Novel Switching Components for Electronic Telephone Exchanges

Switching devices for electronic telephone exchange applications must meet a number of stringent requirements, particularly if used as speech-path crosspoints in space-division system. For a long-term research program, two classes of crosspoint have been considered: those in which the control electrodes have the same return path as the speech-path electrodes, and those in which the control and switching circuits are totally isolated from each other. A research program on new devices in the latter category is in hand, and devices having useful characteristics have been made and evaluated in a private electronic exchange.