US2498723A - Sensitive gas tube pulse receiving and repeating system - Google Patents
Sensitive gas tube pulse receiving and repeating system Download PDFInfo
- Publication number
- US2498723A US2498723A US660269A US66026946A US2498723A US 2498723 A US2498723 A US 2498723A US 660269 A US660269 A US 660269A US 66026946 A US66026946 A US 66026946A US 2498723 A US2498723 A US 2498723A
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- relay
- tube
- receiving
- pulse
- winding
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04Q—SELECTING
- H04Q1/00—Details of selecting apparatus or arrangements
- H04Q1/18—Electrical details
- H04Q1/30—Signalling arrangements; Manipulation of signalling currents
- H04Q1/44—Signalling arrangements; Manipulation of signalling currents using alternate current
- H04Q1/444—Signalling arrangements; Manipulation of signalling currents using alternate current with voice-band signalling frequencies
- H04Q1/446—Signalling arrangements; Manipulation of signalling currents using alternate current with voice-band signalling frequencies using one signalling frequency
- H04Q1/4465—Signalling arrangements; Manipulation of signalling currents using alternate current with voice-band signalling frequencies using one signalling frequency the same frequency being used for all signalling information, e.g. A.C. nr.9 system
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04Q—SELECTING
- H04Q1/00—Details of selecting apparatus or arrangements
- H04Q1/18—Electrical details
- H04Q1/30—Signalling arrangements; Manipulation of signalling currents
- H04Q1/44—Signalling arrangements; Manipulation of signalling currents using alternate current
- H04Q1/442—Signalling arrangements; Manipulation of signalling currents using alternate current with out-of-voice band signalling frequencies
- H04Q1/4423—Signalling arrangements; Manipulation of signalling currents using alternate current with out-of-voice band signalling frequencies using one signalling frequency
Definitions
- the present invention r'elates ⁇ to :pulse ⁇ 'receivk.ing andV repeating circuits for telecommunication systems using signalingV impulses ofalternating' Vcurrent either'ata irequencyffin'thewvoice ffrequency' rangeor 'at some otherpredetermined rparticular frequency'which yis'convenient 'in light Tof available apparatus.
- vThe Ysystem-fhereinsdescribed and claimed isrelated tof thatfdescribed and claimed in 'my copending l application Y'Serial No. 661,493, :filed xApril l2, 1946,:.now'fPatent'No- 2,462,144, issued February '22, 1949.
- a receiving member utilizes an assembly consisting of a dry rectifier, a polarized two-winding relay, and a condenser.
- Anobject'of the present invention is to avoid the shortcomings of the prior arrangements ⁇ by providing simple andeilective means for the ini able by signal current either at a frequency 'inthe Voice frequency range or at some other particular frequency convenient in .light 'ci the availy able apparatus ina telecommunication system.
- the pulse repeating or receiving circuit includes a cold-cathode tube iedirom the input line through a condensertransformer Series circuit and employs a relay larrangement comprising a two-winding retrans- 4 mittinganode-relay, an auxiliary relay for inter nel switching, and a slow relay for neutralizing the signal input equipment of the other channel.
- the auxiliary relay may be omitted and its contacts transferred to the anode-relay.
- One of the Windingsof this anode-relay is energized' by signaling current from ing' this relay :actuated during the period of the 1 incoming signal.
- REP indicates schematically a conventional telephone repeater serving as a couv4block -A is operating.
- Vconvenience relay COR is shown in block'Ai.
- Cor- *of block "A1 is an east-to-west pulse repeater.
- relays Three relays, AOR, BGR-and COR-are actuated duri-ng the operation of block Anand of these the function o'f relay COR is to disable block A1 when However, as a matter cf respondingly a relay 'CERfwhichfis actuated to disable block A whenever block Ar is, opere-ting, is shown in block A.
- the relay windings are con- .nected 'to sources of ⁇ direct current which maybe constituted iby a common low-voltage anda 'hightension supply B2.
- Attcry B1 A source of alterlnating current Spe;A a l56-cycle ⁇ generator is iconn'ectedfto contacts h2 and c2 Aof relay BOR.
