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ST/EST 404
THE TECHNOLOGICAL UNIVERSE
CHAPTER 14 NOTES
CHAPTER 14
Electrical Engineering
(pp.457-483)
1 WHAT IS ELECTRICAL ENGINEERING?
The science of electrical engineering applies to systems for _______________________,
______________________ and using electrical ______________ to _______________________
systems and avionics.
Electrical engineering covers two main areas: _________________ and ___________________.
1.1 ELECTRICITY AND ELECTRONICS
The main difference between electricity and electronics lies in the ____________________ of the
____________________ components.
Electronics
Made with __________________________
Electricity
Made from __________________________ -
(usually ___________________)
metals and alloys (especially _____________)
Have a high degree of
Made for _____________________ circuits.
_______________________________
ex: electric _______________
Can be more ___________________ controlled
Used to process ________________________.
1.2 ELECTRICAL CIRCUITS
An electric (or electronic) circuit consists of a simple or complex set of conductors or components
carrying an ______________________ ______________________.
CONVENTIONAL CURRENT flows from the _________________ terminal to the ____________
terminal.
Normal current flows from the ________________ terminal to the _________________ terminal.
The role of circuit ___________________ are to show how different ______________________
fit together to form a whole circuit. Conventional symbols are used to represent the components.
 Please refer to Table 14.5 on p. 460 of your textbook for a list of symbols for circuit
components.
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ST/EST 404
THE TECHNOLOGICAL UNIVERSE
CHAPTER 14 NOTES
DIRECT CURRENT AND ALTERNATING CURRENT
 DIRECT CURRENT (______) is an electrical current in which the electrons are continuously
moving in the ______________ direction. Ex: ______________.
 ALTERNATING CURRENT (______) is an electrical current in which the electrons move
________________ and _______________ in a ____________________ pattern. Ex:
___________________
1.3 ELECTRICAL FUNCTIONS
 An ELECTRICAL FUNCTION is the role that a component plays in the
______________________ or ____________________________ of electric current.
An electric or electronic circuit is made up of components that serve one of seven different
functions:
1. Power supply
2. Conduction
3. Insulation
4. Protection
5. Resistance (EST ONLY)
6. Control
7. Transformation of energy
2 Power Supply
 POWER SUPPLY is the function performed by any component that can __________________
or ____________________ an electric current in a circuit.
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ST/EST 404
THE TECHNOLOGICAL UNIVERSE
CHAPTER 14 NOTES
The following are some examples of sources of energy supply:

BATTERY OR DRY CELL: A device that transforms ____________________ energy into
_____________________ energy.
ADVANTAGES
DISADVANTAGES
APPLICATIONS: ___________________, watches, _____________________________________

ELECTRICAL OUTLET: A device equipped with contacts that can receive the ______________
of an electric _________________; it is _______________________________ connected to
an electric network.
ADVANTAGES
DISADVANTAGES
APPLICATIONS: ___________________, _________________________, ___________________

PHOTOVOLTAIC CELL (SOLAR CELL): An electronic device that generates an electric current
when exposed to ___________________.
ADVANTAGES
DISADVANTAGES
APPLICATIONS: Solar __________________, solar ____________, ________________________
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ST/EST 404
THE TECHNOLOGICAL UNIVERSE
CHAPTER 14 NOTES
3 The Conduction, Insulation and Protection
3.1 Conduction
 CONDUCTION is the electrical function performed by any component that can
______________________ an electric ___________________ from one part of a circuit to
another.
Examples:

