GB455190A - Method of regulating radio sets and the like - Google Patents

Abstract

455,190. Transformers. KRAMOLIN, L. L. DE, Gross-Glienicke, Kladow, Berlin. Jan. 7, 1935, No. 3850/36. Divided out of 449,240. [Class 38 (ii)] [See also Group XL] Relates to the construction of inductances and transformers for use in high frequency circuits, the inductance or coupling of which may be varied by varying the saturation of their low permeability iron cores. The variable inductances may comprise coils 3, Fig. 1, wound on the outer limbs of a core 4 clamped between the adjustable pole-pieces N, S of an electromagnet 1, 2 provided to enable the saturation of the core to be varied. In another construction, Fig. 2, the inductance of the coil 13 may be varied in opposite directions by currents of opposite direction in the coils 12 on the horseshoe core 10 which also carries coils 11 passing a steady current. An alternative form of polepiece is shown in Fig. 3 for use with an inductance having a fourlimbed core. The coupling between two inductances I, II, Fig. 4, which are decoupled by their disposition on a three-limbed core may be varied by varying the distribution of a steady flux in the core by an electromagnet 40, the two poles 41, 42 of which carry a coil 45 with a steady magnetizing current while the poles 43, 44 carry separate windings 46, 47 wound in opposite directions and fed with the same controlling current. In another arrangement, Fig. 5, the coils are wound on an asymmetric core, the regulating current being passed through the controlling electromagnet 51. Reference has been directed by the Comptroller to Specifications 426,347, 436,482, and 442,392, [all in Group XL].