US2426205A - Pulse selecting circuit for multiplex systems - Google Patents

Pulse selecting circuit for multiplex systems Download PDF

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Publication number
US2426205A
US2426205A US651652A US65165246A US2426205A US 2426205 A US2426205 A US 2426205A US 651652 A US651652 A US 651652A US 65165246 A US65165246 A US 65165246A US 2426205 A US2426205 A US 2426205A
Authority
US
United States
Prior art keywords
pulses
pulse
time
tube
circuit
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
US651652A
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English (en)
Inventor
Donald D Grieg
Arnold M Levine
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.)
Federal Telecommunication Laboratories Inc
Original Assignee
Federal Telecommunication Laboratories Inc
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 BE474955D priority Critical patent/BE474955A/xx
Priority to NL77425D priority patent/NL77425C/xx
Priority to FR954530D priority patent/FR954530A/fr
Priority to US550183A priority patent/US2535061A/en
Application filed by Federal Telecommunication Laboratories Inc filed Critical Federal Telecommunication Laboratories Inc
Priority to US651652A priority patent/US2426205A/en
Priority to ES0178257A priority patent/ES178257A1/es
Priority to CH275028D priority patent/CH275028A/fr
Priority to GB14993/47A priority patent/GB624542A/en
Priority to FR57771D priority patent/FR57771E/fr
Priority to FR57642D priority patent/FR57642E/fr
Priority to FR57904D priority patent/FR57904E/fr
Application granted granted Critical
Publication of US2426205A publication Critical patent/US2426205A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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Classifications

    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
    • G01R29/00—Arrangements for measuring or indicating electric quantities not covered by groups G01R19/00 - G01R27/00
    • G01R29/02—Measuring characteristics of individual pulses, e.g. deviation from pulse flatness, rise time or duration
    • G01R29/027—Indicating that a pulse characteristic is either above or below a predetermined value or within or beyond a predetermined range of values
    • G01R29/0273—Indicating that a pulse characteristic is either above or below a predetermined value or within or beyond a predetermined range of values the pulse characteristic being duration, i.e. width (indicating that frequency of pulses is above or below a certain limit)
    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03K—PULSE TECHNIQUE
    • H03K9/00—Demodulating pulses which have been modulated with a continuously-variable signal
    • H03K9/04—Demodulating pulses which have been modulated with a continuously-variable signal of position-modulated pulses
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B14/00—Transmission systems not characterised by the medium used for transmission
    • H04B14/02—Transmission systems not characterised by the medium used for transmission characterised by the use of pulse modulation
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B14/00—Transmission systems not characterised by the medium used for transmission
    • H04B14/02—Transmission systems not characterised by the medium used for transmission characterised by the use of pulse modulation
    • H04B14/026—Transmission systems not characterised by the medium used for transmission characterised by the use of pulse modulation using pulse time characteristics modulation, e.g. width, position, interval
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04J—MULTIPLEX COMMUNICATION
    • H04J3/00—Time-division multiplex systems
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04J—MULTIPLEX COMMUNICATION
    • H04J3/00—Time-division multiplex systems
    • H04J3/02—Details
    • H04J3/04—Distributors combined with modulators or demodulators
    • H04J3/042—Distributors with electron or gas discharge tubes

