Download Produced By Mike Hartlen Electrical

Produced By Mike Hartlen
Electrical Fundamentals
THIS PRESENTATION
ABOUT AUTOMOBILE
SYSTEMS HAS BEEN
DEVELOPED BY
Mike Hartlen
TEACHER OF
AUTOMOTIVE TECHNOLOGY
AT EASTERN SHORE DISTRICT
HIGH SCHOOL
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Unit Terms
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Matter
Atom
Molecule
Element
Ion
Amperage
Electron
Proton
Neutron
•Insulator
•Conductor
•Semi-Conductor
•Voltage
•Ohm
•Resistance
•Watt
•Direct Current (D/C)
•Alternating Current (A/C)
•Ampere
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Matter
• Everything in the world is made of
matter.
• Matter is anything that has mass
and occupies space.
• Matter can be made up of a group or
series of different atoms to form a
molecule.
• Matter has three states: Solid,
Liquid, and Vapour.
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Molecule Example
• Imagine a lake. Now imagine taking
the smallest particle or piece of water
from the lake. You would have a
single molecule of water, H2O, which
is made up of two hydrogen atoms
and one oxygen atom.
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Water Molecule
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Elements
• Not all materials are made up of
molecules.
• Copper, for example, is made up
of a single copper atom. These
are called elements.
• Each element is a type of matter
that has certain individual
characteristics.
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The Atom
• One of the basic building blocks
in the universe for matter is the
atom.
• All matter - gas, liquid, or solid is made up of molecules or atoms
joined together.
• These atoms are the smallest
particle into which an element
can be divided without losing its
property
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• A single components atom
consists of three basic items: a
proton, a neutron, and an
electron.
• Within the atom there is a
Nucleus. The Nucleus contains
the protons and neutrons.
• Orbiting around the nucleus
are the electrons.
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• An atom is similar to a
miniature solar system. As with
the sun in the center of the
universe, the nucleus is in the
center of the atom.
• Protons and Neutrons are
contained inside the nucleus.
• Orbiting around the nucleus
are the electrons.
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Protons are located within the
nucleus of the atom (shown in blue).
Protons are positively (+) charged.
Neutrons add atomic weight to an
atom (shown in green). Neutrons
have no electrical charge.
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Electrons
• Electrons orbit around the nucleus of
the atom.
• Electrons are negatively (-) charged.
• Since electrons are lighter than
protons and are outside the nucleus,
they can be easily moved from atom
to atom.
• Normally electrons are prevented
from being pulled into the atom by
the forward momentum of their
rotation. (centrifugal force)
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Electrical Charges
• “Opposite” electrical charges always
attract each other. So particles with
opposite charges will tend to move
toward each other.
• “LIKE” electrical charges always
repel. So particles with “like” charges
will move away from each other.
• Atoms always try to remain
electrically balanced.
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Balanced Atoms
• Atoms normally have an equal
number of electrons and protons.
• Atoms have no electrical charge.
• They are electrically neutral or
BALANCED.
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• The negative charge of the electrons
will cancel the positive charge of the
protons, thus balancing the charge
of the atom.
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Ion Particles
• When an atom loses or gains an
electron, an imbalance occurs.
• The atom becomes either a positively
or negatively charged particle called
an ION.
• These unbalanced charged ION
particles are responsible for electron
flow (electricity).
• Ions will take or release an electron
to become balanced again.
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Ion Charge
• A positive (+) ION has one less
electron than it has protons.
• A negative (-) ION has one more
electron than it has protons.
• The positive ION attracts a negative
Ion's electron to become balanced.
This attraction or difference in
electrical potential causes electron
flow.
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Free Electrons
• Only the FREE ELECTRONS in the
outermost shell (Valance Ring) are
free to move from atom to atom. This
movement is called ELECTRON
FLOW.
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• These FREE ELECTRONS are
loosely held because of their
distance from the nucleus and can
easily be moved to another atom or
ion.
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Insulators
• An INSULATOR is any material that
inhibits (stops) the flow of electrons
(electricity).
• An insulator is any material with
more than 4 electrons in the outer
ring.
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• Because, atoms with 5 to 8
electrons in the outer ring are held
(bound) tightly to the atom, they
CANNOT be easily moved to
another atom nor make room for
more electrons.
• Insulator material includes glass,
rubber, and plastic.
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Conductor
• A CONDUCTOR is any material that
easily allows electrons (electricity) to
flow.
• A CONDUCTOR has up to 3 free
electrons in the outer ring.
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• Because atoms with 1 to 3 electrons
in the outer ring are held (bound)
loosely to the atom, they can easily
move to another atom or make
room for more electrons.
• Conductor material includes
copper and gold.
