Due to their very high power to weight ratio, rectified superconducting alternators are being considered as possible sources for a new generation of airborne d.c. power supplies. Since these supplies are intended for very high power applications (tens of megawatts at several kilovolts), weight becomes a prime consideration in the design of the LC output filter. Because of this problem, a considerable amount of research has been conducted to minimize the weight of the inductors and capacitors for these filters. As a complement to this work, this paper describes a design algorithm that selects the minimum weight inductor and capacitor combination for a given set of specifications. Since the behavior of the filter also depends upon the impedance offered by the machine, it is necessary to include the alternator model in the simulations.