Abstract: A bobbin unit for a brushless alternator field coil, which can reduce the diameter of a bobbin, need not wind a tape and can be made easily, has a ring-shaped iron core having a thick wall; a plate having a hole whose inside diameter is as large as that of the iron core and which is composed of a thin wall cylindrical portion having an end which is abutted against and connected by an abutting/connecting operation to an end surface of the iron core with the axial center of the cylindrical portion being in coincidence with that of the iron core, and a flange portion formed at the opposite side of the cylindrical portion and extending outwardly in a radial direction; and a resinous bobbin interposed between the iron core and the plate for insulating and accommodating a field coil.

Abstract: A method of making a rotor of an inductor type alternating current generator formed by connecting opposedly and alternately disposed first and second claws 3a, 3b of first and second inductors excited by an excitation coil 8 in different polarities through a nonmagnetic ring 3c. Contacting portions 22, 23 of the first and second claws and the nonmagnetic ring are connected by a welding means from inner sides of the claws and in a direction inclined to an axial direction by a predetermined angle.