BE344462A - - Google Patents

Description

       

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  "Improvements to Automatic Telephone Systems."
The present invention relates to improvements relating to the automatic telephone system and it is more particularly intended to provide small private centers, but it is understood that the characters. The characteristics of the invention are susceptible of a much broader interpretation.

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   The installation described consists of a private automatic central unit connected to a large central unit, and combined to be actuated exclusively by relays.



   One of the objects of the invention is to provide a small automatic power station actuated exclusively by relays, which is less expensive than those used up to now, while one of the subsidiary goals is to provide a private power station or power station. automatic connection with rac cerdecient to a main control unit, which is operated exclusively by relays, and whose installation is inexpensive.



   Another important feature of the invention is the arrangement whereby a call made on a long distance primary line can be transmitted to another long distance primary line if the call is a local call, but if it is not There is no other main line available, the call can be made locally on the first main line.



   It is possible, according to the invention, to use a group of relays attached to the small primary line to send a call from a local subscriber to the main central office, from a local subscriber to another local subscriber. by transmission on another main line, from a local subscriber to another local subscriber over the original primary line if there is no other main line available, and a call. a subscriber of the large central office to a local subscriber.



  We therefore realize that the group of relays associated with the first long-distance primary line contains many elements in various combinations, which consist of a group of relays capable of satisfying not only all the operations mentioned, but also of 'Indeed-

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 do two. + three or more, in various combinations.



  It will also be appreciated that there is a second primary main line circuit capable, not only of receiving an initiated call, but also of receiving and transmitting a call which is transmitted to it. This transmission is effected when a distinctive number is indicated on the dial to indicate that the call is not intended for the large central office, no distinctive number being necessary in the case of a call from the central office. large central office, and hence new features of the invention result from the fact that according to the route along which a group of relays is actuated it is arranged to act differently depending on whether it is actuated directly or actuated after several series of impulses have already been transmitted.



   Among other new features it is worth mentioning a chain of counter relays in which a single control relay, which is energized after the end of a pulse and which remains energized until the end of the following pulse. vante, controls the operation of the relay chain.



   Another characteristic of the invention consists of relays which, as a whole, have the function. @ to sound ... ner, to., give the busy signal and charge the local battery. This characteristic due to the invention and still others, will be better understood by referring to the accompanying drawings in which:
Figs. 1 to 11 show in diagram the circuits by which various connections can be made.

   Figure 1 shows the line cut and subscriber connection relays in the local exchange; Figure 2 shows the battery supply group connected to the primary line chosen first; figure 3 shows the power supply group

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 of batteries connected to the main primary line chosen second; fig.4 shows the relay recorder connected to the first large, primary line; fig.5 shows the relay recorder connected to the second main primary line; fig.6 shows a recorder different from that shown in fig.4; Fig. 7 shows the battery charging, bells and busy signal devices; fig. 8 shows a variant of the busy signal device.



   Fig. 9 shows the general diagram of assembly at the large central office, that is to say the relationship between figures 10 and 11.



   Fig. 10 shows the repeater of the main central office. pal which is accessed by a sub-control unit and from which the sub-control unit is accessed, while fig. 11 shows a selector switch having access to the normal type selector relay group.



   To follow the assembly diagram, the figures must be arranged in the following order: fig.l on the far left; fig.2 to the right of the upper part of fig.l; Fig. 3 to the right of the lower part of the. fig.l; fig.4 to the right of fig.2; fig.5 below fig.3; fig.7 can be placed either above fig. 2 or above fig. 3 depending on the group of battery power relays used; fig. 10 should be placed on the upper left side of fig. 2 while fig.ll should be placed to the left of fig.10; fig.6 is a variant which can replace fig.45.



   With reference to the drawings, the invention will be better understood by first describing the laecement of a call, sup-

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 assuming that the two battery supply groups are inert.



   Let us suppose that the subscriber number 11 picks up his receiver to establish the communication with the subscriber number 12, - that is to say that one wishes to establish a simple local call.



   It should be mentioned that the subscribers connected to the small private secondary office have a number starting with the digit 1. This, to distinguish them from the subscribers connected to the main office, where the subscriber numbers always start with a different digit. that 1. therefore the first digit distinguishes between a call for a local subscriber and a call for a subscriber of the main office. When subscriber 11 picks up his receiver, the following circuit is established: earth contact 21, subscriber line, contact 22, line relay Lll to the battery.

   The line relay is fully energizing the following circuit: earth, contact 23 normally closed of the release relay RL1lo- ge in the battery power supply group Gl, conductor 24, contact 25, contact 26, a relay LTS 11 , lower winding of relay OTS11 towards the battery. At the same time a second circuit is completed as follows: earth, contact 27 normally closed of relay RL2 of the battery power supply group Gl, contact 28, resistor 29, contact 30, contact 31 of relay LTSII, lower winding from the CES 11 relay to the battery.

   Resistance 29 is calculated such that under the conditions indicated above, the CTSII relay is energized before LIS 11, thus opening contact 31 and preventing the energization of LIS relay 11. Therefore, the call is made from the switch. subscriber line via contacts 32 and 33 of OrS relay 11 on line relay LRO of battery supply group Gl. The IRO line relay therefore

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 is energized, and completes at contact 34, a circuit for the RLI relay, as follows: earth, contact 34, contact 35 of the relay
LS, RLI relay to the battery.

   As a result, relay RL1 is energized and completes at contact 36 a * circuit for the loading relay represented in fi.g7, for a purpose which will be described later. Relay LRI also closes contact 3'7 and opens contact 23; opening this contact prevents the G1 power supply group from being excited by any other subscriber; at contact 37, the relay RL1 connects the earth to the trunk line 38 so as to energize the switch relay COLL by the contact 39 of the relay CTS11. The RL1 relay also provides a blocking circuit for the relay.
OTS 11 from earth, through contact 40, conductor 55, contact 56, OTS 11 relay to the battery;

   this relay consequently remains energized outside the initial exciter circuit.



   The relay COLL on being energized, opens the contacts 22 and 21, thus disconnecting the line relay Lll which becomes inert and opens the circuits by which the power supply groups Gl and G2 had been originally tested, and the circuit Gl had been attacked. However, other operations are occurring in the battery supply group Gl. The energization of the LRO and RLI relays together ?, complete is a circuit for the OS relay as follows: earth, contact 40, contact 41, normally closed contact 42; relay to the battery. RelayOS energizes relay LRI and cuts it from conductors 43 and 44 which lead to the main office at contacts 45 and 46 and instead connects relay BB1 in the following circuit: conductor 43, contact 47, contact 48, contact 49, contact 50, upper winding of relay BB1 on earth.

   The lower winding of the BB relay! is connected from the battery, by the contact

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Turn on contact 52, to conductor 44, so that the battery supply is now connected from relay group Gl to conductors 43 and 44 to energize the line relay at this point, said relay being similar to relay LR1 in that it has neither battery nor earth connection and that it is normally connected across conductors 43 and 44, so that it is energized in series with relay BB1. The subscriber then begins to operate his calling device to send a series of pulses corresponding to the first digit.

   This series of pulses comprises only one number, since the number to be marked on the dial will be the number 12 and consequently the line relay LRO will only deflect inert once * once. The OS relay at contact 53, closes a blocking circuit for itself, independently of contact 42 and contact 41, so that it is directly controlled by contact 40 and relay
RL1. When the IRO relay becomes inert, it opens the contact
49, so that the battery ceases to be supplied by the relay BB1 passing by the conductors 42 and 44 leading to the main office, and the line relay in this office. also becomes inert.

   The LRO relay also closes, at contact 57, a circuit for relay CH1 as follows: earth, contact 40, contact 57, contact 58, contact 71, contact 72y CHI relay to the battery. A branch of this circuit extends through conductor 59, contact 60 of the FRB relay, the normally closed contact 61 of the FRC relay, the winding of the FRC relay, the contacts 62.63.64.65/.66 of the CROY CR8 counter relays, CR6, CR4 CR2 to the CRI relay. The CHI, FRC, and CRI relays are all energized. - By energizing, the CRL relay completes a circuit for the ACH1 relay, as follows: earth, contact 40, contact 70, ACHI relay to the battery.

   Relay

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FRC and CRI are blocked, energized, in the following circuit earth, contact 40 of the RLI relay contact 67 of the ACHI relay, contact 218 contact 68 of the FRA relay, contact 69 of the FRC relay, FRC relay, contacts 62 63, 64, 65 and 66, CRI relay to the battery; the contact 61 is open, but following the closing of the circuit on the conductor 218 and the contact 67, this has no effect. The CHI relay at contact 78, prepares a circuit for its excitation independently of the contacts 71,
72, contact 72 being open when relay ACH1 is energized.

   When this is the first pulse, the LRO relay energizes again, contact 49 closes, re-energizing the main office line relay, contact 34 closes to prevent the RLI relay from becoming inert, this RLI relay being slow to trigger does not lose its energy by momentary opening of the circuit. When the LRO relay is energized, contact 57 is opened, thus opening the circuit of the CHI relay which consequently becomes inert after a short interval. Before this happens however, thanks to the relay excitation
LRO after the first pulse, a circuit is cleared as follows: earth, contact 40, contact 41, contact 76 conductor 219, contact 77 of the FRC relay, lower winding of the FRB relay to the battery.

   The FRB relay is energized in this circuit, opens the contact 60 and connects to the contact 220 the conductor 59 with the FRA relay. However as the conductor 59 is not again connected to the earth, the excitation of the relay FRB in this case has no effect, When the relay ACH1 becomes inert, the following circuit for the relay IS of the second group G2 battery supply is established:

   earth, contact 40, contact 78,

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 contact79. conductor 8u, contact 81, conduction 82, contact
83, conductor 84, contact 85 of relay RL2 of the second battery supply group G2 and upper winding of the relay
IS to the battery. This circuit is established because the first series of pulses consist of only one pulse and therefore the CRI relay was energized when movement ceased. If the movement had consisted of a larger number of pulses, it will be seen from the following description that the CRI relay would not have been energized and that this cireuit would not have been established.

   The purpose of establishing this circuit is that, now that the call is known to be for a local subscriber, it is possible to use a second battery supply group which does not communicate with the main office, and thus leave the GL battery supply group, which communicates with the main office, free for another call. It will be recalled that we have assumed that the battery power pack G2 has not yet been used.

   After the IS relay has been energized, the following circuit is established: earth, contact 27 normally closed, contact 86, conductor 89 LS relay from battery supply group Gl to the battery; as a result the LS relay is energized, its excitation blocks it on contact 88 and establishes on contact 89 the following circuit: earth on contact 34, contact 89, enangement lead 90, contact 91 of the CTS11 relay to the coil. inside the LTSII relay and the battery. Consequently the LTSII relay is energized in this circuit and to the contacts 92 and 93 connects the line relay LRL in circuit with the subscriber line.



  The relay LS when it is energized, opens the circuit of the relay RLI at contact 35, this relay consequently becoming inert and, eu. By turning on contact 40, allows the OS and LS relays to become inert.

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   It also cuts off the earth communication of the conductor 55 and allows the CES 11 relay to become inert. Consequently, the relay OTSII disconnects the group of relays Gl allowing the relays of this group to return to normal, including the relays FRC and CRI As a result of the slowness of the release of the relay RL1, while this has happened, the connection has been transferred and the relay LRL of the battery power supply group G2 is energized on the subscriber line establishing a circuit for the relay RL2 at contact 94 as follows: earth, lower winding of relay IS, contact 94 , relay
RL2 to the battery.

   Consequently, relay RL2 is energized and opens contact 27, thus opening the exciter circuit of relay LS., Which occurs in the event that the relay RL1 of the battery supply group Gl would become inert before relay RL2.

