US2706746A - Figure selection with push buttons - Google Patents

Figure selection with push buttons Download PDF

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Publication number
US2706746A
US2706746A US236242A US23624251A US2706746A US 2706746 A US2706746 A US 2706746A US 236242 A US236242 A US 236242A US 23624251 A US23624251 A US 23624251A US 2706746 A US2706746 A US 2706746A
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US
United States
Prior art keywords
relay
frequency
resistance
contact
contacts
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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
US236242A
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English (en)
Inventor
Hullegard Erik Waldemar
Larshans Anders Georg Valentin
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.)
Telefonaktiebolaget LM Ericsson AB
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Telefonaktiebolaget LM Ericsson AB
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Publication of US2706746A publication Critical patent/US2706746A/en
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    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04M—TELEPHONIC COMMUNICATION
    • H04M1/00—Substation equipment, e.g. for use by subscribers
    • H04M1/26—Devices for calling a subscriber
    • H04M1/30—Devices which can set up and transmit only one digit at a time
    • H04M1/50—Devices which can set up and transmit only one digit at a time by generating or selecting currents of predetermined frequencies or combinations of frequencies
    • 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
    • H04Q1/45—Signalling arrangements; Manipulation of signalling currents using alternate current with voice-band signalling frequencies using multi-frequency signalling
    • H04Q1/453—Signalling arrangements; Manipulation of signalling currents using alternate current with voice-band signalling frequencies using multi-frequency signalling in which m-out-of-n signalling frequencies are transmitted
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04Q—SELECTING
    • H04Q3/00—Selecting arrangements

