Quasi-electronic telephone switching system HE-60

Describes a common-control telephone system for the public network employing electronic circuitry throughout with dry-reed contacts as the only mechanical and moving parts. Operational groups of 2000 lines have individual markers and can therefore work simultaneously and intergroup. Due to the use of registers all special features of indirect systems are incorporated, such as pushbutton operation, repertory dialler, absentee through switching, etc. Block diagrams illustrate the functioning of the system and the establishment of a local and a trunk call.