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Publication of BE514535ApublicationCriticalpatent/BE514535A/xx
H04Q3/42—Circuit arrangements for indirect selecting controlled by common circuits, e.g. register controller, marker
H04Q3/52—Circuit arrangements for indirect selecting controlled by common circuits, e.g. register controller, marker using static devices in switching stages, e.g. electronic switching arrangements
H04Q3/525—Circuit arrangements for indirect selecting controlled by common circuits, e.g. register controller, marker using static devices in switching stages, e.g. electronic switching arrangements using tubes in the switching stages
H—ELECTRICITY
H04—ELECTRIC COMMUNICATION TECHNIQUE
H04Q—SELECTING
H04Q1/00—Details of selecting apparatus or arrangements
H04Q1/18—Electrical details
H04Q1/30—Signalling arrangements; Manipulation of signalling currents
H04Q1/32—Signalling arrangements; Manipulation of signalling currents using trains of dc pulses