   In general, relay RL2 will be energized on: ^ first due to the slowness of relay RLi to become inert, which means that in reality it is the opening of the blocking circuit of relay LS on contact 88 which produces the inertia of the LS relay as has been mentioned above. Relay RL2 at contact 95 connects the earth to the trip conductor of trunk line 96, thus keeping the COII switch relay energized in the following circuit after contact 37 has been earthed by the trip conductor. of the interurban line
38 in group Gl: contact on earth 95, conductor 96, upper winding of relay LTSII contact 97, relay 111 To the battery.

   Immediately that relay RL2 is energized, it completes a circuit for relay BBC2 as follows: earth, contact 95, contact 315, contact 114, relay BBC2 on resistor 113 to the battery; BBC2 is excited in this circuit and opens contacts 116,116,117 and 118 thus disconnecting the

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 conversation conductors of the called subscriber, during the transmission of the impulses. The two relays LTS11 and COII are kept energized in the blocking circuit described above, and everything is now in a state to allow the subscriber to enter the second digit, in this case, the number 2 on the dial. .

   On the first impulse, when the subscriber's line is open, the IRL relay becomes inert and establishes the following circuit: earth, contact 98 to relay RL2 contact 99 of relay BR2, contact 100, contact 101 relay CH2 to the. battery, while a branch circuit extends through the rest contact 102 of the SRB relay, normal contact 103 of the SRCY relay, the SRC relay, contacts 104, 105,106,107 108 of the SRO relays SR8, SR6, SR4, SR2 and the SRI relay to the battery. The SRC and SRI relays are energized in series.

   When the CH2 relay is energized, at contact 110 completes an exciter circuit for the ACH2 relay which also energizes, and at contact 111 completes a blocking circuit for the SRC and SRI relays, as follows: earth, contact 95, contact 111, contact 112, contact 1U9, SRC relay, contacts 104,105,106,107, and 108, SRI relay to the battery.



  After the end of the first pulse, when the LRL relay is energized again, the following circuit is established; earth, cottact 98, contact 123, contact 124, contact 625 of the SRC relay, lower winding of the SRB relay to the battery.



  Relay SRB energizes and closes a blocking circuit for its lower winding through contact 123 and, as the series which has been transmitted has two pulses, relays CH2 and ACH2 remain energized. As a result the second pulse begins and the LRL relay becomes inert again and this time a circuit is established for the SRA and SR2 relays, as follows: earth, contact 98, contact 123, contact 101,

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 contact 125, contact 126, SRA relay, contacts 127, 128,129.



   130, from relays SR9, SR7, SR5, SR3 to relay SR2. The SR2 and SRA relays are energized in this circuit and are blocked, energized, in the following circuit: earth, rail contact 270
ACH2, SRI relay contact 268, contact 131w. 2: SRA relay, 127,128,129,130 con tacts towards the SR2 relay towards the battery. At contact 132, a circuit is established for the upper winding of the SRB relay by the circuit described above, including contacts 124, 123 and 98 to earth.

   The SRB relay remains energized in its upper winding in this circuit, because the releis SRA has opened the contact 112, and thus opened the blocking circuit for the SRC relay and the relay.
SRI, and consequently, has opened the circuit for the lower winding of the SRB relay., The SRC and SRI relays therefore become inert. The blogging circuit for the SRA and SR2 relays is now established as follows: earth, contact 40, contact 111, SRC relay contact 213, contact 131, SRA relay contacts 127,128,129 and 130, relay
SR2 to the battery. It will be seen that the SR2 relay should not close its front contact before the SRA relay has opened the 112 contact because it is important that the BRS relay does not energize, which could happen if the SRA relay was delayed. open contact 112.

   This is easily arranged by anyone familiar with the method of building relationships.



  Relay SR2 is therefore energized and remains energized since there are no other pulses to send to hook up subscriber no. 12. If relays SRI and SR2 being energized successively, the leads of test TII and T12 of subscribers N 11 and 12 are successively energized The SRI relay has been energized when the test lead has been connected to earth over the upper coil of the LTSII relay and therefore it is 'is then established the following circuit:

   earth, contact 95, conduc-

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 Trunk line 96 triggerers, upper winding of relay LTSII, contact 97, conductor T11, contact 134, - conductor 135y contact 136 of relay ACH2, contact 137 of relay IS, contact 138 of relay CH2, relay BR2 to the b-ttery, Consequently the relay BR2 is energized at contact 139, connects the earth through conductor 160 to the busy signal circuit, while at contact 140, it prepares a circuit blocking for itself a circuit which is not established + however because the closing of contact 134 is only temporary,

   the relay SRI becoming inert at the beginning of the second pulse and the relay SR2 exiting and closing the contact 141. The closing of the contact 141 by the relay SR2 completes an eaaai circuit occupying the line of the ahon born Np 12. If this subscriber is busy at the moment, his test lead T12 will be put on earth and consequently relay BR2 will be energized by contact 141 in a circuit similar to that described with respect to closing the contact. 134. Since there are no more pulses, the CH2 relay becomes inert after a short interval.

   The ACH2 relay which becomes very normally inert after a short interval corresponding to the inertia of the CH2 relay, does not become inert at this moment because it is blocked energized in the following circuit: earth, contact 95, contact 142 from IS relay, contact 140, contact 141, ACH2 relay to the battery. The inertia of relay CH2 completes the blocking circuit for relay BR2, as follows: earth, contact 95, contact 142, contact 140, contact 143 of relay CH2, relay BR2 to the battery, relay BR2 connects the occupancy signal of the driver 159 by the contact 144 so as to signal to the ab on ne 11 that the number that he detaande is busy.

   In this case the subscriber will replace his receiver, opening the circuit for the line relay LRL. which in turn

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 opens the circuit of the relay RL2 and the opening of the contact produces the inertia of all the relays which depend on this circuit and the second battery supply group G2 as well as the second recorder return to normal and have slide nibles for a new call.

   Assuming, however, that the subscriber born N 1-. is not occupied, relay BR2 would not be energized by the closing of contact 141 and, when relay CH2 returns to inertia, the following circuit would be established: earth, contact
95, contact 145 of relay CH2, lower coil of relay
RR2, contact 137, contact 136, conductor 55, contact 141, test lead T12 relay C012 to beet, In this circuit, relays RR2 and C012 are energized, and relay C012 disconnects relay L12 from the line of the called subscriber so as to prepare a free circuit for ringing.

   The RR2 ringing relay, when it gets excited, opens contact 114 which thus allows Bêlais BBC2 to return to inertia, so as to close in its contact 148 a short circuit for the lower winding of the relay ER2, relay RR2 on contact
564 short circuits the lower winding of the relay BB @ to the battery, this slows down the operation of the relay BBg which makes it insensitive to the alternating current; furthermore at contact 154, this shunts the top winding of relay BB2 over resistor 155, to aid the above effect.

   However, relay RR2 does not become inert again as a result of its lower winding being short-circuited, since it is blocked energized on its upper winding in the following circuit: bell battery, relay RB (fig. 7) conductor 157 , upper winding of relay RR2. contact 149, contact 315, contact 95 to earth. At the same time the current

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   ring generator is connected to the line of the called subscriber, by the following circuit: generator earth blade, conductor 161, contact 150, conductor 151, contact 115, which is currently closed as a result of this that the BBC2 relay is inert;

   conductor 119, contact 152, contact B12, called subscriber line, N 12 return to conductor A12, contact 153, conductor 121, contact 117, contact 154, resistor 155 to earth. It will be noted that this ringing circuit is not established before the BBC2 relay has become inert, but that it may occur a short time before its exciter circuit has been opened.

   This gives ample time for relay C012 to energize and to trigger relay L12. The ringing continues until the called party answers, which establishes a circuit for relay BB2 as follows: earth, upper entire of relay BB2, conductor 156, contact 117 conductor 121, contact 153, conductor A12, line from the subscriber, conductor B12, contact 152, conductor 119, contact 115, conductor 151, contact 150 ,, conductor 161, winding, H of the transformer, contact 206 of the MR relay (fig. 7) to the battery .

   The relay BB2 energizes in this circuit, opens the contact 315 in the circuit of the upper winding of the relay RR2, which consequently becomes inert, closes the contact 207 so as to short-circuit the capacitor. small capacity 208 whereby the busy signal can be connected to the calling subscriber line, and closes contact 209 to establish the talk circuit.



  The conversation circuit is then the following: starting from the station of the called subscriber, N 11, on conductor A, contact 93, capacitor 210, contact 207, confluence *, tor 156, contact 117, contact 153, conductor A12

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 to subscriber 12 and return via conductor B12, contact 152, cantact 115, conductor 151, contact 211, contact 209, capacitor 212, contact 92, conductor B to return at the subscriber station n ° 11, the battery of the conversat ion circuit being supplied on the side of the calling subscriber by the line relay IRL which, as will be seen, is connected to conductors A and B, while the battery is supplied, on the side of the called subscriber,

   by the BB2 relay which is connected to conductors 151 and 156,
The subscribers can then converse, and when they have finished, the calling subscriber and the called subscriber hang up their receivers. When the calling subscriber hangs up your receiver, the line relay IRL becomes inert and opens the contact 94, which opens the relay circuit BL2 and IS thus rendering them inert. Relay RL2 opens contact 110, thus allowing relay ACH2 to become inert. Relay ACH2 becomes inert and opens contact 111, thus opening a blocking circuit for relays SRA and SR2, which thus become inert. The opening of contacts 153 and 152 opens the circuit of relay BB2 which becomes inert, and consequently everything returns to the normal state.

   However, assuming that the calling subscriber resumes his receiver after the called subscriber has resumed his, the relay BB2 would become inert and would open it. talk circuit to contacts 209 and 207 and at the same time close contact 315, the driver circuit of relay BBC2 thus being established from the battery by relay BBC2 on contacts 114, 315 and 95, to earth. However, this circuit would be its effect. relay BB22 being circulated at the inertia of BB2, in the following circuit: earth, contact 95, contact 142, contact 147, contact 146, contact 216, contact 216 to the left terminal of the input.

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 BBC2 bearing, BBC2 winding, contact 114, contact 315, contact 95 to earth.

   It is therefore.indispensable before the called subscriber can be effectively released, that the calling subscriber has hung up his receiver, which is naturally habitual use in the main automatic telephony systems. It will be seen that the foregoing description relates to the case where the two power supply groups are idle, and a subscriber of a private office wishes to communicate with another local subscriber.

   Briefly, the operation can be summarized as follows: the abcnne's call device is activated for the digits 1,2. The first digit determines that it desires a local call and therefore the main office line 43,44 is triggered and at the same time the call is transmitted to the second battery supply G2.11 then marks digit 2 on its dial and tries the line of subscriber 12. realizes whether this subscriber is busy or not and, if it is busy, receives the busy signal; have the station is free, it rings until answer. After answering, the conversation communication is established, and at the end of the conversation, everything returns to the normal state.



   Now assume that subscriber 11 calls subscriber 12 and the second battery supply group G2 is busy, being used for another call. In this case the trip relay RL2 will be energized and consequently when the contact 81 is closed @@@ # and the changeover relay CH 1 returns to inertia, a circuit will be established, for .The ALS relay as follows: earth, contact 40, contact 78, contact 79, conductor 80, contact 81, conductor 82, contact 83, conductor 84, contact 231, conductor 232, ALS relay to the

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 drums.

   The ILS relay is energized in this circuit and establishes @ circuit: blocking for itself in contact 233; at the same time it opens contacts 48 and 51 and closes contacts 234 and 235. To contacts 47 and 234, it connects the central office conductor 43 on earth and to the contacts
52 and 235, it connects the conductor of office 44 on the resistor 236 to the battery;

   at the same time at contact 51, it disconnects relay BB1 and consequently the battery continues to be supplied to the main office by the driver 44 who is thus occupied, but since the selector in the main office has only reached the first notch , which is deadlock, no other switch kicks in and only conductors 43 and 44 and the related switches in the main office are all busy and unreachable for further calls. Note that contact 49 is isolated from the pulse supply circuit at contact 48, so that the next series of pulses cannot produce any new pulses at the main office.

