Electronic passive components

Electronic passive components

1. ELECTRONIC
PASSIVE
COMPONENTS
SHALET K S
Asst. Prof

2. Page  2
Welcome to the Principles
of Electric Circuits.

3. Page  3
SI Fundamental Units
length
mass
time
electric current
temperature
luminous intensity
amount of substance
meter
kilogram
second
ampere
Kelvin
candela
mole
m
kg
s
A
K
cd
mol
Quantity Unit Symbol

4. Page  4
current
charge
voltage
resistance
power
ampere
coulomb
volt
ohm
watt
A
C
V
W
W
Quantity Unit Symbol

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Scientific and Engineering Notation
47,000,000 = 4.7 x 10
7
(Scientific Notation)
= 47. x 10
6
(Engineering Notation)
0.000 027 = 2.7 x 10
-5
(Scientific Notation)
= 27 x 10
-6
(Engineering Notation)

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Engineering Prefixes
peta
tera
giga
mega
kilo
10
15
10
12
10
9
10
6
10
3
P
T
G
M
k
Can you name
the prefixes and
their meaning?

7. Page  7
10
-3
10
-6
10
-9
10
-12
10
-15
milli
micro
nano
pico
femto
m
m
n
p
f
Engineering Prefixes
Can you name
the prefixes and
their meaning?

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Conversions
0.47 MW = 470 kW
Larger number
Smaller unit
10,000 pF = 0.01 mF
Smaller number
Larger unit

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1. A resistor is an example of
a. a passive component
b. an active component
c. an electrical circuit
d. all of the above
Quiz

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Quiz
2. The electrical unit that is fundamental is the
a. volt
b. ohm
c. coulomb
d. ampere

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Quiz
5. The metric prefix nano means
a. 10
-3
b. 10
-6
c. 10
-9
d. 10
-12

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Quiz
6. The metric prefix pico means
a. 10
-3
b. 10
-6
c. 10
-9
d. 10
-12

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Quiz
7. The number 2700 MW can be written
a. 2.7 TW
b. 2.7 GW
c. 2.7 kW
d. 2.7 mW

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Quiz
8. The value 68 kW is equal to
a. 6.8 x 10
4
W
b. 68, 000 W
c. 0.068 MW
d. All of the above

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Electronic components are the basic building blocks of an
electronic circuit. Electronic components are very small, cheep and have
two or more terminals. When a group of electronic components is
connected together in an printed circuit board (PCB), a useful electronic
circuit is formed. Electronic components are classified as ……
INTRODUCTION

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RESISTORS

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Resistors are electronic components used to oppose the
flow of current. Resistance is the property of material
which opposes the flow of current through it. Unit of
resistance is ohm (Ω).
Symbol of resistor

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Resistor = Speed Breaker
e-
e-
The resistor slows down the flow of electrons.

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???...........

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Standard resistance value

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Power rating – The power rating indicates how much
power the resistor can safely tolerate. Unit is watts.
Tolerance – It is the allowed variation of resistance value
from its normal value. A 100Ω resistor with 10% tolerance ,
means that its value can be any fixed value between 90 to
110Ω

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FIXED RESISTORS
Resistor whose value of resistance is specified
and cannot be varied

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Carbon composition resistors
•Resistive material – finely
powdered carbon/graphite and
an insulating material (ceramic)
• A resin used to bind mixture
• Leads – copper wires
• Resistance value – 1Ω to 22
MΩ.
• Power rating – 1/8W,
1/4W, 1/2W, 1W & 2W.
• Tolerance range 5% to
20%.
• Size increases for high
wattage
• Small in size & rugged in
nature

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Carbon film resistors
•Construction – carbon film on
an insulating core.
• Leads – copper wires
• Resistance value – 1Ω to 10
MΩ.
• Power rating – 1/8W,
1/4W, 1/2W.
• Tolerance range 5%.
• Law power applications.
• Better stability against
temperature and humidity.

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Wire Wound resistors
•Construction – Nichrome wire
is wound around a
ceramic/plastic.
• Leads – copper wires
•Protected with enamel coating.
• Resistance value – 1Ω to 100
KΩ.
• Power rating – 3W -
200W
• Tolerance range 5%.
• Reliable and stable
• Withstand up to 450ºC
• Disadvantage – Large
size, high cost & poor high
frequency response

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Metal film resistors
• Resistive material - Nichrome
• Leads – copper wires
• Resistance value –
• Tolerance range
0.05%.
• Law temperature
coefficient & good
stability.
• More accurate

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VARIABLE
RESISTORS Resistor whose resistance value can be varied
 Applications – changing volume of sound, brightness of a
television picture etc.

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Potentiometer (POT)
• Variable resistor with 3
terminals. 2 at the ends of
resistive material and 1 to a
sliding contact.
•Manufactured as carbon
composition, metallic film and
wire wound resisters.
• Both linear and non linear
• Applications - changing
volume of sound, brightness of
a television picture, contrast
control

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Rheostat
• It is a wire wound variable
resistor
•A resistive wire is wound
over an insulating ceramic
core and wiper slides over
the winding.
• High power applications
• Applications – controlling
the speed of motor, intensity
of light etc

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Presets
• Used where variation of
resistance is not done
frequently. Once the setting
is made it may be
undisturbed.
• Made up of carbonized or
metalized ceramic
•Metallic wiper can be moved
with a screw driver
• Applications – setting line
frequency and frame
frequency in a TV receiver.

