平面磁路形マイクロパラメトリック変圧器の動作特性に関する考察

抄録

Over the past few years, a large number of studies have been made on inductors and transformers for micro do-to-dc converters which will be used in personal phones, card-type electronic devices etc.
A planar parametric transformer, which has already been proposed by us, has various desirable features including voltage regulation, overload protection, and noise rejection. The transformer is formed of a stack of five Amorphous Fe₅Co₇0Si₁₅B₁₀ alloy 0.03mm-thick laminations fabricated by the wire-electric discharge machine, and is composed of a magnetic path with three legs and end bars connecting the ends of those legs. Slots are made in the centers of the outside edges of the end bars, to prevent the magnetic flux in each side leg from entering the other side leg. These slots cause a parametric oscillation in the transformer.
This paper discusses the fundamental performance characteristics of a 5mm×7mm sized transformer, and studies the conditions for generating parametric oscillations in a planar transformer, in order to make clear the operational mechanism of the transformer. This paper also studies the effects of the width of the center leg and the position of the windings, which are very important design factors of the transformer.