   The ALS relay at contact 237 also establishes the following circuit: earth, contact 40, contact 238, upper winding of relay FD, contact 237, conductor 240 'contact 239 of relay CRI, contact 218, contact 68 due to FRA relay, contact 69 from relay FRC, relay FRC, contacts 62,63,64.65,66y relay CR 1 to the battery. Currently the FD relay cannot be energized because its winding is short-circuited on the conductor 218 and the contact 67 of the ACHI relay.

   However, the ACH1 relay will very soon become inert due to its slowness, its circuit being open at contact 70, following the return to inertia of the CHI relay which means that contact 67 is possibly open and that the exciter circuit crossing the winding

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 higher of the FD relay becomes effective. Relay FD activates, locks energized at contact 241 and opens contact 238. Opening contact 238 opens the circuit of relays FRC and CR1, thus rendering them inert, so that the relays loggers return to their normal state, ready to receive the new sets of pulses.

   The FD relay at contact 75 prepares a blocking circuit for the relay
ACHI: at contopat 563 it prepares the occupancy signal circuit over conductor 159, and at contact 242 it prepares the test circuit as will be described later.



   It will be noted that the BB1 relay becomes inert when the ALS relay is energized following the opening of the contacts 48 and 51 and as a result, a contact is established for the BBC1 relay over the contacts 243 and 244. , the BBC1 relay, the 245 resistance to the battery. The relay BBC1 by energizing in this circuit opens the contacts 246, 247 248 and 249 so as to prevent any disturbance of the existing connections which can be used when the following series of pulses are transmitted, and it will be seen that the re - the BBCI remains excited throughout the series of pulses.



  The return to inertia of the BB1 relay after the number 1 has been marked on the dial, simply maintains the excitement of BBC1. Everything is now ready for the indication on the dial of the second digit, which in this case consists of two pulses. The LRO relay responds and opens the contact 49, which however has no effect following the opening of the contact 48 It also temporarily opens the contacts 34 and 41, but this has no effect, in the first phase. due to the slowness of the RLI relay, in the second case due to the contacts 77 and 42 being open, However a circuit is closed on the contact 57

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 for relay CH1 as follows:

   earth, contact 40, contact 57, contact 58, contact 71, contact 72, CH1 relay to the battery. The CHI relay is energized and in the contact 73 establishes a blocking circuit for itself, independently of the contacts 71 and 72. In the contact 70 the relay establishes a circuit on CHI as it was established previously for the relay
ACHI, from earth to contact 40, contact 70, ACHI relay to the battery, while in contact 250 a circuit is prepared for the BRI relay as follows: battery, BRI relay, contact 250, contact 242, conductor test 243, which is successively connected to test conductors T11, T12 etcs since the CRI CRE relays are energized.

   ACHI relay f closes contact 67 and terminates a blocking circuit for itself in contact 74 as follows: earth, contact 40, contact 75w of relay FD, contact 74, ACH1 relay to the battery. The ACHI relay opens the contact 72 which consequently prevents the CHI relay from energizing again after it has once lost its excitation, although naturally it is blocked energized during the whole series of pulses, on the contact 73. The pulse conductor is also connected by contact 73 to conductor 59, passing through contact 60, contact 61 to energize the FRC relay and thence through contacts 62, 63y 64, 65 and 66 to energize the relay. CRI relay.

   The FRC and CRI relays are energized in this cir- Suit and the FRC relay is blocked energized in the circuit: earth, contact 40 contact 57, conductor 218, contact 68, contact 69, FRC relay, contacts 62, 63,64.65 and 66, CRI relay to the battery. At the end of the first pulse, the LRO relay is energized again and closes contact 41 establishing a circuit for the FRB relay as follows: earth, contact

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40, contact 41, contact 76, conductor 219, contact 77, lower winding of the FRB relay to the battery.

   The FRB relay is energized, opens contact 60 and closes the contact
220 and, in contact 231, completes a blocking circuit for its i nf er ieur movement. The following operation occurs when the LRO relay becomes inert during the second pulse, when the following circuit is established: earth, contact 40, contact 67, contact 58, contact 73, relay
CHI to the battery, thus keeping the CHI relay energized, while branching is established on the conductor
59, contact 220, contact 221, FRA relay contacts 222, 223 and 224, CR2 relay to the battery.

   The FRA relay energizes and opens the contact 68 thus forcing the FRC and CRI relays to become inert; in contact 230 a circuit is established for the upper winding of the relay FRB, which thus remains actuated independently of the contact 77 which opens when the relay FRC becomes inert. Relay CR2 also energizes and opens contact 66, disconnecting the CRI relay again, and prepares a circuit on 226 for the CRS relay,
Relay FR5 is blocked when energized in the following circuit: earth, contact 40, contact 67, conductor 218, contact 251 (the FRC relay having become inert) contact 252, relay TRUE contacts 222,223,224,225 relay CR2 to the battery.



  The FRA and CR2 relays are therefore kept energized and as this is the final pulse of the series, a test is made to ascertain whether the called line is busy or not. Assuming that the called line is busy, there will be grounding of conductor T12 as described previously.



  A circuit for the BRI occupancy relay will therefore be established as follows: earth on conductor T12, contact 253 con- -

  <Desc / Clms Page number 22>

 driver 243, contact 242, contact 250, BRI relay to the battery. The BRI relay is therefore energized and blocked when energized in the following circuit: earth on the contact
40, contact 254, contact 255, BRI relay to battery; this circuit being established when the CHI relay becomes inert at the end of the series of pulses, the BRI relay earths the conductor actuate the occupancy signal 160, which gives the occupancy signal through the conductor 159 and contact 563 of relay FD as will be described later.



   The busy signal passes through capacitor 256 to conversation conductor A from where it passes through contact 32 of the OTSII relay to the calling subscriber's apparatus, and informs him that the number it request is busy. The subscriber then hung up his receiver, thus producing the inertia of LRO which in turn causes the return to inertia of the relay RL1, and the opening of contact 40, after which the ALS relays , OS, CHIE FD, BRI in BBC1 become inert; the FRA and CR2 relays also become inert;

   It should be noted that FRB had become inert at the end of the second pulse, its blocking circuit on the lower winding having been opened at contact 77 when the FRC relay had been energized and its exciter circuit on. the upper winding, opening on contact 57 when. that the LRO line relay had been energized at the end of the second pulse. The earthing of the conductor 55 permantt to the opening of the contact 40 produces the release of the OTSII relay while the opening of the contacts 37 and 39 allows the COII relay to become inert; everything is now established in the normal state and can be used by another

  <Desc / Clms Page number 23>

 subscriber.

   However, if the called subscriber was (free, the return to inertia of the CHI relay would establish a circuit as follows; earth, contact 40, relay RR1, contact 257, contact 242 conductor 243, contact 253, test conductor T12, relay C012 to battery Relay RR1 and switch relay CO12 energize in this circuit Relay RR1 at contact 565 short-circuits the lower winding of relay BB1 to battery; this delays the operation of relay BB1 and makes it insensitive to alternating currents.



  At the same time, the upper winding of relay BB1 is shunted over resistor 263 to aid in the above effect. Relay RR1 further opens contact 224, thus allowing relay BBC1 to switch on. become inert again, it closes contact 258, completing a circuit of earth and contact 40 through contact 443, contact 258, the upper winding of relay RR1 to conductor 157 which is connected to the battery.

   The ringing relay RR1 is therefore oblique excited, and at the same time the ringing current returns through the conductor 161 which passes over the contact 259, the contact 247 to the conversation conductor B, the contact 260, the conductor. B12 through the bell to subscriber station N 12, return via conductor A12, contaer 261, contact 248, contact 262, and resistor 263 to earth.

   When the BBC1 relay returns to inertia, the lower winding of the ringer relay RR1 the subscriber's ringtone rings and when he picks up his receiver to respond to a circuit for the BBl relay established as follows: earth , upper coil of relay BB1, contact 248, contact 261. conductor A12, line to a subscriber station,

  <Desc / Clms Page number 24>

 conductor B12, contact 260, contact 247, contact 259 to the battery on conductor 161. Consequently, the BB1 relay is energized, opens contact 443 to open the blocking circuit of the upper winding of relay RR1 which produces the inertia of this relay. The BB1 relay also closes contacts 265 and 266 which establishes a talk circuit on the talk conductors A and B.



  In contact 267 the circuit of relay BBC1 is open to prevent any relay from being energized again if the called subscriber hangs up first, because in this case relay BB1 would be triggered and would complete the original exciter circuit for le Bêlais * 'BBCI; this is not desirable because the trigger must always be under the control of the calling subscriber. When the subscribers have finished their conversation and the calling subscriber hangs up his receiver, a triggering occurs roughly as described above, the only difference in this case being: when the busy signal is received the BR1 relay does not need to be made inert any more than the BBCI relay, but apart from that the RL1, ALS, ACHI and FD relays become inert again
 EMI24.1
 which as before.

   The BB relay is used to supply the battery to the wire of the called subscriber, becomes inert again either because the called subscriber hangs up, if he hangs up first, or because contacts 261 and 260 are ,, open when the CR2 relay returns to inertia so that the battery supply group G! is reset to its normal state regardless of the hooking up of the receiver by the called subscriber.

  <Desc / Clms Page number 25>

 



   The next aas to consider is that when the subscriber
N 11 tries to call subscriber n 12, the first battery power supply group G1 is already in use for another call. In this case, when the line relay Lll operates there will be no circuit to energize the CTS11 relay. The exciter circuit of the relay CTS11, as we said previously, crosses the contact 23, which is now open since the relay RLI is actuated, the relay RL1 being actuated all the time that the power supply group Gl is employee.

   Consequently, the following circuit will be established for the LTS 11 relay: earth, contact 27 of the FLS relay in the battery supply group G2, contact 28 of the IS relay, resistor 29, contact 30, contact 31 , lower winding of relay LTS11 towards the battery. Relay LTS11 energizes in the circuit and closes a blocking circuit for itself on contact 97, this blocking circuit acting when relay RL2 is energized, as will be described later. During operation of relay LTSII, it opens contact 26 so as to prevent the excitation of relay CTS11 in the event that the battery supply group Gl becomes free, closes contacts 92 and 93. thus connecting relay IRL to subscriber thread.

   Then relay LRL energizes and, in contact 94 completes a circuit for relay; RL2 as follows: earth, contact 268 of relay SRI, contact 269 of relay IS, contact 94, relay RL2 to the battery. As a result, relay RL2 energizes and establishes a blocking circuit for relay LTSII as follows: earth, contact 95 upper coil of relay LTS11, contact 97, relay 0011 to the battery. The CO11 relay energizes, disconnects the Lll relay and the earth at contacts 22 and 21 respectively and is kept energized during the entire connection.

  <Desc / Clms Page number 26>

 



   Relay L11 becomes inert and opens contacts 25 and 3v so as to open the original exciter circuit for the ra. But LTS11, relay RL2 closes contact 21 establishing a circuit between conductors 232 and 84 thus preventing a friendly call from being made to group G2 as long as RL2 is energized. Likewise, it will be noted that IS cannot be excited by its upper winding as long as
RL2 is excited. Relay RL2 at contact 162 connects earth to conductor 158 so that, as described later, everything is prepared to start charging battery II also closes contact 98 to allow transmission of pulses.

