Patent GB-338853-A (GB)
Title: Remote indicator and supervisory system
IPC: H02J13/00
Filed: 1929-07-20
Abstract: 338,853. Standard Telephones & Cables, Ltd., McWhirter, E. M. S., and Flint, J. G. July 20, 1929. Selective signalling and distant - control systems. - A central station is connected to remote stations by separate transmission lines and there are provided means at the central station for transmitting impulses to each remote station, means responsive to these impulses adapted to operate in unison at the central station and at each remote station for setting up a succession of circuits for transmitting a plurality of meter reading indications from the remote stations to the central station, means for establishing telephone communication, or for supervisory signalling, between any remote station and the central station, and means whereby the transmission of the meter reading indications is interrupted during the transmission of a telephone call signal or a supervisory signal and subsequently is continued without loss of unison. In the construction shown, the control station, Fig. 1, is provided with pairs of lines such as L1, L2, connecting the control station to remote stations, one of which is indicated by Fig. 2. Watt-meter apparatus W and wattless-meter apparatus WL at each remote station are adapted to transmit readings to corresponding meters W, WL at the control station, the necessary connections being made through the medium of a rotary distributer 9A which is adapted to cause movements of a selector V at the control station in synchronism with the movements of selectors VS, one at each remote station. The arm b, which rotates continuously, closes at contact 59 a circuit through relay MA, whereby relays A1, A2, &c., one for each remote station, operate, and lock up through back contacts of relay RA. Relay A1 at contacts A1/3, A1/4 connects the lines L1, L2 to the contact of impulsing relay S1 When the arm b reaches contacts 1 relays 81, S2 &c. and also relay SB operate. Relay S1 transmits an impulse which is received by relay R, Fig. 2, and transmitted through relay Z to selector VS. Relay SB transmits an impulse to selector V. Three impulses are necessary to step the selectors from normal zero position to contact 1, and two impulses for each subsequent step. The arm b in passing over contacts 1 to 9 causes the selectors V, VS to step up to contacts 3 whereby at the control station relay MW is energized to close a circuit through relay W1, causing contact W1/2 to prepare a circuit connecting the watt-meter receiving apparatus W to lines L1, L2. This circuit is completed when the distributor arm b reaches contact 13 causing the operation of relay RA and the release of relays A1, C. At the remote station selector VS at contact 3 completes a circuit for relay G which at contacts G/2, G/3 connects the watt-meter transmitting apparatus W to lines L1, L2. Readings are transmitted until the arm b reaches contact 28, when relay A1 is energized to de-energize one winding of relay C whereby the transmitting watt-meter is disconnected. At contact 30 the stepping of the selectors V, VS, which are released when the arm b reaches contact 13, is again initiated, the selectors stepping to contacts 4, during which time the watt-meter receiving apparatus W at the control station has been disconnected from the lines L1, L2 now connected to the wattless-meter WL. At the remote station the wattless meter is also connected to the lines L1, L2. Readings are transmitted until contact 59 is reached. If a continuous reading of a meter at a remote station is desired a key such as MK1 corresponding to the remote station is moved to the left or to the right according to whether continuous watt-meter or wattless-meter readings are required. Movement of key MK1 to the left causes the distributor at contact 15 to cause operation of relay X whereby the circuit through relay S1 is broken and further impulses cannot be sent over lines L1, L2 until key MK1 is restored to its centre position. Supervisory indications. Change of position of apparatus at a remote station causes relay SRI. Fig. 2, to transmit a code of impulses and operates relay DSR, the contact of which closes a circuit through earth, contact DSR, battery, relay B, line L2, contact A1/5 during the time A1 is de-energized, relay C, to earth. Relay C operates at C/1 to connect relay SR across the lines L1, L2, and at contacts C/2, C/3 to disconnect the control station metering apparatus. At the remote station relay B at contacts B/2, B/3 disconnects the remote station metering apparatus, and at contact B/4 connects relay SR1 across the lines L1, L2. Impulses transmitted by the relay SRI actuate relay SR which in turn actuates selectors U1, U2, &c., to cause the operation of indicating apparatus. When the indication is complete relay DSR releases, causing the release of relays B and C, and meter reading proceeds in normal manner. Telephone communication. The control station is provided with keys TK1, TK2, &c., one for each remote station. To call a remote station, a key, such as TK1 is moved to the right whereby telephone apparatus TP is connected to lines L1, L2 and a circuit is completed for relay E which locks up and opens the circuit for the upper winding of relays A1, A2, &c. A circuit is also completed through the lower winding of relay A1, when the distributor arm b reaches contact 28 or 59. Contacts 4 and 33 are connected through the operation of relay E to contacts 1, 3 and 5. The distributor sends impulses which cause selector VS to reach contact 1, ringing the telephone bell BE. The bell rings until the receiver is lifted. Selector V at the control station, on reaching contact 1, operates relay D which opens the circuit of relay E, restoring to normal the metering operations associated with the distributor. At the end of telephone conversation key TK1 is restored to normal, whereby a lock-up circuit of relay D is broken, and the telephone set is disconnected from the lines L1, L2. Telephone calls from a remote station to the control station are originated in a manner similar to that in which supervisory indications are transmitted, the call then proceeding by the operation of the telephone key at the control station. Specifications 117,170; and 272,289, [Class 37, Electricity, Measuring &c.], are referred to.