Patent GB-650760-A (GB)
Title: Remote metering and/or remote regulation over a channel belonging to a remote control system
IPC: H02J13/00
Filed: 1946-09-12
Abstract: 650,760. Electric selective signalling. ALLMANNA SVENSKA ELEKTRISKA AKTIEBOLAGET. Sept. 12, 1946, No. 27391. Convention date, Sept. 24, 1945. [Class 40 (i)] The system of Specification 650,755 is modified by the provision of change over means at the control and sub-stations whereby the channels normally used for sending initiating and reply impulse trains for a control or indication operation may alternatively be used for sending regulation impulses from the control station or metering impulses from a sub-station consequent upon a change-over order given at the control station subsequent to selection of the required meter or apparatus. Normally the transmission line K connecting the impulse sender IC at the control station C to the parallel connected sub-station receivers RU carries a direct current and the line L series connecting the substation senders IU to the control station receiver MC similarly carries a direct current. When a meter reading at a sub-station is required the sub-station and the meter thereat are selected by initiating a control operation at the control station, as in Specifications 650,755 and 650,756, the impulse senders coming to rest after the reply impulse train from the substation concerned has'been checked against the initiating train. A switch A at the control station is then operated momentarily to energize a delayed release change-over relay O which re-starts the impulse sender IC to transmit continuously a train of short impulses separated by short spaces to which a relay M at every sub-station responds to connect a meter impulse transmitter MS in the line L in lieu of the normal impulse senders IU. The contacts MSa remain closed at the sub-stations except the selected station, where the contacts MSa are actuated to send metering pulses over normallyclosed contacts ST in accordance with the reading of the selected meter to the metering impulse receiver relay MM at the control station which has been connected to line L in lieu of the receiver MC by the relay O which also maintains the D.C. supply to the receiver MC over contact Oc. Change-over relay O is locked as long as metering impulses are received. If, during metering, a circuit-breaker or the like should change its position and initiate an indication operation as in Specification 650,755, the start contact ST at the sub-station in question opens the metering circuit whereupon relay MM releases and in turn releases changeover relay O to stop the impulse transmitter. Relays M at all sub-stations then relapse to reconnect the impulse transmitters IU in line L. The indication operation is then effected as disclosed in Specification 650,755, after which metering may be resumed. Metering may also be interrupted at the control station by opening a switch B should a controlling operation be necessary. For regulating, the apparatus in question is selected as before and the switch A then closed as for metering. In addition a switch RS is thrown to one of its two operative positions causing the sender IC to send different kinds of impulse trains over line K to which relays Y, Z respond selectively at all stations after relay M has pulled up. The regulation is then effected at the apparatus previously selected by the appropriate Y or Z relay.