   Subscriber 11 then actuated his pulse transmitter to send a pulse train consisting of a single pulse. As a result, the relay IRL becomes inert, and a circuit is established as follows: earth, contact 98, contact 99, contact 100, contact 101, contact 102, contact 103, relay SRC, contacts 104,105, 106, 107 -and 108 from the SRO, SR8, SR6, SR4 and SR2 relays to the SRI relay and the battery respectively. The SR1 and SRC relays are therefore energized and blocked when energized on the following circuit: earth, contact 95, contact 111, contact 112, contact 109, SRC relay, 104,105,106, 107net 108 contacts, SRI relay to the battery.

   In a branch of the pulse circuit, extending from earth, contact 98, contact 99, contact 100, contact 101, relay CH2 to the battery. The CH2 relay energizes and establishes the following circuit for the ACH2 telais: earth, contact 95, contact 110, relay ACH2 to the battery.



  ACH2 relay energizes in the circuit and closes contact 111

  <Desc / Clms Page number 27>

 thus preparing a blocking circuit for the SRC and SRI relays as described above. To the. end of the pulse, the LRL relay is energized again and a circuit is established as follows: earth contact 98, contact 123, contact 124, contact 625, lower winding of the SRB relay to the battery: the relay SRB energizes and closes contact 133 to complete a blocking circuit for its lower winding and also closes contact 125 and opens contact 102. However, as there are no more pulses in the series, the exci - t at ion of the SRB relay does not trigger any operation resulting from the closing of this contact.

   After a short installation, as there are no more pulses, the CH2 relay becomes inert and after another short installation the ACH2 relay also becomes inert. It will be seen that when this occurs, the circuit for relay RL2 is opened at contact 268, due to the energization of relay SRI, and in contact 270 as a result of energization of relay ACH2. Consequently, relay RL2 acts in the following circuit:

   earth, lower winding of relay IS, contact 94. relay RL2 to battery, Relate IS is energized in this circuit, opens contact 269 to prevent its lower winding from energizing again either by relay ACH2 or by the SRI relay and opens contact 28 and closes contact 86, - which have no noticeable effect in this particular example, - and closes contact 137. When relay ACH2 loses its excitation, contact 111 is opened and opens the blocking circuit of relays SRC and SR1. Consequently these relays become inert and contact 268 closes. However, this has no effect on shorting the lower winding of IS, contact 269 being open.

   When the SRC relay becomes inert, contact 625 is opened and consequently SRB becomes inert and the recorder returns to normal.

  <Desc / Clms Page number 28>

 



   Everything is now ready for the transmission of the next digit which consists of two pulses. The first pulse produces the inertia of the IRL relay and a known circuit is established as follows: earth, contact 98, contact 99, contact 100 contact 101, contact 102, contact 103, SRC relay, contacts 104,105,106,107 and 108, SRI relay to the battery. Consequently, the SRC and SRI relays are energized as before, SRC at contact 109 establishing a blocking circuit for itself on contact 101, relays CH2 and
ACH2 also being excited as described above. However, the ACH2 relay is now blocked energized when it energizes in the following circuit: earth, contact 95, contact 142, contact 147, contact 146, ACH2 relay to the battery.

   The test circuit is now established for relay BR2 as follows: battery, relay BR2, contact 138, contact 137, contact 136, conductor 135, contact 134 to test conductor T11, Relay BR2 is energized, but this is only for the duration of the first pulse. At the end of the first pulse, the LR relay energizes again and the contact 124 closes, so that the BRB relay is energized in a circuit already described. When the LRL relay becomes inert at the start of the second pulse, a circuit is established for the SRA relay, namely: earth, contact 95, contact 1111 c have act 213, contact 131, relay SRA contacts 127,128,129, 130, relay SR2 to battery..



  The SRA relay at contact 132, establishes a circuit for the upper coil of the SRB relay independent of contact 625 so that the SRB relay remains energized in the following circuit: earth, contact 98, contact 123, contact 101

  <Desc / Clms Page number 29>

 contact 133, contact 132 ,. upper relay winding
SRB to the battery. This circuit therefore only lasts during the second pulse and as soon as this pulse ceases the SRA relay becomes inert. If the called subscriber n 12 was busy at the moment, a circuit for the BR2 relay would be established as follows: earth on the T12 conductor contact 141, conductor 135, contact 136, contact 137, contact 138, relay
BR2 to the battery. Consequently, relay BR2 would be energized when the pulse ceased.

   When relay CH2 returns inertia resulting from it no longer receiving a pulse, relay BR2 would block energized in the following circuit: earth, contact 95, contact 142, contact
140, contact 143, relay BR2 to the battery. Relay BR2 by closing contact 139 and thus grounding contact 160 would activate the occupancy signal system, which would give the occupancy signal through conductor 159, capacitor 209, capacitor 210, the contact 93, to the calling subscriber n 11, thus indicating to him that the subscriber he wants is busy with another call.

   May if subscriber 12 is free, relay BB2 will not energize and when relay CH2 becomes inert as described, the following circuit will be established: earth, contact 95, contact 145, lower coil of the relay RR2, contact 137 contact 136, conductor 135, contact 141, conductor T12, switch relay C012 to the battery.

   The relays C012 and RR2 are therefore energized in this circuit; relay C012 interrupts line relay L12 and cuts the earth conductors leading to subscriber station 12, while relay RR2 opens contact 114, thus opening the exciter circuit of relay BBC2 which was established as follows when relay RL2 was energized: earth, contacr 95, contact 315, contact 114, relay BBC2, resistor

  <Desc / Clms Page number 30>

 this 113- towards the. drums. The relay BR2 short -circuts across contact 564, the lower winding of relay BB2 towards the battery, and at contact 154 it shunts the upper winding of relay BB2 to earth over resistor 155 This considerably delays the operation of the BB2 relay and makes it insensitive to native aliei currents.

   The inertia feedback of the BBC2 relay for -circuit
21 'lower winding of relay ER2 at contact 148, but this does not become inert because it is blocked energized in the following circuit: earth contact 95, contact 315, contact 149, upper winding of relay RR2 towards battery on conductor 151. Completion of this circuit, as will be seen later, results in the alternating current being connected in series with the battery for conductor 161 so that it establishes a known ringing circuit follows:

   battery, ringing contributor on conductor 181, centact 150, conductor 151, contact 115, contact 5? conductor B12, subscriber's wire and subscriber station 12 through the. ringing of this station, conductor A12 contact 153, conductor 121, contact 117, conductor 156 contact 154, resistor 155 on earth, slum only circuit; derivative extends to earth through the top winding of relay BB2. The ringing continues until the called subscriber picks up his receiver and closes the conversation leads, after which a battery circuit is established through the windings of the relay BB2, producing the excitation of this relay.

   In contact 315 of this relay, the circuit of the upper winding of relay RR2 is opened, thus producing the inertia of this relay, since its lower winding is short-circuited in contact 148. In contact 214. relay BB2 opens the circuit in which the

  <Desc / Clms Page number 31>

 BBC2 relay is bypassed during the ringing period.



   It closes the contacts 207 and 209, switching off the capacitor 208 and completing the conversation line, the battery being supplied at the subscriber called by the windings of the relay BB2. When the subscribers have finished the conversation, the calling subscriber replaces his receiver and thus allows the LRL relay to become inert again. This is followed by the inertia of relay RL2 which in turn opens the circuit of relays CH2 and ACH2. The ACH2 relay opens the 111 contact which produces the inertia of the SR1 and SR2 relays. On becoming inert, relay SR2 opens contacts 152 and 153, allowing relay BB2 to become inert and opening contact 141 and allowing relay C012 to become inert. Everything goes back to normal summer *.

   It should be noted that the triggering is roughly similar in the case where the calling subscriber hangs up after receiving the busy signal. It will be noted that this description is essentially identical to the description of the first arrangement in which the subscriber, after having marked the first number on the dial, one is switched to the second group G2, except that in this case the recording at dial of the number one as the first number, is necessary to actuate the relay IS and to bring the battery supply group G2 to the same state that would have been produced by the original excitation of IS on the group Gl.



   It would be appropriate to consider here the case where the first group Gl is busy but subscriber 11 requests a number from the main office. When it starts to connect, it is switched to group G2 in exactly the same way as described when it wants the common! this ion with subscriber 11, and that the group

  <Desc / Clms Page number 32>

 
G1 was occupied, but in this case the first digit no longer consists of a single pulse, but of a number greater than one, for example four In this case the first pulse produces exactly the same operations as those described previously know that in the absence of the pulse the SRI and SRC relays are energized,

   the CH2 and ACH2 relays are energized and remain energized throughout the sending of pulses, while the SRB relay is energized at the end of the first pulse. At the beginning of the second pulse, a circuit is established as follows: earth, contact 98, contact 123 contact
101, contact 125, contact 126, celais SRA, contacts 127,
128, 129 and 130, SR2 relay to the battery. The SRA and SR2 relays are energized in this circuit, the SRA relay opens the 11A contact thus allowing the SRC and SRI relays to become inert. Relay SR2 in contact 108, opens the circuit of relay SRI and in contact 271 connects relay SR3 in its place.

   The SRA relay establishes a blocking circuit for itself, namely: earth, contact 111, contact 213, contact 131, SRA relay contacts 127,128, 129,130, relay SR2 to the battery. In contact 132 the relay SRA completes a circuit for the upper winding of the relay SRB, contact 101, contact 123, contact 98 on earth for the du. reed of the second pulse, while in contact 272 a circuit is open for relay BR2 as follows: earth, cdntact 95, contact 273, contact 272, relay BR2 to the battery. Relay BR2 is energized and blocks when energized in the following circuit: earth, contact 95, contact 273, contact 274, relay BR2 to the battery. Consequently, relay BR2 remains energized regardless of the number of pulses given by

  <Desc / Clms Page number 33>

 the dial.

   However, the subscriber must not listen to the busy signal, since his calling device is still in operation. When relay BR2 is energized, it opens contact 99. When the. second pulse, the SRB relay becomes inert following the opening of the contact 101, and opens the blocking circuit of the SRA and SR2 relays. At the start of the third pulse, the SRC and SR3 relays are energized in the same way as the SRC and SRI relays were energized by the first pulse. The SRC relay opens the circuit of the SR3 relay. ? This SRA relay does not energize and the SRC relay is blocked energized by contacts 109 and 112 in the same circuit as during the first pulse.



  When the third pulse ceases, relay SRB is energized by contact 625 and its lower winding, and at the start of the fourth pulse, relay SRA and relay SR4 which is now connected to contact 275 at the link u of the relay. SR2, is energized, and the relays SRC and SR3 become inert. At the end of the fourth pulse, the SRB relay becomes inert and after an installation, the CH2 relay becomes inert and opens the contact 123.

   After a short installation the ACH2 relay becomes inert and opens the contact 111 whereby the SRA and SR4 relays become inert and consequently all the relays are brought to the normal state. The ahone can continue to write numbers on the dial without listening to the busy signal, but that. has no effect since contact 99 is open, so that the first impulse cannot pass to the counting relays through the circuit: earth, contact 98, contact 99, contact 100, contact 101 contact 102, contact 103, SRC relay,

  <Desc / Clms Page number 34>

 contacts 104,105, 106 107 and 108 to the SRI relay and to the battery.

   It is evident therefore that no
 EMI34.1
 and impulse can no longer be effective, which means that whoever picks up his receiver he hears the docct5 $ tion signal which was connected by the occupancy relay BR2 connecting the earth to contact 139 with conductor 160 and receiving the 'oc cupat i on signal returned by conductor 159, capacitor 208, capacitor 210, contact 93 to its station through the subscriber line circuit. He then knows that he cannot get the numer he wants and hangs up his receiver, after which the relay IRL and LR2 in turn become inert and allow the relays BR2 and
BBACA and BB2 to become inert again, LTSII relays and the relay
COII also being rendered inert as described above.



   Note that when the RLI relay or the RL2 relay feels energized, the earth is connected to conductor 158 leading to the RBC relay group for buzzer, busy signal, and charging, shown in fig. 7. . Relay RL1 produces this result by closing contact 36, while relay RL2 cooperates with it by closing contact 162.



