A transformer transfers electrical energy from one circuit to another by changing the voltage and current levels using electromagnetic induction. It has two windings, a primary and secondary, wrapped around an iron core. When an alternating current is passed through the primary winding, it creates an alternating magnetic flux that induces an electromotive force in the secondary winding. The ratio of the number of turns in the primary and secondary determines whether the voltage is stepped up or down. Transformers are used to transmit power over long distances by increasing the voltage to reduce transmission losses before stepping it back down for distribution.

1. Prof.Prasant Tiwari
आसान भाषा
में
TRANSFORMER

2. ELECTRICAL TRANSFORMER
Transformer Syllabus
 Definition/Need of transformer
 Principle of Operation
 Construction
 EMF Equation
 Transformation Ratio
 Equivalent Circuit
 Losses in a Transformer
 Efficiency

3. DEFINITION
Transformer is a static device (i.e. it contains no moving parts) that transfer
(1) electrical energy from one circuit to another circuit.
(2) It does so by changing level of voltage and current
(3) It does so by the principle of faraday law of electromagnetic induction.
(4) It does not change the level of input and output frequency
(5) It does not change the level of input and output power ideally.

4. NEED OF TRANSFORMER
TRANSFORMER is used to overcome transmission losses.
 Before transmission the generated electric power of power
plant
( low voltage high current) passes through transformer to step up
voltage and step down current and vice versa at distribution end.

5. PRINCIPLE OF OPERATION
 The working principle of transformer is Faradays Laws of Electromagnetic Induction.

6. PRINCIPLE OF OPERATION
 The working principle of transformer is Faradays Laws of Electromagnetic Induction.
 The two windings; primary and secondary, are electrically separated but wound on same
magnetic core.
 When AC voltage is applied to primary winding, it creates alternating magnetic flux (ϕm)
which links with the secondary winding.
 This alternating magnetic flux will induce an EMF in the secondary winding.
 The magnitude of induced EMF in the secondary can be increased or decreased by increasing
or decreasing the number of turns.
 The induced emf in the secondary winding enables to deliver current to external load.
Where N1 : Number of turns in primary winding
N2 : Number of turns in secondary winding
V1,E1 : Voltage ,EMF at primary winding
V2,E2: Voltage,EMF at secondary winding