Definitions

  • the pulses forming the separate channels are interleaved and have dilferent time displacements with respect to regularly repeated marker or synchronizing pulses.
  • the marker pulses may be single pulses having a distinct characteristic, such as a unique width distinguishing them from the signal pulses, or the marker pulses may consist of pairs of closely spaced pulses having a different time displacement from each other than have the signal pulses.
  • the signal pulses are time modulated but the eX-V tent of modulation is so related to the spacing of the pulses as to prevent a pulse of one channel from moving into a time position received for a pulse of another channel.
  • An object of the present invention is the provision of an improved circuit for selecting channels, and for demodulating the time modulated pulses in the selected channels of a multi-channel pulse communication system of the type hereinabove described.
  • Another object is the provision of a circuit, of the type hereinabove described, which is characterized by its simplicity.
  • the circuit hereinabove described acts as a demodulator by producing rectangular waveforms of variable width (duration) corresponding to the time elapsing between the marker pulses and the associated signal pulses of the channel to be selected.
  • Each of these rectangular waveforms is initiated terminated by the associated signal pulse of the selected channel. Consequently the width of each of these waveforms is a function of the time modulation of the pulse terminating them.
  • variable width rectangular waveforms are applied to a suitable utilization device.
  • each of the rectangular waveforms can only be terminated by a signal pulse occurring during a given interval beginning at a selected time after the marker pulse, the duration of said interval being sulcient to include the extremes of time displacement of the pulse of the selected channel due to the time modulation of said pulse.
  • Fig. 2 is a schematic diagram of one of the selector circuits, shown in block diagram in Fig. I;
  • Fig. 3 is a set of curves used in describing the operation of the selector circuit embodying our invention, these curves having no exact quantitative significance, but being introduced merely to enable easier understanding of the present invention.
  • a plurality of signal pulses as for example, signal pulses I--8, each forming part of a separate channel, are interleaved in sequence and progressively displaced in time with respect to an associated marker pulse 9.
  • the marker pulse 9 is distinguished from the signal pulses for eXample by having a different width (as illustrated in curve A, Fig, 3) or by some other distinguishing means.
  • the marker or synchronizing pulse S may consist of two pulses having a different spacing therebetween than the spacing between the signal pulses.
  • the marker pulses 9 are regularly repeated and so are the signal pulses I--8 except for the variation due to the time modulation of said pulses within relatively narrow limits a and b.
  • Pulses l-9 may be generated, and the signal pulses I- may be time modulated, in a manner known in the art. They may be then used to modulate a carrier and radiated, or carried over a wire, or the pulses I-S may be transmitted to a receiver by any suitable transmission medium. Pulses I-B are preferably all of the same amplitudc.
  • the incoming pulses may go through a receiver unit I 0 which may be used to assure that all the output pulses thereof are of equal amplitude.
  • These equal amplitude pulses similar to those illustrated in curve A (Fig. 3) are then fed to a plurality of channels Ii, I2, I3, etc., over lines I4, I5, I6, etc.
  • the marker or synchronizing pulses 9 are separated by a suitable marker separator circuit I 'I and fed over lines I8, I9 and 2l] into various channels II, I2, I3 respectively.
  • the marker separator circuit II may be any suitable known device Which utilizes the distinct characteristics of the marker pulses 3 to separate them from the signal pulses.
  • the separator I1 may be any known form of pulse Width selector.
  • channel II there is provided a selector circuit 2
  • the selector circuit produces a rectangular waveform in response to pulses of the selected channel, the width of said waveform varying in accordance with the time modulation of the pulse of the selected channel.
  • a suitable integrating circuit 22 which may be for example, an audio lter and are thereafter fed to a suitable utilization device 23, which may consist for example, of audio amplifiers and a sound reproducer.
  • is a multivibrator which is adapted to be tripped by a marker pulse and to be returned by the following signal pulse of the selected channel.
  • the multivibrator will return to its ,original state or output voltage level after a time has elapsed from the initiation of its oscillation equal to the maximum time between any synchronizing pulse and the most extremely displaced pulse of the selected channel.
  • the synchronizing or marker pulses 9 each generate a blocking voltage waveform which has a duration substantially equal to said minimum time, and which blocking voltage preventsI return of the multivibrator to its original level.
  • may include two electron tubes 24 and 25 each of which may be a triode and may be contained within a single envelope.
  • Tube 24 is normally blocked to cut-off as for example by means of a potential derived from the positive side of a source 2S which is applied through a suitable resistor 2'! to the cathode of tube 24 and which may further include a cathode resistor 28 shunted by the usual by-pass condenser 29.
  • the marker pulses 9 are fed to the grid of tube 24 over line I8 and a suitable grid resistor 30 is provided between line I8 and ground.
  • the marker pulses 9 applied to the grid of tube 24 are sufcient in amplitude to cause said tube to conduct.
  • the anode of tube 24 becomes negative.
  • the anode of tube 24 is coupled over a variable condenser 3
  • a negative voltage is thereby impressed upon the grid of tube 25 which causes the anode of said tube to become positive.
