| 摘要 |
716,250. Crystal rectifiers. STANDARD TELEPHONES' & CABLES, Ltd. June 8, 1951, No. 13657/51. Class 37. A rectifier comprises a semiconductor body and an electrode, each of which is secured to a metal plug Which is a force fit in the ends of a tube of insulating material. Fig. shows rectifier comprising a whisker electrode 3 welded to a metal cup 5 and engaging the surface of a crystal 2 which is conductively fixed to a metal cup 4. The metal cups and 5 are formed from flat discs of metal which are forced into the ends of a tube i of insulating material by means of a ram. A projection on each disc is used for connecting the cups to terminal wires 6 and 7 of copper, nickel or copper-clad steel. The ends are sealed with a thermosetting or thermoplastic material 9 such as a lithageglycerine cement or "Araldite" (Registered Trade Mark), the material filling the plugs 4 and 5. The material may be applied as a powder, or in the form of a disc, and alumina may be added together witha pigment to provide colour identification for the ends. The crystal 2 is attached to cup 4 by soldering or by means of a conducting cement such as that described in Specification 716,243, [Group V]. An alternative assembly (Fig. 12) is described in which the whisker 3 is welded to the terminal wire 7 and to a springy wire 15, so that the whisker is held centrally in the tube when the wire 7 is pulled through a central hole in the disc or plug 5. In this case no welding or soldering to plug 5 is necessary. Further modifications provide for the plugs 4 and 5 to be formed solid from a soft metal such as lead, the plug being slightly tapered and then forced into the tube with a ram. Alternatively, two rams might be used to provide a plug shaped as shown in Fig. 17, or the inside ends of the tube i may be slightly enlarged providing a plug formation as shown in Fig. 22. The invention has the advantage that no screws or solder are used in the final assembly, and the units can be soldered into circuit without special precautions for cooling. |
