Page 91 - CITS - Electronic Mechanic - TT - 2024

ELECTRONICS MECHANIC - CITS

Advantages: The sensitivity of capacitive transducer high.The capacitive transducer is useful for small system.
It has good frequency response.It requires small power to operate.
Disadvantages: The capacitive transducer temperature sensitive.It gives non-linear behaviour.The output
impedance depends upon the frequency used.
Linear Variable Differential Transformer (LVDT)
LVDT The term LVDT stands for the Linear Variable Differential Transformer. It is the most widely used inductive
transducer that converts the linear motion into the electrical signal. The output across secondary of this transformer
is the differential thus it is called so. It is very accurate inductive transducer as compared to other inductive
transducers.

Principle of Operation and Working
As the primary is connected to an AC source so alternating current and voltage are produced in the secondary of
the LVDT. The output in secondary S1 is E and in the secondary S2 is E so the differential output is,
1
2
out=E -E
2
1
This equation explains principle of operation of LVDT.

Now there case arise according to the location of core which explains the working of LVDT are discussed below
as,
Case I when the core is at null position (for no displacement) When the core is at null position then the flex linking
with both the windings.

Case II when the core is moved to upward of null position. (For displacement to the upward of reference point)

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CITS : E & H - Electronics Mechanic - Lesson 43 - 47