Patent GB-227610-A (GB)
Title: Remote control system
IPC: H02J13/00
Filed: 1923-12-27
Abstract: 227,610. Coventry Automatic Telephones, Ltd., and Puckette, C. C. Dec. 27. 1923. Selective distant control systems; ; tell-tale apparatus.-In a system for supervising and controlling from a remote point the operation and condition of a number of switches, indicators, &c. at a power substation, the control relays which are selectively energized for effecting the control and supervision, are entirely disassociated from their energizing source when the selecting apparatus is in a non-operated condition. The invention is described as applied, to. a system in which the apparatus at a substation B, Fig. 1, is selectively controlled and supervised by a one-hundred point two-co-ordinate selector C, Fig. 1, operated by tens and units current impulses sent over a two-wire trunk extending from the control station A. The battery for energizing a selected control relay, such as the relay 46, Fig. 1, is supplied over the wipers 53, 54 of the selector C in its operated condition. After the selector C has been set, but before the selected control relay is energized, an audible check signal indicative of the position of the selector is sent back to the control station by a step-by-step switch D, Fig. 2; the operator then causes the energization of the selected control relay by sending a further impulse. A switch E, Fig. 2, is provided for sending to the control station audible signals indicative of the readings of voltmeters, ammeters, depth of water indicators, temperature indicators, &c. Telephonic communication between the substation B and the control station A may be held over the control conductors.. Means are also provided whereby irregular occurrences, such as a tripped circuit breaker at the substation, cause a warning signal to be given to the control operator. An inspector at the substation can isolate it from the control by the remote station and then carry out routine tests. Closure of a starting switch; preparation of con. trol. Assuming the control relay 46, Fig. 1, the control number of which is 72, when energized actuates heavier switch gear to start a generator, the operator at the control station A removes his receiver and dials this number on his impulse transmitter 1. The removal of his receiver causes the response of the line relay 65 and the slowrelease relays 67, 71, and the relapses of the line relay 65, due to the tens impulses, intermittently energize the rotary stepping magnet 57. On the cessation of these impulses, the relay 71, which has been maintained energized over the interrupter contacts 74 of the rotary magnet 57, relapses and energizes a slow-release relay 76, which prepares the circuit of the vertical magnet 58. The units impulses cause the line relay 65 to relapse twice and close the circuit of the vertical magnet 58, which brings the wipers 53 - - - 56 on to the bank contacts 48, 49, 86, 87. (For simplification, the bank contacts are shown in Fig. 1 as though the tens impulses stepped the wipers vertically and the units impulses horizontally.) At the end of the units impulses, the relay 71, which during them is energized over contacts 77 of the vertical magnet 58, relapses and energizes a switching relay 78. Transmission of check signal. The relay 78 grounds the wipers 55, 56, the bank contacts engaged by which are so connected to the bank contacts engaged by the arms 102, 103, Fig. 2, of the switch D, that this grounding causes this switch to send back two audible signals indicative of the position of the selector wipers, in the following manner. A relay 110, Fig. 2, energized over a circuit 84, 120, 118, closes a circuit for a relay 124, which energizes the stepping maguet 101 of the switch D. The magnet 101 opens the circuit of the relay 119, which de-energizes relay 124, which opens the circuit of the magnet 101, and the cycle of operation is repeated. Since the relays 119, 124 are slow releasing, the switch D is stepped at a slow rate, until on the wiper 102 reaching the contact 126 grounded over the selector wiper 55, a relay 127 is energized and locks up over resistance 129. When the wiper 102 engages the next contact 130 and each subsequent alternate contact, a relay 131 is energized and closes the circuit of the signal bell 114, thereby causing seven rings to be transmitted to the control operator through an adjacent microphone 112. When the wiper 102 engages the last contact 133, the relay 127 is shortcircuited, but it is again locked energized on the wiper 103 engaging the contact 135 grounded over the selector wiper 56. At the next contact 136 and each subsequent alternate contact, a relay 137 is energized, causing a buzzer 113 near the microphone to give two short buzzes. This cycle of operations is repeated by the wipers 102, 103 until the control operator either abandons the operation by hanging up, or completes the control. Completion of control. The operator sends a single impulse thereby causing the line relay 65 to relapse and energize a relay 92, which when the line relay 65 again pulls up closes a circuit for a relay 93. Relay 93 locks up, de-energizes relay 78, and energizes relay 50, which connects battery over the retardation coil 49, to the selected control relay 46. A telephone transmitter 45 is inserted in series with the relay 46, so that the starting or stopping of the machine can be heard by the operator. On the relapse of relay 78 the switch C returns to its normal position under the control of wipers 104, 105. Release. When the operator hangs up his receiver, relays 65, 67 relapse and a circuit is closed for the release relay 59, which causes the selector C to restore to normal. Transmission of meter-readings &c. to control station. By dialling a particular number, the operator may energize a control relay, such as 143 or 158, Fig. 2, thereby starting the switch E and earthing an ammeter-reading arm 110, or a voltmeter, reading arm. 109, which earths a particular contact in the bank of the wiper 107. The switch E operates in a similar manner to the switch D to cause the bell 110 to send through the microphone 117 a number of rings indicative of the desired reading. Telephonic communication. By dialling the number " 00 '' the operator can energize a relay 139, Fig. 2, which completes a circuit for a, callbell 141 at the substation. When an attendant at the substation removes the receiver the bellcircuit is broken at the switch hook 142. Testing. An inspector at the substation desiring to carry out routine tests, presses the key 68, thereby opening the circuit of relay 67 and connecting up the bell 141 at the substation, so that should the control operator remove his receiver to initiate an operation, the response of the line relay 6.5 rings the bell 141. Warning signals. Irregular occurrences such as an overloaded machine, are made to bring about the bridging of conductors 98, 99 and thereby cause a ringing switch F similar to that described in Specification 210,960, [Class 40 (iv), Telephones &c.], to ring the operator at the control station. A call signal may also be sent to the operator by depressing the key 97. which bridges the conductors 98, 99. Specifications 3497/12 and 183,835, [both in Class 40 (iv), Telephones &c.] are also referred to.