CH1

POLITEKNIK SULTAN MIZAN ZAINAL ABIDIN

KOD : JA 505KURSUS : AUTOMOTIVE ELECTRONICSPROGRAM : DAD5-S2

ELECTRONIC PRINCIPLES

POLITEKNIK SULTAN MIZAN ZAINAL ABIDIN

COURSE : JA505 AUTOMOTIVE ELECTRONICS

INST DURATION : 15 WEEKS

CREDITS : 2

PRE REQUISITE :JA303 AUTOMOTIVE ELECTRICAL

COURSE LEARNING OUTCOMES

Upon completion this course students should be able to1.Explain the function and basic principle of automotive electronic system2. Sketch the circuit, component & explain the working principles of automotive electronic system3. Identify and solve the problems related to the automotive electronic systems

SUMMARY

SYLLABUS

Chapter 1 Electronic Principle

Chapter 2 Electronic Systems

Chapter 3 Cruise Control System

Chapter 4 System of Body Electronic

Chapter 5 Data Bus System

Chapter 6 Anti theft protection systems immobilizer

Chapter 7 Electronic stability program

Chapter 8 Brake by Wire System

Chapter 9 Electronic Throttle control


CHAPTER 1

Assessment

The course assessment is carried out in 2 sections; i) Coursework (CA) ii) Final Examination (FE)

Assessment Method

Test (2) 40 %

Quiz (4) 20%

Discussion (2) 20%

Case study (2) 20%


The branch of engineering which deal with current conduction through a vacuum or gas or semi conductor is known as ‘Electronics’

The word of electronics derives it’s name from electron present in all material

The electronic devices capable of performing the following functions;

Basic Electronic Principle


i) Rectification The conversion from AC into DC DC supply can be used for charging

storage batteries, field supply of DC generators & etc

DC generators


ii) Amplification The process of raising the strength of

weak signal is known as ‘amplification’ It can accomplish the job of

amplification & thus act as amplifier. e.g: Radio &television


iii) Control Electronic devices find wide application

in automatic control For example speed of motor. Voltage

across a refrigerator can be automatically controlled with the help of such devices


iv) Generation Electronic devices can convert from AC

power to DC power of any frequency. Known as oscillator

The oscillator used in variety of ways eg: Used in Electronic high frequency heating is used for annealing & hardening


v) Conversion of light into electric Electronic devices can convert light into

electricity. Also known as photo electricity

Usually used in burglar alarms, sound recording on motion pictures

iv) Conversion of electricity into lightElectronic devices can convert

electricity into light. Usually utilized in television & radar


S.I Fundamental Units


Some Important Magnetic Units


Scientific & Engineering Notation

Very large and very small numbers are represented with scientific and engineering notation.

47,000,000 = 4.7 x 107 (Scientific Notation)

= 47. x 106

(Engineering Notation)


Scientific & Engineering Notation

0.000 027 = 2.7 x 10-5 (Scientific Notation)

= 27 x 10-6 (Eng Notation)

0.605 = 6.05 x 10-1 (Scientific Notation)

= 605 x 10-3 (Eng Notation)


Engineering Metrix

peta

tera

giga

mega

kilo

1015

1012

109

106

103

P

T

G

M

k

10-3

10-6

10-9

10-12

10-15

milli

micro

nano

pico

femto

m

m

n

p

f

Large Small


Metric Conversion

When converting from a larger unit to a smaller unit, move the decimal point to the right. Remember, a smaller unit means the number must be larger.

0.47 MW = 470 kW

Smaller unit

Larger number


Metric Conversion

When converting from a smaller unit to a larger unit, move the decimal point to the left. Remember, a larger unit means the number must be smaller.

10,000 pF = 0.01 mF

Larger unit

Smaller number


Atomic structure

The electron theory assumes that all electrical and electronic effects are due to the movement of electrons from one place to another.

An atom is the smallest particle of a chemical element and is made up of several subatomic particles:

electrons, protons, and neutrons.


Atomic structure


Atomic structure

Protons and neutrons make up a dense, massive atomic nucleus in the center of the atom and are collectively called nucleons. Orbiting the nucleus in energy levels, or shells, are the electrons.


