Resonance characteristics of piezoelectric ceramic vibrators
Publish Time: 2018-10-31 Origin: Site
Piezoelectric ceramic transformer
A conventional electromagnetic transformer is composed of a core and a coil surrounding the core, and the primary and secondary coils are electromagnetically coupled by a magnetic core.
1) It is difficult to achieve high efficiency and miniaturization, and it has become one of the biggest obstacles to the miniaturization of electronic devices.
2) The inherent magnetic leakage phenomenon of electromagnetic transformers and electromagnetic radiation will cause certain pollution to the environment, which is not conducive to industrial applications.
A piezoelectric ceramics transducers transformer is basically composed of a piezoelectric ceramic resonator or a piezoelectric ceramic transducer and a piezoelectric ceramic actuator in which two mechanical portions are coupled to each other and the circuit portions are insulated from each other. It is a new type of voltage or current conversion device. The working principle is different from the traditional electromagnetic transformer. In the piezoelectric ceramic transformer, the coupling between the primary and secondary is not through the traditional electromagnetic effect, but by mechanical coupling and pressure. The piezoelectric effect of electrical materials is achieved.
Type of piezoelectric ceramic transformer
Piezoelectric ceramic transformer is actually a piezoelectric ceramic vibrator. The vibration mode of the piezio ceramic disc has been divided into three types: stretching vibration, bending vibration and shear vibration. Piezoelectric ceramic transformer can work in any vibration mode. Therefore, there are many types of piezoelectric ceramic transformers, and common basic structural types are:
It consists of a thin strip of 2Mhz piezio ceramic disc that produces a transverse vibration mode and a strip of piezoelectric ceramics with a longitudinal vibration mode. The geometry is shown in Figure 1.
When a certain frequency and a certain amplitude of alternating voltage are applied to the primary end of the PZT material piezio ceramic transformer, due to the inverse piezoelectric effect of the piezoelectric ceramic material, a length stretching vibration is generated at the input end portion thereof, and the vibration direction is perpendicular to the polarization direction. This vibration mode is transmitted to the secondary of the transformer, and an alternating voltage is generated at the secondary side by means of the positive piezoelectric effect of the piezoelectric ceramic material. The magnitude of the alternating voltage depends on the geometrical dimensions of the various parts of the piezoelectric transformer. Vibration mode and material properties of the transformer. In general, the longitudinal length of the Rosen-type piezoelectric ceramic transformer is much larger than its thickness, so its output voltage of piezoelectric ceramics manufracturing is much larger than the input voltage, which is a step-up piezoelectric ceramic transformer.