This document discusses electronic component manufacturing, focusing on resistors. It defines resistors and their key characteristics of resistance and power rating. It describes common types of resistors like wire-wound, carbon-film, metal-film, and surface-mount resistors. It explains resistor color coding systems for determining resistance values and tolerances. It also covers variable resistors like rheostats and potentiometers.

1. ‫الرحيم‬ ‫الرحمن‬ ‫هللا‬ ‫بسم‬
‫مقدمة‬
+
‫المقاومات‬
Introduction + resistors

2. Electronic component manufacturin
g:
Electronics Components
Mechanical and Electro-mechanical:
PCB mounted DIP switches, mains switches, disc drives
Passive Solid State Devices:
Resistors, Capacitors
Active Solid State Devices:
Transistors, Diodes, Thermionic valves, FETs and MOS
FETs

3. Electronic component manufacturin
g:

4. Electronic component manufacturin
g:

5. Electronic component manufacturin
g:

6. Electronic component manufacturin
g:

7. Electronic component manufacturin
g:

8. Electronic component manufacturin
g:

9. Electronic component manufacturin
g:

10. Electronic component manufacturin
g:

11. Electronic component manufacturin
g:

12. Electronic component manufacturin
g:

13. Resistors:
The two main characteristics of a resistor are it
s resistance, R, in ohms and its power rating,
P, in Watts.
The resistance, R, provides the required reduc
tion in current or the desired drop in voltage.
The wattage rating indicates the amount of po
wer the resistor can safely dissipate as heat.

14. Types of resistors:
Wire-wound resistors
Carbon-composition resistors
Film-type resistors
Carbon film
Metal film
Surface-mount resistors (chip resistors)
Fusible resistors
Thermistors

15. Types of resistors:
 Wire Wound Resistor
 Special resistance wire is wra
pped around an insulating core,
typically porcelain, cement, or p
ressed paper.
 These resistors are typically us
ed for high-current applications
with low resistance and appreci
able power.
Large wire-wound resistors with 50-W power ratings.
(a) Fixed R, length of 5 in. (b) Variable R, diameter of
3 in.

16. Types of resistors:
 Carbon Composition Resistors
 Made of carbon or graphite mi
xed with a powdered insulatin
g material.
 Metal caps with tinned copper
wire (called axial leads) are jo
ined to the ends of the carbon
resistance element. They are
used for soldering the connect
ions into a circuit.
 Becoming obsolete because o
f the development of carbon-fil
m resistors.
Carbon resistors with the same physical
size but different resistance values. The
physical size indicates a power rating of
½ W.

17. Types of resistors:
Carbon Film Resistors
 Compared to carbon com
position resistors, carbon-f
ilm resistors have tighter t
olerances, are less sensiti
ve to temperature change
s and aging, and generate
less noise.
Construction of a carbon film resistor.

18. Types of resistors:
 Metal Film Resistors
 Metal film resistors have v
ery tight tolerances, are le
ss sensitive to temperatur
e changes and aging, and
generate less noise.
Construction of a metal film resistor.

19. Types of resistors:
 Surface-Mount Resistors (also call
ed chip resistors)
 These resistors are:
 Temperature-stable and rugged
 Their end electrodes are soldered
directly to a circuit board.
 Much smaller than conventional r
esistors with axial leads.
 Power dissipation rating is usually
1/8 to ¼ W
Typical chip resistors.

20. Types of resistors:
 Fusible Resistors:
 Fusible resistors are wire-wound resistors made to
burn open easily when the power rating is exceed
ed. They serve a dual function as both a fuse and
a resistor.

21. Types of resistors:
 Thermistors:
 Thermistors are temperat
ure-sensitive resistors who
se resistance value chang
es with changes in operati
ng temperature.
 Used in electronic circuits
where temperature measu
rement, control, and comp
ensation are desired.
b: Typical thermistor shapes and sizes.

22. Resistor Color Coding:
 Carbon resistors are small, so their R value in oh
ms is marked using a color-coding system.
 Colors represent numerical values.
 Coding is standardized by the Electronic Industrie
s Alliance (EIA).

23. Resistor Color Coding:
 Resistor Color Code
0 Black
1 Brown
2 Red
3 Orange
4 Yellow
5 Green
6 Blue
7 Violet
8 Gray
9 White
Color Code
How to read color stripes on carbon resisto
rs for R in ohms.