  • the anode of tube 25 is connected over a coupling condenser 32 to the output. This the potential in the output of multivibrator circuit 2
  • the anode of tube 25 is coupled by means of the 1usual condenser 33 to the grid of tube 24.
  • is selected so that in the absence of any signal pulse, its duration is equal to the maximum time displacement between a signal pulse of the selected channel and the marker pulse with which it is associated.
  • will terminate substantially at a time T4, corresponding to the maximum displacement 3b of pulse 3 from marker pulse 9.
  • pulses occurring after time T4 will have no effect upon the rectangular wave form produced by the multivibrator since their application at point I4 to the grid of tube 25, will have negligible effect especially in view of the fact that the voltage swing of the multivibrator may be, for example, of the order of volts, whereas the amplitude of the pulses may be for example, l0 or 20 volts. Moreover since the pulses applied over line I4 cannot trigger the multivibrator, it will not be tripped again until the next marker pulse 9 arrives.
  • the grid of tube 25 is coupled to the anode through condenser 3 I, but due, however, to the constants of the condenser 3
  • the shape of the curve 4I) which is made as linear as possible, and the time it begins may be adjusted by adjusting the value of condenser Ei and its associated resistors. Pulses I and 2 occurring before time T2 are insufficient to cause tube 25 to conduct and return the multivibrator to its original state.
  • an adjustable tuned tank circuit 43 which may be in the form of a permeability-tuned nductance coil 44, (which for example may be tuned by moving slugs in and out of said coil to vary its permeability) said coil having an inherent capacity 45 making it a resonant or tuned circuit.
  • Coil 44 is shunted by a rectifier 4S.
  • thev anode goes negative, thereby shock-exciting tank circuit 43 and producing a negative undulation 41 (curve C, Fig. 3)
  • the negative undulation 41 has a duration slightly less than the minimum interval between the selected pulse and the marker pulse and slightly more than the maximum interval between the pulse preceding the selected pulse and the marker pulse.
  • the negative undulation 41 will have a duration from time T1 to slightly less than time T2 but slightly more than the widest separation of any pulse 2 from its associated marker pulse 9.
  • the positive undulation which would normally follow the negative undulation 41 is damped out by rectier tube 45, which preferably has as low an internal impedance as possible to assure rapid and complete critical damping of the positive undulation.
  • pulses will be capable of causing ⁇ the multivibrator to return to its original position because these pulses will cause the level of the grid of tube 25 to reach the critical level 4
  • the multivibrator will be returned to its original level at time T3 and the resulting output voltage will have a duration equal to time T1 to T3 and having a rectangular waveform 50. If pulse 3 is in position 3a at one extreme of modulation at which it is nearest to the marker pulse, the resulting output voltage Will have a rectangular waveform as shown in curve E at 5
  • the rectangular waveform of the resulting voltage will be that designated by numeral 52. Accordingly, voltages of rectangular waveforms of different duration, depending upon the time modulation of the signal pulses will be produced. These voltages will have diiferent energy content and any one of various suitable utilization means, which may include for example, an integrating circuit 22, may be used to respond in accordance with the energy content of these rectangular waveforms.
  • may be made to select any desired channel.
  • and resistor 34 may be ganged together to enable simultaneous tuning of these elemenits in one manual movement.
  • a single selector circuit may be employed to successively select different ones of a number of pulse signal channels. If, however, it is desired to simultaneously receive several channels, then an equal number of selector circuits, as illustrated in Fig. 1, may be employed, each of said selector circuits being tuned to a separate channel.
  • selector circuit While we have described the selector circuit as being primarily Ia multivibrator, it will be apparent to those versed in the art that other types of circuits, such as various forms of flip-flop circuits, may be used in place thereof.
  • a receiving system wherein said circuit is a multivibrator.
  • a receiving system including adjustable means associated with said circuit and responsive to each of said synchrcnizing pulses to produce a blocking voltage having a duration substantially equal to the minimum interval between la synchronizing pulse and an associated signal pulse of the channel to be selected.
  • a receiving system wherein said circuit comprises a multivibrator.
  • a receiving system for receiving a desired one of a, plurality of channels of pulses interleaved in sequence in the form of a single multichannel pulse train, the pulses of one of the channels being provided with an identifying characteristic distinct from the pulses of the other channels for use as synchronizing pulses, and the pulses of at least the selected one of said channels being time modulated signal pulses; a multivibrator adapted to have a normal period of oscillation substantially as great as the maximum interval between a synchronizing pulse and the associated signal pulse of the selected channel, means for applying the synchronizing pulses to said multivibrator to trip it, means for applying the signal pulses to said multivibrator tending to re-trip it, adjustable means associated with said multivibrator and responsive to each of said synchronizing pulses to produce a blocking voltage having a duration substantially equal to the minimum interval between said associated signal pulse of the channel to be selected and its synchronizing pulse, and utilization means responsive to the output of said multivibrator.