- a cold-cathode tube CFO comprising the rcathode Ca, anode Au, and auxiliary electrode Esc,
- Front contact b1 of relay AOR is also closed, which establishes a circuit to connect ground to battery B1 feeding the auxiliary relay BOR, which pro-y Jerusalems the following operations: First, by opening its contact a2 it inactivates tube CFO. Second, by closing its contacts b2 and cz, it connects the alterhating-current source S to wires of east-side line E. After each inactivation of tube CFO, relay AOR remains energized, throughout the duration of the pulse, through its left-hand Winding as described.
- the cold-cathode tube is energized only between the instant each pulse begins and the instant relay BOR operates.
- auxiliary relay BOR might be omitted and its contacts b2, c2 transferred to relay AOR; this would necessitate replacement of high-tension supply B2 by an equivalent source of alternating current, thus assuring prompt extinction of the tube at the end of each impulse and the provision of a condenser of rather large capacity in shunt to the anode winding, to prevent vibration of the combined relay.
- relay AOR the rapid operation of relay AOR is elected by virtue of the inertia-free response of tube CFO to the signal voltage, with the aid of the energy taken from high-tension source B2 or its equivalent.
- the incoming signal energy which would be too weak to cause this rapid excitation, is used merely to hold this same relay duringthe remainder of the pulse. It is clear that, under these conditions, distortion will be particularly low.
- condenser CO and transformer TO will depend on the kind of signal currents which are to be transmitted, i. e., whether they are of commercial or acoustic frequency. It will be understood that these elements may be adjustable so as to respondv to frequencies of either range.
- a pulse receiving or repeating system for telecommunication networks comprising a tube having a cold cathode, an auxiliary electrode and an anode, means for impressing an incoming signal across said cathode and said auxiliary electrode for causing ionization of said tube, a relay having a winding connected in the cathode-anode circuit of said tube, a local source of current in said circuit for actuating said relay, a second winding on said relay for causing the holding of the relay operated during the signal period, and current rectifying means receiving incoming signal energy and transmitting said energy through said second winding for retaining said relay operated.
- a pulse receiving or repeating system for telecommunication networks comprising a tube having a cold cathode, an auxiliary electrode, and an anode, means for impressing an incoming signal across said cathode and said auxiliary electrode for causing ionization of said tube, a relay having a winding connected in the cathode-anode circuit of said tube, a local source of current in said circuit for actuating said relay, a second winding on said relay for causing the holding of the relay operated during the signal period, current rectifying means receiving incoming signal energy and transmitting said energy through said second winding for retaining said relay operated, and means controlled by operation of said relay for deenergizing the first winding of said relay and the cathode-anode circuit of said tube.
- Impulse receiving apparatus comprising first and second transmission lines, means for receiving impulses from the first line and repeating themto the second line, means for receiving impulses from the second line and repeating them to the first line, each of the means for receiving comprising a 'gaseous discharge tube having a main gap and a control gap, a means for applying received impulses to the control gap to ionize the tube, a local source of potential connected to the tube for energizing the main gap when the tube is ionized, a relay having two windings, means for connecting in series said local source of potential, the main gap and one of the windings for initially operating the relay upon the ionization of the tube, a means for applying the received impulses to the other winding for holding the relay operated for the duration of an impulse, a local source of signaling energy, and a means responsive to operations of the relay for applying impulses from said source of signaling energy to one of the transmission lines in accordance with impulses received from the other, and means responsive when one of the means for receiving is engaged
- impulse receiving apparatus as in claim 3 in which the impulses received from at least one of the lines are impulses of alternating current having a predetermined frequency
- the means for applying those received impulses to the control gap of one of the tubes comprises a transformer with its secondary connected across said control gap and its primary connected across said one of the lines over a circuiti including in series a condenser and the input terminals of a bridge rectiner, said condenser and said primary being tuned to said frequency
- the second Winding of the relay initially operated'by said tube is connected across the output terminals of said bridge rectifier for holding said relaylfor the duration of each received impulse by energy derived therefrom over said bridge rectlner.
- Impulse receiving-apparatus as in claim 3 also comprising means4 responsive to the initial operation of the relay of either of the means for receiving to disconnect from the tube thereof said local source of main gap energizing potential to deionize the tube.
