GB510012A - Improvements in or relating to telecommunication systems - Google Patents

Abstract

510,012. Automatic exchange systems. STANDARD TELEPHONES & CABLES, Ltd., and WRIGHT, E. P. G. Jan. 25, 1938, No. 2408. [Class 40 (iv)] In a system in which information used for computing charges for calls is recorded by printing or like equipment, apparatus associated with the connection stores the calling and called numbers and the duration of the call and the printing equipment comes into use at the termination of the call and receives the records from the storage apparatus. The storage apparatus (Fig. 1) which is individual to a toll junction comprises a pair of registers R1, R2 which control code relays A-F in the printing equipment (Fig. 2) when the latter is associated with the storage apparatus over a finder F. The digits of the called number are recorded in turn on R1, to which impulses are repeated at contact ta, and the settings are transferred to R2 as positive or negative charges on condensers connected to successive positions of wipers rm24-28. The relapse of CC at the end of each train restores R1 and advances R2 one step. The digits of the calling number are received in a similar manner from identifying equipment to which a starting signal is sent by means not shown, and these are stored in subsequent positions of R2. On the reply of the called party, relay M energizes at contact tm and R2 restores, whereupon CC pulls up and places R2 under the control of time pulses on wire 3SGL. When R2 reaches position 20, after one minute of conversation, C pulls up and disconnects CC to advance R1 one step, and R2 goes quickly to normal and starts a fresh cycle. Upon release, the relapse of B connects up C, S, R1 takes a step to record the uncompleted minute of conversation and R2 restores. The finder F now picks up the storage apparatus and T energizing in the test circuit connects up W, which connects wipers rm24-28 to relays A-F. One of relays A-E is operated by the charged condenser and F operates if the charge is of a particular polarity. The operated relay or relays lock in series with G and send a code signal to the printer, the printing magnet of which opens the locking circuit at contact TMC. The relapse of G advances R2 one step. The duration of the conversation in minutes, tens and units digits, is transferred in positions 18, 19 of R2 which are cross-connected to the banks of wipers rm14, 15, the former being connected to positive battery (since the tens digit cannot exceed 5) and the latter to positive or negative battery over wiper rm12. Relay W falls back in position 19 and disconnects M to free the apparatus. In blank positions 10, 17 of R2 interposed between the three records, relay G alone energizes and operates the tape-stepping magnet which releases G at contact SMC. The calling number may be recorded at the end of the conversation instead of before reply, or it may be recorded during conversation if separate means are employed for recording the duration. Specifications 440,348, 484,568 and 507,431, [Group XXXVII], are referred to.