US2414440A - Voice frequency ringer - Google Patents

Voice frequency ringer Download PDF

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Publication number
US2414440A
US2414440A US579126A US57912645A US2414440A US 2414440 A US2414440 A US 2414440A US 579126 A US579126 A US 579126A US 57912645 A US57912645 A US 57912645A US 2414440 A US2414440 A US 2414440A
Authority
US
United States
Prior art keywords
frequency
signalling
branch
circuit
relay
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US579126A
Other languages
English (en)
Inventor
Brandt Walter
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
STC PLC
Federal Telephone and Radio Corp
Original Assignee
Standard Telephone and Cables PLC
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority to BE467777D priority Critical patent/BE467777A/xx
Application filed by Standard Telephone and Cables PLC filed Critical Standard Telephone and Cables PLC
Priority to US579126A priority patent/US2414440A/en
Priority to GB4826/46A priority patent/GB608117A/en
Priority to FR922528D priority patent/FR922528A/fr
Priority to ES172956A priority patent/ES172956A1/es
Application granted granted Critical
Publication of US2414440A publication Critical patent/US2414440A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04J—MULTIPLEX COMMUNICATION
    • H04J1/00—Frequency-division multiplex systems
    • H04J1/02—Details
    • H04J1/14—Arrangements providing for calling or supervisory signals
    • 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

Definitions

  • This invention relates to signalling as exemplied in voice frequency ringing circuits. It has been found advantageous in various types of cornmunication system to employ an A.C. frequency for ringing or other signalling which lies within an important portion of the voice frequency range. The currents for both voice and signalling traverse the same path to some extent. in
  • An object of the present invention is to provide a signalling system wherein, the case cf two-branch channel terminal between a trunking cnice and a carrier frequency line, the oscillator of the receiving branch is detuned under control of the low frequency signal-control cul'- rent from the oiiice, and the currents of altered frequency are applied over the remaining portion of the receiving branch and thence through the hybrid coil to the transmitting branch and there treated and transmitted in the same manner as voice currents.
  • Another object is to provide at a receiving point an arrangement for separating signalling or ringing and voice currents as they are received over a common circuit without altering such circuit.
  • a related object is to (so-ordinate the transmitting and receiving signalling arrangements for proper operation in a two-branch trunking terminal of the type above mentioned.
  • a further object is to provide a discriminator capable of translating effectively, the signalling current energy in the voice frequency range as received over a common circuitl into a ringing control form and suppressing the effect for that purpose of voice currents received thereover.
  • Fig. 1 shows diagrammatically one embodiment of my invention as applied to a two-way terminal between a trunk cfce and acarrier line in a. telephone system
  • Fig. 2 shows in similar manner a, modified form of the receiving and discriminating portion.
  • a. two-branch terminal which in its general aspects is conventional.
  • my invention has been applied in such a, way that-the one direction signalling or ringing ⁇ current is transmitted over one branch and in the opposite direction it is received and translated into signal controlling form in the other branch.
  • the incoming trunk from an oice transmits a control signal which, for example may be alternating current of 20 cycles per second.
  • Bridged across this incoming line is an A.C. relay RELI.
  • Contact RII of this relay controls the continuity of the incoming line at a point on the ⁇ terminal side of the bridge.
  • contact RIZ controls the continuity of the primary Winding of the output transformer of this demodulator while contact RI3 controls continuity of the neutral line in the demodulator so that by a change of this contact, a, secondary winding of the transformer, coupling oscillator 2 to the demodulator, is switched from said neutral circuit to the half of the primary winding which is not controlled by RI2. In this way the demodulator is unbalanced and the output of oscillator 2 is applied in series with the said half of the primary of the output transformer.
  • Contact RM of said relay RELI controls a variation of capacitance in the tank circuit of oscillator ⁇ 2 so as to alter its frequency to a point where it may be used for producing the modulation in accordance with the desired signalling, for example, in the order of 2500 cycles per second.
  • the receiving portion of my invention is con- 3 stituted as follows:
  • the output transformer TR has an additional secondary winding. This serves to couple the conventional receiving branch path over contacts RIS of relay RELI to a receiving discriminator arrangement RD.
  • this arrangement comprises a thermionic tube which as shown is a pentode, although it could be of other yadaptable construction.
  • This tube has the usual biassing parallel arrangement C2-R2 and the control grid is coupled back over the capacitor Cl to said additional secondary winding.
  • the tube is provided with an output circuit which is connected across an additional grid, such as a screen grid, and the anode. Across this circuit is bridged relay REL 2. This circuit is extended also to a network which may be properly termed the discriminator itself.
  • the L-C circuit offers only a low impedance while R3 offers a high impedance so that the energyV produced by a resistance drop in R3 is rectified by rectier D2 in a proper direction so that a D.C. potential appearing across the combination R'I-Cl will be of the polarity opposite to that produced in case of the single frequency thereby producing by way of the feed-back a sufficiently negative biassing potential for maintaining relay RELZ inoperative.
  • the demodulated lringing orsingle frequency signal by operating relay REL2 shifts contacts R2l, R22 so as to break the connection of the incoming olce trunk to the hybrid coil and apply low frequency control current to said office trunk for indicating the incoming signalling or ringing operation. It will be noted also that the shifting of contacts R'l, R22 prevents the direct application of the ringing or signalling current itself to the olice trunk line.
  • a desired time delay can be effected by a proper choice of values among the elements R4, R5, R6, Rl, C5 and Cl.
  • the feed-back arrangement offers the advantage of increased sensitivity and reliability in the operation of the discriminator.
  • a receiver discriminator RD which is modified from that inFig. 1.v
  • This discriminator comprises in general, an amplifying tube A andan input therefor consisting of av terminal by way of transformer TR is like that inV Fig. l. Between its upper two terminals C and D, ⁇
  • this network has two paths.
  • One comprises a narrowband-pass lter consisting of a series resonant circuit Fl and an anti-resonant circuit F2; the other path comprises an antiresonant circuit F3 and a rectier E so poled as to pass only the negative half waves.
  • the return circuit of antiresonant loop F3 is by way ofV resistance L, of low value which acts asa lo-ad for said loop circuit F3.
  • the return from the opposite pole of the rectifier is by way of the high resistance M which acts as a D.-C. path for the rectifiedV current and also, along with aV parallel capacity C9, constitutes delay circuit.
  • the incoming energy is essentially only that of a particular signalling frequency to which above described narrow band-pass lter without traversing the rectifier and is applied to the grid of the tube in such a way as to materially increase the iiow of plate current and, thereby, operate relay RELZ.
  • the incoming en- .ergy is of various frequencies in the voice band
  • Apparatus according to claim 1 wherein said means responsive to said control currents includes means for unbalancing the demodulator and establishing a path for oscillations from the oscillator to the outgoing end of the receiving branch.
  • a signalling apparatus having a two-branch telephone trunking circuit having an oscillator in a transmitting branch and an oscillator in the receiving branch, means responsive to control currents to alter the tuning of the receiving branch oscillator to produce signalling currents of voice frequency, means for transferring said signal currents to the transmitting branch to control the energy of the transmitting oscillator and means for transmitting said controlled energy.
  • a signalling apparatus wherein the hybrid coil connects the two branches to the line carrying the incoming control currents, and the responsive means conditions the hybrid coil for said current transferring.
  • a signalling apparatus comprising a line transmitting a band of low frequency alternating currents, a bridge thereacross including in series a loop circuit antiresonant to substantially a single frequency in said band and a resistance, a thermionic relay coupled to said line, means for biassing said relay to control its operation including means for translating thereto differentially the band and the single frequency energies respectively as determined by said bridge.
  • a signalling apparatus according to claim 6 wherein the translating means includes a rectifier for determining the polarity of the biassing means.
  • a signalling apparatus comprising a line transmitting a band of low frequency alternating currents coupled to the input of a thermionic re-v lay, an output circuit for said relay, a bridge thereacross including in series a loop circuit antiresonant to substantially a single frequency in said band and a resistance, means for reotifying selectively the low frequency energies across the anti-resonant loop and resistance, and means for combining their direct current products to bias the tube for selective operation.
  • Apparatus according to claim 8 having means for differentially combining the direct current energies.
  • a signalling apparatus comprising a line transmitting a band of low frequency alternating currents, a frequency discriminating network comprising a band lter passing substantially only a single frequency with further means for passing with little attenuation frequencies. ⁇ of said rst mentioned band other than said single frequency, said network including means for deriving from said frequencies a direct current potential, a thermionic relay connected to said network and means for selectively controlling operation of the thermionic relay in accordance with the output energy of said filter and said further means.
  • Apparatus according to claim 10 wherein the network includes an impedance bridge across said line having in series a loop anti-resonant to said single frequency and a resistance.

