US2148915A - Telephone system - Google Patents

Description

Feb. 28, 1939.

R. TRECHCJNSKI TELEPHONE SYSTEM -4 Sheets-Sheet l Filed April 24, 1935 m SK Filed April 24, 1935 4 Sheets-Sheet 2 TC m 'T/( T12 7:13 7'0! rs/ T82 1TB! 7'53 1 l l Feb.28, 1939.

R. TRECHCINSKI TELEPHONE SYSTEM Filed April 24, 1935 4 Sheets-Sheet 3 a is we. a QR h w A L T 3 Q E Patented F eb. 28, 1939 UN STATES PATENT OFFICE TELEPHONE SYSTEM Roman Trechcinski, Warsaw, Poland Application April 24, 1935, Serial No. 17,962

' In Poland April 28, 1934 1 Claim.

* with amplifiers are based on:

(1) Application of by-path repeaters,

(2) Application" of transit repeaters,

(3) l Transmitting of alternating current impulses, (4) Transmitting of inducting vibrations.

When ap l the m hod at Ma 3 d is ecessar t n te t t e Phonic curre errseuse. also m -v rations w i h may fluence the receiving apparatusand cause an undesirable (faulty) signal. Likewise, temporary disturbances in the amplifiers-whistles-may be the-cau o w on i na Teelim ate th abov tion ha mf l 1nfluences, it is possible to apply a transmitting apparatus generating current of a fixed frequency, and a receiving station provided with an electric filter, permitting exclusively the reception of only one fixed frequency. The probability that the disturbing current will have just the same frequency is a "very'small'one, and, therefore, in

certain cases of technical application this system provides asufiicient security.

The primary'object of the present invention is to provide a device which considerably decreases the probability of the occurrence of faults of the aforesaid kind, and. which is based on the ap:

plication of successive transmitting of several fixed frequencies. According to the invention, therefore, my improved system of transferring impulses and signals through lines comprises in combination: a transmitting apparatus having one generator only; means associated with this generator for enabling it to supply and forward through the line signals eachformed by a succession of several, i'. e. at least two, currents of' different definite fixed frequencies-the order of succession of. these currents, the time of duration of eachof them, and the number. of currents of dliferent and equal time of duration respectively of different and the same frequencies respectively" in one signal, being characteristic forthe above mentioned diiferent signals, means associated with said generator for controlling the intervals between two successive signals, said intervals" being characteristic by the definite time of interruption of the signalling currents, and by the definite time of duration of a definite frequency respectively, said time of interruption as well as that of duration of a definite frequency having a definitelower limit, the above mentionedmans beinga'dapted to be controlled both by the telephone subscriber and. by the personnel at the telephone exchange; means for receiving said signals from the line; and means for controlling the succession, the number and the time of duration of the said frequencies in 5 each signal, as well as the said intervals between two successive signals. The receiving apparatus will not react on one vibration of some fixed frequency only, and will act only when after a previous transmitting of this vibration of 10 the current having some fixed frequency, there is created another current of a difierent but again strictly fixed frequency. The succession in which the separate frequencies are created, as well as the length of time of the duration of the separate vibrations are applied in order to receive various signals and impulses.

As an example, I describe below the duotone'method of impulsing and signaling.

Fig. 1 shows a simplified scheme of cord connecting circuit.

Figs, 4 and 5 give the scheme of an equipment according to the invention, Fig. 4 showing the transmitting side and Fig. 5 the receiving side of the equipment.

Fig. 2- shows the connections by means of which equipments shown in Figs. 1, 4 and 5 co-operate with one another.

Fig. -3 shows the diagram of the transmitted current.

Fig. 6 illustrates a scheme of a device adjusting the receiving repeater filter successively to the reception of separate frequencies.

By means of manipulations which are very well known in the telephony, and, therefore, need not be minutely described here, the calling subscriber reaches the out-going repeater, the scheme of which is shown on Fig. 4.