  When this occurs the CH relay is energized, the CH relay closes contact 163, and establishes a circuit for the DC relay which then completes a blocking circuit for itself on contacts 165 / and 168.



   But nothing more happens until the contactor 158 is no longer on earth after which the CH relay becomes inert and together with the CC relay establishes a circuit for the MR relay on the contacts 166 and 164.

  <Desc / Clms Page number 35>

 



   Thereafter, the MR relay is energized and remains energized until the load conductor 158 is re-connected to earth following a call from a subscriber, after which the contact 164 is opened and the MR relay becomes inert, or until the high voltage relay HVR whose circuit is closed on contact 167 of the MR relay is energized. This high voltage relay is a relay which is only energized when the battery voltage reaches a set voltage above normal while the battery is charging, so it cannot be switched on. 'excite that when the.

   battery is sufficiently charged and in this case it opens contact 168, thus opening the blocking circuit for the DC relay which in turn opens the circuit for the MR relay. It will thus be appreciated that in neither of the two cases, that is to say when a subscriber is called or when the battery is fully charged, does not charge the battery. This arrangement has the advantage that loading never occurs while a. conversation is initiated, while at the same time the battery is kept fully charged between conversations. The purpose of the MR relay, as we have already indicated, is to start charging and we will give a brief description of the charging device.



   We will first assume that there is a DC power source available. In this case, fuses Dl and D2 will be placed and the charging circuit is established as follows: positive blade of the energy source connected to conductor 170, contact 171, fuse d2, conductor 172y coil of delay 173 towards the pole

  <Desc / Clms Page number 36>

 positive of the battery, while the negative blade of the battery is connected by the fuse dl to the conductor 174, to the contact 175 and axis; conductor 176 connected to the negative pole of the energy source. However, if the local source of energy is alternating current, it is necessary to provide a current rectifier, which is obtained by the polarized relay PR.



   Note that when the MR relay is energized, it closes contact 169, establishing a circuit for the relay.
PR as follows: earth, battery, resistor 177, contact 169, lower windings of the PR polarized relay on earth. These windings do not produce any operation of the relay by themselves, but simply serve as polarizing windings. another circuit is established as follows; conductor 170, capacitor 178, contact 17 ', upper windings to polarized relay PR, contact 180 to conductor 176.

   Therefore the alternating current passes through these windings and forces the armature of the polarized relay to alternately close the contacts 181 and 182 according to the frequency of the alternating current. The current 181 is currently inactive, but the contact 182 directly connects the earth through the contact 183 of the MR relay and the low voltage winding L of the transformer, to the negative pole of the power plant battery.

   Under these conditions, that is to say, when charging with alternating current, the * cartridges- * ': dl and are removed. The high voltage winding H of the transformer is then connected directly through the conductors 170, 176 of the energy source,

  <Desc / Clms Page number 37>

 on contacts 171 and 184 respectively. This produces the generation of an alternating current of the same frequency and of an appropriate voltage, in the low voltage winding.
L of the transformer. Normally, this would simply serve to ensure the passage of alternating current through the battery.

   However, not a suitable arrangement of the windings of the relay PR, the contact 182 is only closed for a half cycle, that is to say the half cycle during which the direction of the current is such as to charge the battery; during the other half cycle, contact 182 is open and therefore no charge occurs. The result is therefore efficient battery charging.



   It will also be noted that when the BRI relay or the BR @ relay is energized, the earth is connected by contacts 185 and 139 respectively to the conductor for setting in motion the occupancy signal 160. This has the effect of exciting the relay 13 on contact 186 of relay RB. This relay 13 is energized and closes contact 187 lice energizes relay 112 Relay 112 is energized and closes on contact 188 a circuit for relay 11 while on contact 189 an earth circuit is established on the conductor 160 via contact 189 to the LV occupancy signal relay, resistor 190 to the battery.

   The LV relay is energized and, by closing its contact 191, is short-circuited so that it immediately becomes inert and re-energizes intermittently, thus producing the intermittent charge and discharge of the condensate, eur 192 and sending a sound through the conductor 159. The relay 11 when energized, closes the contact 193 in parallel with the contact 189 and at the same time closes the contact 194. The contact 194 completes a short-

  <Desc / Clms Page number 38>

 circuit by relay 113, resistor 195 preventing the battery from being switched on, Consequently relay 13 becomes inert after an interval and, as it is slow to act, and is made slower still by the short - circuit of its windings.

   By tripping, it opens contact 187 which opens at contact 196 the winding of relay 12 in order to short-circuit it, as switching springs are provided to make this short-circuit effective in order to reduce the time the relay trips. 12 a resistor 197 is provided to prevent the battery from being connected directly to earth. Likewise, the relay
12 when it trips, opens contact 188 and closes contact 198, which bypasses relay 11. Resistor 199 is provided for the same purpose as resistor 197, that is to say to prevent shorting. circuiting the. battery while contacts 188 and 198 are momentarily closed.

   For a moment the contacts 199 and 193 are open and the intermittent operation of the LV relay ceases, thus giving an interruption in the busy signal, but as soon as the contact 194 opens again, the relay 13 is energized and produces the re-energization of relay 12, which in turn produces re-energization of relay 11, after which the relays successively become inert, as stated previously and consequently the busy signal is given intermittently, the cycle of operation of relays 11 12 and 13 continuing as long as the earth is connected to the start conductor of the busy signal 160.

  <Desc / Clms Page number 39>

 



  It will be seen that the earthing of the start conductor of the busy signal 160 produces the intermittent connection of a busy signaling current with the conductor 159 which is insulated from all the batteries and the devices. to earth through capacitor 192.



   We will notice that each time one of the RR! or RR2 is energized, the upper winding of these relays is connected to conductor 167 which passes through the bell relay RB to the battery. Each time this occurs, relay RB is energized and established in contact 200 a circuit for relay 13 which in turn causes the work of relay 12 and 11 in the manner described above.

   Therefore this relay works intermittently and, although the closing of contacts 189 and 193 is. without effect due to the fact that the conductor actuating the occupancy signal 160 is not on earth, the contact 201 is open and closed intermittently, and at the same time the contact 202 of the relay RB completes a circuit on the contact 203 through the upper windings of the PR relays, the contacts 204 and 205 of the MR relay, and resistor 177, to the battery. Therefore the active windings act in one direction for grounding on the contact 181 to short-circuit the active winding of the polarized relay, which relay therefore acts to open the contact 181, removing the short circuit, and by therefore the polarized relay gets energized again.

   The oscillation of its armature produces an intermittent closure of contact 182, which means that the office battery is permanently connected in series with the low voltage winding L of the transformer, the direct current must pass intermittently to through one-

  <Desc / Clms Page number 40>

 bearing L through contacts 182 and 201. this produces an alternating current in series with the battery transmitted through contact 206 to conductor 161 of the generator which is connected to the conversation conductors whenever relays RR1 or RR @ are actuated; this current is intermittent depending on whether the contact 201 is open or closed.

   A variant of an arrangement for generating a ringing current by the office battery is shown in fig. 8 and although this arrangement is described for the ringing only, it is evident that by employing a switching relay ap - property such as MR one could easily apply it to loading. However, it will be sufficient to understand the operation by the simple description from the point of view of the generation of the ringing current. When contact 202 is closed, a circuit is established for relay PR as follows: earth, contact 202, lower winding of the polarized relay PR to the battery. The polarized windings of PR are energized in this circuit.

   The active windings are excited in this following circuit: earth, contact 202, contact 403, resistor 412 actuating the windings of the PR relay. windings 404 from transformer to battery. At the same time, it will be noted that a branch circuit passes through the winding 405 to the battery so that more current flows through the winding 406 than through the winding 404.

   However, the current flowing through 404 is sufficient for the polarized relay to act on its armature and close the contact of said 406, after which a circuit is established for the relay 407 as follows: earth, contact 202, contact 406, contact 408 relay 407 to battery. Relay 407 is energized and is blocked energized by the

  <Desc / Clms Page number 41>

 contact 409 and earth on contact 202, simultaneously opening contact 403 and closing contact 410. Closing contact 406, as will be seen, grounds through contact 410 the right side of winding 404.

   As a consequence, current passes from le. battery for the left winding 405, the upper windings of the polarized relay PR, the contact 410 the contact 406 and the contact 202 to earth. This is equivalent to saying that a reduced current passes through winding 405 and a current in the opposite direction passes through the upper windings while at the same time through the. direct grounding of the right-hand winding 404, a reinforced current flows through this winding. Strengthening current 404 and decreasing current 405 mutually result in their inducing effect on the secondary coil SC.

   The PR bias relay, acting in this reverse direction, closes contact 411 thereby grounding through contact 202 the left side of the top windings of the bias relay and thereby increasing the current through winding 405. , decreasing the current through 404 and reversing the current through the windings of the PR bias relay. This reversal produces a new operation of the armature and in this way a very efficient generation of alternating current is obtained which is created in the secondary coil SC connected to the ringing circuit where it can be used at the time. wanted by the calling subscriber to ring the subscriber he wants.



   We will now describe communication with the main office. We will assume again that the two groups of battery power are free and that the subscriber hangs on the group Gl in the same way as described previously, but in the present case, as the call is made to a main office, the preferred series of impulses

  <Desc / Clms Page number 42>

 sions recorded on the dial do not consist of an impulse, but a larger number. For example, we will assume that this number is four; after the first pulse when the CRI relay has been actuated in series with the FRC relay, it is blocked energized by contacts 69 and 68, conductor 218, con ect 67 of relay ACil, contact 40 towards earth.

   As the pulse does not stop at the first digit on the dial, the CHI and ACHI relays remain actuated. At the end of the First pulse the FRB relay is energized by the contact 77 of the FRC relay and its inner winding, and at the beginning of the second pulse, the contact 57 is closed and a circuit is established as follows : earth, contact
40, contact 57, contact 58, contact 73, conductor 59, contact 220 of relay FRB, contact 221 of relay FRA, relay
ENG contacts 222,223,224,225 of relays CR9, CR7, CR5, CR3, respectively, and relay CR2 to the battery.

   The relays CR2 and FRA are energized in this circuit; the FRA relay opening contact 68 so as to force FRC and
CRI to become inert; the CRA relay being also switched off by the CR2 relay at contact 66, the CR3 relay being connected in its place to the 226 contact. The FRA relay when energized, closes the 227 contact, thus establishing a circuit for the occupancy signal relay BRI as follows: earth, contact 40, contact 228, contacts 227, relay BR1 to the battery.

   Consequently, relay BR1 is energized and is blocked energized in the circuit by contacts 229 and 228, independently of the contact.

  <Desc / Clms Page number 43>

 
227, but does not connect to the. contact 662 signed it ,! of occupation, because contact 563 of relay FD1 is open.



   Consequently, the FRB relay does not become inert when the contact 77 is open when the FRC relay is made inert, because it is kept energized by its upper winding the contact 230 of the FRA relay to earth on the conductor 59.



   At the end of the second pulse, when the conductor 59 is disconnected from earth, the FRB relay becomes inert. When the next pulse begins, a circuit is established for the FRC and CR3 relays as follows: earth, contact 40, contact 57ù contact 58, contact 73, conductor 59, contact 60, contact 61, relay FRC, contacts 62 , 63,64,65 226, relay
CR3 to the battery.

   The relays CR3 and FRC are then energized, the relay FRC, opens the contact 251, thus triggering the relays FRA and CR2, while the relay CRC opens the contact 225 and closes the contact 276, thus connecting the relay CR4. At the end of the third pulse, the FRB relay is energized in the following circuit: earth, contact 40, contact 41 contact 76, conductor 219, contact 77, lower coil of the FRB relay to the battery. At the start of the fourth pulse, a circuit is established as follows: earth, contact 57, contact 58, contact 73, conductor 59, contact 220, contact 221, relay FRA, contact s 222, 223,224,226, relay CR4 to the battery.

