Patent GB-247193-A (GB)
Title: Improvements relating to electrical signalling and/or controlling systems
IPC: H02J13/00
Filed: 1926-02-03
Abstract: 247,193. Metropolitan-Vickers Electrical Co., Ltd., (Assignees of White, T. U.). Feb. 3, 1925, [Convention date]. Selective distant control systems and apparatus; tell-tale apparatus.-Relates to a system for the distant and supervisory control of electric . power sub-station apparatus of the typedescribed in Specification 243,021 wherein chains of counting relays at the control office and substation actuate auxiliary relay chains which select the required apparatus units. Figs. 1 to 3 show the control apparatus and Figs. 4 to 6 the apparatus at the substation. The control station is provided with a key k<1> for preparing the operating circuit of each unit, e.g. a circuit breaker c, Fig. 4, and the keys and their corresponding apparatus units are associated with groups of selecting relays 205 - - 214, 405 - - 414 respectively, which are energized and de-energized in succes. sion under the control of groups of counting relays 100 - - 123, 600 - - 623, which are operated by pairs of line relays 311. 513 and 314, 510 adapted to be alternately connected to the line 32. In order to ensure synchronous operation of the relay selecting apparatus and to prevent incorrect operation of the control circuit by inductive interference, relays 305, 501 open the circuit over the line 32 after each impulse. The system is also modified in the following respects : (1) The impulse transmitters associated with each selecting key are replaced by a controlling key K which is common to all the selecting keys. (2) Instead of a single relay being provided at each station for connecting the supervisory and apparatus unit control lines 30, 31 to the selecting relays, pairs of relays 215, 216 and 415, 416 are provided and are operated successively by tha counting relays 110, 123 and 601, 612 respectively. Modified means for ensuring synchronous operation. In tne above mentioned Specification two relays at each station energized alternately by the selecting relays during the cycle of operations control the line relays over the line 32 and thereby ensure synchronous operation. In this invention, relays 304, 305 at the control station and relays 480, 501 at the substation are energized alternately by the selecting and counting relays respectively to close and open the line circuit. When a selecting key such as K<1> is operated, together with the " start " key, impulses are transmitted over the line 32 to operate the counting relays 100 - - 123, 600 - - 623 which in turn operate the selecting relays 205 - - 214, 405 - - 413. The counting relays at the control station operate the relay 305, which interrupts the line circuit after each impulse. Upon operation of the corresponding selecting relay, the relay 304 is operated to deenergize the relays 305, and again complete the line circuit ready for the next impulse. Upon operation of the relay corresponding to the operated key, however, the circuit of the relay 304 is maintained open until after the receipt of the supervisory signal corresponding to the operation of the selected circuit breaker. A relay 501 which transfers the line from one line relay to the other and controls a relay 509 which operates further contacts in the line relay circuits. The selecting relays are operated by the counting relays 613, 603, 615, &c. when the line circuit over the relays 314, 510 is opened. Each selecting relay operates a relay 480 which deenergizes the relay 509 and thereby ensures the transference of the line to the relay 513 ready for the next operation. The Specification as open to inspection under Sect. 91 (3) (a) states that instead of a pair of counting relays being provided for each selecting key and apparatus unit, a single relay having a split winding may be employed. This subjectmatter does not appear in the Specification as accepted.