| 摘要 |
346,653. Static contact rectifiers. DICKER, S. G. S., 20, Holborn, London.- (Naamlooze Vennootschap Philips' Gloeilampenfabrieken; 6, Emmasingel, Eindhoven, Holland.) Oct. 7, 1929, No. 30419. [Class 37.] An asymmetrical resistance for use as a wireless detector or for other purposes consists of two electrodes and an intermediate layer, one of the electrodes and the intermediate layer being mutually adsorbed, i.e. one of the materials is deposited from the other from a vapour, the deposited substance having a lower vapour pressure than in its normal condition ; the Specification describes a test by which it can be determined whether this is the case. The intermediate layer may consist of halides, such as common salt or calcium fluoride. The adsorbal electrode preferably consists of a material having a higher electron emissive power than the other electrode and having no component in common with the intermediate layer. The electrodes may be enclosed in an airtight box-like casing of "Bakelite" &c., one electrode consisting of a sheet of brass or tinfoil on which common salt is deposited by spraying or volatilization. The other electrode consists of magnesium deposited on the salt from vapour and adsorbed thereto. The device shown in Fig. 2 comprises a glass envelope 11 silvered inside and provided with electrodes 13, 16, the electrode 13 being connected to the silvering. The electrodes are at first connected by wires 18, 19 and a spring 17 secured to the wire 19 by fusible material. The wires are coated with common salt which is volatilized by passing a current through them and deposits on the silvered surface. The temperature of the wires is then raised until the spring 17 is liberated and presses against the wall of the tube as shown. Vapour of magnesium, sodium, or potassium is then admitted to the envelope and is adsorbed to the salt. The envelope is then exhausted or filled with inert gas. Instead of a glass envelope a metal envelope, which may itself form the electrode, may be employed. |
