Electric coil device for use as a transformer or the like.

摘要

An electric coil device such as a transformer or a choke has one or more windings (18, 20) around a core (12). In order to dispense with the conventional insulation means that have added much to the bulk of the coil device, each winding (18, 20) is formed by a conductor wire (24) on which at least two insulating tapes (26, 28) are wound one over the other and each with an overlap. The ratio of the width (W1 or W2) of the overlap of one of the two insulating tapes (26, 28) to the width (T1 or T2) of said one insulating tape differs from the ratio of the width (W2 or W1) of the overlap of the other insulating tape to the width (T2 or T1) of said other insulating tape. Preferably, a third insulating tape may be wound overlappingly over the two insulating tapes, with the ratio of the overlap of each tape to the tape width made progressively less from the inmost toward the outmost tape.