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Semiconductors
• Any material with exactly 4 free
electrons in the outer orbit are called
SEMICONDUCTORS.
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• A semiconductor is neither a
conductor nor an insulator.
• semiconductor material includes
carbon, silicon, and germanium.
• These materials are used in the
manufacturer of diodes,
transistors, and integrated circuit
chips.
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Electricity Flow Theories
• The Electron Theory states that
current flows from NEGATIVE to
POSITIVE.
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Conventional Theory
• States, current flows from
POSITIVE to NEGATIVE.
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Voltage
• Voltage is the electrical force that
moves electrons through a conductor.
Voltage is electrical pressure also
known as EMF (Electro Motive Force)
that pushes electrons.
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Measurement
• A VOLTMETER measures the voltage
potential (difference) across
(parallel) to the circuit.
• Available Pressure.
• Voltage can exist
between two points
without current
flow.
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Voltage Units
• Voltage is measured in units called
VOLTS.
• Voltage measurements can use
different prefixes such as millivolt,
volt, and kilovolt.
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Current (Amperes)
• CURRENT is the quantity or flow
rate of electrons moving past a
point within one second. Current
flow is also known as amperage, or
amps for short.
• Higher voltage will produce higher
current flow, and lower voltage will
produce lower current flow.
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Measurement
• An AMMETER measures the
quantity of current flow. Ammeters
are placed in series (inline) to
count the electrons passing
through.
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Amperage Units
• Current flow is measured in units
called Amperes or AMPS.
• Amperage measurements can use
different prefixes, such as micro amp,
milliamp, and Amp.
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Affects of Current Flow
• Two common effects of current flow
are Heat Generation and Magnetism.
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Heat Generation
• When current flows, heat will be
generated. The higher the current
flow, the greater the heat generated.
An example would be a light bulb. If
enough current flows across the
filament, it will glow white hot and
illuminate to produce light.
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Electro Magnetism
• When current flows, a small magnetic
field is created. The higher the
current flow, the stronger the
magnetic field.
• Electromagnetism principles are
used in alternators, ignition systems,
and other electronic devices.
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Resistance
• Resistance is the force that
reduces or stops the flow of
electrons. It opposes voltage.
• Higher resistance will decrease the
flow of electrons and lower
resistance will allow more
electrons to flow.
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Measurement
• An OHMMETER measures the
resistance of an electrical circuit or
component.
• No voltage can be applied while the
ohmmeter is connected,
or damage to the meter
will occur.
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• Resistance is measured in units
called OHMS.
• Resistance measurements can use
different prefixes, such as Kilo ohm
and Mega ohms
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Resistance Factors
• LENGTH of the conductor. The longer the
conductor, the higher the resistance.
• DIAMETER of the conductor. The narrower
the conductor, the higher the resistance.
• TEMPERATURE of the material. Depending
on the material, most will increase
resistance as temperature increases.
• PHYSICAL CONDITION (DAMAGE) to the
material. Any damage will increase
resistance.
• TYPE of MATERIAL used. Various
materials have a wide range of resistances.
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Types of Electricity
• STATIC ELECTRICITY is electricity
that is standing still. Voltage potential
with NO electron flow.
• DYNAMIC ELECTRICITY is electricity
that is in motion. Voltage potential
WITH electron flow. Two types of
Dynamic electricity exist:
• Direct Current (DC) Electron Flow is
in only one direction.
• Alternating Current (AC) Electron
flow alternates and flows in both
directions (back and forth).
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Static Electricity
• Voltage potential with NO electron flow.
• Example: By rubbing a silk cloth on a
glass rod, you physically remove
electrons from the glass rod and place
them on the cloth. The cloth now has a
surplus of electrons (negatively
charged), and the rod now has a
deficiency of electrons (positively
charged).
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Dynamic Electricity
• Electricity in motion, meaning you
have electrons flowing.
• Can be either
• Direct Current (DC)
• or
• Alternating Current (AC)
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Direct Current
• Electricity with electrons flowing in
only one direction is called Direct
Current or D/C.
• D/C electrical systems are used in
cars.
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Alternating Current
• Electricity with electrons flowing
back and forth, negative - positivenegative, is called Alternating
Current, or A/C.
• The electrical appliances in your
home use A/C power.
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Sources of Electricity
• Electricity can be created by several
means: Friction, Heat, Light,
Pressure, Chemical Reaction, or
Magnetic Action.
• The battery produces electricity
through chemical action, and the
alternator produces electricity
through magnetism.
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• Friction creates static electricity.
• Heat can act upon a device called a
thermo couple to create D/C.
• Light applied to photoelectric
materials will produce D/C
electricity.
• Chemical Reaction of certain
chemicals will create electricity.