Improvements in or relating to magnesium-containing electrolytes

1,038,131. Capacitors. PLESSEY CO. Ltd. May 2, 1963 [Feb. 9, 1962], No. 5069/62. Heading H1M. A low resistance electrolyte for an electrolytic capacitor comprises an acidic and a basic component, the basic component comprising a salt of magnesium. The electrolyte may comprise magnesium dissolved in concentrated citric acid solution. Crystals of tri-ammonium citrate may be dissolved in the solution, or the solution may be mixed with di-ammonium hydrogen citrate or with a solution of magnesium acetate. Another composition comprises a mixture of ammonium acetate solution, magnesium acetate solution, and solutions in water of ammonium hydrogen tetraborate and ammonium hydrogen citrate. Glycol or a glycol composition may be added to the electrolyte in amounts up to 50% by volume. The glycol composition may comprise ethylene glycol mixed with anhydrous ammonia and boric acid or with water and ammonium pnitrobenzoate. The nitrobenzoate solution has the advantage of possessing fungicidal properties. The electrolyte allows the capacitor to be sealed without providing a vent, though a normally resiliently closed vent may be provided. The capacitor may be of the miniature etched foil or plain foil type.