Landscapes

  • Engineering & Computer Science (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Signal Processing (AREA)
  • Telephonic Communication Services (AREA)
  • Devices For Supply Of Signal Current (AREA)
US579126A 1945-02-21 1945-02-21 Voice frequency ringer Expired - Lifetime US2414440A (en)

Priority Applications (5)

Application Number Priority Date Filing Date Title
BE467777D BE467777A (es) 1945-02-21
US579126A US2414440A (en) 1945-02-21 1945-02-21 Voice frequency ringer
GB4826/46A GB608117A (en) 1945-02-21 1946-02-15 Voice frequency ringer
FR922528D FR922528A (fr) 1945-02-21 1946-02-18 Perfectionnement aux procédés de signalisation à fréquence vocale
ES172956A ES172956A1 (es) 1945-02-21 1946-03-20 Mejoras en aparatos de llamada a frecuencia vocal

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US579126A US2414440A (en) 1945-02-21 1945-02-21 Voice frequency ringer

Publications (1)

Publication Number Publication Date
US2414440A true US2414440A (en) 1947-01-21

Family

ID=24315671

Family Applications (1)

Application Number Title Priority Date Filing Date
US579126A Expired - Lifetime US2414440A (en) 1945-02-21 1945-02-21 Voice frequency ringer

Country Status (5)

Country Link
US (1) US2414440A (es)
BE (1) BE467777A (es)
ES (1) ES172956A1 (es)
FR (1) FR922528A (es)
GB (1) GB608117A (es)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2585019A (en) * 1945-02-06 1952-02-12 Int Standard Electric Corp Voice frequency signaling circuit
US2751436A (en) * 1952-03-27 1956-06-19 Automatic Elect Lab Carrier current telephone systems
US2837604A (en) * 1954-01-22 1958-06-03 Lignes Telegraph Telephon Signal receiving device

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE1004860B (de) * 1952-12-18 1957-03-21 Roland Laraque Brennkraftmaschine mit gegenlaeufigen Kolben

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
None *

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2585019A (en) * 1945-02-06 1952-02-12 Int Standard Electric Corp Voice frequency signaling circuit
US2751436A (en) * 1952-03-27 1956-06-19 Automatic Elect Lab Carrier current telephone systems
US2837604A (en) * 1954-01-22 1958-06-03 Lignes Telegraph Telephon Signal receiving device

Also Published As

Publication number Publication date
GB608117A (en) 1948-09-09
ES172956A1 (es) 1946-05-01
FR922528A (fr) 1947-06-11
BE467777A (es)

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