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CAPACITORS

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A capacitor is a device that stores electric charge.
A capacitor consists of two conductors separated by an
insulator.
Symbol of capacitor

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Types of Capacitors
Parallel-Plate Capacitor Cylindrical Capacitor
A cylindrical capacitor is a parallel-plate capacitor that has
been rolled up with an insulating layer between the plates.

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Capacitors and Capacitance
Charge Q stored:
CVQ=
The stored charge Q is proportional to the potential
difference V between the plates. The capacitance C
is the constant of proportionality, measured in
Farads.
Farad = Coulomb / Volt
A capacitor in a simple
electric circuit.

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EXERCISE
1.Calculate the capacitance of a capacitor
that stores 1.584 ´ 10
-9
C at 7.2V

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Fixed capacitors
 Capacitor whose capacitance value is fixed.

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Electrolytic capacitors
• A Electrolytic capacitors are a type
of capacitor that is polarized.
• Made of aluminum plates & oxide
as dielectric
• They are able to offer high
capacitance values - typically above
1μF
• Low frequency applications -
power supplies, decoupling and
audio coupling applications as they
have a frequency limit if around 100
kHz.

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Mica capacitors
• Not polarized.
• Made of metal plates & mica as
the dielectric.
• Range – 5 to 10000 Pf
•Rated upto 500 v
• High frequency applications –
resonance circuits and high
frequency filters.

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Ceramic capacitors
• Not polarized.
• Made of silver/copper plates &
titanium/barium as the dielectric.
• Range – 3pf to 2µf
• High frequency applications

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Paper capacitors
• Not polarized.
• Made of aluminum foils separated
by strips of paper soaked in
dielectric (wax, plastic or oil).
• Range – 0.0005 µf to several µf
• Disadvantage – large size
• High voltage applications

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variable
capacitors
 Capacitor whose capacitance value can be varied

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Gang capacitors
• Rotor – stator arrangement with two sets of metal plates
• Fixed plates – Stator, Movable plates – Rotor
• Movable plate connected to the shaft & capacitance is
varied by rotating the shaft.
• Applications – tuning of radio receivers.

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Trimmer
• Construction – metal plates separated by dielectric (mica/ceramic )
• Capacitance variation is done by rotating the screw.
• Range – in pf
• Applications – used where tuning is not very frequent (tuning of
broadcast receivers).

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Padder
• Construction – aluminium plates separated by dielectric (air)
• Capacitance variation is done by rotating the screw.
• Range – 5pF to 600pF

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NUMBERING OF CAPACITORS
Number > 1 = PF
Number < 1 = µF
104 means
10,0000pF

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NUMBERING OF CAPACITORS
10k means 10kpF
47n means 47nF
47M means 47MF
4k7 means 4.7kpF
2M2 means 2.2MpF
104k means 10% & 104M
means 20% tolerance

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INDUCTORS
TRNSFOMERS

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When an electrical current flows through a coiled wire,
an electromotive force will be generated in such a way
that it opposes the flow of current.
LAW OF INDUCTION

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INDUCTOR

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• Values specified in henries (H), millihenries (mH) and
microhenries (μH)
• Inductance is the property of inductors by which it opposes
any change in the flow of current.
•A coil of wire that may be wound on a core of air or other
non-magnetic material, or on a magnetic core such as iron
powder or ferrite.
•Two coils magnetically coupled form a transformer.

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Ferrite core
Iron core inductor
Air core inductor
TYPES OF INDUCTOR

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TRANSFORMER

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What is transformer
A transformer is a static piece of apparatus by means
of which an electrical power is transferred from one
alternating current circuit to another electrical
circuit
There is no electrical contact between them
The desire change in voltage or current without any
change in frequency
it Works on the principle of mutual
induction

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STEP-DOWN TRANSFORMER
A step-down transformer is one who’s secondary windings are fewer
than the primary windings. In other words, the transformer’s
secondary voltage is less than the primary voltage. So, the
transformer is designed to convert high-voltage, low-current power
into a low-voltage, high current power and it is mainly used in
domestic consumption.

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STEP-UP TRANSFORMER
A step-up transformer is the direct opposite of a step-down transformer.
There are many turns on the secondary winding than in the primary winding
in the step-up transformers. Thus, the voltage supplied in the secondary
transformer is greater than the one supplied across the primary winding.
Because of the principle of conservation of energy, the transformer converts
low voltage, high-current to high voltage-low current. In other words, the
voltage has been stepped up.

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INTERMEDIATE FREQUENCY
TRANSFORMER
Intermediate Frequency (IF) Transformers work at frequency of
455kHz and cased with aluminium can. Tuning is achieved by using
parallel capacitors across primary and secondary windings.
Application – Radio recievers

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Audio Frequency (AF) Transformers work at frequencies between
about 20Hz to 20kHz and are used in audio amplifier circuits, they
were essential in valve (tube) designs for matching the high
impedance outputs of theses amplifiers to low impedance
loudspeakers, but transistor amplifiers have much less need for
output transformers.
AUDIO FREQUENCY TRANSFORMER

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RELAYS
CONTACTORS

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High power source
Low power source
Relay
Load
RELAY

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When a relay is used to switch a large amount of electrical power
through its contacts, it is designated by a special name: contactor.
CONTACTORS

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Thank You !!!