Electrical Engineering
Grade 10 ST
May 2012
Electricity
• Static electricity: the jumping of electrons from
one object to another causes static electricity.
• However, because the movement doesn’t last,
this form of electricity is not capable of
supporting our electrical devices
• Current electricity is the steady flow of electrons
which lights our homes and streets and runs our
household appliances and electronics.
Electrical Engineering
• Electrical engineering involves the designing and
developing of electrical objects and electrical
systems
• Electrical Engineering covers two main areas:
– Electricity
– Electronics
• All electrical appliances, like a toaster and
electronic devices, like computers depend on
ELECTRICAL CIRCUITS
Electricity vs. Electronics
• The main difference between electricity and
electronics lies in the design of the circuits
– An electrical circuit provides a path in which a
constant source of electrons can flow.
Cont...
Electricity
Electronics
Electrical components are made up of
materials that are conductors like metals
and alloys
Electronic components are made up of
materials called semiconductors like
silicon
Electrical components are larger and are
designed for more powerful circuits with
higher intensity like motors
Electronic components are very small and
are designed for circuits with lower
intensity
The conduction is not finely controlled
The electrical conduction is finely
controlled allowing electronic devices to
process information
Working on an electrical field in a house
would belong to the field of electricity
Working on a computer circuit would
belong to the field of electronics
Examples
• Electronics
– Cell phone
– TV
– Computers
• Electrical devices
– car motor
– toaster
– ovens
AC vs. DC
• Not quite...
• Direct current is electrical current which supplies a
constant flow of electricity in the SAME direction.
– A battery is a common example of DC current
• Alternating current is electrical current which
comes from a generator. As the electromagnet is
rotated in the permanent magnet the direction of the
current alternates once for every revolution.
– A power plants generate AC current at a rate of 60 Hz,
which means the electrons move back and forth at a rate
of 60 times per second.
– AC current is easy to transport over long distances
Electrical functions
• Power Supply:
• Conduction:
• Insulation:
• Protection:
• Resistance:
• Controls: