GB653596A - Improvements in or relating to electrical coil formers - Google Patents

Abstract

653,596. Transformers and inductances. PHILIPS ELECTRICAL, Ltd. Nov. 18, 1948, No. 30005. Convention date, Nov. 21, 1947. [Class 38 (ii)] Relates to low-frequency transformers and chokes which have formers made of moulded material, the windings comprising at least three sections which are separated by partitions, and the cores having substantially rectangular cross-sections at right-angles to the axes of the coils. Special provision is made for accommodating leads to the inner ends of coil-sections which are not easily accessible. In Figs. 3, 4, a transformer has a moulded former 21 with three compartments 23, 25, 27. A space between the inner wall of the compartment 23 and core 29 is partly filled with moulding material wherein a channel 31 is formed to accommodate a lead 33 to the central coil. The lead may be secured to the inner wall of the former by means of adhesive tape (Fig. 1, not shown), channels being provided to accommodate further leads, if necessary, at not more than two other sides of the rectangular core. The channels may be constituted by a number of grooves in the moulded material (Fig. 2, not shown). The former may have five compartments, a channel giving access to the central winding space, shorter channels being provided for the winding-spaces adjacent to the centre (Fig. 5, not shown). The Specification as open to inspection under Sect. 91 comprises also an arrangement in which the channel giving access to the inner end of the centre winding of a three-section former is placed externally of the other windings. This subject-matter does not appear in the Specification as accepted.