Magneto-Strictive Transducers
A magneto-striction transducer is a device that is used to convert mechanical energy into magnetic energy and vice versa. A change in mechanical stress of a ferromagnetic material causes its permeability to change. This phenomenon is called as Joule effect.
The reverse process of Joule effect is called as magneto-striction or Villari effect.
Magneto-striction or Villari effect is found in ferromagnetic materials. example, Nickel Iron alloys.
The permeability of Magneto-strictive material is changed due to dimension change as a result of stress, tension or torque applied.
Joule effect is commonly applied in magneto-strictive actuators and Villari effect is applied in magneto-strictive sensors.
Magneto-Elastic Transducers
Magneto-elastic transducers are magneto-strictive transducer in which a strain develops in the material when subjected to a magnetic field.
Magneto-elastic vibrations in magneto-elastic transducers occur when the applied magnetic field is time varying in nature. This property is used in Magneto-elastic accelerometer.
Applications
The applications of this transducers can be divided into two modes. That is, one implying Joule Effect and the other are Villari Effect.
1. In the case where magnetic energy is converted to mechanical energy, it can be used for producing force in the case of actuators and can be used for detecting the magnetic field in the case of sensors.
2. mechanical energy is converted to magnetic energy it can be used for detecting force or motion.
3. In early days, this device was used in applications like torque meters, sonar scanning devices, hydrophones, telephone receivers, and so on. Nowadays, with the intent of “giant” magnetostrictive alloys, it is being used in making devices like high force linear motors, positioners for adaptive optics, active vibration or noise control systems, medical and industrial ultrasonic, pumps, and so on. Ultrasonic magnetostrictive transducers have also been developed for making surgical tools, underwater sonar, and chemical and material processing.