   The relays CR4 and FRA are blocked when excited in series by the contact 252, the contact 251, the contact 67 and the contact 40 on the earth, opening in the contact 68 the excitation circuit of the relays CR3 and FRC which thus become inert. The FRB relays being kept energized as they have been previously described for the. second impulse. As there are no more pulses, relay CH1 becomes inert after a short interval and opens contact 73; it also opens the lesson

  <Desc / Clms Page number 44>

 tact 70 and allows the ACHI relay to become inert. During this period four pulses were sent to the main office by relay LRO which opened contact 49 four times.

   Subsequent pulses are unable to actuate the counter relay because contact 71 is now open and therefore neither CH 1 nor the counter relays can be actuated again. In addition, the inertia of the ACHI relay opens the contact 67 which causes the FRA and CR4 relays to also become inert, restoring the counter relays to the normal state. The subscriber can therefore continue to send pulses to operate the switches at the main office in the ordinary manner as will be described below with reference to Figs. 9,10 and 11.

   To trigger the connection when he has finished the call at the main office, he simply hangs up his receiver, opens the LRC relay circuit which comes back inert and opens contact 49, thus releasing the switch at the main office. The LRC relay also opens the circuit of the RLI relay which becomes inert and opens the contact 40, triggering the OS, BBl and OTSII relays. As all the other relays are triggered, we will see that the group Gl is restored to its state. normal and can be used by another subscriber.



   The next operation which we will describe is that in which the subscriber of the main office desires a local subscriber. In this case, he will mark the number of the private branch office on his dial and hook a repeater to it as described by referring to figs. 9,10 and 11, whereby the battery is supplied by conductors 43 and 44 so that a circuit is established for the LRI relay as follows: battery on conductor 43, contact

  <Desc / Clms Page number 45>

 
45, relay LR1 contact 46, conductor 44 on earth at main office.

   Relay LR1 when energized, closes contact 277 thus energizing relay RL1 opens contact 58 and closes contacts 278 and 279. Relay RLl closes cents and 40 which establishes a cricuti for the relay
BBCi as follows: earth, contact 40, contact 443, contat
244, BBC1 relay, resistance 245 to the battery. Relay BBC1 is then energized and opens contacts 246,247 248,249 and 264. In contact 40 a second circuit closes as follows: earth, contact 40, contact 278, lower winding of relay FD towards the battery. Relay
FD is then energized and is blocked energized in the following circuit: from the dairy, upper winding of the FD relay contact 241, contact 241 on earth.

   In contact 563, relay D prepares the busy signal circuit.



   In contact 242 is connected a test circuit, which for the moment has no effect, contact 228 is open and contact 75 closed. The subscriber at the main office does not mark the first number on the dial, but marks the second number of a subscriber of the secondary office, for example, assuming that he wants subscriber no.12 he marks the number 2 on the dial. when the first impulse is received at the secondary office, the pattery will cease to be supplied by the conductors 43 and 44 and the relay LR1 will be energized.

   It will be established in the following circuit: earth, hcontacr 40, contact 57, contact 58, contact 71, contact 72, relay C-1 to the battery, a bypass extending to conductor 50 contact 60 of the FRB rail, contact 61, FRC relay contested 62,63,64,65 66 CR1 relay to battery. The FRC and CR1 relays are energized in this circuit and are blocked when energized by the

  <Desc / Clms Page number 46>

 conta, and 69, the contact 68, the contact 218, the contact 67 the contact 40 to the earth,: the relay CHI by energizing having previously closed retort the contact 70, which establishes a circuit 'for the ACHI relays as follows: earth, contact 40 contact 70, ACHI relay to the battery. Consequently the ACHI relay is energized and closes contact 67.

   The FRC relay also closes contact 77 so that at the end of the first pulse, when the LRI relay is energized again, the following circuit is established - earth, contact
40, contact 279, contact 219, contact 77, lower winding of the FRB relay to the battery. The FRB relay is then energized, closes contact 231 and contact 22u and opens contact 60 so that when relay LR1 is energized for the next series of 4 * pulses, the following circuit is established: earth, contact 40, contact j57 , contact
58, contact 73, conductor 59, contact 220, contact 221, relay FRA contacts 222.223,224 and 225 relays CR2 to the battery.

   The FRA and CR2 relays are then energized and the contact 68 is open thus allowing the FRC and CRI relays to become inert; contact 252 is closed so as to block the energized relays FRA and CR2, by contact 251, contact 67, and contact 40 on earth.



  The FRB relay being kept energized by its upper winding, the contact 230 of the FRA relay on the earth by the conductor 59. At the end of the second pulse the FRB relay becomes inert and shortly after, as there is no more. pulses to be received, the CHI relay becomes inert. SL "subscriber N 12 had been busy, a circuit for relay BR1 would have occurred before this as follows: earth on the conduc-

  <Desc / Clms Page number 47>

 tor T12, contact 253, contact 242, contact 250, relay BRI to the battery ,, and when relay CH1 becomes inert, a blocking circuit would be completed for Bêlais BRI as follows: earth, contact 40, contact 254, contact 255 re - leave BR1 to the battery.

   Consequently, the BRI relay relays the earth through contact 185, to conductor 160, to start the occupancy signaling device, connecting the occupancy signal through conductor 159, contact 563 of the PD relay to the contact. 562, to. through capacitor 256 and conductor A to the post of the maid called N 11. On the other hand, if the called subscriber had been free, a circuit would have been established for relay C012 as follows: earth, lower winding of relay RR1 , contact 257, contact 242, conductor 243, contact 253, test conductor T12, relay CTOL2 to battery.

   The RR relay! and the C012 relay are energized in series, the C012 relay is energized to disconnect the line relay L12 and the earth of the line of subscriber n 12 and the ringing relsi is energized to complete a circuit as follows: earth, contact 40, contact 258, contact 443, upper winding of the RR1 conductor relay 157 towards the battery passing through the relay actuating the bell circuit, so that the alternating current and the battery in series, are connected by the conductor 161, the contact 259, contact 247, contact 260, plague conductor B12 of subscriber 12, conductor A12, conductor 261, contact 248, contact 262, resistor 263 to. battery o Therefore the.

   the subscriber's bell is activated and when he lifts his receiver, a circuit is established for relay BB1, the upper winding of which is connected to a branch of the circuit which has just been

  <Desc / Clms Page number 48>

 described in resistor 263. The relay BB1 by energizing opens the contact 443 to produce the inertia of the relay RR! and at the same time to prevent the BBC1 relay from being energized when the RR relay! becomes inert. The ringing is interrupted by opening contacts 258 and
259 when relay RR1 becomes inert, contact 279 is closed to connect the lower winding of the relay
BB1.

   The BB1 relay closes contacts 265 and 266 in the conversion circuit which is established as follows: conductor 43, contact 45,, contact 280w, capacitor 281, contact
265 contact 248, contact 261, conductor A12, subscriber extension, conductor B12, contact 260, contact 247, contact
279. contact 266, capacitor 282, contact 46, conductor
44 to the main office.

   When the subscribers have finished speaking, the subscriber calling at the main office hangs up his receiver in addition to thus producing the release of the subscriber at the secondary office, he disconnects the cattery of conductors 43 and 44, producing thus the inertia of relay LR1. Relay LR1 becoming inert opens, in contact 278, the circuit of relay FD and in contact 277 the circuit of relay RL1. Relay RL1 becomes inert and opens in contact 40, the circuit of relay ACH1 which is also opened by relay FD in contact 75, so that relay ACH1 becomes inert and opens contact 67 thus allowing relays FRA and CR2 to become inert.



  Opening contacts 260 and 261 allows BB relays! to become inert, while the opening of contact 263 allows relay C012 to become inert. It will thus be seen that all the relays are now restored to the normal state and that the battery power supply group Gl is free for other calls.

  <Desc / Clms Page number 49>

 



   Of course, various modifications can be made in the counter relay arrangement shown in Fig. 4, without departing from the spirit of the invention. A variant is shown in the. fig.6, in which the FRA and FRC relays are eliminated, the functions of said relays being performed by contacts with the individual relays in the chain. The resemblance between these two figures will be obvious when it will be understood that the contacts 300,501, 302,303, and 304 are equivalent to the contact 77 of the FRC relay, the contacts 305.306,307.308 309 equivalent to the contact 230 of the FRA relay, the contacts 310 , 311.312313 contact equivalent.

   61 of the FRC relay, while the contacts 314,315,316,318, 318 are equivalent
69 to the / contact of the FRC relay, the contacts 319,320,321, 322,323 equivalent to the contact 221 of the FRA relay and the contacts 324; 325,326,327,328, equivalent to the 252 contact of the FRA relay. The other relay contacts of: figure 6 are designated by the same reference letters as in fig. 4 so that the relationship between this series of meter relay chains can be easily established.



  It will be remembered that the conductor 59 is connected to earth as soon as the line relay LRO becomes inert after the first pulse. The conductor 218 is still connected to the. earth as long as the ACHI relay is energized and conductor 219 is connected to earth between the interrupts. The conductors 80 and 82, 218 and 240 and the conductors connected by the contact 329 serve exactly the same put as the conductors bearing the same reference numbers; If: as those connected by the contact 227 of fig. 4.



   To understand how it works, we will assume that four pulses are transmitted. Immediately on

  <Desc / Clms Page number 50>

 IRO line relay becomes inert on the first pulse and a circuit is established as follows: earth on conductor 59, contact 60, Contacts 62, 63, 64, 65, 66, CRI relay to the battery. The CRI relay is energized and closes a blocking circuit for itself on contact 314 in the following circuit: earth on conductor 218, cont acts323,
313, 322, 312, 321, 311, 320, 310, 319, 314, CRI relay to battery.

   At the same time it closes the contact 300 so that at the end of the first pulse, the conductor 219 being connected to the earth, a circuit is established for the lower winding of the FRB retort relay follows: earth, conductor 219, contact 300, lower winding of the FRB relay towards. drums. The FRB relay is then energized, opens the corsa and 60 and closes the contacts 220 and
231. At the start of the next pulse, conductor 59 is grounded again, this grounding. earth extending through contacts 220, 222, 223, 224, 225, relay CR2 to the battery.

   Relay CR2 is energized, opens contact 319 thus allowing relay CRI to become inert, and completes a blocking circuit for itself as follows: earth, conductor 218, contacts 323 313,322, 312, 321, 311, 320, 310 , 324, CR2 relay to the battery. Relay CR2 opens contact 66 and closes contact 22 &; it also closes contact 305 thus completing a circuit for the upper winding of the FRB relay as follows: +. earth on the conductor 59, contact 305, upper winding of the FRB relay towards the battery.

   It will be noted that "the FRB relay is kept energized from the end of the first pulse until the beginning of the second, by its lower winding, then when the contact 300 opens after the CRI relay has been returned. inert, the FRB relay remains energized until the end of the second im

  <Desc / Clms Page number 51>

 pulse by its upper winding in the circuit described above. When the conductor 59 is removed at the end of the second pulse, this last circuit is opened and the relay FRB becomes inert, the earth connected and being the second and the third implosion to the conductor 219 having no effect. this time because all contacts 301, 302,303 and 304 are open.

   At the beginning of the third irtiptilsion, the conductor 59 is again earthed, now passing through the contacts of the primitive circuit 62, 63, 64, 65 but this time passing through the contact 226 to the relay CR3 and battery. Relay CR3 is energized, opens contact 310 to trigger relay CR2 and closes contact 315 to establish a blocking circuit for itself as follows: earth, conductor 218, contacts 323, 313, 322, 312, 321, 311, 320, 310, 315, CR3 relay to battery. Relay CR3 opens contact 225 and closes contact 276, it also closes contact 31′0 to prepare a new exciter circuit for relay FRB.

