Geophone Equivalent Circuit for Simulation Tasks in SPICE Packages

Abstract

Introduction. In modern electronic equipment the inductive seismic receivers (geophones) are the most widespread as sensors for registration of seismic signals. In developing seismic receiving devices, the most significant attention is paid to input amplifiers, which are directly connected to the geophones. Depending on the type of seismic research it is necessary to allocate specific ranges of input frequencies. For filtration and frequency response form correction to geophone is adding additional circuits. Therefore, the work of the geophone should be considered in conjunction with the input cascades of the seismic waves receiver.
The main part. The main parameters from the documentation of geophones are analyzed and parameters for the assess of created model adequacy are selected. The analysis was carried out on an example of the model GS-ONE produced by Geospace (USA). The structure of the geophone and the principle of electromechanical analogies for equivalent circuit creating are considered. The equivalent circuit, taking into account parasitic parameters, and the measuring and calculating methods ofthe schemeelements are given. The influence on the work of the geophone of the shunt resistance connected to the output geophone terminals is considered.The calculation of the circuit elements according to the following method is carried out on the example of the GS-ONE geophone, the amplitude and phase frequency responses as the results of simulation in the package of NI Multisim are introduced. The simulation results are assessed according to their similarity with geophone parameters from documentation.
Conclusions. The accuracy of the given model is increased compared to known models due to the consideration of the presence of the output geophone branch in the form of inductance coil and its parasitic parameters. This method can be used for equivalent circuit parameters calculation and for modeling in electronic simulation packages. The model does not take into account absolutely all processes in geophone, which leads to deviation in the amplitude values of amplitude frequency response to 8% and the deviation of phase frequency response to 2 degrees. However, further additions to the model will complicate its use in engineering practice and from this point of view it is not expedient.