Definitions

  • the present invention relates to such automatic telephone systems, in which the subscribers instruments are for the sending of figures provided by means of push buttons instead of dials, and besides comprise a tone frequency generator for emission of different tone frequency currents depending on which one of the push buttons is pressed down.
  • the tone frequency currents actuate a tone signal receiver at an exchange and are transmitted to a register, which provides for the connection to a called line.
  • Each tone signal receiver is suitably connected with a register and the so connected units are common to a great number of subscribers lines. Due to the subscribers lines being of varying lengths and having different electrical properties difficulties thereby arise in separating tone frequency signals by means of filters and preventing the effect of disturbing voltages.
  • disturbances from harmonies in non-sinusoidal waves which are prevented by for at least one of the voice frequency currents to be a harmonic at the fundamental frequency for another one of the voice frequency currents, and by connecting the band pass filters to allow a harmonic to pass to only one receiving circuit to designate a signal in the receiver, while a band pass filter for a fundamental frequency is connected to at least two receiving circuits, one of which is also connected to the filter for one harmonic corresponding to the fundamental frequency, and which two circuits in combination designate a separate signal.
  • Fig. 1 shows a subscribers instrument
  • Fig. 2 shows on the upper part of the drawing a part of a connecting link and on the lower part of the drawing a part of the tone signal receiver in a register comprising a trigger and a device for supplying the subscribers instrument with direct current;
  • Fig. 3 shows relays for the register and filters for the tone signal receiver in the register
  • Fig. 4 shows how Figs. l-3 must be assembled.
  • M designates a microphone, H a telephone receiver and T11 a transformer and R a bell connected in series with a condenser C11.
  • the switch hook actuates the contacts 11-14, which are shown in their rest position on the drawing.
  • a push button K with contacts 16-16 depends in such a manner on the switch hook of the instrument, that if the push button is pressed down while the micro-telephone rests on the switch hook it is gifend held by a spring 17 until the micro-telephone is
  • the instrument further comprises a tone frequency generator consisting of an electron tube E1, two transformers T12 and T13, the resistances m11--m14 and the condensors C13C14. The frequency developed by the generator can be varied by means of push buttons Pl-Plt) and a condenser C15.
  • the subscribers line a--b is connected to a telephone exchange and upon originating a call is connected over a line finder SaCc in Fig. 2 to a connecting link SN, which is connected to a register REG by means of a register finder VaVc.
  • the electron tube E21 and the discharge lamp G2 form,- together with the resistances m22m25, a device for supplying the calling subscribers line with constant current.
  • the electron tube E23 together with the resistances m215-m223, forms a Wave shaper connected between the two amplifying tubes E22 and E24.
  • the transformer T2 is an output transformer for adapting the tube E24 to its load, which consists of the resistance m227 and the filters F1-F11 in Fig. 3.
  • Fl-Fll are filters for eleven (11) different frequencies, of which F1-F10 correspond to the push buttons Pl Plll in Fig. 1.
  • the frequency F11 is developed by the generator E1 in the subscribers instrument, when the push button K alone is pressed down and the microtelephone is not lifted.
  • the combined filters Fl-F 10 are over the rectifiers e1--e5, and others, connected to the discharge lamps 631-642.
  • a relay R11R22 is connected to each discharge lamp.
  • Four (4) discharge lamps with associated relays are used for each figure which is to be registered.
  • Relay R7 is a current feeding relay, which holds the connection between the calling subscriber and the register during dialing and establishing of the connection.
  • a call from the subscribers instrument in Fig. 1 starts when the push button K is pressed down, after which it is locked by the spring 17.
  • the contact 15 is closed and the contact 16 is broken.
  • the line circuit is closed over the contact 15, the right winding on transformer T12, resistance m12, the filament in the electron tube E1, with the parallel resistance m14, the right winding on transformer T13 and resistance r1113.
  • a line relay at the telephone exchange starts a line finder SaSc, which tests the cut off relay BR of the calling line.
  • the test relay SR3 attracts its armature.
  • the contacts 231-234 are closed.
  • the register finder Va--Vc selects a free register, after which relay SR1 attracts its armature and the contacts 211-213 are closed.
  • the electron tube E1 in Fig. l is actuated by said circuit.
  • the filament is heated, the screen grid is energized over the resistance mill and the anode is energized through transformer T12.
  • the control grid is energized with help of suitable current over the left winding on transformer T13 through the voltage drop in resistance m13.
  • the left winding on transformer T13 forms together with the condenser C14 an oscillating circuit, the frequency of which corresponds with the resonance frequency for the filter P11 in Fig. 3.
  • the oscillations in the oscillating circuit T13-C14 actuate the electron tube E1, which begins to oscillate and emits a tone frequency current through the transformer T12, the primary side of which is closed through the condenser C12.
  • the voltage on the screen grid is thereby kept relatively constant by means of the condenser C13.
  • the energizing current from the telephone exchange is kept constant by means of the electron tube E21 in Fig. 2.
  • the voltage of the screen grid is kept constant with relation to the cathode of the tube by means of the discharge lamp G2, which is energized through a series circuit including the resistances m24 and m25.
  • the voltage of the control grid of the electron tube B21 is kept constant by means of the resistances m22 and m23.