24. Resistor Color Coding:
 Resistors under 10 Ω:
 The multiplier band is either gold or silver.
 For gold, multiply by 0.1.
 For silver, multiply by 0.01.
Examples of color-coded R values, with percent tolerance.

25. Resistor Color Coding:
 Applying the Color
Code
 The amount by w
hich the actual R
can differ from th
e color-coded val
ue is its toleranc
e. Tolerance is u
sually stated in p
ercentages.
00 is the nominal value.
4 
7
Violet = 7
Red = 2
Gold = 5%
5% of 4700 = 235
4700 + 235 = 4935
4700 - 235 = 4465
The actual value can range from 4465 to 4935 .
00 is the nominal value.
4 
700 is the nominal value.
4 
00 is the nominal value.
00 is the nominal value.
4 
7
Violet = 7
Red = 2
Gold = 5%
5% of 4700 = 235
4700 + 235 = 4935
4700 - 235 = 4465
Violet = 7
Red = 2
Gold = 5%
5% of 4700 = 235
4700 + 235 = 4935
4700 - 235 = 4465
The actual value can range from 4465 to 4935 .
Yellow = 4

26. Resistor Color Coding:
 What is the nominal value and permissible ohmic rang
e for each resistor shown?
1 k (950 to 1050 )
390  (370.5 to 409.5 )
22 k (20.9 to 23.1 k)
1 M (950 k to 1.05 M)

27. Resistor Color Coding:
 Five-Band Color Code
 Precision resistors often use a
five-band code to obtain more
accurate R values.
 The first three stripes indicate
the first 3 digits in the R value.
 The fourth stripe is the multipli
er.
 The tolerance is given by the fi
fth stripe.
 Brown = 1%
 Red = 2%
 Green = 0.5%
 Blue = 0.25%
 Violet = 0.1%.
Five-band code.

28. Resistor Color Coding:
 Using the five-band code, indicate the colors of the b
ands for each of the following resistors:
a) 110 Ω ± 1%
b) 34 kΩ ± 0.5%
c) 82.5 kΩ ± 2%
Tolerance
Brown = 1%
Red = 2%
Green = 0.5%
Blue = 0.25%
Violet = 0.1%.
0 Black
1 Brown
2 Red
3 Orange
4 Yellow
5 Green
6 Blue
7 Violet
8 Gray
9 White
Color Code

29. Resistor Color Coding:
 Zero-Ohm Resistor
 Has zero ohms of resistan
ce.
 Used for connecting two p
oints on a printed-circuit b
oard.
 Body has a single black b
and around it.
 Wattage ratings are typica
lly 1/8- or 1/4-watt.
A zero-ohm resistor is indicated by a s
ingle black color band around the bod
y of the resistor.

30. Resistor Color Coding:
 Chip Resistor Coding System
 Body color is usually white or off-white
 End terminals are C-shaped
 Three (four) digits on the body or on the film
 First 2 (3) digits indicate the first two (three) numbers
 Third (fourth) digit indicates the multiplier
 Are available in tolerances of ±1% ±5% but tolerances ar
e not indicated on the chip
 The letter R is used to signify a decimal point for values b
etween 1 to 10 ohms (1R5 means 1.5 ohms)

31. Types of resistors:
 Variable Resistors
 A variable resistor is a resistor whose resistance value c
an be changed.

32. Types of resistors:
 Variable resistors
 Decade resistance box
 Provides any R within a wide range of valu
es
 First dial is the units or R × 1 dial.
 Second dial is the tens or R × 10 dial
 The hundreds or R × 100 dial has an R of
0 to 900Ω
 Etc.
 Dials are connected internally so that their
values add to one another.

33. Types of resistors:
 Rheostats and potentiometers are variable resistances used t
o vary the amount of current or voltage in a circuit.
 Rheostats:
 Two terminals.
 Connected in series with the load and the voltage source.
 Varies the current.

34. Types of resistors:
 Potentiometers:
 Three terminals.
 Ends connected across the voltage source.
 Third variable arm taps off part of the voltage.

35. Types of resistors:
Wiping contact
Fixed contact
Rheostats are two-terminal devices.
Wiper arm
Wiping contact
Fixed contact
Rheostats are two-terminal devices.
Wiper arm