A device for conversion of thermodynamic energy into electrical energy includes a piston/cylinder unit (16), a generator (18), and a controller (14). The piston/cylinder unit (16) includes a pressure cylinder (24) and a piston (26) arranged in the pressure cylinder (24) and linearly movable by a change in volume of a working medium. The generator (18) includes a coil (22) and a magnet (20). The magnet (20) is coupled to the piston (26) such that a linear movement of the piston (26) effects a linear movement of the magnet (20) within the coil (22). The controller (14) controls the working stroke of the device as a function of at least one measured process parameter.