What is LVDT?
The major use of LVDT is to convert the Rectilinear Physical Motion into Equivalent electrical signal. So LVDT is the sort of transducer which, by means of change in the electrical field of charged coil, changes the output and this change in the output is used to measure the displacement of the object.
Construction of LVDT:
LVDT is provided with two windings
- Primary Winding.
- Secondary Winding.
The plunger is provided in the centre which is capable of having linear motion. The ferrite core is mounted on this core which remains in the centre and equidistant form all windings at zero displacement. When this plunger moves towards left or right the imbalance is created in the external circuit connected to measure and this signal is used to measure the displacement of the plunger.
Application of LVDT:
- LVDTs are used for position feedback in servomechanisms.
- For measurement in automated machine tools.
- For many other industrial and scientific applications.
Practical Examples of LVDT:
- Soil Strength Testing Machine.
- Weighing Machine.
- Robot Manipulator.
- Robot Cleaner.
- Pill Making Machine.
Limitation:
Major restriction of LVDT is that it can not measure the rotary displacement. But this restriction of LVDT can be overcome by making some change in its construction. i.e. by RVDT(Rotary Variable Displacement Transformer).