   Therefore at the end of the third pulse the conductor 219 is grounded by the contact 301, the lower winding of the FRB relay and the battery. The FRB relay is energized, opens contact 60 and closes contact 220; it also closes the contact 231 At the beginning of the fourth pulse, the conductor 59 is again earthed, this time passing as for the second pulse, through contact 220, contacts 222,223,224, but this time through contact 276 and relays CR4 to the battery.

   Relay CR4 is energized and locks energized in the following circuit: earth, conductor 218

  <Desc / Clms Page number 52>

 contacts 323,322, 312, 321, 311, 320ù 310, 325, relay CR4 turns the battery; it opens contact 320 to produce the inertia of relay CR3 and closes contact 306, thus completing a circuit for the top winding of relay FRB. The FRB relay remains energized by the earthing of the conductor 59 and becomes inert at the end of the pulse.



   It will be understood from the above how the subsequent pulses will actuate the relays CR5, CR6, CR7 and c. To trigger the counter relays so that they can then feel to return to the normal state, it is simply necessary to cut the earth of conductor 218,
So that one can understand how calls are transmitted from a subscriber from a main office to the secondary office by the TL trunk line comprising conductors 44 and 43, and also the manner in which calls are to be transmitted from a secondary office by the long distance line TL to a subscriber of the main office, we will first refer to fig. 9. The different operations will be described next ... referring to figs. 10 and 11.



   We first assume that a call arrives through conductors 43 and 44. This call arrives at the RG relay group to which a TLS trunk switch is connected. When the battery is supplied from a trunk line through the relay group, the TLS trunk switch operates to choose a first selector D at the main office; 'consequently this first selector D responds to the first series of pulses and searches for a second free selector E.

  <Desc / Clms Page number 53>

 



   This second selector E responds to the following series of pulses and then searches for a free connector F which responds to the next two series of pulses and establishes it. connection with the desired subscriber wire. Note that the operations of the first selector D, of the second selector E and of the connector F are normal, and are well known in telephony. However, the call comes from a subscriber at the main office, when the receiver is lifted, his SLS line switch will operate to choose a first free selector such as D.

   Selector D will respond to the first series of pulses entered on its dial and automatically search for a second selector E., The second selector will then respond to the next series of pulses, and as we assume that the call is for a local subscriber, it will go up to a certain level and choose a secondary SES desktop selector. The secondary office selector SES is arranged to respond to a series of pulses only and, depending on whether a trunk line chosen such as TL will be busy or not, it will either give the busy signal or transmit. calling the trunk line through the RG relay group which converts the subscriber's normal pulses to battery power pulses suitable for operating the secondary office machine.

   The last digit of the secondary office number, which contains exactly the same number of digits as a number of the main office, is then received in the manner described by the secondary office to choose the subscriber's line in this secondary office.

  <Desc / Clms Page number 54>

 longed for.



   Coming back to the freezes. 10 and 11 in which the briefly described circuits are shown, it will be appreciated that the call arriving through conductors 43 and 44, which are indicated by connecting the battery through these conductors to the main office, as has been described previously, will produce the excitation of the line relay LRE Supposedly the relay LRM is energized, closes contact 505 and completes the circuit for the triggering relay RRM.



     RRM is energized and closes contact 510 which completes a circuit as follows: battery, EST relay, contact 513, contact 510, contact 511, RTM delay relay, contact 5v7 contact 518 to earth. The LRT relay is then energized.



  The RRM relay when energized also opens contact 509, disconnects the SRM switching relay and closes the contact; 508 connecting ground to conductor 545, thereby preventing the trunk line from being taken by an SES secondary office selector. The RRM relay also closes contact 546. The LBR relay, when energized, closes contacts 520 and 544 and this completes a test circuit as follows: test contact 547 of selector D, wiper 548, contact 516, contact 544 and contact 519 , MLS magnet towards the battery.

   In the event that the selector on which the wipers 548,549 and 550 rest were occupied, earth would be connected to test contact 547 which is connected to the wiper 548 and therefore a circuit would be established for the synchronization magnet. MLS

  <Desc / Clms Page number 55>

 which will run intermittently as long as the charterer 548 touches, a contact on land. We will however assume that the first selector D is free and in this case the SRT switch relay will be energized in the following circuit: earth, contact 520, SRT relay, contact 519, MLS magnet towards. drums.

   It will be seen that the SRT relay is shorted and cannot be energized in this circuit as long as the 548 slider is grounded, so the SRT relay is only energized when a selector is encountered. free. Likewise, the resistance of the SRT relay is chosen such that the MLS magnet cannot be excited in series with it. The SRT relay is energized, leaves contacts 513 and 518 allowing the LRT relay to become inert and closes the contacts 514 and 517, thus extending the connection to the first selector D. The operation of the selectors D, E, F is well known and it is unnecessary to describe them.



  Suffice it to say that when selector D is energized, the line relay cheerfully energizes, connects the trip relay which in turn connects the earth with contact 547, thus completing a blocking circuit for the relay. STR outside of contact 520, this circuit being completed before contact 520 is opened, because relay LRT only slowly becomes inert. A circuit is then established as follows: earth, contact 547, wiper 548, contact 515, SRT relay, contacts 519. MLS magnet to the battery. The next series of pulses are received by the line relay.

   Selectors D and E are of a well-known type operating in rotation and then in a vertical direction

  <Desc / Clms Page number 56>

 so that the first series of pulses forces the rubbers of the first selector D to rise one level, according to the number of pulses in the series; after that. it automatically searches for a second selector E; the first select
D is switched off and the second selector E operates in a similar manner for the. second series of pulses, and then automatically chooses an F connector.

   Connector F differs in its operation from selectors in that not only does it respond to the third set of pulses, but also responds after the third set of pulses to the. fourth series of pulses, by its rotary movement so that these rubbers are brought to the line of the desired subscriber.

   Then the subscriber's line is tried for whether he is busy or free; if it is busy, a busy signal is given to the called subscriber *; if it is not busy, the called subscriber is rung and, when he answers, the communication is established., At the end of the conversation, the connection is triggered as a result of the card being withdrawn from the conductors 43 and 44 which allows the RRM relay to trigger and open the contact 507. The RRM relay triggers poorly, opens the contact 510 and withdraws it.

   earthing of contact 508
It is evident that any impulse received through conductors 43 and 44 allowed the LRM relay to trip and establish a circuit for the OHM switching relay as follows: earth, contact 506, contact 546 CHM relay to battery. The OHM relay is energized, opens contact 511 and closes contact 512, thus completing an independent pulse circuit of the delay relay on RTM Intermittent opening of contact 507 transmits the pulse to the line relay of the first selector and then to the second selector and the connector.

   The pulse circuit

  <Desc / Clms Page number 57>

 can therefore be indicated as follows: starting from wiper 549, contact 514, contact 510, contact 512, contact 507,, contact 517, wiper 550. As is known, the line relays of the successive switches D, E and F are connected by conductors whose wipers 549 and 550 are successively connected.



     Having thus studied the call of a secondary office, we will now study a call from a subscriber of the main office to a subscriber of the secondary office When a subscriber of a main office picks up his receiver, his switch de lagn SLS acts to choose a first free selector such as D. Its first series of pulses causes the first selector to operate in a manner similar to that which has just been described and this in turn chooses a second selector free such as E.

   Free selector E responds to the next series of pulses, in a similar fashion, but this time it is brought to a level having access to secondary office selectors such as SES (fig. 11). When the call is sent to a secondary office selector such as SES, the LRS line relay is energized by passing through the subscriber wire, closes contact 521, opens contact 522. Closing contact 521 completes a circuit for the RRS trip relay. The RRS relay is energized, closes contact 524 to connect ground to test lead 551, thus maintaining switches D, E, and SLS and at the same time protecting them against intrusion from other subscribers. The RRS relay also closes contact 525 and opens contact 526.



  As we have already said the SES switch is a single stage switch having an active OMS magnet and an RMS trigger magnet. This switch is arranged for

  <Desc / Clms Page number 58>

 respond from 1 to 10 pulses to choose a special relay group such as RG communicating with a secondary office.



   We will suppose that the subscriber wishes to communicate with the secondary office already described in figs.l to 8, that is to say that he chooses; the TL trunk line comprising the conductors 43h and 44. Consequently, the relay SES responds to the third series of pulses entered on the dial and the following operations take place.

   At the beginning of the. first pulse, the LRS relay becomes inert and the following circuit is established: earth, coptact 522, contact 525, contact
536, contact 542, active magnet OMS to the battery, while a bypass of this circuit is established as follows: earth, contact 522, contact 525, contact 536, CHS relay to the battery. The CHS relay energizes and opens contacts 527 and 529, and closes contact 528 so that a circuit can be established as follows: from test wiper 522 contact 528, contact 541, occupancy relay BRS to battery. The CES relay also closes contact 532 but this has no effect for the moment.

   The CHS relay also closes the contact 531 thus bypassing the contact 536 during the series of pulses and preventing the active circuit from being opened by the energization of the BRS relay when the wiper 552 passes over the contacts. After a series of 4 pulses has been completed and the frother 522 is in engagement with the connected contact 553. to test conductor 545 of relay group RG, relay BRS is energized if conductor 545 is earthed, that is, if relay group RG and intra-city line TL are used.

     If both are busy, the BRS relay is energized and when CHS becomes inert at the

  <Desc / Clms Page number 59>

 end of a pulse train, due to its circuit being open on contact 522, the BRS relay is blocked energized in the next circuit earth, contact 524, contact 535, contact 529 of the BHS relay contact 541 BRS relay to the battery.

   The BRS relay closes contact 533 thus linking the busy signal to the conductors in reverse.! superior ion informing the calling subscriber that he cannot communicate with the subscriber of the secondary office that he requests. He then resumes his receiver releasing the LRS relay which in turn releases the RRS relay, the two sets completing a circuit of the. earth by contact 522, contact 526 by normal closing contact 530, the RMS tripping magnet to the battery.

   The RMS trip magnet is energized and returns the sub-office selector to its normal state, the BRS circuit being opened on contact 524 at the time the previous switch train is tripped, and everything resets to. normal state.

   But if the TL trunk line is dead, no earthing is established on contact 545 and, when the CHS relay returns to inertia, the BRS relay is in its normal position. a circuit is established + as follows: earth, contact 524, contact 534, lower winding of the SRS switch relay, contact 527, wiper 552, test contact 553, conductor 545, contact 509, SRM relay, SRT relay, , switch contact 519, MLS magnet to the battery. In this circuit, the SRS, SRM and SRT relays are energized. The MLS magnet does not work in this circuit, as we have already said.

   SRT relay is energized to open contacts 518 and 513, thus disconnecting LRT relay SRM relay is energized and opens contacts 501 and 504, thus disconnecting LRM line relay, and it closes contacts 502

  <Desc / Clms Page number 60>

 and 503 so as to connect the conductors 43 and 44 of the trunk line TL to the conductors 554 and 555 respectively. The SRS relay when energized, closes contact 540 thus completing a blocking circuit for itself as follows:

   earth, contact 524, contact 540, upper winding of the SRS relay to the battery and at the same time it closes contact 539, bypassing its lower winding and establishing, an earth potential on the test wiper 552 and therefore on test lead 545 so as to protect it against
The intrusion of other subscribers.

   The SRS relay opens contact 542, thus preventing the continuation of the OMS magnet and it closes contacts 537 to 538, which causes the battery to be supplied by the TL trunk line to the selector of the secondary office in the following circuit: battery, upper winding of the feedback bridge relay
BBS, contact 537, wiper 556;: tale, and 557, conductor 554 conductor 502, conductor 43, contact 45, via line relay LR1, contact 46, conductor 44, contact 503, conductor 555, contact 558, wiper 559, contact 538, contact 523, lower winding of the BBS relay to earth.



