Explain the working and principle of LVDT.

Explain the working and principle of LVDT.
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1 Answer

Answer :

LVDT: Principle: The differential voltage of two secondary windings of a transformer is varied by positioning the iron core through an externally applied force.


Working 

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When the pressure inside the bellows changes, its free end gets deflected along with the movable core. When the core is symmetrically positioned between the two secondary coils, the magnetic coupling of the core with both the secondary coils is equal. In this position, equal but opposite emfs are developed in the coil, and hence the net voltage between two secondary coils is zero. When core takes any other position, the magnetic coupling with each secondary coil is different, that induces different voltages in the secondary coils. Hence some unbalance voltage is produced between the coils that depend upon the position of the core which in turn depends upon the pressure fed inside the bellows.

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