Application of acoustic surface wave to power electronics

Design of surface acoustic wave filters for the multiplex transmission system of multilevel inverter circuits

“…In addition, high dielectric withstanding voltages are required to fulfill the basic requirements of power electronics circuits. Although gate drive circuits involving optical isolation, 9) a resonant circuit, 10) a piezoelectric transformer, 11) a microwave transformer, 12) and the application of a surface acoustic wave (SAW) to control the ignition of thyristors 13) have been studied, there is no transformer system that fulfills the simple signal wiring, high-temperature operation, and high dielectric withstanding voltage requirements.…”

High power multi-output piezoelectric transformers

“…If we assume the solution for the previous equation is C, = ,4-sin Ax+ 5 cos Ax, (2)(3)(4)(5)(6)(7)(8)(9)(10)(11)(12)(13)(14)(15)(16) where k = -, and A and B is the integral constants. The value of A and B can be v derived according to £, and <^2 ; so the displacement can be expressed in the…”

“…From (2)(3)(4)(5)(6)(7)(8)(9)(10)(11)(12)(13)(14)(15)(16)(17) and (2)(3)(4)(5)(6)(7)(8)(9)(10)(11)(12)(13)(14)(15)(16)(17)(18), the mechanical vibration equations can be expressed in the following form…”

“…It is seen that the maximum output power and the efficiency of the transformer decrease with the increase of the thickness at a fixed input voltage. From equations (4-9a) and(4)(5)(6)(7)(8)(9)(10)(11), it is known that the equivalent resistance is proportional to the square of the thickness. Thus the resistance increases Chapter 4 Modeling and analysis of dual-output thickness shear vibration mode PT rapidly with the increase of the thickness (co 0 <x / ').…”

“…But £ 0 decreases with increasing the length and become saturated after the length reaches a certain value when R x is constant. From equation (5-17a),(5)(6)(7)(8)(9)(10)(11)(12)(13)(14)(15)(16)(17)(18)(19)(20)(21)(22)(23) and(5)(6)(7)(8)(9)(10)(11)(12)(13)(14)(15)(16)(17)(18)(19)(20)(21)(22)(23)(24), it can be concluded that the equivalent mass m e increases and equivalent inductance L decreases with increasing the length, and the increase of m e and decrease of I induces the decrease of displacement of input section £ 0 when the load resistance and other dimensions are constant. But this influence will be counteracted by the decrease of impedance Z/ when the load resistance is matched.…”