US2518341A - Pulse modulation system - Google Patents

Pulse modulation system Download PDF

Info

Publication number
US2518341A
US2518341A US95910A US9591049A US2518341A US 2518341 A US2518341 A US 2518341A US 95910 A US95910 A US 95910A US 9591049 A US9591049 A US 9591049A US 2518341 A US2518341 A US 2518341A
Authority
US
United States
Prior art keywords
voltage
pulse
control electrode
pulses
resistance
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
US95910A
Other languages
English (en)
Inventor
Libois Louis Joseph
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.)
Individual
Original Assignee
Individual
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
Application filed by Individual filed Critical Individual
Application granted granted Critical
Publication of US2518341A publication Critical patent/US2518341A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03K—PULSE TECHNIQUE
    • H03K7/00—Modulating pulses with a continuously-variable modulating signal
    • H03K7/02—Amplitude modulation, i.e. PAM
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04J—MULTIPLEX COMMUNICATION
    • H04J3/00—Time-division multiplex systems

Definitions

  • the present invention relates to an amplitude modulating device forelectric pulses.
  • the amplitude pulse modulation device which is the'object ofthe invention, ofier's, with respect to other-known devices,generally utilized, a num- 1 her of advant'agesnamely: simplicityand economy, linearity of modulation, stability as regards the- 'variations' of the supply voltages, the possibility of replacing the modulating electron tube by another one, without the necessity of altering any adjustment,- the possibility of transmitting wide modulation bands without any difficulty and of using'low values of the low frequency excitation.
  • the modulating device comprises the-'superpositionon the control grid of an electron tube of the low frequency modulat ingvoltage and of unblocking pulses, the modulating voltage being applied to the primary of a transformer whose secondary is located between the grid of theelectron tubeand the point common to a resistance and to a-detector which clips the signals from a pulse generator.
  • a, low frequency transformer energizes a relatively low resistance placed in series with the detector.
  • Figure 1 shows a device which can be adapted particularly well tomultiplex transmission
  • Figure 2 shows a modification of the device of Figure 1, designed especially for the transmission of wide frequency bands.
  • I shows a sourceof pulses having the desired characteristics for the type-of trans mission utilized.
  • the pulse sources may be taps uniformly distributed on a delay line.
  • Resistance 3 is a resistance sufiiciently large with respect to the internal impedance of detector 4 for the peaks of the pulses generated at l, assumed to be imperfectly rectangular, appearing on the input grid of the electron tube 5 to be well Characteristically and according to a feature June '10; 1948- (Cl. 332 v clipped. The eifect of this clipping action is primarily to limit to. a predetermined value the amplitude of the pulse voltage as supplied by this generator to the grid of tube 5.
  • electrode voltage can be made'to lie inside the linear portion of the anode current/control electrode voltage characteristic curve of said tube 5.
  • Resistance 6 and condenser I give, on the other hand, 1 abiassing voltage of such a value that the electrontube 5 is rendered operative only at the time of occurrence of a pulse 2.
  • the low frequency modulating voltage' is applied between 8 and 9 to the primary of a trans- 15,- ;former l0 whose se'condary winding is connected across a suitable impedance'l i.
  • This transformer is designed so as to offer the least possible amount.
  • [3 V is the load impedance of the tube.
  • l4 shows an output pulse modulated in amplitude.
  • the plates of the modulating tubes such as 5 are connectedtogether. If the type of modulation ultimately desired in the considered multiplex transmission system is not that of amplitude modulation, it will be sufficient to eifect later the change in type of modulation in elements common to all channels. H
  • Figure 2 shows a modification, in accordance with the invention, of the circuit described previously. This modification is of particular interest in case very wide modulation bands have to be transmitted over a single transmission channel.
  • I5 is a generator delivering pulses with asuitable recurrence period and whose duration is large enough with respect tosaid period, a condition not troublesome for a single transmission channel.
  • the pulse generator does not transmit a direct current, (a transformer or a resistance-capacity Ii suitablybiasses the electron tube coupling are suflicient to this effect) the pulses, at the output of [5, have the shape shown in [6, the dotted line H representing ground potential.
  • These pulses are applied to the detector [9 through the resistance [8.
  • the low frequency modulating voltage is applied, between 2
  • the resistance 20 must be comparatively low with respect to the resistance l8.
  • the signal on the grid of the electron tube 23 is thus the superposition of the low frequency voltageand of the I pulses.
  • Resistance 24 fixes the bias during the passage of one pulse and, futher, improves the,
  • the whole of this device doesnot comprise any condenser, any. especially designed transformer nor any time constant and may, if de-.
  • electrodes such as pentodes, for instance, can be utilized.
  • an electronic tube having a cathode, control electrode and anode; generator of recurrent electric pulses, a transformer to the primary winding of which the modulating voltage is applied, a circuit connecting said pulse generator and control electrode and including a resistor and the secondary 1.
  • an electronic tube having anode and controlelectrodes, means forapplying to a, .controlelectrode a modulating voltage and a pulse voltage of the recurrence of the aforesaid pulses, means for applying to said control electrode a biassing voltage of suchvalue as to block the. flow of anode current in the absence of the applied pulse voltage, and
  • circuit means to modify the amplitude of tube having a cathode, control electrode and.
  • the applied pulses to such a degree that in-the absence of modulating voltage the voltage of the control electrode due topeaks of the modi-' sing means for said detector causing it to clip the pulses applied thereto.
  • an electronic tube having an anode and control electrode, means for applying to the control electrode a modulating voltage and a pulse voltage,'a detector having output means connected to said control electrode and means applying the pulse voltage to;
  • said detector means for biassing said detector to such a degree that, in the absence of modulating voltage, the voltage of the control electrode dueto the peak pulse voltage lies within the linear portion of the control electrode-anode cur- Number winding of said transformer connected in series;
  • a transmission system in which the point of constant potential to which the. detector terminal is connected, is a. terminal of, a resistorconnected in series in the anodecathode circuit of the tube.
  • a transmission system for recurrent am plitude modulated electric pulses; an electronic anode; a pulse voltage generator, a circuit connecting said generator and controlelectrode; a detectorzand resisto connected in series, one terminal of saiddetector being connected to said circuit whereby the peak pulse voltage applied to said control electrode is limitedto a predetermined value; the resistance of said resistor being substantially less than the internal resistance of the pulse generator, means for applying the,
  • circuit connecting the. pulse generator and control electrode includes a secondresistor connected in series, said second resistor having a resistance substantially greater than that of the resistor in series with the detector.

