Linear Variable Differential Transducer(LVDT)

LVDT is device which is used to measure displacement.

1. LINEAR VARIABLE DIFFERENTIAL TRANSDUCER (LVDT) PREPARED BY E CHIRANJEEVI M.TECH ASST. PROFESSOR RISE KRISHNA SAI PRAKASAM GROUP OF INSTITUTIONS ,ONGOLE , AP

2. LINEAR VARIABLE DIFFERENTIAL TRANSDUCER (LVDT) Principle of LVDT : LVDT works under the principle of mutual induction , and the displacement which is a nonelectrical energy is converted into an electrical energy . It is also called as LINEAR VARIABLE DIFFERENTIAL TRANSFORMER

3. Construction of LVDT LVDT consists of a cylindrical transformer where it is surrounded by one primary winding in the centre of the former and the two secondary windings at the sides. The number of turns in both the secondary windings are equal, but they are opposite to each other. The Primary Winding is Connected to an ac source

4. Working of LVDT: The Displacement to be Measured is applied to an arm attached to the Soft iron core

5. Case 1: When the Core is in its normal position. Equal Voltages induced in the two secondary windings The Output Voltage of secondary winding S 1 is E s1 and secondary winding S 2 is E s2 The Differential output Voltage E =E S1 ~E S2 At Normal Position E =0 ,because The Flux linking with both secondary windings is equal , hence equal emf are induced in them. ( i.e E S1 =E S2 )

6. Case 2: When the Core is moved to the left of null position

7. Case 3: When the Core is moved to the right of null position

8. Cont …

9. Cont … The Characteristics are linear from O-A and O-B , But a fter that they become non-linear.

10. Advantages of LVDT

11. Advantages of LVDT Disadvantages of LVDT

12. Applications of LVDT : Acting as a secondary transducer, LVDT can be used as a device to measure force, weight and pressure, etc .. Testing of soil strength PILL making Machine “Brain Probing” medical device Robotic Cleaner Dollar bill thickness in ATM Machine. Hydraulic cylinder Displacement.