GB1290885A - - Google Patents

Abstract

1290885 Converting A R DAVIS 3 Nov 1969 [12 Nov 1968 (2)] 53834/69 Heading H2F [Also in Division H1] An inductive winding 35 with integral terminals 36, 37 is formed by spirally cutting side walls 22-25 of a tubular member 30 which is a good thermal and electrical conductor and may be of aluminium. The member surfaces are then treated by anodizing or with epoxy resin to insulate the turns from each other and the resilient winding is axially compressed. Cooling fins 26-28 may extend along the winding 35 in which case they are also spirally cut (Fig. 3, not shown). The wall 24 of the member 30 is cut back at both ends forming notches 51 to receive a pair of U-shaped laminated cores, the legs of which abut at the centre of the member 30 with mica spacers (67, Fig. 1, not shown) between the abutting core ends. The terminal 37 is extended and carries a device such as a controlled rectifier in thermal and electrical contact therewith. Two tubular members 120, 121 may be fitted side by side on one pair of core members held together by a strap (164, Fig. 11, not shown) which is secured by a clip or by adhesive. The magnetic core is potted by pouring silicone rubber into the tubular members after closing their bottom ends by means of an insulating piece (166, Figs. 10, 12, not shown) held in place by screwed prongs 167, 168. An air-cored arrangement is also envisaged, see Fig. 13, not shown. A printed circuit board 171 is bolted to the tubular members and carries a firing circuit to control solid state rectifiers (143, 144, Fig. 9, not shown). Prongs 174-176 are connected to the firing circuit and receive a control signal from a preset board, not shown. Applications such as rectifiers, inverters, D.C. to D.C. converters, and choppers are suggested. An embodiment is suggested in which the tubular member is bent to form a toroidal winding.