Power supplies for fiber optic subscriber systems

Power supplies for remote terminal (RT) fiber optic subscriber systems have been developed at NTT. The authors describe the requirements for RT power supplies in buildings and in transportable containers, as well as their design concepts and performance. Two types of power supplies have been developed by applying single-ended forward power converter techniques for RTs in customer buildings. A highly efficient, small-sized and lightweight power supply has been developed by applying new series resonant converter techniques for an RT in a transportable container. These RT power supplies are being rapidly implemented and are contributing to the expansion of integrated services digital network (ISDN) services