GB606291A - Improvements in or relating to audio frequency transformers - Google Patents

Abstract

606,291. Transformers. JONES, K., (trading as ELECTRO-VOICE PRODUCTS). Jan. 11, 1946, No. 1049. [Class 38 (ii)] [Also in Group XXXVI] A transformer, which may be used at audio frequencies in radio telephony systems, comprises a casing having plug-and-socket elements at opposite ends, connected to the transformer windings, one of said elements being electrically connected to the casing to provide continuity of screening. The metal casing of the transformer D comprises a cylinder B with two hemispherical caps A, A and is filled with an insulating compound. One cap carries a jackplug E, having a central conducting rod and a conducting sleeve connected respectively to tags g, h, which are connected to the secondary. The other cap carries a jack socket F with two contacts b, c, connected to the primary winding and a contact spring a which connects contacts b, c, and short-circuits the primary until a plug is inserted when the connection is broken. One end of each winding are connected together and to the casing'where the jack-plug sleeve enters the casing cap. Copper foil screens the windings from each other. The transformer may be plugged into an amplifier panel, and the lead plugged into the transformer, and two or more transformers may be plugged together in series. The jacks may be replaced by ordinary pin-type plug-and-sockets, and a further pin may be connected to a tapping on the primary. There may be a socket at each end of the casing.