1. SUMMARY
• Transformer is a static device (and doesn’t contain on rotating parts, hence no
friction losses), which convert electrical power from one circuit to another
without changing its frequency. it Step up (or Step down) the level of AC
Voltage and Current.
Presentation title 1
5. Introduction
• The transformer in the simplest way can be described as a thing that steps
up or steps down voltage. In a step-up transformer, the output voltage is
increased and in a step-down transformer, the output voltage is decreased.
The step-up transformer will decrease the output current and the step-down
transformer will increase the output current for keeping the input and the
output power of the system equal.
• The transformer is basically a voltage control device that is used widely in
the distribution and transmission of alternating current power. The idea of a
transformer was first discussed by Michael Faraday in the year 1831 and
was carried forward by many other prominent scientific scholars. However,
the general purpose of using transformers was to maintain a balance
between the electricity that was generated at very high voltages and
consumption which was done at very low voltages.
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6. What is
transformers?
A transformer is a device used in the power
transmission of electric energy. The transmission
current is AC. It is commonly used to increase or
decrease the supply voltage without a change in the
frequency of AC between circuits. The transformer
works on basic principles of electromagnetic
induction and mutual induction.
8. Working principle of
tranformer
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According to the principle of mutual inductance, when an alternating voltage is
applied to the primary winding of the transformer, an alternating flux ϕm which
is called as the mutual flux is produced in the core. This alternating flux links
both the windings magnetically and induces EMFs E1 in the primary winding
and E2 in the secondary winding of the transformer according to Faraday’s law
of electromagnetic induction. The EMF (E1) is called primary EMF and the
EMF (E2) is known as secondary EMF and being given as,
E1=−N1dφmdt and E2=−N2dφmdt
Therefore,
E2E1=N2N1
From the above expression it can be seen that the magnitude of EMFs
E1 and E2 depend upon the number of turns in the primary and secondary
windings of the transformer respectively, i.e., if N2 > N1, then E2 > E1, thus the
transformer will be a step-up transformer and if N2 < N1, then E2 < E1, thus the
transformer will be a step-down transformer.
If a load is now connected across the secondary winding, the EMF E2 will
cause a load current I2 to flow through the load. Therefore, a transformer
enables the transfer of power from one electric circuit to another with a
change in voltage level.
