The reduction of operational amplifier electrical outputs to improve piezoelectric shunts with negative capacitance

Strategies for Reducing Operational Amplifier Outputs in Piezoelectric Shunt With Negative Capacitance

“…3 have been obtained using a multi-modal model presented in [18], which is based on the analysis presented here. More details and test results can be found in [18].…”

“…More details about the way to obtain all these expressions can be found in [18]. Equations ( 5) to ( 8) are dependent on parameters influencing the attenuation (i.e., R and either C 1 or C 2 ), which are not changed because the first analysis proposed here attempts to study how to reduce the OP-AMP outputs without affecting the control performance.…”

“…In this section, the values of R and either C 1 or C 2 (depending on the considered connection type) are changed to check the effect on the OP-AMP outputs. To do this, the SDOF system is considered because it allows an easier comprehension of the results without any loss of generality, Using the variables k i , ki (i.e., the EMEMCF [10]) and τ (τ = RC eq , where C eq is an equivalent capacitance depending on the NC value and C p,i [10]), the expressions of the frequency response functions G for the i-th mode become [18]:…”

“…In general, it is possible to conclude that OP-AMP outputs are reduced in series NCs increasing R, and in parallel NCs decreasing R. As for the value of the NC, the closer the NC is to C p,i , the larger the OP-AMP outputs are. More detailed analyses can be found in [18].…”