Method of making cathode assembly for high pressure sodium lamps

摘要

Variable backspace in electrode assemblies for high pressure sodium lamps is achieved by employing a hollow electrode base which has one end formed to frictionally engage an electrode, which electrode includes a solid core having a coil about one end thereof. The solid core is inserted into the electrode base a given distance and is maintained in this position by friction until welding is accomplished. The electrode base is provided with a positioning ring which is formed at the time the base is first formed. The electrode assemblies can be utilized with lamps having different arc lengths while using arc tubes having the same size.