Regimes of piezoelectric transformer operation II

Abstract

Piezoelectric transformers (PTs) have some attractive features for using them in power supply systems such as high efficiency and high power density, a high level of isolation between primary and secondary sides, a flat design which is well suited for a lot of applications and a low level of electromagnetic noise, just to name a few. For any application it is of utmost importance to know the behavior of a piezoelectric transformer under different conditions, which we call regimes of transformer operation. Based on this knowledge, criteria for safe operation of the PT in the power supply system and hence for the whole system as well can be derived. After having introduced the regimes of piezoelectric transformer operation in a first article on this topic in 2006 [1], in this paper we will present the derivation of important parameters based on measurements by way of an example of a symmetric PT. These measurements facilitate the basic understanding for choosing the appropriate transformer parameters necessary for its optimal as well as safe and controlled operation in power supply systems.

Piezoelectric Direct Discharge: Devices and Applications

“…It is known that, with increasing temperature, the input impedance and the resonance frequency of the RPT decrease [79]. It means that, for the constant power, the input current increases and the input voltage decreases with temperature.…”

Atmospheric pressure plasma jet powered by piezoelectric direct discharge

“…For instance, silica capillary nozzles were treated before dipping into a silanisation solution [31] or polymer brushes were grafted on the plasma-treated polytetrafluoroethylene, polypropylene, and polyethylene surfaces for allowing better wettability of these surfaces. [32] From 2006 to 2009, EPCOS in Deutschlandsberg gathered extensive experience in development [33,34] and production of PTs with voltage transformation ratio, which is high enough for ignition of atmospheric pressure discharges in the air even for small primary voltages in the range of 5-25 V. The result of the high-performance PT development is the CeraPlas™ F [35] allowing for piezoelectric direct discharge (PDD). This PT enabled the development of the first handheld piezoelectric device worldwide, generating plasma with ambient air as ionization gas.…”

“…From 2006 to 2009, EPCOS in Deutschlandsberg gathered extensive experience in development [ 33,34 ] and production of PTs with voltage transformation ratio, which is high enough for ignition of atmospheric pressure discharges in the air even for small primary voltages in the range of 5–25 V. The result of the high‐performance PT development is the CeraPlas™ F [ 35 ] allowing for piezoelectric direct discharge (PDD). This PT enabled the development of the first handheld piezoelectric device worldwide, generating plasma with ambient air as ionization gas.…”

Bar piezoelectric ceramic transformers

“…The analytical formulae for the specific one-dimensional vibration modes were calculated for ringdot PTs [3], rosen-type PTs, and their shear modification [4], [5]. The electrical driving conditions and their limitations with respect to the mechanical and electrical losses were discussed in [6] and [7] for the high-power operation.…”