PROCESS OF MANUFACTURE OF ZINC OXIDE VARISTORS Russian patent published in 1995 - IPC

FIELD: electronics. SUBSTANCE: varistors are manufactured by broaching of drosses which are produced by mixing zinc-oxide mixture with dextrin in the amount of 10-15 per cent by mass of mass of mixture and suspension including polyvinyl alcohol or methyl cellulose in the amount of 13-15 per cent by mass, glycerine 3-5 and tung oil 3-5 per cent by mass. Working stock of varistor formed by broaching of dross is baked in two stages: preliminary baking at temperature 590-610 C and final baking at temperature 1180-1200 C for the course of 1.0 and 1.5 h correspondingly. Electrodes are formed by method of burning in of silver-containing paste. EFFECT: capability for manufacture of varistors having outer diameter between 1.5-3.0 mm, inner diameter 1.0-1.5 mm for working voltages from 20 to 200 V and nonlinearity factor of volt-ampere characteristic not less than 15. 2 cl