LVDT
A LVDT (Linear Variable Differential Transformer, for its acronym in English) is an electromechanical sensor that converts linear displacements into proportional electrical signals. It is widely used in applications requiring precise position or displacement measurements.
Operating Principle
An LVDT consists of two or more coils arranged in a line. A movable ferromagnetic core moves along the axis of these coils. When an alternating current is applied to the primary coil (typically between 60 Hz and 20 kHz), this generates induced voltages in the secondary windings, which have opposite polarities due to their reverse arrangement. The position of the core determines the magnitude and phase of these induced voltages, allowing linear displacement to be measured with high accuracy. The output of the LVDT is the difference of the voltages induced in the secondaries. When the core is centered, the voltages are equal but opposite, resulting in zero output. As the core moves, the magnetic coupling changes, resulting in a linear variation of the output voltage with respect to the displacement of the core within an operating range.
Main Features
- High PrecisionLVDTs can detect extremely small movements, from micrometers to several hundred millimeters.
- Without Direct Mechanical Contact: The core moves without friction within the sensor, reducing wear and increasing the life of the device.
- Sturdiness: They are suitable for harsh environments, including high temperatures, vibrations and underwater conditions.
