The nature of acoustic charge, which works with an electronic generator to generate high intensity ultra-acoustic field is very various in function of application used . The values of elements from equivalent scheme may be to vary in time in function of technologic process . This fact determines the variation of accord frequencies and value of acoustic charge. In this manner the efficiency can be modified in time if it no take measures to minimize these influences of complex impedance that works with electronic generator . In this paper it is presented a method to analysis the influence of variation of acoustic charge and to minimize this influences for to assure an optimum operation of electronic generator, it is presented a program to calculate the power variation in function of acoustic charge and to chart the diagram of this variation. It is presented the experimental results obtained with the theory presented.