Description
Class H04Q : SELECTING
Subclass 1/34: Details of selecting apparatus or arrangements Electrical details Signalling arrangements; Manipulation of signalling currents (multiplex systems providing for calling or supervisory signals H04J 1/14, H04J 3/12 ) using trains of dc pulses (H04Q 1/39 takes precedence) Impulse regenerators with mechanical or other non-electrical marking arrangements