Circuit 1 is closed then:

01: Fig. 1': ,-irelay SL, wipers W, terminal 3, 40

strips I.-II. Fig. 2: terminal 3 of the strip I-II, relay TC relay TS operates closing circuit 2. 02: Fig. 4: +,self-inductance Si, relay TSI, contact TC At the same time the cathode valves KB! and KR! are lit as per circuit 3:

As the result of the forming of the circuit 2, relay TSI, forming together with the self-inductance Sz'3 the time factor at about 300 milliseconds provided for warming up of the valves and the stabilization of the work of the valve generator, will operate and connect the valve generator to the line as per circuit 5:

05: Fig. 4: the top transformer terminal Tr2, TS3 TSI TQ2 term. I, strips HIIV, line, terminal 2, strips IIIIV. TQZ TSl T33 bottom terminal Tr2.

500 cycles per second. At the just discussedmoment,'i. e. when the valve generator is connected with the line, there will be connected the condenser Cr2 over the contact TS2, consequently "the line is fed by the current of 500 cycles per second.

Circuit 6 is closed as the result of the operation of the relay TSI.

. 06: Fig. 4: Si l, TS2, TSI in consequence G 3 and 4; at the two parallelly connected con- 0'7: Fig. 4: Si5, TS3, TSZ

of which after about 300 milliseconds relay TSZ operates disconnecting contact TS2, separating GT2, causing an immediate break in transmitting of the 500 cycles per second currentinstead of which the current of a 1000 cycles per second frequency will be transmitted.

After the operation of TS2 circuit 7 is closed.

at about 300 milliseconds relay TS3 operates and will cut the circuit and 5 thus causing a break in the transmitting of the current to the line.

mitted currents is shown.

The above described currents reach the receiving repeater over the line the scheme of which is shown on Fig. 5 as per circuit: out-going re-, peater, terminal I, strips III-JV, coiling of the transformer TT3, terminal 2, strips IH'IV and back to the out-going repeater.

An aperiodic amplifier consisting of the valve KR will forward the above current-to the relay RA which by means of the rectifying device LTI will accept the same regardless of their frequency, r

'When RH releases the desired telephone exin consequence of which the relay RA will operate. The circuit 8 will be closed then.

08: Fig. 5 the top terminal '1', RA, filter for 500 cycles per second RU RN, RU tom terminal T14.

The filter of the in-coming repeater. consists of self-inductions Si6, Si'l, Si8 and condensers botdensers GT3 and CM this filter lets the 500 cycles per second current through, but in case of a disconnected Cr4the 1000 cyclesper second current. At the described moment both condensers are. parallelly connected, consequently the filter accepts then 500 cycles per second. The relay RN is quickly acting (about 3 milliseconds) and disconnects sooner the contact RN before the relay RU has time to operate on circuit 9 On the Fig. 3 the proper diagram of thetranse 09: Fig. 5:+, RU, RA, RN,

As the operating time of the latter is longer (about milliseconds) at the moment of the acting of RN circuit 9 is immediately disconnected, RU remains inactive.

By operating of the relay RN circuit 10 is closed:

010: Fig. 5: RQ, RH RS RNP, in consequence RQ operates.

After about 300 milliseconds the out-going repeater disconnects the 500 cycles per second current transmitting in its stead the 1000 cycles per second current which is not let through by the filter and therefore the relay RN becomes inactive. Circuit 9 is then closed again and (after about 10 milliseconds) RU operates disconnecting C14 by opening the contact RU; the altered filter will let through the current of the 1000 cycles per second frequency which sets in motion the relay RH as per circuit 11: i

011: Fig, 5: top terminal T14, RA filter RU,RI-I,

RU bottom terminal TR4.

The relay HR is quicklyacting (about 3 milliseconds) and before RU has time to be de-magnetized (from the additional circuit 12:

012: Fig. 5: bottom coiling of the opposite winding relay RU, RU, RH,

013; Fig.5: RQ, RH RQ which supplies further the current to the relay RQ.