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- Engineering & Computer Science (AREA)
- Computer Networks & Wireless Communication (AREA)
- Interface Circuits In Exchanges (AREA)
- Devices For Supply Of Signal Current (AREA)
- Electrotherapy Devices (AREA)
Description
Feb. 28, 1950 c. M. THEILLAUMAS SENSITIVE .SAS TUBE PULSE RECEIVING AND REEEATING SYSTEM Filed April e, 194s i l l 1 I R 4. O E D C IJ. u n -|L .f||||| f a# llk| k llllmml u G a TR mA n NS n AK Z uw. mm P n w D wm. ma E C \|1 P MF n 0 O T O B u A U l l I |I l p I m E Ill Ill!! /MM i l ll IY L P 1 R R W .h w E a |.\|\||II l l l l l I l l I l I l l l l l l Il -A A A IN VEN TOR. C ZEITEN T IY. THIILLAUJIAS ATTORNEY.
Patented Feb. 28, 1950 VV.SENSITIVE GAS IUBE PULSE RECEIVING AND'REPEA'TING SYSTEM y Clement v'Ehe'illaumas, BoulogneLBillancourt, F France, assi'gnor to International Standard -`Electric Corporation, New York, N. Y., a corporation; of Delaware Application April 6, 1946, Serial No. .660,269 4vIn' France January 7, 1944 5 Claims. 1
The present inventionr'elates `to :pulse `'receivk.ing andV repeating circuits for telecommunication systems using signalingV impulses ofalternating' Vcurrent either'ata irequencyffin'thewvoice ffrequency' rangeor 'at some otherpredetermined rparticular frequency'which yis'convenient 'in light Tof available apparatus. vThe Ysystem-fhereinsdescribed and claimed isrelated tof thatfdescribed and claimed in 'my copending l application Y'Serial No. 661,493, :filed xApril l2, 1946,:.now'fPatent'No- 2,462,144, issued February '22, 1949.
v'Ifhefsignal receiving and/or repeating circuits lto which this invention'relates shduldbesensitive,
conveniently adjustable, vand faithful in reproduction. A-variety of relays are ycustomarily em- `ployed ffor this purpose; Iamong thoseirequ'ently usedare 'the tout-ofephase ,flux relays :which .may
comprise either 'one "or twovmagnetic': circuits. lrIln "the former case, fa'` phase difference of the ux in the Yuseful y:air gap' :is :articiallyfproduced by 'a phase shifting device. Relays ofeither'of the above types have the disadvantages 'of lnarrow adjustment limitsfcontact vibrations, and a limited number -of lfaithful repetitionsfevenvwhen'a pulse-correcting system is used during `each retransmission.
Another known arrangement of .a receiving member utilizes an assembly consisting of a dry rectifier, a polarized two-winding relay, and a condenser. those named above, its chief drawbacks 'are bulky construction and high cost.
Anobject'of the present invention is to avoid the shortcomings of the prior arrangements `by providing simple andeilective means for the ini able by signal current either at a frequency 'inthe Voice frequency range or at some other particular frequency convenient in .light 'ci the availy able apparatus ina telecommunication system.
Inv a pulse receiving and repeating Vcircuit according to' this invention, detection ofthe incoming signal is eiiected ybymeans'of a space vdis- .chargetube preferably of the cold-cathodetype;r
While such' a device is Apreferable to.'
and pulse repetition is assured through a relay arrangement in the plate circuit of the tube. `The moment of beginning of a pulse is determined by the actuation of the cold-cathode tube which causes the initial energization ci the relay. The end of the pulse is determined by the falling back of this relay and not by inactivation of the tube. An auxiliary relay which is energized by the operation of the iir'st relay effects the extinction of the tube'and also the application to the outgoing line of the current source used to retransmit a signaling pulse train.
For each signaling direction, the pulse repeating or receiving circuit includes a cold-cathode tube iedirom the input line through a condensertransformer Series circuit and employs a relay larrangement comprising a two-winding retrans- 4 mittinganode-relay, an auxiliary relay for inter nel switching, and a slow relay for neutralizing the signal input equipment of the other channel. With certain modications, the auxiliary relay may be omitted and its contacts transferred to the anode-relay. One of the Windingsof this anode-relay is energized' by signaling current from ing' this relay :actuated during the period of the 1 incoming signal.
the input line by means of a rectiiier for hold- YA circuit illustrating the invention is Shown,
vby way of example, in the single figure of the vfaccompa-nying drawing.
In the drawing, REP indicates schematically a conventional telephone repeater serving as a couv4block -A is operating. Vconvenience relay COR is shown in block'Ai. Cor- *of block "A1 is an east-to-west pulse repeater.