  • the energizing current over the subscribers line actuates relay R7 in Fig. 3.
  • the contacts 371-372 are closed.
  • Relay R7 is slow operating owing to the resistances m20 and m21 and the condenser C31, whereby relay R6 has time to attract and actuates the contacts 361362 before contact 372 is closed.
  • Relay R6 is actuated by the tone frequency current, the frequency of which is determined by condenser C14 in Fig. 1 and is allowed to pass through filter F11.
  • the contacts 361362 are actuated.
  • the a. c. generated by the electron tube E1 in Fig. 1 passes the condenser C21 and the resistance 171213 in Fig. 2.
  • the voltage over resistance m213 actuates the control grid of the amplifying tube E22, the screen-grid voltage of which is determined by the resistances 111226 and m216218.
  • the resistance 111212 and the condenser C23 keep the voltage of the screen-grid constant.
  • the amplified a. 0. passes over condenser C22 and resistance 111215 to the above mentioned trigger.
  • the trigger consists of a double tube E23 with resistances m219m223. At rest the left half of the tube E23 is energized and the voltage drop over resistance m220 produces a negative voltage on the control grid for the right half. If a voltage wave comes in over condenser C22 and resistance m215, one of its half waves will produce a change of the current through the tube E23 from the left half to the right half, so that the voltage drop over resistance m219, together with the voltage drop over resistance m220, produces on the control grid in the left half of the tube a negative voltage. When the current in the left half of the tube decreases, the voltage drop over the resistance m220 decreases, and the voltage on the right control grid increases. The current through resistance m221 suddenly ceases.
  • a rectangular current wave is obtained through the tube E24, the resistance 111225 and the transformer T2.
  • the transformer T2 is matched to the filters F1-F11 and the load resistance 111227.
  • the electron tubes E22E24 are energized with anode current from a battery with an electromotive force of 250 volts.
  • the transformer T2 in Fig. 2 is connected through the conductors t3t4 to the filters F1-F11 in Fig. 3.
  • Each filter comprises a transformer, two condensers, a coil and a load resistance, which are connected as is shown for filter F1 in Fig. 3.
  • the filter F11 is resonated for the frequency determined by condenser C14 and transformer T13 in Fig. 1.
  • Each one of the filters F1-F10 allows one of the ten frequencies to pass, these being developed by connecting the condenser C15 by means of one of the push buttons P1-P10 to different terminals on the left winding of transformer T13.
  • the push button P1 is pressed down, voltage arises over resistance 11141.
  • the transformer in filter F1 is energized through the resonance filter F1.
  • One of the half waves passes the rectifier el and the resistance m31 and the other one passes the rectifier e2 and the resistance m41.
  • the voltage over resistance 11141 is added to a voltage of 65 volts on the discharge lamp G31, which then glows.
  • Relay R11 attracts its armature through the following circuit; +150 volts, contact 371, winding on relay R11, discharge lamp G31, contact 311 to which is at ground potential.
  • the contact 301, and other contacts for registering operated by relay R11 (which are not shown on the figure), are actuated.
  • Relay R11 holds itself with an auxiliary voltage of +100 volts.
  • two circuits are closed, one from contact 361 through the upper winding of relay R5 over contact 351 and one over contact 341 through the lower winding of relay R5 to contact 372.
  • the two windings of relay R5 counteract each other, and therefore the said two circuits do not actuate relay R5.
  • relay R5 attracts its armature.
  • the contacts 3513S2 are actuated. Simultaneously the following circuit is closed; contacts 362, 343 and 315, winding on relay R1, contact 372 to negative.
  • Relay R1 attracts its armature.
  • the contacts 311-315 are actuated.
  • Relay R1 is thereafter kept energized over contact 314.
  • relay R6 releases its armature again.
  • the lower winding on relay R4 is energized over the contacts 361, 352 and 372. Since the two Windings on relay R4 counteract each other, relay R4 releases its armature.
  • Relay RS on the other hand is kept energized through its lower winding until the end of the signal and relay R6 attracts its armature, whereby the current is broken by contact 361.
  • Relay R5 releases its armature.
  • the following circuit is closed; contacts 362, 344 and 325, winding on relay R2, contacts 313 and 372 to negative.
  • Relay R2 attracts its armature. Contacts 321-325 are actuated. Relay R2 is kept energized over contact 324.
  • the voltage drops across resistances 21141 and m43 are added to the voltage of +65 volts and the discharge lamps G35 and G37 glow in the following circuit; contacts 312 and 321, discharge lamps G35 and G37 winding on relays R15 and R17, contact 371 to volts. Relays R15 and R17 attract their armatures and are held across contacts 302 and 303. Simultaneously other contacts of the relays G35 and G37 are also closed (which contacts are not shown on the drawing, since they are now essential to the invention).
  • the combination G35 and G37 indicates the figure corresponding to the signal.
  • a third figure can also be indicated in the register after relay R2 has attracted its armature.
  • One or two of the discharge lamps G39-G42 thereby glow and the corresponding relays R19-R22 attract their armatures.
  • Contact 331 breaks the current through the discharge lamps and a circuit is closed over contacts 312, 322 and 332 and wire t5 actuating parts of the register, which are not drawn on the figure, whereby an indication is given, that three figures have been received.
  • the register REG thereafter arranges a communication and is released by being connected to wire t6 in Fig. 2, whereby a circuit for relay SR2 is closed over the contact wiper Vc and contact 213.
  • Relay SR2 attracts its armature and the contacts 221-226 are actuated.
  • the current for relay SR1 is broken by contact 226.
  • Relay SR1 releases its armature and the register is released.
  • Relay SR2 is kept energized over contacts 225 and 233. A communication is established between the wires ab and the wires a1-b1.
