Views:19 Author:Site Editor Publish Time: 2017-03-17 Origin:Site
The underwater acoustic transducer is operated by the piezoelectric effect of the crystal (quartz or potassium tartrate) piezoelectric ceramics (barium titanate and lead zirconate titanate) or the magnetostrictive effect of iron-nickel alloy. The so-called piezoelectric effect is to cut the crystal in a certain direction into a thin film, and the pressure on the crystal sheet, in its both ends will produce positive and negative charge. On the other hand, when the tensile force is applied to the crystal sheet, the opposite end of the charge is generated on both end faces. In contrast to the piezoelectric effect, the electrostrictive effect, that is, the alternating voltage is applied to both ends of the crystal, and the crystal will produce a corresponding mechanical deformation. We use electrostrictive effects and piezoelectric effects to produce and receive ultrasound.
When the ultrasonic wave encounters a target, it produces a reflection.The echo acts on the crystal of the underwater acoustic transducer, and the electrical signal may be obtained on both end faces of the piezoelectric effect underwater acoustic transducer. As with radar antennas, the underwater acoustic transducer not only emits and receives ultrasonic signals, but also has sharp directionality, only to determine the orientation of the target.
When the sonar emits ultrasonic waves, the ultrasonic oscillation voltage is applied to both ends of the crystal sheet. So the thickness of the piezoelectric ceramics crystal will change with the ultrasonic oscillation voltage, resulting in ultrasonic vibration. The crystal vibrates to promote the radiation generated by the surrounding water.