| 摘要 |
<p>713,929. Dry plate rectifiers. STANDARD TELEPHONES & CABLES, Ltd. Oct. 10, 1952, [Dec. 14, 1951.] No. 25435/52. Drawings to Specification. Class 37. A selenium rectifier comprises a compound of nickel selenide at the interface between adjacent layers of selenium and nickel, which is produced by heating the layers to a temperature of at least 400‹C. The base electrode may consist of iron, aluminium, magnesium, beryllium or alloys thereof, which is nickel plated and then roughened by sand blasting or etching. The selenium layer may be added by rubbing a stick of selenium across the surface, or spreading powder or pellets on the heated surface, or by vaporization. During the heating process at 400‹C. to form the nickel selenide, the electrode may be spun to remove surplus selenium, but this is not necessary if the selenium is in a finely divided state sufficient to pass through a 200 mesh screen. A second coating of finely divided amorphous selenium may then be applied which may include other material such as the halides of selenium. The coated electrode may then be subjected to annealing heat treatment at about 220‹C., which converts the amorphous selenium to the crystalline state. A laquer barrier layer is applied, followed by a counter electrode of a cadmium-bismuth eutectic alloy. The device may be subjected to electroforming. Specification 591,412 is referred to.</p> |