Three relays, AOR, BGR-and COR-are actuated duri-ng the operation of block Anand of these the function o'f relay COR is to disable block A1 when However, as a matter cf respondingly a relay 'CERfwhichfis actuated to disable block A whenever block Ar is, opere-ting, is shown in block A. 'The relay windings are con- .nected 'to sources of `direct current which maybe constituted iby a common low-voltage anda 'hightension supply B2.
attcry B1 A source of alterlnating current Spe;A a l56-cycle^generator is iconn'ectedfto contacts h2 and c2 Aof relay BOR.
A cold-cathode tube CFO, comprising the rcathode Ca, anode Au, and auxiliary electrode Esc,
fhas its. input' connected to the: secondary .of the current impulses coming from the west ionize the cold-cathode tube CFO between lcathode Ca and auxiliary electrode Ex through the secondary winding of the transformer TO over the following circuit: Back contact a3 of relay CER, rectifier bridge RD by way of left-hand winding of relay AOR, primary of transformer TO, condenser CO. The current will not be strong enough to actuate relay AOR, but the voltage stepped up by the transformer will suiilce to effect ionization between cathode Ca and auxiliary electrode Esc of the tube CFO the instant a signal appears. The excitation of the tube results in the passage of anode current from high-voltage source B2 through the right-hand winding of relay AOR. Thus, the front contact ai of AOR is closed, which causes the operation of slow-releasing relay COR which, through its back contact a4, disconnects,
throughout the duration of the pulse train, the
block A1 devices for preventing the retransmission of pulses in the east-west direction. Front contact b1 of relay AOR is also closed, which establishes a circuit to connect ground to battery B1 feeding the auxiliary relay BOR, which pro-y duces the following operations: First, by opening its contact a2 it inactivates tube CFO. Second, by closing its contacts b2 and cz, it connects the alterhating-current source S to wires of east-side line E. After each inactivation of tube CFO, relay AOR remains energized, throughout the duration of the pulse, through its left-hand Winding as described.
In the embodiment illustrated, the cold-cathode tube is energized only between the instant each pulse begins and the instant relay BOR operates. As an alternative, however, auxiliary relay BOR might be omitted and its contacts b2, c2 transferred to relay AOR; this would necessitate replacement of high-tension supply B2 by an equivalent source of alternating current, thus assuring prompt extinction of the tube at the end of each impulse and the provision of a condenser of rather large capacity in shunt to the anode winding, to prevent vibration of the combined relay.
In either case, the rapid operation of relay AOR is elected by virtue of the inertia-free response of tube CFO to the signal voltage, with the aid of the energy taken from high-tension source B2 or its equivalent. The incoming signal energy, which would be too weak to cause this rapid excitation, is used merely to hold this same relay duringthe remainder of the pulse. It is clear that, under these conditions, distortion will be particularly low.
The dimensioning of condenser CO and transformer TO will depend on the kind of signal currents which are to be transmitted, i. e., whether they are of commercial or acoustic frequency. It will be understood that these elements may be adjustable so as to respondv to frequencies of either range.
While I have shown and described a particular embodiment of my invention, it will be apparent to those skilled in the art that variations and modifications thereof may be made without departing from the underlying principles of the invention. Thus, although the drawing relates to a repeater, it is quite evident that the system may be used in a terminal station, with suitable modi- -ications consistent with each particular case. I, therefore, desire the following claims to include within the scope of my invention all such substitutions and variations whereby substantially the results of my invention may bey obtained by the use of substantially the same or equivalent means.
What is claimed is:
1. A pulse receiving or repeating system for telecommunication networks comprising a tube having a cold cathode, an auxiliary electrode and an anode, means for impressing an incoming signal across said cathode and said auxiliary electrode for causing ionization of said tube, a relay having a winding connected in the cathode-anode circuit of said tube, a local source of current in said circuit for actuating said relay, a second winding on said relay for causing the holding of the relay operated during the signal period, and current rectifying means receiving incoming signal energy and transmitting said energy through said second winding for retaining said relay operated.
2. A pulse receiving or repeating system for telecommunication networks comprising a tube having a cold cathode, an auxiliary electrode, and an anode, means for impressing an incoming signal across said cathode and said auxiliary electrode for causing ionization of said tube, a relay having a winding connected in the cathode-anode circuit of said tube, a local source of current in said circuit for actuating said relay, a second winding on said relay for causing the holding of the relay operated during the signal period, current rectifying means receiving incoming signal energy and transmitting said energy through said second winding for retaining said relay operated, and means controlled by operation of said relay for deenergizing the first winding of said relay and the cathode-anode circuit of said tube.
