In a rectifier supporting device for (three-phase) generators which is intended particularly for motor vehicles, buses and the like, cooling plates carrying the rectifier diodes are constructed as heat sinks following the circular shape of an end shield of the generator and segment-like cut out portion for a brush holder of the generator. Each of the heat sinks is supported at an axial distance from, but coaxial with, a circuit board arranged between the two heat sinks. The circuit board has a shape corresponding to that of the heat sinks and provides electric connections to the diode head wires and stator wires.In an advantageous construction of the circuit board, sheathe-like guides extend downward until adjacent to the stator phase windings and receive the stator wires guided up toward the circuit board in an insulated passage through the facing three-phase generator housing parts and heat sink areas.