Views:6 Author:Site Editor Publish Time: 2019-12-19 Origin:Site
The displacement of the ultrasonic piezo ceramic transducer is estimated by using the inverse piezoelectric effect, that is, when a voltage is applied to the piezoelectric ceramics, the piezoelectric ceramics will be deformed and displaced under the influence of the electric field.
Rough estimate of displacement
The displacement of the ultrasonic piezo ceramic component under the maximum withstand voltage is usually about 1 ‰ of the length in the displacement direction. For example, 1 mm thick piezo ceramic sheet with a maximum withstand voltage of 1000 v, a maximum withstand voltage of 1000 v, and a maximum displacement in the thickness direction is approximately 1 μm.
Displacement estimation of ultrasonic piezoelectric ceramics;
Where: u: applied voltage [v], h: ceramic height [m], e: electric field strength [v / m], d: piezoelectric coefficient [m / v], w: ceramic width [m].
It can be seen from the above formula that the displacement of the sheet-shaped ultrasonic piezoelectric ceramic transducer is only related to the material and the supplied voltage, but for the same material, as long as the same voltage is applied, the displacement generated by the piezo ceramic sheets of different heights is basically the same (Remember: the voltage cannot exceed the maximum voltage that can be withstood). According to this calculation formula, other shapes can also be used to estimate displacement.
The single-layer piezo ceramic produces the largest amplitude when is operating at the resonance frequency. When it is sensing or generating electricity, estimate the output voltage. When an ultrasonic piezoelectric ceramic transducer is used as a sensor, it utilizes its positive piezoelectric effect. It deforms by applying an external force to output a charge. The output voltage theoretical estimation formula: where: d33 is the material constant, f: is the force, h: is the height, r: is the radius of the wafer.
For example, the material coefficient of the wafer NCE41-DISC-OD20-TH5 is 25.5 * 1013. When a force of 12500 N is applied, the theoretically estimated voltage is 5000V.
Model selection of single-layer piezo ceramic crystals: Ultrasonic piezoelectric ceramic sheet products are usually customized on a large scale, so we do not provide ultrasonic piezoelectric ceramic sheet components as standard products. However, there will also be some model inventory. It is recommended that you select a model from the inventory for performance testing, short delivery time, and simple cost control.