  • the tone frequency currents received by the filters have a constant amplitude and a determined wave shape, whereby it becomes possible to avoid disturbances caused by harmonics.
  • the wave shaper in Fig. 2 gives a rectangular voltage wave with marked harmonics. These are however determined as to their frequency and amplitude, and therefore it is possible to prevent disturbing effects. This can be done by selecting the eleven frequencies, which are used for signal emission, so that by means of well tuned filters they can be certainly distinguished from the disturbing harmonies.
  • Another way of preventing disturbances from harmonies is to select the eleven frequencies so that the high frequencies act as harmonics with respect to rectangular waves of some of the low frequencies and to connect a filter for a low frequency with a filter for a high frequency, the latter being a harmonic for the low frequency, and let the frequency combination represent a signal.
  • This method has been used in the above described embodiment and will be more clearly illustrated below with the aid of an example.
  • the frequencies for which the filters F1F10 are resonated are indicated in relation to those of the discharge lamps G31-G34, which glow at the first figure, and to the figures lcorresponding to the push buttons P1-P10 in Fig. 1.
  • the filter F5 allows the frequency 1060 cycles per sec. to pass, the second hamonic of which is about 2000 cycles per sec. and passes the filter F1.
  • the filter F5 is connected across the rectifier e6 to the discharge lamp G31, as well as the filter F1, and the combination of the discharge lamps G31 and G32 corresponds to the figure 5.
  • the filter F8 is resonated for 670 cycles per sec., the third harmonic of which is about 2000 cycles per sec., and therefore F8 is connected as well to G31 as to G34 and the combination G31+G34 corresponds to the figure 8.
  • a line circuit at least one sending station including a sender and at least one receiving station including a receiver therein, a voice frequency generator in said sender for transmitting voice frequency currents and a key set in said sender connected to said voice frequency generator for controlling the frequency of the currents transmitted by the sender over the line circuit to the receiver, a plurality of band pass filters in said receiver tuned respectively to the currents generated by said generator, and a plurality of designating circuits connected to said filters to be energized by the respective currents, the frequency of at least one of said currents being substantially a harmonic with respect to the fundamental frequency of another of said currents, the band pass filter for said harmonic being connected to only one of said designating circuits, and the band pass filter for said another of said currents being connected both to the last-named designating circuit and to at least one other of said circuits for designating another signal through the combination of the said latter two circuits.
  • a line circuit at least one sending station including a sender and at least one receiving station including a receiver, a voice frequency generator in said sender for transmitting voice frequency currents and a key set connected to said voice frequency generator for controlling and selecting the frequency of the currents transmitted by the sender over the line circuit to the receiver, a wave shaper in said receiver connected to the incoming end of the line circuit for transforming incoming alternating voltage waves from said line circuit into alternating voltage waves of predetermined shape and constant amplitude having the same fundamental frequency as the incoming waves, said receiver also including a plurality of band pass filters connected to said wave shaper and individually tuned to the frequencies produced by said generator, and a plurality of circuits connected to said filters to be energized by the respective currents, the frequency of at least one of said currents being an harmonic with respect to the fundamental frequency of another of said currents, the band pass filter tuned to said harmonic being connected to only one of said circuits for designating a signal, and the band pass filter tuned to said fundamental frequency being connected both to
  • a line circuit at least one sending station including a sender and at least one receiving station including a receiver, said sender including a switch and a tone frequency generator which emits tone frequency current having a fundamental frequency which indicates a signal and which frequency is determined by the position of said switch, in said receiver at least one registering device consisting of relays connected to be energized in combinations, and filters connected thereto, and a wave shaper connected ahead of said filters for transforming incoming alternating waves of arbitrary shapes and amplitudes into wave shapes of predetermined forms and constant ampiltude with the same fundamental frequency as the incoming alternating wave, at least one of said filters tuned to pass a low frequency signal being connected to more than one registering relay in said registering device, whereby signals passed by said filter are indicated by more than one simultaneously actuated registering relay, and another of said filters tuned to pass higher frequency signals being connected to only a single registering relay in said registering device, said higher frequency being harmonic with respect to the fundamental frequency of said low frequency signal, and one of said sender including a switch and
  • a first and a second registering device in said receiver each consisting of relays which are energized in combinations, means including a switch in the sending station for tuning said tone frequency generator to a predetermined frequency when said switch is in its rest position, and for changing said certain frequency to a signaling frequency when operated and restoring said predetermined frequency upon return to its rest position, controlling means in said receiver responsive to said predetermined frequency and a relay device operated by said controlling means for disconnecting said first and connecting said second registering device to said filters when said switch is operated and returns to its rest position.

