and electrical devices depend on electrical circuits
Electrical component are made with a particular
type of material: - Semiconductor (silicon)- Conductors (metals & alloys)
Symbols for circuit components
Direct current & Alternating current Direct current (DC): is an
electric current in which the electrons are continuously moving in the same direction.
Alternating current (AC): is an electrical current in which the electrons move back and forth in a regular pattern
Electrical Function Is the role that a component plays in
the control or transformation of electric current.
Power supply: is the electrical function preformed by any component that can generate or provide an electric current in a circuit
Types of power supplies Battery: Transforms
chemical energy into electrical energy
Advantages: portable, many appliances run on batteries
Disadvantages: batteries must be
replaced, contaminate the environment around the landfill by leaking heavy metals
Electrical outlet: contains contacts and is permanently connected to an electrical network
Advantages: stable and long lasting power supply
Disadvantages: hydroelectric dams cause flooding of vast areas of land. Appliances cannot be moved far from the wall outlet
Photovoltaic cell: (solar cell) electronic device that generates an electrical current when exposed to light.
Advantages: portable, do not produce green house gases, have a lifespan of 20 to 30 years.
Disadvantages: Depends on sunny conditions. Much more expensive to install than other sources of power.
Conduction, insulation & protection Conduction:
When a component can transmit electric current from one part of a circuit to another
Examples of conductors: copper, gold, etc...
Insulation :
When a component prevents an electric current from flowing.
Examples of insulators: ceramic, rubber, plastic
Protection: Cut current flow in the even of a power surge Fuses
A filament melts/breaks if current exceeds a certain level
Breakers
A strip becomes hot and bends if current exceeds a certain level. A switch is thrown to restore circuit operation
Open/closed circuit
Closed circuit: electric current lows in a loop
Open circuit: electric current cannot flow in a loop
In class work P. 479
#1,2,3,4,5,6,7,8,9,10,11,13,14
Transformation of energy The transformation of energy is the
electrical function performed by any component that can convert electrical energy into another form of energy
Forms of energy Chemical
Thermal
Mechanical
Radiation
Examples of electrical components used to transform
electrical energy Incandescent light
bulbs (luminous energy)
Heating elements (thermal energy)
Piezoelectric crystals (mechanical energy)
Electromagnets (magnetic energy)
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