Dept of Electrical & Electronics

ELE 1001: BASIC ELECTRICAL TECHNOLOGY

LECTURE 01

INTRODUCTION TO ELECTRICAL CIRCUIT ELEMENTS &

SOURCE TRANSFORMATION

Dept of Electrical & Electronics

Ganesh KudvaDept. of Electrical & Electronics Engg.

E-mail: ganesh.kudva@manipal.edu

Dept of Electrical & Electronics

Required: Scientific Calculator

Casio- fx-991ES Casio- fx-991MS

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We will learn here…

Classify electrical circuit elementsActive & PassiveLinear & Non linearUnilateral & BilateralLumped & 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

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Classification of Circuit Elements Active & Passive Elements

Active Elements (Source): Voltage & Current Sources

Passive Elements (Sink): Resistor, Inductor & Capacitor

Linear & Non-linear ElementsLinear (Satisfies Superposition): Resistor, Inductor,

CapacitorNonlinear: 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.

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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]

Dept of Electrical & Electronics

Types of Active Elements

Ideal Voltage Source: Maintains constant

voltage irrespective of connected load.

Internal resistance, Rs = 0

+ -

I d e a l V o lta g e S o u rc e (D C )

V s

V s

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Types of Active Elements contd…

Ideal Current Source: Maintains constant current

irrespective of the load connected.

Internal resistance, Rs = ∞

I d e a l C u rre n t S o u rc e (D C )

I s

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Practical Sources

+ -

P ra c tic a l V o lta g e S o u rc e

V s R s

V-I Characteristics of battery

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Practical Sources contd…

P ra c tic a l C u rre n t S o u rc e

I s R s

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Practical Source Transformation Conversion of Practical Voltage source to

Current source & vice versa The terminal characteristics of both the

sources are same

Vs

R

+-

+

-

a

b

Is R

+

-

a

b

𝐼 𝑠=𝑉 𝑠

𝑅

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Example 1

Convert a voltage source of 100 V having an internal resistance of 5 Ω to its equivalent current source. Draw the circuit representation of both forms of sources.

+-

+

-

a

b

+

-

a

b

VS = 100 V

RS = 5 Ω

IP = 20 A RP = 5 Ω

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Example 2

1 5 V

6 V

9 V

6

6

6

2

Find the power dissipated in 2 Ω resistor

Ans: P = 12.5 W

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Example 3

1 0 V

5

2 0

1 5

1 A

5 V

0 .5 A

Find the power dissipated in 15 Ω resistor using source transformation

Ans: P15Ω = 0.9375 W

Dept of Electrical & Electronics

Summary

We started withHow a typical electric circuit looks like

Then looked intoDifferent types of circuit elements &

their classificationsIdeal & practical sources

Finally concluded withHow to transform practical voltage &

current sources