INTERTOLL TRUNK CONCEXTKATI\<i lOQUlI'MKXT 



319 



the time interval, between the operation of the select and hold maj>;nets, 

 to release and the connection to proceed. If, however, the hold niaji;net 

 lead is crossed to another hold magnet lead the resistance in the hold 

 magnet arm of the bridge will be lower than expected causing the xh 

 relay to release. The release of this relay will prevent the release of the 

 timing relay, thus causing a time out and trouble registration. 



If no trouble cross is found on the hold magnet lead the ht relay re- 

 leases when the select magnet is operated. This is a slow releasing relay 

 and provides the time for allowing the selecting bar to come to rest be- 

 fore the hold magnets are operated. When this relay has released low 

 resistance ground through the hs relay and 12-ohm resistance is con- 

 nected to the hold magnets as an operating path. The hs relay is polarized 

 and the current flowing from the hold magnets is in the direction to 

 non operate the relay. The operation of the hs relay will be discussed 

 below. 



Outgoing Trunk Seizure and Continuity Check 



Up to this point the select and hold magnets have been operated. The 

 crosspoint of the switch is now closed and the outgoing trunk seized. 



OUTGOING TRUNK 



TO DISTANT OFFICE 



VIA INTERTOLL 



CIRCUIT 



SINGLE 

 FREQUENCY 



SIGNALING 



CIRCUIT 

 RG 



HilK? I— vw- 



_^.iH^r';Ta 



SWITCH 

 CROSS 

 POINTS 



>h- 



EORF 



RTl HS1 

 OR OR 

 RT2 HS2 



HG1 OR 

 HG2 



n 



HGt 

 OR HG2 



A OR 

 B 



RELAY DESIGNATIONS: 

 --1 ARE INCOMING 



LOW TO HIGH 

 --2 HIGH TO LOW 



H' 



CCI OR 

 CC2 



E OR 



HG1 OR 



HG2 



H 



A OR B 



J I 



INCOMING TRUNK CONTROLLER 



Fig. 9 — Outgoing trunk seizure and continuity check. 



