Improvements in or relating to processes for the production of selenium rectifier plates

摘要

728,088. Dry plate rectifiers. SIEMENSSCHUCKERTWERKE AKT.-GES. Nov. 20, 1952 [Nov. 20, 1951], No. 29360/52. Drawings to Specification. Class 37. In the manufacture of a selenium rectifier, a thin film of selenium is applied to the carrier plate at a temperature of or above 220‹ C. which is then converted to the grey crystalline condition, and then the main relatively thick selenium layer is applied. The process improves the crystallization of the main layer. The conversion of the black selenium into grey crystalline selenium may be effected by heating to about 210‹ C. for five minutes. The second selenium layer may be applied by vaporization or pressure. The base electrode may be nickel coated.