A pulse inverter for operating an electric machine of a motor vehicle from a motor vehicle battery, including a housing for delimiting an interior, a power electronics system, provided in the interior of the housing, for converting direct current to alternating current, a first cooling circuit configured to dissipate heat from an outer side of the housing facing away from the power electronics system, and a second cooling circuit, which is separated from the first cooling circuit and communicates with the interior of the housing, configured to directly liquid-cool the power electronics system with an electrically insulating fluid. (FIG. 1)