   The LR1 line relay at the secondary office is energized in this circuit. It is not necessary that we give in detail the subsequent operations of LR1 as they have already been described, but we will describe the transmission of
1'3. next series of pulses.



   It will be noted that when LRs becomes inert, it opens the contact 523 thus opening the loop circuit for the relay LR1 as described previously, and allowing

  <Desc / Clms Page number 61>

 the LRI relay to become inert and to repeat the pulses in the manner already described e. The LRS relay also completes a circuit for the CHS relay as follows: earth contact 522, contact 525, contact 536, CHS relay to battery.

   The CES relay closes the contact 532, thus circulating the lower winding of the BBS glow to improve the impudiator circuit; further pulses are received in the same manner as described above, and the connection is established with the line of the desired subscriber. As we have already described, if the requested line is busy, a / busy signal is connected to the. trunk line, so that the subscriber (calling party hears the signal and hangs up his receiver. If the line is unoccupied, the called subscriber is rung and the following: payment takes place; when the transfer is finished , the calling and called subscribers hang up their receiver.

   In both cases when the calling subscriber hangs up his repeater, the LRS relay becomes inert, opens contacts 521 and 523. By opening contact 523 it allows the LRL relay of the secondary office to become inert, while in contact 521 opens a circuit for the RRS relay. The RRS relay becomes inert, opens contact 524 to allow switches D and E and the subscriber line SLS switch to return to the normal state, and it opens the interlock circuit of the subscriber. upper bearing of the SRS relay.

   The SRS relay then becomes inert. The RRS relay also closes contact 526, thus completing a circuit for the RMS tripping magnet, from earth to contact 522, contact 526, standard contact: .- open element 530, RMS tripping magnet to the bat-

  <Desc / Clms Page number 62>

 laughs. The RMS trigger magnet then operates and returns the SES selector on the secondary office to normal, and everything is now in normal state.



   It is of course understood that this invention is susceptible to considerable modifications of the circuits as described and shown. For example the invention is applicable to a small automatic private office, in which case the relay groups and the data loggers. The pulses will look roughly like the G2 relay group when removing the IS relay. In this case, of course, it would suffice to have a single digit and therefore the test would occur during the. first series of pulses instead of waiting to start, the second series of pulses, There would be no ion between the groups of relays and the busy signal would only be given after a called line would have been tried and found busy.

   It is of course possible to have more than two circuits of these versions, for example there could be three conversation circuits having a third relay such as OS. This would necessitate changes in the intercom arrangements and increase the number of contacts on the earth relay somewhat, but apart from that it will be appreciated that it can be easily arranged by all parties. technicians.



   Another variant might be necessary in certain cases where a second exchange line would be necessary; the relay groups would then be similar to G1 and again there would be no need to forward the call unless there is a third talk circuit.

  <Desc / Clms Page number 63>

 



   It is also understood that the dimensions of this system are not necessarily limited to ten lines because most of the pulse transmitters are arranged for ten lines and this number is therefore the most suitable, but either a more considerable number of lines could be made accessible to the central office with a larger capacity switch, or alternatively without increasing the capacity of the pulse transmitter, it could be disposed of so that one of the relays in the counter relay chain , or a dead relay in such a way that when if the relay would be chosen by entering a figure, it would be possible to return to the normal state, to receive other pulses on other counter relays above ten. .


    

Claims (1)

CLAIMS 1 - A telephone system comprising a secondary office having access to a main office in which certain primary lines at the secondary office give access to the. both main office subscribers and secondary office subscribers, while. that other primary lines only give access to local subscribers. 2- A telephone system comprising a central office giving access to two categories of subscribers in which certain primary lines give access to two categories of subscribers while other primary lines give access to only one category of subscribers. subscribers. 3 -a telephone system as claimed in 1 or 2 in which the primary lines giving access to the two categories of subscribers are arranged to be chosen in the first place while the primary lines giving access to only one of said categories are established to be chosen second. 4- A telephone system as claimed in 1, 2 or 3 in which selector devices are combined with the primary line giving access to the two categories of subscribers, and carry out the transmission of the call to a primary line only giving access to a category of subscribers if the call is for a subscriber of this category. 5 A telephone system as claimed in 4 in which transmission to a primary line giving access to a category only of subscribers is prevented if there is no <Desc / Clms Page number 65> no primary line available, after which switching can take place in the first primary line to enable the call to be terminated via said th line. 6 In a telephone system, a group of relays combined with a primary line giving access to two categories of subscribers and with which are combined selector devices responding to the first series of pulses entered on the dial by a subscriber calling party, which determines whether the call should "and re-transmitted to one or another category of subscribers and, depending on the category chosen, different switchings are made either to transmit the call on a route independent of the primary line or, if this route is not available, to allow the call to continue by a second route comprising the. primary line, or to allow the call to continue through a third route, also including the primary line. 7 A telephone system in which the subscriber lines are extended to primary lines by relays and in which a circuit extends from a primary line through the contacts of the relay which connects the subscriber line to the primary line to a relay arranged to connect the subscriber line to another primary primary line thus allows a call to be transmitted from one primary line to another. 8- A telephone system in which the subscriber lines are extended to primary linespsr relays in which calls can be transmitted from one primary line to another when the number of pulses in the first series generated by a calling station is of a value determined in advance. <Desc / Clms Page number 66> 9- A telephone system employing a relay train to record the pulses marked on the dial by a calling subscriber, in which the relay train is arranged to respond to a series of pulses to establish a temporary connection through the contacts of the relay cit and to be actuated by another series of pulses to establish the connections during the entire period that a relay train is in service. 10- In a telephone system employing a relay train for recording the pulses given to the dial by a calling subscriber, in which the relay train is arranged to record a series of pulses and, after being sent to the normal state, to record a second series of pulses and then establish a conversation circuit with the line of the subscriber called by the contacts of a relay in the train. 11.- A telephone system comprising a main office and a secondary office, and a double main line connecting the main office to the secondary office, in which the double main line, at its end in the secondary office ends in a group relays connected to a primary line, which relays are actuated when a call is initiated to allow a subscriber of the secondary office to establish a connection with a subscriber of the main office, and are actuated upon arrival of a call, to allow a subscriber of the main office to establish a call to a subscriber of the secondary office. 12- In a telephone system a group of relays combined with a device responding to pulses and arranged for use through one of two <Desc / Clms Page number 67> all by the same subscriber, to establish the. communication with another subscriber, in which the device responding to the pulses is arranged to respond successively to two series of pulses if it is used by a route, and to respond only to one series of pulses if it is used by the other road. 13- A telephone system in which the subscriber has direct access to a number of primary lines each of which can be used for the start of a call depending on whether said primary lines are free or busy, characterized by switched devices. phones arranged to allow the call to be transferred from one main line to the other. 14- A telephone system as claimed in 1, in which the switching devices are arranged to be actuated after the first pulse saw has been transmitted by the calling subscriber. 15 - A telephone system in which a free primary line can be used directly by a calling subscriber and can also be used by the same subscriber after he has transmitted a predetermined number of pulses. 16 - A telephone system as claimed in 15 in which digit receiving devices are combined with the primary line and act when the primary line is used directly by a calling subscriber to receive the first series of pulses transmitted by the telephone. said subscriber and then make a subsequent series of pulses effective to complete the establishment of a call, while remaining inoperative when the main line is attacked after a series of pulses have been transmitted. <Desc / Clms Page number 68> 17- A telephone system as claimed in 16 with the characteristic that the device absorbing the digits is only arranged to operate if the first series of pulses is of a predetermined number, switching devices operating when the first series of pulses is other than a predetermined number, being arranged to prevent the establishment of a communication. 18- A telephone system as claimed in 17 in which the operation of the switching device causes the transmission of a busy signal to the calling subscriber. 19 - A telephone system as claimed in 12,13 13, 15, 16, 17 or 18, in which a relay is arranged to be actuated after the first series of pulses has been transmitted, if said series of pulses is of a predetermined value when the primary line is driven by the 'one of two routes, 20- A telephone system comprising a main office and a secondary office in which a primary line to the main office is permanently linked with a primary line through which a subscriber from the office to the secondary can establish a communication either with the main office or with another subscriber of the secondary office depending on the value of the first series of pulses transmitted. 21- A telephone system comprising a main office and a secondary office in which a primary line from the secondary office is accessible by both. - <Desc / Clms Page number 69> subscribers of the main office and subscribers of the secondary office, the characteristic is that selector devices combined with the primary line are arranged so that a local call can be established to a route different from the route by which a the main office's call is even asleep if both calls are to the same subscriber. 22- A telephone system in which a subscriber has access to a main line having a group of relays combined with it, and a pulse repeater which, by responding to a series of pulses generated by a calling station, prepare a transmitting circuit by which the call can be transmitted to another main line ... whatever the first above-mentioned main line and in which, if such a line is not available, the call can be completed by the first mentioned main line. 23- a telephone system as claimed in 22 in which the first mentioned main line is chosen first, the second mentioned main line being chosen second when the call is to be initiated. 24- A telephone system comprising a main office and a secondary office in which a primary line extending from the main office to the secondary office terminates in a group of relays (combined with a primary line at the main office , so that calls can be made on the same primary line for both local calls and calls from the main office to the secondary office. 25- A telephone system as claimed in 24, in which the number of series of pulses after hooking up the primary line is greater for a local call <Desc / Clms Page number 70> only for a call from the main office, and in which switching devices operating when a call is initiated by the primary line are arranged to be actuated only when the excess series of pulses have been transmitted when the call is made. initiated by a local subscriber. 26 - A chain of meter relays comprising a group of relays where the number corresponds to the maximum number of pulses to be entered at one time and a controller relay available to change after the. end of an impulse and to be maintained in this state until the end of the. second pulse. 27- A counter relay chain comprising a group of relays the number of which corresponds to the maximum number of entries to be recorded at one time, and a controller relay whose state changes after the. end of a pulse to prepare an exciter circuit for one of said relays, and returns to its original state at the end of the following pulses to prepare a circuit for the relay which is to be energized thereafter e. 28 - A counter relay chain as claimed in 26 u 27 in which the controller relay is energized by means of a conductor to which is connected a source of exciting current between the pulses, and which is blocked energized on a circuit to which a exciter current source is connected during each pulse to be recorded. 29- A chain of counter relays as claimed in 26, 27, or 28 in which the relay group is divided into a number of subgroups (e.g. two) and in which the same basic circuit is employed to energize the different members of the subgroup. <Desc / Clms Page number 71> 30., A chain of counter relays as claimed in 26, 27, 28, or 29 in which an auxiliary relay is connected in series with all the relays of the group which are energized by the same base circuit, and is provided with contacts to close and open circuits which otherwise would have to be closed and opened by each relay individually. 31- A main line with two branches extending between two offices in which relays responding to pulses having neither battery nor earth connections, are normally connected by the main line to the two ends, and in which when a main line is in service at any end, the relay at that end is disconnected and the battery is supplied to energize the relay at the other withdrawn, 32- In a telephone system, a combined ringing arrangement and Wisely comprising a polarized relay arranged to produce the generation of a ringing alternating current while a connection is made, and to convert an alternating current to direct current to charge the battery when there is no power. 'other connections. 33-In a telephone system, a combined ringing and charging assembly comprising a polarized relay arranged to produce the generation of alternating current for the ringing, and to convert the alternating current into direct current for the charging. 34-In a telephone system, a battery charging arrangement in which charging is started automatically at the end of a communication and in which charging ends either automatically when the battery is charged at a determined point, either under control <Desc / Clms Page number 72> subscriber calling when the call begins. 35- In a telephone system, a polarized relay to convert the direct current into alternating ringing current, in which after each movement the closing is activated. the current flowing through the active windings is automatically reversed in direction.