Methodological specifics of calculation of electret transducers

Abstract

Methodological problems of electret transducer calculation are discussed. It is shown that the electret transducer insert is too complicated object for modeling. Therefore, it is necessary to make some simplifying assumptions in the model. For example, the transducer membrane is assumed to have a dome-shape. Since the amplitude of membrane oscillations is small, the object under consideration is studied in the linear approximation. A method of calculating the sensitivity of the electret microphone depending on the frequency of oscillation, transducer geometry, voltage and charge of the electret, etc. is proposed. The deflection of the membrane under the action of electrostatic forces is taken into account. It is shown that this procedure leads to a relatively simple analytically feasible solution. Application of the procedure allows to develop nondestructive testing methods for electret microphones, to optimize the design of electret microphones, to use the design of electret transducer in the educational process, etc.