3. Impulse receiving apparatus comprising first and second transmission lines, means for receiving impulses from the first line and repeating themto the second line, means for receiving impulses from the second line and repeating them to the first line, each of the means for receiving comprising a 'gaseous discharge tube having a main gap and a control gap, a means for applying received impulses to the control gap to ionize the tube, a local source of potential connected to the tube for energizing the main gap when the tube is ionized, a relay having two windings, means for connecting in series said local source of potential, the main gap and one of the windings for initially operating the relay upon the ionization of the tube, a means for applying the received impulses to the other winding for holding the relay operated for the duration of an impulse, a local source of signaling energy, and a means responsive to operations of the relay for applying impulses from said source of signaling energy to one of the transmission lines in accordance with impulses received from the other, and means responsive when one of the means for receiving is engaged in repeating impulses to prevent the other of them from receiving impulses.
4. Impulse receiving apparatus as in claim 3 in which the impulses received from at least one of the lines are impulses of alternating current having a predetermined frequency, the means for applying those received impulses to the control gap of one of the tubes comprises a transformer with its secondary connected across said control gap and its primary connected across said one of the lines over a circuiti including in series a condenser and the input terminals of a bridge rectiner, said condenser and said primary being tuned to said frequency, andthe second Winding of the relay initially operated'by said tube is connected across the output terminals of said bridge rectifier for holding said relaylfor the duration of each received impulse by energy derived therefrom over said bridge rectlner.
5. Impulse receiving-apparatus as in claim 3 also comprising means4 responsive to the initial operation of the relay of either of the means for receiving to disconnect from the tube thereof said local source of main gap energizing potential to deionize the tube.
CLEMENT M. THEILLAUMAS.
REFERENCES CITED UNITED STATES PATENTS Number Name Date 2,029,693 Anderson Feb. 4, 1936 2,045,402 Myers June 23, 1936 2,047,729 Fisher July 14, 1936 2,056,235 Swart Oct. 6, 1936 2,091,551 Low Aug. 31, 1937 2,222,248 Blount Nov. 19, 1940 2,253,621 Horton Aug. 26, 1941 FOREIGN PATENTS N umber- Country Date 323,804 Great Britain Jan. 13, 1930 Certificate of Correction Patent N o. 2,498,7 23 February 28, 1950 CLEMENT M. THEILLAUMAS It is hereby certified that errors appear in the above numbered patent requiring correction as follows:
In the grant, line 15, strike out of Seventeen years; same line, after grant insert until January 8, 1964; in the heading to the printed specification, line 9, foreign filing date, for January 7 1944" read January 8, 1944; line 10, before 5 Claims,
insert the following: Section 1, Public Law 690, August 8, 1.946, Patent expires January and that the said Letters Patent should be read with these corrections therein that the same may conform to the record of the oase in the Patent Oce.
Signed and sealed this 22nd day of August, A. D. 1950.
[SEAL] THOMAS F. MURPHY,
Assistant ommsszoner of Patents.
Certificate of Correction Patent No. 2,498,7 23 February 28, 1950 CLEMENT M. THEILLAUMAS It is hereby eertied that errors appear in the above numbered patent requiring correction as follows:
In the grant, line 15, strike out of Seventeen years; same line, after grant insert until January 8, 1964 in the heading to the printed specification, line 9, foreign filing date, for January 7, 1944 read January 8, 1944; line 10, before 5 Claims,
, w insert the following: Section 1, Publio Law 6.90, August 8, 1,946, Patent expires January and that the said Letters Patent should be read with these corrections therein that the same may conform to the record of the oase in the Patent Ofliee.
Signed and sealed this 22nd day of August, A. D. 1950.
[SEAL] THOMAS F. MURPHY,
Assistant ommzsszoner of Patents.