After operation of RH circuit 14 is closed: 014; Fig. 5: RK, RQ", RH, as),

RK operates.

When after further 300 milliseconds the 1000 cycles per second current disappears, relay RA releases, in consequence of which circuits 9 and.

11 are disconnected; RH and RU release; RK operates still, at first per circuit 15:

015: Fig.5: BK, RKE, RQF,

relay,

and after further 30 milliseconds when RQ releases, per circuit 16:

016: Fig. 5: BK, RK RQ RH, RS

change is alarmed in the known customary manner by closing of the loop per circuit 17:. i

017: Fig. 5: terminal I, strips IX-X, Si9, RK RH terminal 2, strips IX-X.

The alarmed telephone exchange or central station puts up then an alarming lcallsignal, e. g. in the form of a current of 200 cycles per second frequency. This current is to signal the calling subscriber the possibility of starting the the r y T JJ- ig-. whi h ne ai qmrqu h l.

loop of the subscriber relay SJ (Fig. 1) will m ulses- "When TJI operated, circuit 18 is closed:

parallelly to the feeding receive the subscribers 01,82 Fig. 4: TK, TJ I relay TK operated,

but as'the same is a relay with a delayed activity (it releases after about 200 milliseconds) it is on operationalso during the impulsing by the subscriber.

When TJ l releases, the circuit 19 is closed:

019: Fig. 4: TQLTKa TJl relay TQI operates;

After the operation of the relay TQI, the 500 :cycle current is closed to the line as per circuit 20:

020: Fig. 4: top terminal TrZ, TQI RQZ terminal I, strips III IV, line, and back, terminal 2, strips ZUIIV, TQZ TQ l and bottom terminal Trl.

The condenser Cr2 is connected to the circuit 21: r

21: Fig. 4; GT2, TJ3, TQI parallelly to CTI.

When TJI releases, then the circuit 22 is closed:

and disconnects Cr2, cancelling the circuit 21, so that the generator begins to produce the 000 cycle current instead of the 500 cycle current.

As TJ3 and TJ2 are pulsating in accordance with TJ I (but with some delay), this line will be then successively fed by the current vibrations of 500 or 1000 cycles per second and the number of the 1000 cycle vibrations will be equal to the number of impulses in the subscribers series.

After the last impulse still another vibration of 500 cycles per second will be forwarded, viz.:

= when TJI operates the circuits 22 and 23 will be cut, in consequence of which after about 60 milliseconds TJ3 will release closing circuit 21 and as TQI is still active the 500 cycles per second pulsation will go through the line, but, later on, because of disconnecting of the contact TJ l TQI will release (after about 200 milliseconds) as from the moment of disconnecting) and the transfer is terminated.

When the first 500 cycle vibration was taken Over by the receiving repeater, causing as the result-in accordance with the above elucidated course of operation of the relays RA, RN, RQ (Fig. then after some time there will arrive the first 1000 cycle vibration, corresponding to the break of the first impulse. In consequence of the disconnection of the circuit 8, the relay RN releases: circuits 9 and 11 are closed, causing that RN and RU operate, and RH will break the central loop by means of the contact RH (RQ operates during all this time.) After some time the 1000 cycles per second vibration alters into one of 500 cycles per second corresponding to the closing of the first impulse. In consequence the circuit 11 will becancelled and the relay RH releases; then through RH the bottom coiling of the opposite winding relay RU will get the currentand RUreleases, and by closing the circuit 8, RN will operate. When, after some time, the 500 cycle current will fade, RN and RQ will release.

