Patent GB-539550-A (GB)
Title: Improvements in remote control and supervisory systems
IPC: H02J13/00
Filed: 1940-03-13
Abstract: 539,550. Distant control systems. AUTOMATIC TELEPHONE & ELECTRIC CO., Ltd., BURNS, G. A., and IRGIN, C. R. March 13, 1940, No. 4680. [Class 40 (i)] In a system for controlling circuit-breakers &c. at a number of sub-stations along a party-line, in order to reduce the time during which the line is held for a controlling operation, the check signal that is returned to the control station after the sub-station and circuit-breaker have been selected initiates the executive signal automatically in dependance on a pre-operated "close" or "open" key. A signal is then returned to indicate the new condition of the circuitbreaker, and the line becomes available for supervisory signals initiated by automatic changes at the sub-stations, which may be transmitted in the manner described in Specification 375,325. Detailed operation.-The control station, Figs. 1-4, has a set of selecting keys 1-39 BSK and a rotary switch M for each sub-station on the line 18, 19, and it is assumed that the keys and switch shown are individual to the substation shown in Figs. 5, 6. The operation of a selection key connects up 1SK, individual to the desired sub-station, and KA, and the selecting operations are initiated by the momentary depression of "close" key CK or "open" key OK to energize CRO or OPE, either of which connects up KR, KRM, PT, SR, SRR, BU. The line 18, 19 is now seized, and a train of 50 impulses is sent thereover by inter-action between relays E, BP, the polarity of the impulses being changed within the first ten to select the sub-station and again within the next forty to select the circuitbreaker thereat. The switch SC is stepped until the contact from which battery is removed at 1sk3 is reached, when reversing relay PT releases, and the switch SD is then stepped until the first ten impulses are completed, when PTA operates over 1sk3 and transfers the stepping circuit to the switch S. Relay PT re-operates over a contact of the latter marked by the operated selecting key, and the switch M is then stepped until a further marking is picked up to short-circuit E and energize K, thus terminating the impulse train. At the substations, the normal and reverse impulses affect polarized relays N, R, which control the stepping of a switch A over wipers 2, 3 thereof, the contacts being connected to CO in such a way that this relay pulls up at some stage at each of the unwanted sub-stations and prevents further stepping. With the switch A in position 11, the reverse and normal impulses for selecting the circuit-breaker at the wanted sub-station are directed respectively to switches B, C. Relays S, HRR, PI, HR are up during inpulsing, and on the relapse of S, provided a proper selection has been made, HD, H energize over cross-connected contacts of B, C and connect up SEN, REC to send back a checking signal of a polarity determined by RV according to the condition of the selected circuit-breaker. The signal is terminated by the relapse of PI, HR, HRR, the receiving condition is restored and the switch A goes to position 12. At the control station, polarized relays O, I are bridged across the line 18, 19 by the relapse of KRM consequent on the operation of K, and one of these relays responds and applies battery to wire 13 or 14 to check the position of the appropriate indicating relay ICON. Relay SH lights lamp SCL individual to the sub-station and advances the switch OP to position 2. At the end of the check signal, SH falls back and OP continues its advance to position 48, and the executive signal is sent by the operation of OPB, KRM, the polarity of the signal being reversed by PT if OPE is up. The signal is repeated by N or R over the wipers of A, B to the appropriate operating relay, and operation and release of S causes the sending back of a signal indicating the new condition of the circuit breaker. This is received in the same way as the check signal and reverses the position of the indicating relay. All the switches then return to normal.