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Chapter 13Transformer Applications

Huseyin Bilgekul

Eeng224 Circuit Theory II

Department of Electrical and Electronic Engineering

Eastern Mediterranean University

Chapter Objectives: Understand magnetically coupled circuits.

Learn the concept of mutual inductance.

Be able to determine energy in a coupled circuit.

Learn how to analyze circuits involving linear and ideal transformers.

Be familiar with ideal autotransformers.

Learn how to analyze circuits involving three-phase transformers.

Be able to use PSpice to analyze magnetically coupled circuits. Apply what is learnt to transformer as an isolation device and power

distribution

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Different Transformers

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LVDT Transformer:

LVDT transformer: (a)

construction; (b) maximum

displacement; (c) minimum

displacement; (d) graph of

induced voltage versus

displacement.

The linear variable differential transformer (LVDT) is a sensor that can reveal displacement

using transformer effects.

A constant low-level ac signal is applied to the primary.

Voltage level induced in the secondary is based on core position, which is moved by some

external force. Position of the core can be related to the secondary voltage.

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Three phase transformer connections A Y-Y three phase transformer connection.

A - three phase transformer connection.

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Transformer for Power Supply Application

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(a) general appearance

Fluorescent Lamp

(b) internal view with ballast.

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(a) Schematic of single-bulbfluorescent lamp; (b) starter;

(c) internal view of ballast

transformer.

Fluorescent Lamp

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A transformer providing AC isolation in a rectifier circuit.

Electrical Isolation

Electrical ISOLATION exists between two devices when there is no physical

connection between them. A transformer provides AC isolation in a rectifier circuit

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DC IsolationA transformer providing DC isolationbetween two amplifier stages

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Impedance MatchingA transformer used as a IMPEDANCE MATCHING device

A transformer matching the speaker to the amplifier.

A transformer is used to

match the load resistance to

the source resistance to

provide Maximum Power

Transfer to the load.

A transformer is used to

match the loudspeaker to

the output impedance of

the amplifier.

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Impedance Matching

Impedance Matching for public address system

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Impedance Matching Transformer for TV Antenna

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Power Distribution A typical power distribution system