Metric Conversion

When converting from a smaller unit to a larger unit, move the decimal point to the left. Remember, a larger unit means the number must be smaller.

10,000 pF = 0.01 mF

Larger unit

Smaller number


Faraday’s Law

Any change in the magnetic field around a coil of wire will cause an emf (voltage) to be induced in the coil. The change could be produced by changing the magnetic field strength, moving the magnetic field towards or away from the coil, moving the coil in or out of the magnetic field, rotating the coil relative to the magnetic field and so on


Faraday’s Law

Where:V = Voltage generated in voltsN =Number of turns on the coilB = Magnetic field strength in webbers per metre squared (teslas)A = Area of the pole perpendicular to the field in metres squaredt =time in seconds Michael Faraday was a British physicist and chemist, well known for his discoveries of electromagnetic induction and of the laws of electrolysis.


Faraday’s Law of induction

Electromagnetic Induction

a) Current induced in the loop

b) No Current induced in the loop

c) No Current induced in the loop

o Faraday’s experiment demonstrates that an electric current is induced in the loop by changing the magnetic field.

o The coil behaves as if it were connected to an emf source. Experimentally it is found that the induced emf depends on the rate of change of magnetic flux through the coil.


Stepper motor

A stepper motor is an electromechanical device which converts electrical pulses into

discrete mechanical movements. The shaft or spindle of a stepper

motor rotates in discrete step increments when electrical command pulses are applied to it in the proper sequence.


Stepper motor

Working Principle


Stepper motor

Stepper motors consist of a permanent magnet rotating shaft, called the rotor, and electromagnets on the stationary portion that surrounds the motor, called the stator

Type of stepper motor• Variable Reluctance• Permanent Magnet Motors• Hybrid Motors


Stepper motor

Variable reluctant

• Consists of a soft iron multi-toothed rotor and a wound stator.

• When the stator windings are energized with DC current the poles become magnetized.

• Rotation occurs when the rotor teeth are attracted to the energized stator


Stepper motor

Permanent Magnet

• Higher starting torque & also have holding stock when not energized

• Permanent magnet motor have step angles of 450

180 ,150 or 7.50• Rotation occurs when the rotor teeth are

attracted to the energized stator


Stepper motor

Hybrid

• Combination of previous two motors to develop try to combine the high speed operation & good resolution of variable reluctant type with the better torque properties of the permanent magnet motors


PRINCIPLE OF FREE ELECTRON


Electric current flow

When electrical pressure is applied to a conductor, a directional movement of electrons will take place .

This is because the electrons are attracted to the positive side and repelled from the negative side.

Certain conditions are necessary to cause an electron flow:

A pressure source, e.g. from a battery or generator.

A complete conducting path in which the electrons can move (e.g. wires).


Simple electrical circuit

Electric current flow


Conventional Current -assumes that current flows out of the positive side of the battery, through the circuit, and back to the negative side of the battery. This was the convention established when electricity was first discovered, but it is incorrect!

Electron Flow- is what actually happens. The electrons flow out of the negative side of the battery, through the circuit, and back to the positive side of the battery.

Electron Flow

Conventional Current

ElectronFlow


Electron Flow


Effect of Current flow

Current flows in a circuit can produce only three effects:• Heat.• Magnetism.• Chemical effects.

The heating effect is the basis of electrical components such as lights and heater plugs.

The magnetic effect is the basis of relays and motors

and generators. The chemical effect is the basis for electroplating

and battery charging


Ohm’s Law Ohm’s law states that in a closed circuit

‘current is proportional to the voltage and inversely proportional to the resistance’.

When 1 volt causes 1 ampere to flow the power used (P) is 1 watt.

Using symbol this means

Voltage Current Resistance (V = IR) or (R= V/I) or (I =V/R)

Power Voltage Current (P = VI) or (I = P/V) or (V = P/I)

ELECTRONIC PRINCIPLESOhm’s Law

Quantities Abbreviations

Units Symbols

Voltage V Volts V

Current I Amperes A

Resistance R Ohms Ω

V=IR I=V/R R=V/I

The mathematical relationship between current, voltage, and resistance

Current in a resistor varies in direct proportion to the voltage applied to it and is inversely proportional to the resistor’s value

V

I Rx

Cover the quantity that is unknown.