In thev described manner one series consisting of one impulse is received; in an analogous manner a series of any number of impulses will be accepted causing a corresponding number of operations of the relay RH.

vThe termination signal takes place as follows: when the subscriber puts the hand-set on the forks, TJ l releases. If the repeater has no special apparatus with a registration of impulses from the subscriber and forwarding them after cumulation, then the described simple device in the out-going repeater at the hanging up of the hand-set, will forward one superfluous impulse in the form of vibrations: the 500 cycles per second and then the 1000 cycles per second. In the meanwhile, however, one cord circuit line in the central will be released and the relay TC may release within some undefined time what would cause undesirable (faulty) signals,

To avoid this eventuality the relay TBI is added giving a guaranty that TC will release by 200 milliseconds later than TQI, as TBI is set in motion by TCI, as per circuit 24:

024: Fig. 4: TBI, TQl

TBI has a delayed activity and keeps TC as per circuit 25:

026: Fig. 4: TQZ, TS3 To relay TQ2 operates.

At the same time circuit 2 is cut: TSI releases and a 1000 cycle vibration is forwarded; then circuit 6 is cut and TCZ releases after about 200 milliseconds altering the 1000 cycle current into a 500 cycle current.

As the result of releasing of the relay TS2 the circuit '7 is out and after about the expiration of further 200 milliseconds TS3 releases cuttingcircuit 26, then TQZ releases, cutting the termination signal. From the above it is clear that the termination signal is forwarded in the form of 2 vibrations: at first one of 1000 cycles per second and then one of 500 cycles per second.

The incoming repeater (receiving) accepts a 1000 cycle vibration by means of a filter through the relay RH which operates and closes circuit 27:

027 Fig. 5: +,RS,RH ,RQ relay RS operates receiving because of the opening of the contact RS an additional minus for RK; then, if after the fading of the 1000 cycle vibration the 500 cycle vibration occurs and the relay RN becomes active by opening its contact RN taking off the current from the relay RK, the latter, in consequence of the loss of the additional minus from RS releases sooner than RS (with a delayed activity) will have time to release because of the inactivity of RH and gives it back its minus; the subscribers loop is out.

After the termination of forwarding of the 500 consequently cycle current the relays RA and RN release and the whole receiving repeater-becomes inactive.

Therm-tone system The above described duo-tone system may have not only a theoretical, but also a practicalapplication. However, the apparatus for the separate processes is simpler when applying a trio-tone system, which, in principle, differs only very little 105 from the duo-tone system.

:To describe full all separate technical processes which have to be signalized, i. e.the necessary connection and disconnection, repeated ringing, the compulsory disconnection, the inter- 15; ;ception of catching connections from both sides,

the control of the state of organs-further impulsing and the then following new connections and disconnections, aswell as signalization of zones, would be only a useless complication of the 20-";whole. system, and, therefore, I shall limit my description to some fundamental things, viz.: only to a few fragments of the whole system.

Thesignaling currents may be of e. g. three following frequencies: 500, 1000 and 1500 cycles 25;per second. On Fig. 6 is shown a scheme of a device adjusting the receiving repeater filter sue-- cessively to the reception of separate frequencies; in this case all terminals of the strips XL-XII with the exception of terminal I to which the plus 30 ;pole of the storage batte'ry'is connected, should be understood as:insulated; the relays RVI and RV2 are not necessary.

After receiving by the aperiodic amplifier of the receiving repeater of the 500 cycle vibration 351current, the relay RA operates, consequently, be-

cause of the longer time needed by the relay RV! for operation than RN (similarly as in the formerly described duotone system) the latter operates on circuit 28:

0.28: Fig. 6: from TM, RN (through the rectify ing device) RUl,RA to Tr' l; v and .cuts the minus pole from the relay RUI. which remains inactive and will operate only 45 ,then, when after cutting of the vibration of the 500 cycle current and altering the same by the 1000 cycles per second current, the relay RN- will'release; the circuit29 will be closed then:

' 'to TM and remain active during the whole .time of the duration-.ofthe 1000 cycle.

current. I

a 1500 cycles per second current, which is not let through the filter, the relay RM becomes in-.

