Circular piezoelectric vibrator Xin Jue bone conduction device
Theory known by the speaker:
① point source of radiation in the form of a spherical wave. Xin tone in the direction of the wavefront is always consistent, get fidelity phase, phase-frequency curve flat, accurate sound field positioning;
② point source on the concept of having a relative degree of geometric lines, it could be heard angle has a direct correlation. When the angle between the line of the edge of the sound source and sound Xin who formed connections can not be ignored, the sound source can not be considered a standard point source, then the more symmetrical structure more sound sources tend to point source. Relative to other forms of piezoelectric vibrator, the piezoelectric oscillator more nearly circular at the point source.
Piezoelectric vibrator as a vibration sound source devices, if the vibration displacement is small, that is, the amplitude is small, will cause Xin Jue loudness enough, and people will feel weak voice. Bone conduction Xin feel sensitive area 800 ~ 2500Hz, the piezoelectric vibrator by the resonance region that is closer to the resonance frequency of the audio area Xin sleep, the piezoelectric vibrator vibrating in the audio area to achieve resonance, so that the amplitude becomes large, the loudness can be improved . The resonant frequency and the structural parameters and the circular piezoelectric vibrator fixed the way, the following circular piezoelectric oscillator for finite element analysis.
Pressure telegraph child support emulation mode and select displacement characteristics
As can be seen from Figure 2, the surface deformation around the fixed DC voltage of the piezoelectric vibrator is the parabolic, and have the same diameter on the same deformation, the center of maximum deformation, the farther the distance from the center of the deformation is smaller.
Known from Figure 3, the deformation is similar to the piezoelectric vibrator is fixed around the surface of the piezoelectric vibrator deformed simply supported under a DC voltage is also parabolic. However, the maximum deformation should be less than the center point of the periphery of the piezoelectric vibrator is fixed at the case.
The middle of the piezoelectric vibrator is fixed (see Figure 4) the surface modification after the DC voltage has the form of a paraboloid, the deformation of the same diameter is the same, the center point of the piezoelectric vibrator is fixed, the deformation of the center is zero, the farther away from the center of the greater amount of deformation, the deformation amount at the maximum diameter of the piezoelectric vibrator is maximized.
In summary, the surrounding fixed piezoelectric vibrator is superior piezoelectric vibrator intermediate fixed and simply supported case, so the authors used a circular structure around the fixed piezoelectric bone conduction Xin Jue piezoelectric vibrator device support the way.
