Electrical Engineering and Analog
Electronics
Course Instructor: Dr B.Rajkumarsingh
Office: RM 4.6 Engineering Tower
Email: b.rajkumarsingh@uom.ac.mu
Module Structure
Introduction to Electric Circuits
DC Circuit Theory
AC Circuits
Magnetism and Electromagnetism
Basic Electronics
Operational Amplifiers
Introductory Circuit Analysis by R.Boleystad
Please refer to MSS for further details
Class Schedule

Mini-project – Term Report
Team of 3-5 students: To be announced
 Class
 Labs
Test – To be announced
– Starts 2nd Week –
Marks will be awarded for both report and one-one Q & A.
What is Voltage?
V = “Electrical pressure”
- measured in volts.
H2O
High Pressure
Low Pressure
Figure 1.1
7
A battery in an electrical circuit plays the same
role as a pump in a water system.
8
The pressure of the water flowing through the pipes
on the last slide compare to the voltage (electric
potential) flowing through the wires of the circuit.
The unit used to measure voltage is volts (V).
The flow of charges in a circuit is called current.
Current (I) is measured in Amperes (A).
Low Potential
High Potential
Electron
Pump
• When the potentials are equal, the
current stops flowing
– To increase the potential of the electrons an
electron pump must convert (do work)
another form of energy into electrical
potential energy.
• Electron pump examples:
–
–
–
–
Voltaic or galvanic cell (dry cell)
Several cells connected (Battery)
Photovoltaic cell (solar cell)
Generator
What Produces Voltage?
V = “Electrical pressure”
Lab Power Supply
A Battery
9V
Solar Cell
1.5 V
Electric Power Plant
13,500 V
Nerve Cell
A few millivolts
when activated by
a synapse
A few
Volts
11
Other Symbols Used for
Specific Voltage Sources
+
+
_
_
~
Battery Time-varying
source
.
Figure 1.2
Generator
(power plant)
Solar Cell
These are all…
Voltage Sources
12
• Direct Current
• DC
• Provided by batteries
• Alternating
Current
• AC
• Provided by power
companies
Two types of current
•
Direct Current – (D.C.) Flow of electrons in only one
direction
–
•
Battery
Alternating Current – (A.C.) Flow of electrons at
first in one direction and then the other direction.
–
–
–
Generator
In your House
50 Hertz
Electric
Current:
• The flow of
electric charges.
Electric Current, I
I=q
t
• Rate
• Unit: Coulomb / sec = Ampere (A)
• Andre Ampere (1775-1836)
Conventional current has the direction
that the (+) charges would have in the
circuit.
http://media-2.web.britannica.com/eb-media/36/236-004-D4AA985F.gif
Example:
• What charge flows through a cross sectional
area of a wire in 10min, if the ammeter
measures a current of 5mA?
• Answer: 3C
Ammeter
• Measures electric current.
• Must be placed in series.
What are electric circuits?
Circuits typically contain a voltage source, a wire conductor,
and one or more devices which use the electrical energy.
What is a series circuit?
A series circuit is one which provides a single pathway for the
current to flow. If the circuit breaks, all devices using the
circuit will fail.
What is a parallel circuit?
A parallel circuit has multiple pathways for the current to flow.
If the circuit is broken the current may pass through other
pathways and other devices will continue to work.
What is the difference between an open circuit and a
closed circuit?
A closed circuit is one in which the pathway of the electrical current
is complete and unbroken.
An open circuit is one in which the pathway of the electrical current
is broken. A switch is a device in the circuit in which the circuit can be
closed (turned on) or open (turned off).
How is household wiring arranged?
Most household wiring is logically designed with a
combination of parallel circuits. Electrical energy enters the
home usually at a breaker box or fuse box and distributes the
electricity through multiple circuits. A breaker box or fuse
box is a safety feature which will open
What is electrical resistance?
Resistance (R)is the opposition to the flow of an
electric current, causing the electrical energy to be
converted to thermal energy or light.
The metal which makes up a light
bulb filament or stovetop eye has a
high electrical resistance. This
causes light and heat to be given
off.
Resistance
• Resistance of an object to the flow of
electrical current.
• R= V / I
• Resistance equals the ratio of voltage to
current.
• Unit: Ohm (Ω)
Ohmic Resistor
• A device that obeys Ohm’s Law, who’s
resistance does not depend on the voltage.
Resistor
• An object that has
a given resistance.
Understanding the
Resistor Color Code
Dr. Deb Hall
Electronics Engineering Technology
Valencia Community College
Resistor Color Code
• Manufacturers typically use a color band
system known as the resistor color code
• Within this power point, you will learn how
to identify the nominal resistance and the
tolerance of a resistor
Resistor Color Code
• The power rating is not indicated in the resistor
color code and must be determined by
experience using the physical size of the resistor
as a guide.
• For resistors with 5% or 10% tolerance, the
color code consists of 4 color bands.
• For resistors with 1% or 2% tolerance, the color
code consists of 5 bands.
4-Band Resistors
The resistor nominal value is encoded in the color code in Powers of
Ten Notation. The template for determining the nominal value and
tolerance of a resistor with 4 color bands is given below:
1st Band =
1st Significant Digit
2nd Band =
2nd Significant Digit
3rd Band =
Multiplier
4th Band =
Tolerance
___ ___  10    ____ %
How do we know which color corresponds to
which number?
Answer: Using the Resistor Color Code Table
Example 1. Determine the nominal resistance value and the tolerance
for the resistor shown below.
Solution:
Brown =1
Black =0
1 ___
0  10
___
2

Nominal value
Red =2
Gold =
5%
5 %
  ____
= 10102
= 1,000
Tolerance = 5%.
• It is typical to express the resistance value in:
k if the resistance  1,000
M if the resistance  1,000,000.


