Download Basic Electrical Theory

Electricity & Electronic Systems
SAFETY
When are Safety Glasses required?
All students and visitors MUST wear safety glasses at
any time there is any active lab activities
This includes the classroom and the larger lab area
Loaner glasses are available for visitors
Students must supply their own glasses
How do I get Safety Glasses?
Glasses can cost as little as $1.00 a pair
Instructor can sell you glasses
Tool trucks that visit school have very
comfortable glasses
Any auto parts store will stock a variety of
glasses
Contact lenses do not belong in
the shop
Many solvents, chemicals, fuels and particles
can be trapped next to, and damage, the eye
Damage compounded by wearing contacts.
Do not wear contacts in the shop environment
How do I see without contacts?
Wear safety glasses over prescription
glasses
Obtain side shields to use with prescription
glasses (available in Welding dept.)
Prescription safety glasses with side shields
are a good investment
Basic Electrical Theory
What can you learn from this lesson?
If you understand how an electrical circuit
is supposed to work
And
You can use a Voltmeter
You can fix electrical stuff
Define Electricity
The ability to perform “work” by moving
electrons between atoms
What do we need to make an
electrical circuit “Work”
Break into groups and write a list of
the basic requirements to control and
use electricity
Think of what has to happen to turn on
a light.
What do we need to make an
electrical circuit “Work”
Power Source
Wiring or Conductors
(insulated side and ground)
Control Device (switch)
Load
Circuit Protection (fuse)
Power Source
Alternator provides power for running vehicle
(Alternator provides power for running vehicle)
Load
Alternator provides power for running vehicle
Light bulb, motor, solenoid, etc.
Control Device
Alternator provides power for running vehicle
Switch, Relay, Computer
Wiring or Conductors
Alternator provides power for running vehicle
Insulated and Ground
Circuit Protection
Alternator provides power for running vehicle
Fuse or Circuit Breaker
Alternator provides power for running vehicle
Alternator provides power for running vehicle
Electrical “work” can be in the form of heat energy
Alternator provides power for running vehicle
The light gets hot and gives off light
Alternator provides power for running vehicle
Electrical
work can
be
magnetism
Magnetism
pulls in the
solenoid
and makes
the starter
turn
Start on Lab #2
Power Source
Wiring or Conductors
(insulated side and ground)
Control Device (switch)
Load
Circuit Protection (fuse)
Diagrams show the Power Source
at the top, ground at the bottom
Diagrams show the Power Source
at the Left, ground on the Right
Wiring Diagrams
• Wiring diagrams illustrate how a circuit is
supposed to work
• If you know how it should work, it is easier
to figure out why it doesn’t work
What can cause an electrical
circuit to fail?
• A bad or defective:
Power Source
Wiring or Conductors
(insulated side and ground)
Control Device (switch)
Load
Circuit Protection (fuse or circuit breaker)