# INFORMATIONAL TECHNOLOGY IN EDUCATION

## Presentation on theme: "INFORMATIONAL TECHNOLOGY IN EDUCATION"โ Presentation transcript:

INFORMATIONAL TECHNOLOGY IN EDUCATION
Name: Farah Eliza Binti Mansor Matrix: db130320 Name:Nurul Qurraisyia Binti Zulkafli Matrix: DB130085 Name: Fatinnazihah Binti Abdul Rahman Matrix: DB130322 Name: Faridah Zahirah Binti Ismail Matrix: Db130321

CONTENTS No Title 1 1.0 Introduction 2
2.0 Basic Construction Of A Transformer 2.1 Core 2.2 Windings 3 3.0 Operation Of Transformers 3.1 Winding Ratio 3.2 Voltage Ratio 3.3 Current Ratio 4 4.0 Loss And Efficiency Of Transformers 4.1 Ideal Transformers 4.2 Non-ideal Transformers 4.3 Transformers Efficiency 5 5.0 Application Of A Power Transformer 6 Quiz

INTRODUCTION OF TRANSFORMER Self inductance Mutual inductance
Electrical device that transfers electrical energy from one circuit to another Made up of two electromagnetic coils Self inductance Mutual inductance Only operate with AC or DC that is constantly changing

2.0 BASIC CONSTRUCTION OF A TRANSFORMER
Consist of 2 conductor wound around a core as shown in Figure 1.2.1 Figure 1.2.1 Core is wounded with insulated copper conductor with specific number of turns

2.1 CORE Constructed by : laminated sheets of silicon steel insulated from each other :soft iron , powdered iron and ferrite Thickness of the laminated sheets : between 1mm โ 5 mm Charecteristics : robust , low hysteresis Made up of thin layers (Avoid power loss by the build-up of eddy currents ) Two major construction of the core of transformer Shell-type form ( E-I) Core-type form (U-I)

2.2 WINDINGS Transformer consist of 2 kind of windings around the core
Winding that is connected to the voltage source ( primary winding ) Winding that is connected to load circuit and is the output path for the transformer ( secondary winding ) In an auto transformer , one winding serves as both the primary and secondary winding . The secondary winding is tapped from the primary winding Types of winding methods : Common winding Coupling winding

TYPES AND SYMBOLS OF TRANSFORMERS
Transformer Name Air-core Transformer Iron-core Transformer Iron Powder-core Transformer Auto Transformer Centre-tapped Transformer Multiple Winding Transformers Types Of Core Air-core Iron-core Powdered Symbol

BASIC OPERATION OF TRANSFORMERS
3.1 WINDING RATIO Ratio of number of turn in the primary winding to the number of turn in the secondary winding winding ratio , n = ๐๐๐๐๐๐ ๐๐ ๐๐๐๐๐ ๐๐ ๐๐๐ ๐๐๐๐๐๐ ๐๐๐๐๐๐๐ ๐๐๐๐๐๐ ๐๐ ๐๐๐๐๐ ๐๐ ๐๐๐ ๐๐๐๐๐๐๐๐๐ ๐๐๐๐๐๐๐ = ๐ต ๐ ๐ต ๐ Step up transformer : number of turns in secondary winding exceed the number of turns in the primary winding Step down transformer : number of turns in primary winding exceed the number of turns in the secondary winding Isolation transformer : same number of turns in primary and secondary winding

3.2 VOLTAGE RATIO 3.3 CURRENT RATIO
Ratio between the primary voltage , V1 and the secondary voltage V2 is called the voltage ratio of a transformer Formula of voltage ratio : ๐ฉ๐ซ๐ข๐ฆ๐๐ซ๐ฒ ๐ฏ๐จ๐ฅ๐ญ๐๐ ๐ ๐ฌ๐๐๐จ๐ง๐๐๐ซ๐ฒ ๐ฏ๐จ๐ฅ๐ญ๐๐ ๐ = ๐ ๐ ๐ ๐ Voltage ratio is related to the winding ratio. Formula of voltage ratio : ๐ฝ ๐ ๐ฝ ๐ = ๐ต ๐ ๐ต ๐ = n 3.3 CURRENT RATIO When AC supply is connected to transformerโs primary winding , the existing flux around the winding produces self โ induction Flux shifts to secondary winding through the transformer core to produce inductance at the secondary winding This indicates the emf at the secondary winding is equivalent to the emf of the primary winding

LOSS AND EFFICIENCY OF TRANSFORMERS
4.1 IDEAL TRANSFORMERS Anย Ideal Transformerย is an imaginary transformer which does not have any loss in it, means no core losses, copper losses and any other losses in transformer. Efficiency of this transformer is considered as 100%. 4.2 NON-IDEAL TRANSFORMER We can replace a nonideal transformer with an idealized transformer by including a lumped resistance equal to the winding resistance of series with each winding The efficiency is less than 100% because power losses in corand its primary windings. Power loss : iron & copper

4.3 TRANSFORMER EFFICIENCY
For an ideal transformer, the power received by the load is equivalent to the power transferred by the primary winding Non-ideal transformer does not reach 100% efficiency because there is power loss that is unavoidable in the core and winding By choosing an optimum size for your winding wire and designing a suitable core that reduces iron loss to minimum, up to 99.5% efficiency can be achieved Transformer efficiency, ๐= ( ๐๐๐๐๐๐ ๐๐๐๐๐ ) ๐๐๐๐๐ ๐๐๐๐๐ ๐ ๐๐๐% Non-ideal transformer ,๐ก= ๐จ๐ฎ๐ญ๐ฉ๐ฎ๐ญ ๐๐๐๐๐ ๐ฉ๐จ๐ฐ๐๐ซ ๐ฅ๐จ๐ฌ๐ฌ + ๐จ๐ฎ๐ญ๐ฉ๐ฎ๐ญ ๐๐๐๐๐ ๐ ๐๐๐% OR ๐= ๐ฐ ๐ ๐ฝ ๐ ๐๐๐ ๐ฝ ( ๐ท ๐๐๐๐๐๐ + ๐ท ๐๐๐๐ ) + ๐ฐ ๐ ๐ฝ ๐ ๐๐๐ ๐ฝ ๐ ๐๐๐% V2 = Output voltage or secondary voltage I2 = Secondary current Cos = power factor at the load P copper = copper loss P iron = iron loss

5.0 APPLICATION OF POWER TRANSFORMER
Theย most important uses and applications of a transformer are: It can rise or lower the level of level of Voltage or Current It can increase or decrease the value of capacitor, an inductor or resistance in an AC circuit. It can act as an impedance transferring device.ย ย  It can be used to prevent DC from passing from one circuit toย the other.ย  It can isolate two circuits electrically