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  • Engineering & Computer Science (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Signal Processing (AREA)
  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Manipulation Of Pulses (AREA)
  • Synchronisation In Digital Transmission Systems (AREA)
  • Selective Calling Equipment (AREA)
US651652A 1944-08-19 1946-03-02 Pulse selecting circuit for multiplex systems Expired - Lifetime US2426205A (en)

Priority Applications (11)

Application Number Priority Date Filing Date Title
BE474955D BE474955A (da) 1946-03-02
NL77425D NL77425C (da) 1946-03-02
FR954530D FR954530A (da) 1946-03-02
US550183A US2535061A (en) 1944-08-19 1944-08-19 Electrical pulse width shaper and selector
US651652A US2426205A (en) 1946-03-02 1946-03-02 Pulse selecting circuit for multiplex systems
ES0178257A ES178257A1 (es) 1946-03-02 1947-05-30 Mejoras en sistemas receptores
CH275028D CH275028A (fr) 1946-03-02 1947-06-02 Récepteur pour installation de communication à voies multiples.
GB14993/47A GB624542A (en) 1946-03-02 1947-06-06 Improvements in or relating to receivers for multichannel pulse communication systems
FR57771D FR57771E (fr) 1946-03-02 1947-08-07 Systèmes de signalisation et de commande par impulsions électriques
FR57642D FR57642E (fr) 1946-03-02 1947-08-07 Système de signalisation et de commande par impulsions électriques
FR57904D FR57904E (fr) 1946-03-02 1947-08-07 Système de signalisation et de commande par impulsions électriques

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US651652A US2426205A (en) 1946-03-02 1946-03-02 Pulse selecting circuit for multiplex systems

Publications (1)

Publication Number Publication Date
US2426205A true US2426205A (en) 1947-08-26

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Application Number Title Priority Date Filing Date
US651652A Expired - Lifetime US2426205A (en) 1944-08-19 1946-03-02 Pulse selecting circuit for multiplex systems

Country Status (7)

Country Link
US (1) US2426205A (da)
BE (1) BE474955A (da)
CH (1) CH275028A (da)
ES (1) ES178257A1 (da)
FR (4) FR57642E (da)
GB (1) GB624542A (da)
NL (1) NL77425C (da)

