In der Art von gedruckten Schaltungen ausgebildete Spule

摘要

1,218,681. Inductors; electromagnetic coils. SIEMENS A.G. 13 Match, 1969 [14 March, 1968], No. 13277/69. Headings H1P and H1T. A printed circuit coil is formed by interconnection of printed conductors arranged in two sets 15, 151 (Fig. 1) on insulating substrates 4, 41. The substrates 4, 41 may be held apart by an insulating frame 2 which may have an aperture 3 accommodating a ferrite core member 1. The inductance of the coil may be made variable by having the core member slidable (Figs. 2 and 3, not shown). Alternatively the distance between the substrates 4, 41 may be made variable, the printed conductors being interconnected by flexible leads (201, Fig. 4, not shown). Some of the coil turns may be parallel connected. A four-terminal device for producing a circularly polarized A.C. magnetic field may be formed from two such coils arranged around the core member 1 (Fig. 6) with their axes perpendicular. The axes of the two coils may be coplanar as for the Fig. 6 arrangement, or may be in parallel planes (Fig. 11, not shown).