GB1029282A - Improvements in or relating to encapsulation of electrical components - Google Patents

Abstract

1,029,282. Transformers and inductors. PLESSEY CO. Ltd. May 14, 1963 [Feb. 14, 1962], No. 5662/62. Heading H1T. A method of producing an encapsulated electrical component, e.g. a transformer bobbin, toroid &c., comprising a first moulding operation to produce a first part of a thermoplastic material, contact or connecting pins or other conductor means being integrally moulded into position during said first moulding operation, positioning the electrical parts of the component on the first part and making the required electrical connections between the pins and electrical parts, and enclosing at least said electrical parts with further thermoplastic material which integrally unites with the first-mentioned thermoplastic part to form a hermetically tight seal therewith. The bobbin for a transformer may be moulded from polypropylene such that the connection pins 5 are secured in the material by initially loading them in the moulding die. The windings 7 and laminations 8 (Fig. 3) may then be positioned on the bobbin and necessary connections made. The bobbin is then placed in a moulding press, pins 5 engaging suitable holes in the die and a further moulding made to form a casing, integral with the bobbin, leaving only the tops of pins 5 uncovered. In a similar method for the encapsulation of a toroid, the toroid is located in a depression in the initial moulding. Further several components may be encapsulated together with the help of locating depressions. Mounting lugs and code markings may be formed into the material at the moulding stage.