Patent GB-663458-A (GB)
Title: Alarm and control circuit for electrical telecommunication systems
IPC: H04B17/40
Filed: 1949-11-11
Abstract: 663,458. Repeating systems. WESTERN ELECTRIC CO., Inc. Nov. 11, 1949 [Nov. 12, 1948], No. 28953/49. Class 40 (iv). The invention relates to means for supervising the operation of any one of a series of Unattended Repeater Stations (URS) from an Attended Repeater Station (ARS) by means of a transmission line consisting of three signalling channels plus one channel for interference suppression. The four channels are connected between the ARS and the URS's in series, and facilities are provided whereby the ARS may select any one of the URS's and request information, which is supplied by the URS through any intermediate URS's by a series of pulses which, at the ARS, are used to operate appropriate indicators. Means are also provided for indicating and locating major and minor faults at the URS or in any of the four channels. Station alarm circuit, (Figs. 9, 10, 20, 3). A fault occurring at any one of a series of unattended stations grounds lead 340 (or 347) bringing fault relay 2 (or 4) into operation to obtain control of lead 348 between the URS and ARS, if not already transmitting an alarm signal from one of another series of URS's, and also starts a pulse generator circuit to send a number of pulses indicative of that URS over lead 348, which are counted by a relay counting chain at the URS' to stop after the desired number of pulses have been sent, and by another relay counting chain at the ARS to register the appropriate alarm. As shown for a minor fault at one of a series of URS's, lead 340 is grounded, causing relay 1 to operate, followed by relay 5 and the release of relay 6, if held up by a previous alarm. Relay 1 energizes relay 2, which releases relay 1 and 5, and operates relays 7, 8 and 9 in sequence, thus breaking the alarm circuit from more remote URS's, and is followed by the energization of relays 12 and 32 together, the latter sending a ground signal through winding 43 of relay 36 to line 348, which operates relays 54 and 61 at the ARS to ground lead 351a. This causes the operation of relay 447, followed by relays 64, 65 and 66 in sequence, relay 65 being a slow-release type and thus holding for the duration of all subsequent pulses. The operation of relay 66 produces a battery signal on lines 349a, 348 to disconnect the receiving circuit of Fig. 3 from stations in other directions, and to initiate the sending of identifying signals at the URS in question by operating relays 36 and 14 in sequence, thus grounding the junction of resistor 15 and condenser 16. The charging and discharging of condenser 16 causes relay 13 to operate and release successively, causing relays 12 and 32 to release and operate successively, thereby sending a series of battery signals over, lead 348. The action of relay 12 causes a frequency divider group of relays 22, 23, 24 to operate in such a way that an earth is produced on leads 384, 385 alternately. These leads are taken to counting chain relays 25-30, which operate in sequence, relays 29 and 30 completing their own holding circuit, so that for the arrangement shown, at the eighth ground pulse, lead 432 is grounded through the'contacts of relays 26, 30, which causes the operation of relay 6 and stops the pulse generating circuit including relay 13. At the attended station, the series of signals cause the operation of slow-releasing relay 67, and the pulses are sent through frequency divider relays 68, 69, 70 to counting chain relays 71-76, whereby lead 387 is successively connected to leads MJ1, MN1, MJ2, MN2, &c. At the end of the pulse series, relay 67 releases to ground lead 387 and, through the appropriate MN lead, operates relays 77, 79, 81, 83 to register the alarm on a lamp 78, 80, &c. and give an audible alarm. Finally, all the relays except 2 and 6 at the URS, and 77, 79, 81, 83 at the ARS are returned to normal, whereby the apparatus of Fig. 10 is restored to its normal through-circuit for more remote stations. To test for transitory faults, relay 159 (Fig. 11) may be operated to release relay 6 when the alarm signal is repeated, if the fault is still there, or the alarm relays 77, 79, 81, 83 may be cleared by operating relay 96 (Fig. 5). A major fault at the URS grounds lead 347, operating relays 3 and 4 instead of 1 and 2, the subsequent pulses being one less than those for the corresponding minor fault. Director circuit, (Figs. 4, 5, 11, 12, 13). The director circuit comprises means for sending three coded series of impulses over channel 2- line 354-from a dial 89 at the ARS, whereby the 1st digit chooses the required URS, and removes any alarm signal at the ARS associated with that URS, and the chosen URS proceeds to count the two following digits to connect ground to a corresponding order lead. To transmit an order, key 457 is operated to bring the ground from lead 352 on to lamp 90, and to cause the pulses produced by dialling to operate relays 91 and 