introduction to automotive electrical and electronic system , LE THANH PHUC

University of Technical Education
Ho Chi Minh City

INTRODUCTION TO AUTOMOTIVE
ELECTRICAL AND ELECTRONIC
SYSTEMS
Le Thanh Phuc
Faculty of Automotive Engineering
Email:


Automotive electrical and electronic systems


Main systems
1.
2.
3.
4.
5.
6.
7.
8.
9.

Starting
Charging
Ignition
Lighting and signal
Information
Engine control

Automotive control
Air conditioning
Accessories


Components of a circuit


Series Circuits


Series Circuits
•A series circuit has only one path for current.
That means current is the same through every
part of the circuit.
• If any part of the circuit is broken or
disconnected, the whole circuit will stop
working.
•No current is present in a series circuit unless
there is continuity through the entire circuit.
•You can use Ohm's Law to predict the behavior
of electricity in a circuit.


Voltage Drops in a Series Circuits


Parallel Circuits

Parallel Circuits
A parallel circuit has these key features:
• Total current equals the sum of the branch currents.
• Resistance of each branch determines the current
through each branch.
• If the branch resistances are the same, branch
currents will be the same.
• If the branch resistances are different, the current in
each branch will be different.
• The voltage drop across each load resistance is the
same. This is because the source voltage is applied
equally to each branch.
• The equivalent resistance of the circuit is less than
the smallest branch resistance.


Circuit Connection


Source Control and Ground Control Circuits


Electrical Symbols


Wiring Diagram


Inductors

A Simple Electromagnet
A simple electromagnet
can be made from a
length of wire, a battery,
and a nail. Depending on
the size of the battery,
this circuit might require
some added resistance to
keep excess current from
burning the wire.


Voltage Generated by Induction
When a current flowing
through a coil is cut off,
the collapsing magnetic
field generates a
voltage spike.


Ignition Coil
An ignition coil takes
advantage of the
collapsing magnetic field
to generate a high voltage
pulse for the spark plugs.


Relay

Relays are used throughout the automobile.
Relays which come in assorted sizes, ratings,
and applications, are used as remote control
switches


Relay
A relay uses an
electromagnetic
coil to move a set
of contacts.


Relay


Capacitor
Capacitors have the ability to absorb and store an
electrical charge and then release it into the circuit.
Noise suppression— Noise in an audio system is
often caused by AC electrical voltage riding on top of
the DC voltage supplying power to a radio or tape
player.
Spike suppression— A capacitor can absorb voltage
spikes in a circuit.
Timers— A resistor put in series with a capacitor can
keep current flowing in a circuit for a specified amount
of time
after power from the source has been removed.

Diode
Diodes block current flow in one direction and pass
current in the opposite direction.
This is accomplished by joining a layer of P type
material and a layer of N type material during
manufacturing.


Diode
Rectification— Since a diode will allow current to
flow in one direction and not the other, it can be used
to turn alternating current into direct current.


Diode

Application of diodes on alternators


Transistor
A transistor can be used as an amplifier
to control electric motor speed such as AC
blower motors, or as solid state switches
to control actuators such as fuel injectors.