Our research is inspired by the Space Thermoacoustic Radio-Isotopic Power System Project SpaceTRIPS for deep space applications: a radio-isotopic source produces heat, a thermoacoustic engine converts it into sound. The MHD generator further converts sound into electricity. The present paper does not refer to the full project, but to an internal process inside the MHD generator. Reasonable parameterization allows analyzing the MHD generator in two steps. At first, we convert our knowledge about the magnetic field and generator geometry into an equivalent circuit with three inductances and two resistances. Afterwards a standard circuit calculation gives all working properties. For decades, the Institute of Physics has been developing conductive MHD generators acting in a DC mode. Now we have to adopt our experience in an AC mode.