Improvements in or relating to electric signalling systems

Abstract

Abstract 267,556. Siemens &, Halske Akt.- Ges. March 13; 1926, [Convention date]. Selective signalling apparatus.-In an electric signalling system, more particularly for indicating at a central station the location of an operative fire alarm transmitter, the panels of an indicator board are illuminated selectively by groups of relays which are energized by step-bystep switches responsive to characteristic impulse codes transmitted over the line wires. As shown, the switch arms L'. L<2>, L<3> are operated successively by the electromagnet R according to the incoming impulses to select corresponding relays in the groups A<1> - - A<4>, B<1> - - B<4>, C<1> - - C<4>. At the end of the impulse train, the delay-acting relay V retracts its armature and energizes the selective relays to effect the illumination of the corresponding panel in the indicators. The relays are arranged in such a manner that the contacts of a relay in the group B are associated with different relays in the group C and each relay in the group B is associated with a different group of relays A. Corresponding relays in the different groups A are connected in parallel. Alternatively groups of contacts may be operated simultaneously by each relay in the group A.

Inventors

No inventors recorded.

Bibliographic Details