Cited By (16)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2499844A (en) * 1947-01-16 1950-03-07 Philco Corp Receiver for pulse-position-modulation systems
US2516867A (en) * 1948-06-12 1950-08-01 F A R Liquidating Corp Stabilized one-shot multivibrator
US2524708A (en) * 1947-02-06 1950-10-03 Gen Electric Co Ltd Pulse multiplex receiving system
US2529172A (en) * 1948-12-30 1950-11-07 Gen Electric Pulse discriminating circuits
US2553752A (en) * 1947-04-15 1951-05-22 Bell Telephone Labor Inc Combined multivibrator and sweep circuit
US2567203A (en) * 1946-02-05 1951-09-11 Marcel J E Golay Multiplex communication system utilizing successive, different pulse modulation techniques
US2589240A (en) * 1945-04-07 1952-03-18 William E Frye Double pulse generator
US2589617A (en) * 1947-07-07 1952-03-18 Alfred C Kowalski Pulse amplitude modulation communication system
US2639385A (en) * 1947-09-05 1953-05-19 Bell Telephone Labor Inc Alternating wave generator
US2722601A (en) * 1949-08-01 1955-11-01 Electronique & Automatisme Sa Electric impulse counting chains
US2866894A (en) * 1952-09-02 1958-12-30 Ericsson Telefon Ab L M Device for demodulating duration modulated pulses
US2891148A (en) * 1953-09-01 1959-06-16 Rca Corp Multivibrator with cathode stabilized by a capacitor
US2898478A (en) * 1957-03-21 1959-08-04 Bendix Aviat Corp Reduction of multivibrator recovery time
US2899552A (en) * 1959-08-11 X e electric pulse generating apparatus
US2911595A (en) * 1955-06-14 1959-11-03 Gen Electric Relaxation oscillators and control method therefor
US2984833A (en) * 1948-12-16 1961-05-16 Robert T Nieset Super-regenerative radio ranging device

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE2545891C2 (de) * 1975-10-14 1984-04-26 Efka-Werke Fritz Kiehn Gmbh, 7218 Trossingen Schacht-Abfüllvorrichtung für Filterzigaretten-Hülsen
US6935504B2 (en) 2002-10-18 2005-08-30 Smurfit-Stone Container Enterprises, Inc. Passive interlock structure

Non-Patent Citations (1)

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

Cited By (16)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2899552A (en) * 1959-08-11 X e electric pulse generating apparatus
US2589240A (en) * 1945-04-07 1952-03-18 William E Frye Double pulse generator
US2567203A (en) * 1946-02-05 1951-09-11 Marcel J E Golay Multiplex communication system utilizing successive, different pulse modulation techniques
US2499844A (en) * 1947-01-16 1950-03-07 Philco Corp Receiver for pulse-position-modulation systems
US2524708A (en) * 1947-02-06 1950-10-03 Gen Electric Co Ltd Pulse multiplex receiving system
US2553752A (en) * 1947-04-15 1951-05-22 Bell Telephone Labor Inc Combined multivibrator and sweep circuit
US2589617A (en) * 1947-07-07 1952-03-18 Alfred C Kowalski Pulse amplitude modulation communication system
US2639385A (en) * 1947-09-05 1953-05-19 Bell Telephone Labor Inc Alternating wave generator
US2516867A (en) * 1948-06-12 1950-08-01 F A R Liquidating Corp Stabilized one-shot multivibrator
US2984833A (en) * 1948-12-16 1961-05-16 Robert T Nieset Super-regenerative radio ranging device
US2529172A (en) * 1948-12-30 1950-11-07 Gen Electric Pulse discriminating circuits
US2722601A (en) * 1949-08-01 1955-11-01 Electronique & Automatisme Sa Electric impulse counting chains
US2866894A (en) * 1952-09-02 1958-12-30 Ericsson Telefon Ab L M Device for demodulating duration modulated pulses
US2891148A (en) * 1953-09-01 1959-06-16 Rca Corp Multivibrator with cathode stabilized by a capacitor
US2911595A (en) * 1955-06-14 1959-11-03 Gen Electric Relaxation oscillators and control method therefor
US2898478A (en) * 1957-03-21 1959-08-04 Bendix Aviat Corp Reduction of multivibrator recovery time

Also Published As

Publication number Publication date
FR57642E (fr) 1953-03-17
NL77425C (da)
CH275028A (fr) 1951-04-30
FR57771E (fr) 1953-09-09
FR57904E (fr) 1953-09-18
GB624542A (en) 1949-06-10
FR954530A (da) 1950-01-03
BE474955A (da)
ES178257A1 (es) 1947-07-16

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