GB657658A - Improvements in or relating to a switching arrangement comprising crossbar switches - Google Patents

Abstract

657,658. Automatic exchange systems. MODEE, G. V. G., STRANDLUND, J. H., and EK, F. Nov. 28, 1945, No. 9666/49. Divided out of 657,612. [Class 40 (iv)] Each hold magnet of a primary cross-bar switch operates two contact bars so that, in effect, two switches are controlled by one set of hold magnets and select magnets and the switch to be connected is determined by means of two auxiliary select magnets either in a secondary cross-bar switch or in the same switch. Combined line finder and final selector, Fig. 1. A selector comprises three primary switches, each divided into two parts 401, 402 to 405, 406 and three secondary switches each divided into four parts 411, 414 to 419, 422. The primary hold bars are doubled and the auxiliary select magnets 499, 500 of the secondary switch determine which bar of the primary is connected to the secondary switch. The secondary is controlled by select magnets 491 to 498 and hold magnets 461 to 480. Group selector, Fig. 2. Incoming trunks 1579 are distributed over primary switches 1501 to 1508 and the outgoing trunks 1549 are connected to tertiary switches 1531 to 1546, the select magnets 1590 to 1599 in each tertiary switch corresponding to the ten groups of the stage. In the primary switch, the auxiliary select magnets 1509, 1510 discriminate between the doubled hold bars of the same switch. The auxiliary magnets 1529, 1530 in the secondary switches 1511 to 1526 discriminate between the doubled bars of the tertiary switch. A marker 1589 is connected to the incoming line by hold magnet 1580 and is permanently connected to test wires 1550 of the outgoing trunks 1549.