active, and, therefore, circuit 31 is closed:

031; Fig. 6: RU'Z, RUl RM the relay RUZ operates opening the contact RUE cutting off C15 and byeclosing the contact RU2, switches over the filter to the relay RH. The filter begins to let 75 !through .the 1500 cycle current which is. accept:

ozeiri 6: topcoiling RHI, RAE, Rug- I osmrigcz from TM, RM, RU2 RUl RAP,

At the moment of altering of this current to.

ed byRHloperating quicker than RU3) on circuit',32:

032: Fig. 6: from Tr4, RH, RUZ, RUI, RA, to T414; relay RH operates.

After thefading of the 1500 cycle current RH releases, then RUB will operate on the circuit 33.: V

wired RUI will receive the current from its own plus and 'minus through RU3 then the relay RUI releases and circuits 31 and 33 are cancelled, in view of which RU2 and RU3 become inactive and because of the connecting back of condensers CM and C15 the filter is adapted for the reception of the 500 cycle per second current and a collaborationwith RN.

By this means this device will successively connect the line currents to the proper relays, altering the properties of the filter by the contacts RUl RU2 separating the condensers C14 and GT;

In some cases, however, as e. g. for pulsation, the duo-tone system might be more convenient than the trio-tone system. And just to facilitate in some circumstances a passing over from a trio-tone system to a duo-tone and the necessary changing of. a receiving repeater from a trioto a duo-tone, there is foreseen a device consisting of relays RVI and RV2 (terminals of strips 'X[XII are now not insulated).

As an example the following disposition is given: the repeater is in each case transformed intoa duo-tone, if after a former appearance of" a" 500cycle current a 1000 cycle current is received; in all other combinations a 1500, 1000,

be closed: 034: Fig. 6: RVI, RN, -:"consequently RVI operates.

When" the 1000 cycle current will appear after the fading of the 1000 cycle current, RN releases, RUl operates and RM receives the 1000 cycles per second current; circuit 35 is closed then:

035': Fig. 6: RVLRVIgRM relay RVZ operates and opening the contact RVZ takes the plus pole from the storage battery to the relay RU2 which, afterdisappearing of the 1000 cycle vibration, when RM releases, cannot operate in the circuit 31,.and owing t the closed RV2, circuit 36 is closed: 036: Fig. 6: RUI, RUl RUZ-l RV2, RM",

the opposite wired RUl releases, owing to which operate, and the circuit 34 will the receivingdevice becomes, immediately after current adapted for the reception of the 500 cycle current.

Instead of electromagnetic relays for the adape tation of filters and connection of the separate receiving apparatus, also other relays may be applied, .e. g; valve devices; these apparatus, as quite non-essential for the above system, were not described at all.

The whole system is understood as acting on both sides.

Iclaim: System of transferring impulses and signals throughJines, particularly for usewith amplithe disappearance of the 1000 cycles per second fiers for manual, half-automatic and full-automatic telephony, comprising in combination: a transmitting apparatus having one generator only; means associated with this generator for enabling it to supply and forward through the line signals each formed by a succession of severa], 1. e. at least two, currents of different definite fixed frequenciesthe order of succession of these currents, the time of duration of each of them, and the number of currents of different and equal time of duration respectively of diiferent and the same frequencies respectively in one signal, being characteristic for the above mentioned different signals, means associated with said generator for controlling the intervals between two successive signals, said intervals being characterized by the definite time of interruption of the signalling currents, and by the definite time of duration of a definite frequency respectively, said time of interruption as Well as that of duration of a definite frequency having a definite lower limit, the above mentioned means being adapted to be controlled both by the telephone subscriber and by the personnel at the telephone exchange; means for receiving said signals from the line; and means for controlling the succession, the number and the time of duration of the said frequencies in each signal, as well as the said intervals between two successive signals, substantially as described.

ROMAN TRECI-ICINSICL

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