Solve for V

V=IR


V

I RI=V/R


Solve for I


V

I RR=V/I


Solve for R



Ohm’s LawThe flashlight shown uses a 6 volt battery and has a bulb with a resistance of 150 . When the flashlight is on, how much current will be drawn from the battery?

VT =+

-VR

IR

Schematic Diagram

mA 40 A 0.04 150

V 6

R

V I R

R

V

I R


Ohm’s Law

The current flowing through a resistor is 0.8A when 20V is applied. Determine the value of the resistance.

From Ohm’s law, resistance R= V/I = 20/0.8= 200/8=25 Ω

Example 1 :


Ohm’s Law

Example 2:

A coil has a current of 50mA flowing through it when the applied voltage is 12V. What is the resistance of the coil?Resistance, R = V/I= 12/50 × 10−3

= 12 /0.05= 240 Ω


Describing Electrical Circuit Open circuit-This means the circuit is broken therefore no current can flow.

Short circuit- This means that a fault has caused a

wire to touch another conductor and the current uses this as an easier way to complete the circuit.

High resistance- This means a part of the circuit

has developed a high resistance (such as a dirty connection), which will reduce the amount of current that can flow.


A bulb, motor and battery – heat, magnetic and chemical effects

An electrical circuit demonstrating links between voltage, current, resistance and power


Resistance & Resistivity

The resistance of an electrical conductor depends onfour factors, these being: (a) the length of the conductor(b) the cross-sectional area of the conductor, (c) The type of material and (d) the temperature of the material.

R = ρl/a ohms

R= Resistance

a = area (m2)

ρ = rho (Ω )

l = Length (m)


Electronic Circuits Electronic circuits are used in systems to perform

a wide variety of tasks. The main uses of electronic

circuits are to do the following:• Control and process data.• Distribute and convert to/from electric

power.

Both of these applications involve the creation and/or detection of electromagnetic fields and electric currents.


Circuit Component The minimum requirements for a simple

circuit are a power source, load device(s), and conductor(s).


PRINCIPLE OF ELECTRONICCOMPONENT


Batteries

A battery is a device that converts chemical energy to electrical energy. A multicell battery consists of two or more cells in a series (connected end-to-end).

The negative terminal of one cell is connected to the positive terminal of another cell and so on to increase the battery’s voltage potential.


Identify Resistors

A resistor is a passive device used to regulate current in a circuit. Electronic equipment uses a wide variety of resistors made of resistive wire, metal film, or carbon composition.

Types of resistors • fixed • variable.


Fixed resistor

Many fixed resistors use a pattern of four, five, or six colored stripes (or bands) painted around the body of the resistor to indicate their resistance and tolerance values


The variable resistor is a resistor whose resistancevalue can be adjusted, which in turn allows a circuit’s current value to be increased or decreased.

Variable Resistors

Variable Resistors


Diodes

A diode is an active component that restricts the direction of movement of charge carriers.

Essentially, it allows an electric current to flow in one direction but blocks it in the opposite direction.


A transistor is a semiconductor device that uses a small amount of voltage or electrical current to control a larger change in voltage or current.

A transistor can be thought of as an electronic version of a switch and is the fundamental building block of the circuitry that governs the operation of all modern electronics.

Transistors


Transformer

Device that converts an alternating (A/C) current of a certain voltage to an alternating current of different voltage, without change of frequency , by electromagnetic induction .

A 'step up' transformer receives a low voltage and converts into a higher voltage, and a 'step down' transformer does just the reverse.


When a fluctuating electric current flows through a wire, it generates a magnetic field or "magnetic flux" all around it

The strength of the magnetism is directly related to the size of the electric current. So the bigger the current, the stronger the magnetic field

The current in the first coil is usually called the primary current and the current in the second wire is the secondary current


There are 2 types of transformer Step up transformer Step down transformer

Step up transformer Step down transformer


step-up transformer • More turns on the secondary coil than

the primary• Boosts a low voltage into a high one

step-down transformer • The first coil has more turns that the

second coil, the secondary voltage is smaller than the primary voltage


Working of transformer


An instrument used to measure the properties of an electrical circuit, including

Voltage VoltsCurrent AmpsResistance Ohms

Multimeter

CH1

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