To convert from  to k,  to M, or vice-versa, use the table
below:
In the previous example we would say the resistor has a
nominal value of: 1,000
 1k
1,000
Example 2. a) Determine the nominal value and tolerance for the
below.
b) What is the minimum resistance value this resistor
actually have?
c) What is the maximum resistance value this resistor
actually have?
Solution:
Yellow =4
Violet =7
___4 ___7  10
3
Orange =3
Gold = 5%
5 %
  ____
Resistor nominal value = 47103
= 47,000
= 47k.
Tolerance = 5%
resistor
can
can
Solution: continued
• Minimum resistance value:
Multiply the nominal value by the tolerance and then subtract this
from the nominal value:
 47 k  47 k * 0.05
 47 k  2.35k
 44.65k

Maximum resistance value:
Multiply the nominal value by the tolerance and then add this to
the nominal value:
 47 k  47 k * 0.05
 47 k  2.35k
 49.35k
Example 3. a) Determine the nominal value and tolerance for the
below.
b) What is the minimum resistance value this resistor
actually have?
c) What is the maximum resistance value this resistor
actually have?
Solution:
Orange =3
White =9
___3 ___9  10
5

Green =5
Silver = 10%
10 %
  ____
Resistor nominal value = 39105
= 3,900,000
= 3.9M.
Tolerance = 10%
resistor
can
can
Solution: continued
• Minimum resistance value:
nominal value – nominal value * tolerance:
 3.9 M  3.9 M * 0.1
 3.9 M  0.39 M
 3.51M

Maximum resistance value:
nominal value + nominal value * tolerance:
 3.9 M  3.9 M * 0.1
 3.9 M  0.39 M
 4.29 M
5-Band Resistors
• For resistors with 1% or 2% tolerance, the color code consists of 5
bands.

The template for 5-band resistors is:
1st Band =
2nd Band =
1st Significant 2nd Significant
Digit
Digit
3rd Band =
3rd Significant
Digit
4th Band =
Multiplier
5th Band =
Tolerance
___ ___ ___  10    ____ %
Example 4. Determine the nominal resistance and tolerance for the resistor
shown below.
Solution:
Brown = 1
Black =0
Black = 0
Brown = 1
1
1 ___
0 ___
0  10 
2 %
___
  ____
Resistor nominal value
Tolerance = 2%
= 100101
= 1,000
= 1k.
Red =  2%
Example 5. Determine the nominal resistance and tolerance for the resistor
shown below.
Blue = 6
Solution:
Gray = 8
Black = 0
Orange = 3
3
6 ___
8 ___
0  10 
1 %
___
  ____
Resistor nominal value
Tolerance = 1%
= 680103
= 680,000
= 680k.
Brown =  1%
Which side of a resistor do I read
from?
• A question that often arises when reading the color code
of real resistors is: how do I determine which side of a
resistor do I read from?
Answer:
• For 4-band resistors a gold or silver band is always the last
band.
• If the resistor has 5 bands or if there is no tolerance band
(20%), then the first band is the one located closest to a
lead.
Converting the Nominal Resistance and
Tolerance into the Color Code
We are given the nominal value and the tolerance and we have to
come up with the color code.
4-Band Resistors
1.
Resistors with 5% and 10% Tolerance will have 4-bands
2.
Convert nominal value to ohms ()
3.
1st digit (from left to right) of nominal value = 1st color band
4.
2nd digit of nominal value = 2nd band
5.
Number of zeros remaining = 3rd (multiplier) band
6.
Tolerance = 4th band
Example 6. Specify the color code of a resistor with nominal value
of 27k and a tolerance of 10%.
Solution:
1) Since resistor Tolerance = 10% it will have 4-bands.
2) Convert the nominal resistance value to  from k.
27,000 
Red = 2
Violet = 7
Orange = 3
10%
Example 7. Specify the color code of a resistor with nominal value
of 1.5k and a tolerance of 5%.
Solution:
1) Since resistor Tolerance = 5% it will have 4-bands.
2) Convert the nominal resistance value to  from k.
1,500 
Brown = 1
Green = 5
Red = 2
5%
Converting the Nominal Resistance and
Tolerance into the Color Code
5-Band Resistors
1.
Resistors with 1% and 2% Tolerance will have 5-bands
2.
Convert nominal value to ohms ()
3.
1st digit (from left to right) of nominal value = 1st color band
4.
2nd digit of nominal value = 2nd band
5.
3rd digit of nominal value = 3rd band
6.
Number of zeros remaining = 4th (multiplier) band
7.
Tolerance = 5th band
Example 8. Specify the color code of a resistor with nominal value
of 2.5M and a tolerance of 1%.
Solution:
1) Since resistor Tolerance = 1% it will have 5-bands.
2) Convert the nominal resistance value to  from M.
2,500,000
Red = 2
Green = 5
Black = 0
Yellow = 4
1%
Congratulations!
You now know how to work with the
resistor color code
It’s that simple!