In order to realize light and small power supplies, we propose here a film shape transformer named the film transformer. The basic operating principle of this transformer is the skin effect similar to those of the coreless transformer which is exploited previously by us. Both the primary and secondary coils composed of thin film conductors are arranged coaxially on one layer film base, and the film transformer is constructed by the lamination of these films.
In this paper, experimental as well as numerical studies are carried out about basic characteristics of the film transformer in order to examine possiblities in practical use. As a result, it is revealed that the film transformer may be applicable to the high frequency swiching power supplies.