electric ________________

two pieces of _____________________ in contact with each other

the human ________________

an _________________________ solution
PRINTED CIRCUITS (EST ONLY)
 A PRINTED CIRCUIT is an electrical circuit _______________________ on a solid
support called a ______________________ ____________________.
 Needed for _________________________, __________________________, and
portable __________________ games.
3.2 Insulation
 INSULATION is the electrical function provided by any component that
__________________ an electric current from flowing.
Wires are insulted with __________________ to prevent electrons from leaving wires and to
prevent short-________________, which occur when bare wires come in contact with each other.
Inside an electrical outlet, all the wires are
insulated with plastic casings and
connectors.
The ground wire is not
insulated because it is a safety device that
does not usually carry a current.
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ST/EST 404
THE TECHNOLOGICAL UNIVERSE
CHAPTER 14 NOTES
3.3 Protection
 PROTECTION is the electrical function performed by any component that can automatically
_________________ the current flow in the event of a short-circuit or power
___________________ (when too many appliances are plugged into the same outlet).
 __________________ and circuit ____________________ are protection devices.
FUSES
When the circuit is functioning properly, the electric
current passes through a conductive filament. If the
current intensity _______________ a certain level,
the
filament
melts
________________________
and
breaks,
the current
from
flowing through the fuse. Once the fuse has blown,
it must be replaced with another one of equal value.
CIRCUIT BREAKERS
A circuit breaker is a protective device that can be
reset as many times as necessary.
Inside the
breaker, the current passes through a bimetallic
strip. When the current exceeds a certain level, the
strip becomes ____________, it bends and breaks
the contact. At the same time, a mechanism deploys
which keeps the circuit open.
There are other
http://electronics.howstuffworks.com/circuit-breaker2.htm
circuit breakers that work with the help of an
electromagnet. (ex. Fire doors in hospitals)
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ST/EST 404
THE TECHNOLOGICAL UNIVERSE
CHAPTER 14 NOTES
3.4 Electrical Resistance (EST ONLY)
A ________________ is a component designed to ________________ the flow of electrons
through an electrical circuit.
The resistance of a resistor is usually indicated with a colour code. Four coloured bands appear
on the resistor, as shown below.
What is the resistance of the resistor below?
http://www.finders.com.au/uploads/images/content_images/res-color-code.gif
http://www.token.com.tw/resistor/image/tw-resistor-color-code-ex22ohms.gif
Answer: ____________________________
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ST/EST 404
THE TECHNOLOGICAL UNIVERSE
CHAPTER 14 NOTES
4 Control
For electric current to flow through a circuit, the circuit must form a _________________ loop.
 CONTROL is the electrical function performed by any component that can _____________
or ________________ a circuit, in other words, turn the circuit _________ or _________.
A(n) __________________ CIRCUIT is a circuit in which the current flows in a loop.
 When the switch is ________________, the light is ______________.
A(n) __________________ CIRCUIT is a circuit in which electric current cannot flow in a loop.
 When the switch is ________________, the light is ______________.
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ST/EST 404
THE TECHNOLOGICAL UNIVERSE
CHAPTER 14 NOTES
4.1 Types of Switches (EST ONLY)
TABLE: DIFFERENT TYPES OF SWITCHES
Switch
# of contacts
that are opened
or closed at a
time
# of possible
paths for the
electrons
Diagram
Example
Single-pole,
single-throw
Single pole,
double- throw
Double-pole,
single-throw
Double-pole,
double-throw
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ST/EST 404
THE TECHNOLOGICAL UNIVERSE
CHAPTER 14 NOTES
5 The Transformation of Energy
The TRANSFORMATION OF ENERGY is the electrical function performed by any component
that
can
convert
__________________________
energy
into
another
form
of
______________.
Examples of electrical components that are used to transform of electrical energy:

Incandescent light bulbs: Electrons
flow
through a ___________ filament in the bulb.
The filament resists the current which causes it to
heat up and emit _________ ______________.
(Hence the expression “White Hot”)
Form of energy obtained
Applications
 Heating Elements: Electrons flow through a material that
_________ the current. The material _______ up, converting
_________________ energy into ______________ energy.
Form of energy obtained
Applications
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ST/EST 404
THE TECHNOLOGICAL UNIVERSE
CHAPTER 14 NOTES

Piezoelectric Crystals: When the crystal is exposed to an electric current, the crystal starts to
________________.
Form of energy obtained
Applications
 Electromagnet: Electrons flow through a coil of electrical wire wrapped around an iron core.
The current flow gives the iron a ____________________ charge, creating a ______________
field.
Form of energy obtained
Applications
http://cr4.globalspec.com/thread/19100/M
agnetize-and-Demagnetize-anElectromagnet
ST 4 - END OF CHAPTER 14: ELECTRICAL ENGINEERING NOTES
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ST/EST 404
THE TECHNOLOGICAL UNIVERSE
CHAPTER 14 NOTES
6 Components with Other Functions (EST ONLY)
6.1 Capacitors
 A _________________ is a device composed of two electrical surfaces separated by
a/an ______________ material. The device can store an electrical ______________.
The ability to store energy is called _______________________.
It is expressed in
______________, represented by the letter ________.
6.2 Diodes
 A diode is a device that allows electric current to flow in only
________ direction.
The technical symbol for a diode is:
There are many types of diodes.

Some guide and block current.
Ex. Diodes in TV remote controls prevent current from flowing if the operator installs the batteries
backwards. This protects the fragile electronic parts within the circuit.

Some diodes are used for rectification.
Ex. They convert alternating current to __________ current.

Some diodes are electroluminescent (a.k.a. light up)
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ST/EST 404
THE TECHNOLOGICAL UNIVERSE
CHAPTER 14 NOTES
Ex. Light emitting diodes (LEDs) used to make Christmas lights. They consume less energy than
traditional incandescent light bulbs.
END OF CHAPTER 14: ELECTRICAL ENGINEERING NOTES
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