121, followed by relays 93, 94, which remain operated for the duration of the pulses as 93 is slow to release. The release of 91 causes 95 to operate and hold till the end of each digit, followed by the operation of 109. The pulses of the 1st digit are fed to a frequency-dividing circuit, relays 98, 99, 100, and a relay counting chain 101, &c. so that at the end of the pulses of the 1st digit, say 4, relay 104 is operated, relay 95 releases to operate 96, which breaks the pulsing lead to the frequency-dividing circuit, and breaks the H lead to the alarm signal circuit of Fig. 3 for that particular URS. The pulses from-dial 89 are also passed through relays 91, 121 to reverse the condition of current or no current on line 354 to cause the pulsing of relays 123, 127 (Fig. 13) and produce a corresponding series of ground pulses on line 355, which at the URS (Fig. 11) operate relays 133, 135, 136, slow-releasing relay 137 and 138 in that sequence. The pulses are passed through a frequency-dividing circuit, consisting of relays 139, 140, 141 to a relay counting chain 142- 147 to connect contact 153 of relay 137 in turn to each of the ten. leads interconnecting relays 149, 164, so that at the end of the 1st digit relay 137 restores, and puts a ground on the appropriate one of these 10 leads. If the URS is not the one coded by this digit. relay 151 operates to break the circuit to the frequency-divider relays. If it is the appropriate digit for this URS, relay 159 also operates to reconnect the pulsing circuit and prepare the counting chain for the next digit. The start of the following digit operates relays 161, 154 to connect the ten output leads of the counting chain to ten 163 relays, so that at the end of the series of pulses, one of these leads is grounded and one relay 163 is operated, followed by relay 168 and the release of relay 154 to disconnect the ten 163 relays from the counting chain. The third digit operates 170 to provide a new ground for the counting chain, grounding one contact of 149 when 137 is released, and passing this ground to one of the ten RD leads of relay 163. This ground stays on until key 457 of Fig. 5 is released, when all relays return to normal. Indicator circuit, (Figs. 14, 15, 16, 17, 13, 4, 6, 7). The indicator circuit comprises means for indicating at the ARS each of a preselected group of conditions at an URS by lighting individual lamps in a bank of lamps at the URS. The URS to be examined is determined by placing a ground on the appropriate RD line as previously described under " Director circuit ". This causes the operation of relay 173 (Fig. 14) to start a pulse generator circuit comprising relay 177 and associated components, the pulses being taken to two relay counting chains to connect a lead 359 to each of 168 contacts in turn to send a ground impulse along the line when the contact is earthed. At the same time a similar series of pulses are sent over lead 360 to operate two similar relay counting chains at the ARS to scan a group of 168 lamps, so that each grounded contact at the URS lights a corresponding lamp at the ARS. At the URS selected (Fig. 14), ground on RD operates relays 173 and 174 to isolate more remote URS's and start the pulse generator relays 177, 178 to produce a series of 195 pulses, each of which interrupts the ground on lead 360, which are taken via frequency dividing relays 188, 189, 190 to a relay counting chain 192-199 (Fig. 16). Relay 173 also operates the first relay 207 of a group of 14 relays, so that as the counting chain proceeds, lead 359 is connected in turn to each of the 12 contacts of relay 207. The 13th pulse prepares a second relay counting chain 213- 220 (Fig. 15), via frequency dividing relays 210, 211, 212, and the 14th pulse operates relay 222 to release the 1st relay 207 and energize the 2nd relay 207 from the second counting chain. This sequence proceeds for all 14 relays 207 until, at the 195th pulse, relay 191 is operated to release relay 173 and restore all relays to normal. The synchronizing pulses on line 360 operate relay 226 (Fig. 13) to produce a corresponding series of synchronizing ground pulses on lead 354, causing relay 113 (Fig. 4) to follow the synchronizing pulses; but relay 114 is prevented from acting in like manner by relay 231, which only frees it on receipt of an indicating pulse from leads 359, 363. Thus synchronizing pulses are sent on by line 364, and indicating pulses are sent on by line 365 in exact time relationship with the corresponding synchronizing pulses. At the ARS (Figs. 6, 7), the synchronizing pulses operate in sequence relays 236, 237, 238 and the 1st relay 275 of 14 relays. Further orders from the director circuit (Fig. 5) are prevented by the removal of ground from lead 352. Each synchronizing pulse connects a lead from relay 235 via frequency-divider relays 240, 241, 242 and a counting chain relays 243-250 to each of the 12 contacts of the 1st relay 275. Thus when the synchronizing pulse is accompanied by an indicating pulse over le