The document summarizes the basics of a transformer. It explains that a transformer transfers electrical energy from one circuit to another through mutual induction of two coils, the primary and secondary. It works for alternating current but not direct current since it requires a changing current. Transformers can be classified by their cooling system, core type, output voltage, number of phases, power rating, and intended use. Common applications include impedance matching, voltage transformation for power transmission and distribution, and use in devices like voltmeters and rectifiers.

1. PREPARED BY- ARUNA.J.VASAVA

2. Introduction:
What is a transformer ??
The transformer is a static piece
of apparatus by means of which an
electrical power is transformed
from one alternating current circuit
to another with desired change in
voltage and current, without any
change in the frequency.

3.  Principle of working:
 The transformer works on
the principle of mutual
induction.
 It transfers an electrical
energy from one circuit to
other when there is no
electrical connection
between the two circuits.

4.  A transformer consists of
two types of coils or
windings:
A) Primary- The coil
connected to the source
of supply is called primary
winding or only ‘primary’.
B) Secondary- The coil
connected to the load is
called secondary winding
or only ‘secondary’.

5. Can D.C supply be used for Transformers ?
Why?
 The D.C. supply can not be used for the transformers.
 The transformers works on the principle of mutual induction, for
which current in one coil must change uniformly. If D.C. supply
is given, the current will not change due to constant supply and
transformer will not work.
 Practically winding resistance is very small. For D.C., the
inductive reactance XL is zero as D.C. has no frequency. So
total impedance of winding is very low for D.C. Thus winding will
draw very high current if D.C. supply is given to it. This may
cause the burning of windings due to extra heat generated and
may cause permanent damage to the transformer.

6. Classification of Transformers:
 Transformers can be
classified on the following
grounds:
 As per cooling system-
 Self cooled
 Air cooled
 Oil cooled
 Oil pressure cooled
 Water cooled
 As per core-
 Core type
 Shell type
 Berry type
 As per output-
 Voltage step-up type
 Voltage step-down type
 As per phase-
 Single phase
 Three phase

7.  As per power rating-
 Power
 Lighting
 As per use-
 Mains or power
 Auto
 Battery eliminator
 Driver
 Output
 Push-pull
 I.F.
 R.F.
 E.H.T.

8. Applications of transformer:
 The transformer used for impedance matching.
 The transformer used for isolate two circuits electrically.
 It is used to increase or decrease the alternating voltages in electric
power applications.
 The transformer used in voltmeter, ammeters, protective relay etc.
 The transformer used for step up low voltage in case of
measurement.
 The transformer used for step down high voltage for safety.
 The transformer used in rectifier.
 It is used in voltage regulators, voltage stabilizers, power supplies
etc.

9. Power Generation, Transmission &
Distribution:

10. Sources:
 Wikipedia
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