Patent GB-268515-A (GB)
Title: Improvements in or relating to electrical remote control systems
IPC: H02J13/00
Filed: 1926-02-22
Abstract: 268,515. General Electric Co., Ltd., and Collyer, J. E. Feb. 22, 1926. Selective distant-control systems; tell-tale apparatus.-Relates to a system for the distant supervisory control of apparatus units, such as circuit breakers at a number of substations. The system is identical with that described in S,pecifications 263,926 and 265,661 but is characterized in that the circuit of a selected unit at a substation is automatically closed upon the receipt at the control station of a correct checking signal of the selection. Selection of a unit at any particular substation is effected 'by 'three characteristic trains of impulses transmitted over line wires common to the substations. The first train selects the substation and locks out unwanted stations from the control wires and the second and third trains prepare the control circuit of the selected unit. When the selecting operation is completed, a signal characteristic of the selection is transmitted back to the control station over a second group of common line wires to operate a supervisory signal and if this signal corresponds to the selection desired, initiate the transmission of a further impulse to effect the control operation. Fig. 2 shows the apparatus at the control station and Fig. 3 shows the equipment at each substation. Circuit breakers, such as 330, 331 are controlled by corresponding keys 101, 102 and the condition of the circuit breakers is indicated by supervisory lamps 103 - - 106. When a key is operated, a corresponding relay in the chain 107 - - 112 is energized and impulses, the number of which is determined by the selected relay, are transmitted over the lines 138, 139 and are stored by similar chains of relays 301 - - 306 at each substation to select the desired substation and lock out all' unwanted stations. Two further trains of impulses are then transmitted under the control of a sequence control relav chain 113 - - 118 to select the appropriate relays in the groups 325, 326 &c. and 327, 328, 329, &c at the selected substation, prepare a control circuit for the selected unit, and initiate the transmission of the supervisory checking signal. Operation of the selected unit. When the appropriate switches in the groups 325, 826 &c. and 327, 328, 329 &c. are operated, a relay such as 384, individual to the selected unit is energized to initiate the supervising checking signal. This signal comprises three trains of impulses which are transmitted to the control station to operate appropriate relays in the groups 131, 132 &c., 133, 134 &c., 135, 136, 137 &c. operation of these relays energizes a relay in the groups 146, 185, 253 &c. which if the selection is performed correctly, corresponds to the operated control key. When a key is operated one or other of an associated pair of relays such as 183, 184, 144, 145 or 271, 272 is energized and locks up in series with a relay 156, 157 or 158 common to a group of keys individual to a substation over the back contacts of a relay in the group 146, 185, 253. The operated relay in the group 156, 157, 158 &c. energizes a relay 148 which operates a relay 230. Upon the receipt of a correct checking signal, the relay in the group 156, 157, 158 &c, is de-energized to open the circuit of the relay 148 and thereby complete a circuit over the back contact of the relay 230 and the line 138 to effect the operation of the selected substation unit. The relays 146, 185, 253 also control the supervisory lamps at the control station. Specification 185,722, [Class 40 (iv), Telephones &c.], also is referred to.