Voltage amplification transfer function analysis of the operational amplifier in the negative capacitance circuits for vibration control with piezoceramics

• Published in: Proceedings in applied mathematics and mechanics 2007-12, Vol.7 (1), p.4130013-4130014
• Main Authors: Oleskiewicz, Robert, Neubauer, Marcus, Krzyzynski, Tomasz
• Format: Article
• Language: English
• ISSN: 1617-7061; 1617-7061
• DOI: 10.1002/pamm.200700273

Piezo elements due to their ability of converting mechanical energy into electrical energy and vice versa can be found in numerous mechanical vibration damping and absorbing applications. A desired effect may be customized by an external impedance shunt branch connected to the plates of the piezo element. The negative capacitance connected in serial with the passive shunt significantly improves the damping and absorbing performance of such systems. Negative capacitance circuit is built of an impedance converter realized by the operational amplifier. Since the amplifiers are not the ideal elements, the performance of the proposed systems is limited. This is due to the maximum voltages and currents that the operational amplifiers are able to generate. This effect causes instabilities and limits the operational area of the impedance converter. In the paper, the amplification transfer function of the non‐ideal operational amplifier in the negative impedance converter is studied, and the necessary modification with the additional passive elements is proposed. The influence of the certain imperfections in the design, and its improvements are shown on the system consisting of the 1DOF mechanical oscillator, and a shunted piezo element. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)