ELE 1001: Basic Electrical Technology
Lecture 01
Introduction to Electrical Circuit Elements &
Source Transformation
Dept of Electrical & Electronics
Required: Scientific Calculator
Casio- fx-991ES
Dept of Electrical & Electronics
Casio- fx-991MS
Optional
My Mobile No.: 9663611063
My Email: satyakam.deo@manipal.edu
Dept of Electrical & Electronics
We will learn here…

Classify electrical circuit elements
 Active & Passive
 Linear & Non linear
 Unilateral & Bilateral
 Lumped & Distributed

Ideal & Practical Active Elements

Source Transformation
Dept of Electrical & Electronics
Electric Circuit
Definition:
An
interconnection
of
simple
electrical devices with at least one
closed path in which current may
flow
Dept of Electrical & Electronics
Classification of Circuit Elements
 Active & Passive Elements
 Active Elements (Source): Voltage & Current Sources
 Passive Elements (Sink): Resistor, Inductor & Capacitor
 Linear & Non-linear Elements
 Linear (Satisfies Superposition): Resistor, Inductor,
Capacitor
 Nonlinear: LDR (Light Dependent Resistor), Thermistor
 Unilateral & Bilateral Elements
 Unilateral (Current Flow in one direction): Diode,
Transistor
 Bilateral: Resistor, Inductor, Capacitor*
 Lumped & Distributed
Discuss only lumped linear bilateral circuit elements.
Dept of Electrical & Electronics
Passive Elements
 Energy Consuming Elements:
 Resistor (R): RI2
 Energy Storing Elements
 Inductor (L): Stores Energy In Its Magnetic Field
[0.5LI2]
 Capacitor (C): Stores Energy In Its Electrical Field
[0.5CV2]
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Types of Active Elements
Ideal Voltage Source:
 Maintains constant voltage
irrespective of connected
load.
 Internal resistance Rs = 0
Ideal Voltage Source (DC)
Vs
Dept of Electrical & Electronics
+Vs
Types of Active Elements
Ideal Current Source:
contd…
Ideal Current Source (DC)
 Maintains constant current
irrespective of the load
connected.
 Internal resistance Rs = ∞
Dept of Electrical & Electronics
Is
Practical Sources
Practical Voltage Source
Vs
+-
Rs
V-I Characteristics of battery
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Practical Sources
contd…
Practical Current Source
Is
Rs
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Practical Source Transformation
Conversion of Practical Voltage source to Current
source & vice versa
R
+a
+a
Is
+
Vs -
R
-b
𝑉𝑠 = 𝑅 × 𝐼𝑠
Dept of Electrical & Electronics
-b
𝑉𝑠
𝐼𝑠 =
𝑅
Example
Convert a voltage source of 100 V having an internal
resistance of 7.5 Ω to its equivalent current source.
Draw the circuit representation of both forms of
sources.
+a
+a
RS = 7.5 Ω
VS = 100 V
+
-
IP = 13.33 A
-b
Dept of Electrical & Electronics
RP = 7.5 Ω
-b
Summary
We started with
 How a typical electric circuit looks like?
Then looked into
 Different types of circuit elements & their
classifications
 Ideal & practical sources
Finally concluded with
 How to transform practical current & voltage
sources?
Dept of Electrical & Electronics