The transducer used for measurement of angular displacement is:

Explanation:

Rotary Variable Differential Transformer (RVDT)

• A Rotary Variable Differential Transformer (RVDT) is an electromechanical transducer used for measuring angular displacement. It operates on the same principle as the Linear Variable Differential Transformer (LVDT) but is specifically designed to measure rotational positions. The RVDT converts angular displacement into an electrical signal, which can be accurately measured and analyzed.
• The RVDT consists of a primary winding and two secondary windings symmetrically placed around a rotary core. When an AC excitation voltage is applied to the primary winding, it induces voltages in the secondary windings. The core’s rotation alters the magnetic coupling between the primary and secondary windings, causing a differential output voltage proportional to the angular displacement.
• As the core rotates, the induced voltage in one of the secondary windings increases while the voltage in the other decreases. This differential voltage is then processed to provide a precise measurement of the core's angular position. The output is typically a sine wave, which can be demodulated to obtain a DC voltage proportional to the angle of rotation.

Advantages:

• High accuracy and linearity in measuring angular displacement.
• Robust and reliable operation in various environmental conditions.
• Non-contact measurement, reducing wear and tear on mechanical components.

Disadvantages:

• Requires an AC excitation voltage, which may necessitate additional circuitry.
• Limited range of angular displacement measurement compared to some other technologies.

Applications: RVDTs are widely used in aerospace, industrial automation, and robotics for precise angular position feedback. They are also employed in control systems for servo mechanisms, where accurate measurement of rotational positions is crucial.