GB1015040A - Improvements in or relating to electric capacitors - Google Patents

Abstract

1,015,040. Capacitors. PHILIPS ELECTRONIC & ASSOCIATED INDUSTRIES Inc. Aug. 18, 1964 [Aug. 21, 1963], No. 33697/64. Heading H1M. - A capacitor comprises a body of non-plastic dielectric material with first and second electrodes disposed on opposite sides thereof; the first comprising a duct of non-ferromagnetic electrically conductive material having an inlet and an outlet conveying a cooling medium ; a parallel sided gap between the first electrode and the dielectric body being filled by an electrically and thermally conductive granular material forming a thermal and electric path between the dielectric and the duct. Fig. 1 shows a ceramic tube 1 covered with conductive inner and outer electrode layers 2, 3 of metal, e.g. silver, applied by heating a suspension thereof, the outer being restricted to leave an uncovered annular end zone 4. A metal ring 5 and flange 6 is soldered to the outer electrode and to a support plate 7 and a non- ferromagnetic metal duet of, e.g., copper or brass 9 coaxial of the ceramic tube has closures 11, 12 carrying inlet and outlet tubes 13, 14 for coolant e.g. water, and is electrically connected through the tubes, while a gap between the duct and the layer 2 is filled with non-ferromagnetic metal, e.g. silver or silvered copper powder containing a proportion of plate-shaped granules. The ends of the gap are closed by masses 17, 18 of synthetic material, e.g. epoxy resin or dimethyl siloxane polymer. The coolant may be gaseous nitrogen, enabling the granules to be of copper or brass. The outer wall of the duct may be silver-plated. Fig. 2 shows a pot-shaped ceramic dielectric 21 with projecting edge 23 and its inner and outer walls covered with metal, e.g. silver electrodes 22, 24 deposited by heating a suspension thereof; the latter being restricted to the underside of edge 23. A cooling duct 25 of non-ferro magnetic metal, e.g. brass, is inserted within body 21 to leave a narrow gap 26 and is closed by a plate 27 carrying inlet and outlet coolant tubes 28, 29 also serving for electrical connection. The gap 26 is filled with metal, e.g. silver, powder and is closed by a synthetic material mass 32 also covering the head of the cooling duct. A further duct 35 comprises concentric connected vessels 36, 37 of non-ferromagnetic metal, e.g. brass, having inlet and outlet coolant tubes 39, 40 also serving as electrical connections. The gap 41 between duct and electrode 24 is filled with metal powder, e.g. silver, and is closed by a mass 42 of synthetic material which with mass 32 may be epoxy resin or dimethyl siloxane polymer. The coolant may be gaseous nitrogen and the metal powder may then be of brass or copper. The inner side of vessel 37 and the outer side of duct 25 may be silvered.