Improvements relating to the manufacture of alternating electric current rectifiers

摘要

To improve the characteristics of a dry surface rectifier of the copper-copper oxide type, the copper &c. blanks are subjected to a heat treatment, at preferably 400-700 DEG C. and in vacuo, prior to the treatment for the formation thereon of the compound, e.g. oxide. The surface of the metal may be etched or otherwise chemically removed after the preliminary heat treatment.