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  • Engineering & Computer Science (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Signal Processing (AREA)
  • Circuit Arrangements For Discharge Lamps (AREA)
  • Selective Calling Equipment (AREA)
  • Exchange Systems With Centralized Control (AREA)
  • Alarm Systems (AREA)
US236242A 1950-07-21 1951-07-11 Figure selection with push buttons Expired - Lifetime US2706746A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
SE691237X 1950-07-21

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US2706746A true US2706746A (en) 1955-04-19

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US236242A Expired - Lifetime US2706746A (en) 1950-07-21 1951-07-11 Figure selection with push buttons

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US (1) US2706746A (enrdf_load_html_response)
DE (1) DE886929C (enrdf_load_html_response)
GB (1) GB691237A (enrdf_load_html_response)
NL (2) NL81161C (enrdf_load_html_response)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2909609A (en) * 1954-10-25 1959-10-20 Ericsson Telefon Ab L M Connecting device for sending tone frequency alternating current signals over a two-conductor line
US3076059A (en) * 1958-06-20 1963-01-29 Bell Telephone Labor Inc Signaling system

Families Citing this family (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE1001713B (de) * 1953-12-07 1957-01-31 Telefonbau & Normalzeit Gmbh Telefonteilnehmerstation mit tastengesteuerter Frequenzwahl und einem Schichttransistoren enthaltenden Mikrophonverstaerker
DE1085201B (de) * 1955-01-19 1960-07-14 Josef Dirr Schaltungsanordnung zur Auswertung von ueber abgeriegelte Leitungen uebertragenen, zeitlich versetzten Wechselstromimpulsen einer Frequenz fuer die Identifizierung von Leitungen zur Gebuehrenerfassung in Fernmelde-, insbesondere Fernsprechanlagen
DE1017661B (de) * 1956-01-30 1957-10-17 Telefonbau & Normalzeit Gmbh Einrichtung zur Nummernsendung in Form codifizierter Signale in Fernsprechapparaten
DE1039107B (de) * 1956-06-28 1958-09-18 Standard Elektrik Lorenz Ag Schaltungsanordnung fuer elektrische, ueber Fernleitungen an eine Zentralbatterie angeschlossene Einrichtungen
CH379584A (de) * 1958-09-03 1964-07-15 Standard Telephon & Radio Ag Elektrische Signalisier-Einrichtung
DE1090273B (de) * 1959-05-09 1960-10-06 Philips Nv Schaltungsanordnung zur Auswertung von Signalen verschiedener Frequenzen in Fernmeldeanlagen
DE1082300B (de) * 1959-06-04 1960-05-25 Siemens Ag Schaltungsanordnung fuer Teilnehmerstellen in Fernmelde-, insbesondere Fernsprech-anlagen mit Tastaturwahl
GB961545A (enrdf_load_html_response) * 1959-10-02
DE1152447B (de) * 1960-03-10 1963-08-08 Neumann Elektronik Gmbh Wechsel-Lautsprechanlage mit tongesteuerten Verbindungswegen

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2250100A (en) * 1939-11-14 1941-07-22 Bell Telephone Labor Inc Signaling system
US2554201A (en) * 1946-06-19 1951-05-22 Ericsson Telefon Ab L M Key-sending automatic telephone signaling system

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2250100A (en) * 1939-11-14 1941-07-22 Bell Telephone Labor Inc Signaling system
US2554201A (en) * 1946-06-19 1951-05-22 Ericsson Telefon Ab L M Key-sending automatic telephone signaling system

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2909609A (en) * 1954-10-25 1959-10-20 Ericsson Telefon Ab L M Connecting device for sending tone frequency alternating current signals over a two-conductor line
US3076059A (en) * 1958-06-20 1963-01-29 Bell Telephone Labor Inc Signaling system

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DE886929C (de) 1953-08-20
GB691237A (en) 1953-05-06
NL162796B (nl)
NL81161C (enrdf_load_html_response)

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