Describe the construction and working principle of auto transformer.

Describe the construction and working principle of auto transformer.
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1 Answer

Answer :

An auto transformer has single winding which is used as primary and secondary winding. This winding is wound on laminated enameled magnetic core.

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OR

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As shown in fig. 1 the input is given to winding worked as primary and output is taken from the part of the same winding. Thus the one winding serves as primary and secondary. This transformer is known as step down autotransformer 


As shown in fig.2 the input is given to the part of winding and output is taken across the whole winding. So the part of winding acts as a primary winding and the whole winding acts as a secondary winding. With this construction we can step up the voltage. So this transformer known as step up autotransformer.

 

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