Crosspoint elements and relays with miniaturised reed contacts

Large scale production of reed type contacts has proved them to be economic and technically suitable substitutes for conventional mechanical types used in telecommunications switching networks. This article deals in particular with the use of a proprietary type of reed contact for crosspoint switching and considers various types of crosspoints and their functional principles. The inherent difficulties of control, due to the magnetic circuit, are noted and a survey is made of the various possibilities that are available. In considering the choice of crosspoints, it is stated that the choice of the smallest replacement unit is influenced by the performance reliability of the reed contacts themselves. The relatively high closing and opening forces of the particular reed contact considered enhances its use for switching control circuits which, in conjunction with its suitability for crosspoint elements, makes it a universal miniaturised contact for relays. It is moreover quite suitable for mass production methods.