### Ticker

6/recent/ticker-posts

# Working Principle of Transformer Machine

## Transformer Working Principle

Transformer is an electromagnetic static device in which input is in form of electrical energy and output is also in electrical form also the input and output both are in alternating form primarily transformers are used to change level of voltage and current For example;

In case of step-down transformer the input high voltage is transformed to a low voltage whereas the magnitude of current is increases because input and output power has to be remain same working of a transformer can be understand by taking a simple example of a small piece of wire carrying Current.

When it is connected to a battery as a result of magnetic flux gets set up  around the conductor if another piece of wire comes in the vicinity of this flux an electro-motive force is get induced in the conductor which we can see here form deflection in needle of a Galvanometer but after some time deflection  becomes zero because both conductors are stationary means there is no relative movement between them this is known as  dynamically induced e-m-f further.

We can also experience that EMF is again induced in this second conductor when we remove battery this is because of the reduction in flux density around the first conductor and the second conductor try to oppose this change in flux as per Faraday's law of electromagnetic induction the magnitude of EMF induced is given by e to is directly E2 ∝ dÑ„/dt.

This electromagnetic coupling between the two Conductors can be improved by two methods number one by using coil on both side instead of using single wire this results in increase of flux number two by using a magnetic core between the coils.

Which gives low reluctance path to the flux and improve magnetic coupling within the coils as you can see here in this case coil of left side or we can call it primary coil has lesser number of turns than the coil on right side or we can call it secondary coil and the transformer is called as step-up transformer in this case voltage which induced on secondary coil V out is higher than the voltage which is applied V in the primary coil where as the current get reduced as the power has to remain constant similarly when primary coil has more number of turns than the number of turns in secondary coil the transformer is called as a step-down transformer and the voltage induced on the secondary side V out is less than the applied voltage V in primary side the core which is practically used in a transformer is actually not a solid core it is made up of number of thin sheets of metal called laminations this type of construction is used to reduce Eddy-current loss which occurs inside the core when it carries changing or alternating Flux as score is used to provide a low reluctance path to the magnetic flux but the core is subjected to circulating electric currents.

These circulating currents called eddy currents produced heating and energy  losses  within the core results in decreasing the transformers efficiencythe circulating current is produced mainly due to EMF induced in the iron core as it is constantly being subjected to the changing magnetic field set up bythe external sinusoidal supply voltage vin to reduce these unwanted power  losses thin steel laminations is used to construct the transformer core laminations are made up of highly permeable material that is slick on steal these laminations are assembled together to build a solid core the resistivity of the steel sheet it self is high reducing the eddy current losses while making the laminations very thine the thickness of these laminations is vary between 0.25 mm to 0.5 mm and steel is conductor laminations are electrically insulated from each other by a very thin coating of insulating varnish or by the use of an oxide layer on the surface the problem with the construction which is so far discussed here is that the two windings are well separated from each other andthere is considerable reduction of magnetic coupling and hence the efficiency of the transformer this disadvantage can be over come by using constructing coal like this in which the two bindings are bring close to each other there by improve magnetic coupling between then hope now you have little bit idea about principle of working of electrical transformer and about its construction we will discuss it in more details and other topics related to electrical transformer in our up coming post till then thank you for Reading my post.

www.eengineeringtech.in