PARTY AND COIN DETECTION ARRANGEMENT FOR A COMMUNICATION SWITCHING SYSTEM

摘要

A register-sender common control communication switching system having a plurality of registers sharing common memory and logic circuits on a time division multiplex basis and having a plurality of register junctors individually associated with the registers for connection to calling lines to receive signals therefrom includes a party and coin detection arrangement for identifying the calling party of a two party line and for identifying a coin deposit at a paystation. The arrangement includes a switching device in each one of the register junctors for connecting a source of current for a predetermined time interval to one side of a calling line to charge the ringer capacitors and line capacitance connected thereto to the potential of the source prior to connecting a sensitive indicating device to such a side of the calling line to respond to a detection signal supplied thereover indicative of one party of a two party line, or alternatively of a coin deposit at a paystation, and a second switching device for connecting the indicating device to that same side of the line at the end of the time interval so that the capacitance cannot cause a momentary erroneous actuation of the indicating device due to a transient discharge thereof in the absence of the detection signal since the capacitance is fully charged before the indicating device is connected to the line.