Structure and working principle of the piezoelectric ceramic transformer
Now applications are piezoelectric ceramic transformer Rosen (ROSEN) type, Figure 1 shows the structure and vibration mode piezoelectric ceramic transformer.
Horizontal - vertical-type piezoelectric ceramic transformer equivalent circuit shown in Figure 2. Figure Y, O is representative of the desired input terminal of the transformer, the output transformer ratio, and it is the geometry of the piezoelectric constant of the piezoelectric ceramic material is determined. C01, C02 denote capacitors much lower than the free resonance frequency of the transformer (1KHZ) measured at the input terminal of the piezoelectric ceramic transformer and an output terminal. L0, C0, and R0 is the resonance frequency of the piezoelectric transformer in the vicinity of the concentration of the mechanical parameters of the system, respectively, the equivalent inductance, and the equivalent impedance of the equivalent capacitance.
Such a rectangular plate of piezoelectric ceramic transformer laid on the lower left part of the electrode in the thickness direction of polarization, the polarization direction of the short arrows as shown, perpendicular to the length direction. When it is an alternating electric field is applied, the piezoelectric ceramic will produce mechanical vibration, this part referred to as driving parts. Laying the end face of the right part of the electrode and the longitudinal direction of polarization, the polarization direction of the long arrow, as shown, this part can convert mechanical energy into electrical energy, known as the power generation portion. This cross - basic working principle is to use vertical-type piezoelectric ceramic transformer power - mechanical energy - energy secondary electromechanical energy conversion, and get the highest boost output at the resonance frequency. The frequency of the alternating electric field must be applied to the actuating section (thickness direction), the mechanical deformation generated by the inverse piezoelectric effect, thereby causing a mechanical resonance, but also by the piezoelectric effect, the end face of the power generating portion of the ceramic aggregate a large number of bound charge; bound charge, the more and more space charges attract, to obtain a relatively high voltage output of power generation part of the end electrodes.
Above 1 times Rosen type piezoelectric ceramic transformer manufactured by Murata, Sony and Hitachi and other companies, while NEC and Hitachi has developed into three times Rosen (Rosen) piezoelectric ceramic transformer. Figure 3 is a transformer structure and the vibration mode.
Reson 3 times the output impedance of the piezoelectric transformer 1 is only Reson piezoelectric transformer output impedance 4, a higher power can be output.
In order to increase the power of the piezoelectric transformer, the Japanese NEC Corporation has launched a three-layer piezoelectric transformer. Figure 4 is a three-layer structure and the vibration mode 3 Rosen-type piezoelectric transformer.