Applications Claiming Priority (3)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
FR2498723X | 1944-01-07 | ||
FR636253X | 1944-01-08 | ||
FR2462144X | 1945-03-27 |
Publications (1)
Publication Number | Publication Date |
---|---|
US2498723A true US2498723A (en) | 1950-02-28 |
Family
ID=32233873
Family Applications (2)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US660269A Expired - Lifetime US2498723A (en) | 1944-01-07 | 1946-04-06 | Sensitive gas tube pulse receiving and repeating system |
US661493A Expired - Lifetime US2462144A (en) | 1944-01-07 | 1946-04-12 | Pulse receiving and repeating system |
Family Applications After (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US661493A Expired - Lifetime US2462144A (en) | 1944-01-07 | 1946-04-12 | Pulse receiving and repeating system |
Country Status (4)
Country | Link |
---|---|
US (2) | US2498723A (en) |
BE (1) | BE477477A (en) |
FR (2) | FR54628E (en) |
GB (1) | GB636253A (en) |
Cited By (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2579530A (en) * | 1947-04-29 | 1951-12-25 | Int Standard Electric Corp | Four-wire to two-wire connecting circuit |
US2914615A (en) * | 1952-10-09 | 1959-11-24 | Int Standard Electric Corp | Electric signal repeaters |
US3166642A (en) * | 1961-12-21 | 1965-01-19 | Bell Telephone Labor Inc | Signaling arrangement |
Citations (8)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
GB323804A (en) * | 1928-10-11 | 1930-01-13 | Western Electric Y | Improvements in impulse controlling arrangements for use in electrical signalling systems |
US2029693A (en) * | 1934-09-07 | 1936-02-04 | Bell Telephone Labor Inc | Telephone system |
US2045402A (en) * | 1935-01-17 | 1936-06-23 | Bell Telephone Labor Inc | Signaling system |
US2047729A (en) * | 1933-09-29 | 1936-07-14 | Bell Telephone Labor Inc | Transmission control in two-way signaling systems |
US2056235A (en) * | 1935-05-22 | 1936-10-06 | Bell Telephone Labor Inc | Resetting circuit for trigger devices |
US2091551A (en) * | 1935-06-22 | 1937-08-31 | Bell Telephone Labor Inc | Signaling system |
US2222248A (en) * | 1939-04-18 | 1940-11-19 | Bell Telephone Labor Inc | Ringing system |
US2253621A (en) * | 1940-04-05 | 1941-08-26 | Bell Telephone Labor Inc | Signaling system |
Family Cites Families (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
NL215077A (en) * | 1931-07-02 |
-
0
- BE BE477477D patent/BE477477A/xx unknown
- FR FR960757D patent/FR960757A/fr not_active Expired
-
1945
- 1945-03-27 FR FR54628D patent/FR54628E/en not_active Expired
-
1946
- 1946-04-06 US US660269A patent/US2498723A/en not_active Expired - Lifetime
- 1946-04-12 US US661493A patent/US2462144A/en not_active Expired - Lifetime
- 1946-10-04 GB GB29660/46A patent/GB636253A/en not_active Expired
Patent Citations (8)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
GB323804A (en) * | 1928-10-11 | 1930-01-13 | Western Electric Y | Improvements in impulse controlling arrangements for use in electrical signalling systems |
US2047729A (en) * | 1933-09-29 | 1936-07-14 | Bell Telephone Labor Inc | Transmission control in two-way signaling systems |
US2029693A (en) * | 1934-09-07 | 1936-02-04 | Bell Telephone Labor Inc | Telephone system |
US2045402A (en) * | 1935-01-17 | 1936-06-23 | Bell Telephone Labor Inc | Signaling system |
US2056235A (en) * | 1935-05-22 | 1936-10-06 | Bell Telephone Labor Inc | Resetting circuit for trigger devices |
US2091551A (en) * | 1935-06-22 | 1937-08-31 | Bell Telephone Labor Inc | Signaling system |
US2222248A (en) * | 1939-04-18 | 1940-11-19 | Bell Telephone Labor Inc | Ringing system |
US2253621A (en) * | 1940-04-05 | 1941-08-26 | Bell Telephone Labor Inc | Signaling system |
Cited By (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2579530A (en) * | 1947-04-29 | 1951-12-25 | Int Standard Electric Corp | Four-wire to two-wire connecting circuit |
US2914615A (en) * | 1952-10-09 | 1959-11-24 | Int Standard Electric Corp | Electric signal repeaters |
US3166642A (en) * | 1961-12-21 | 1965-01-19 | Bell Telephone Labor Inc | Signaling arrangement |
Also Published As
Publication number | Publication date |
---|---|
GB636253A (en) | 1950-04-26 |
FR960757A (en) | 1950-04-25 |
FR54628E (en) | 1950-07-07 |
US2462144A (en) | 1949-02-22 |
BE477477A (en) |
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