Landscapes

  • Engineering & Computer Science (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Signal Processing (AREA)
  • Amplifiers (AREA)
  • Particle Accelerators (AREA)
  • Digital Transmission Methods That Use Modulated Carrier Waves (AREA)
US95910A 1948-06-10 1949-05-28 Pulse modulation system Expired - Lifetime US2518341A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
FR823605X 1948-06-10

Publications (1)

Publication Number Publication Date
US2518341A true US2518341A (en) 1950-08-08

Family

ID=9281442

Family Applications (1)

Application Number Title Priority Date Filing Date
US95910A Expired - Lifetime US2518341A (en) 1948-06-10 1949-05-28 Pulse modulation system

Country Status (6)

Country Link
US (1) US2518341A (en))
BE (1) BE489276A (en))
CH (1) CH280042A (en))
DE (1) DE823605C (en))
FR (1) FR967489A (en))
GB (1) GB669364A (en))

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2798153A (en) * 1953-02-19 1957-07-02 Vitro Corp Of America Switching circuitry
US2956158A (en) * 1957-04-23 1960-10-11 Sperry Rand Corp Voltage discriminating circuit
US3131248A (en) * 1961-12-04 1964-04-28 Sigel David Amplitude modulator
US3240859A (en) * 1962-07-11 1966-03-15 Horace N Rowe Electronic tremolo unit

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE1281491B (de) * 1962-04-02 1968-10-31 Akad Wissenschaften Ddr Schaltungsanordnung zur amplitudenmaessigen Beeinflussung von elektrischen Impulsen

Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR793162A (fr) * 1934-08-09 1936-01-18 Loewe Opta Gmbh Poste èmetteur de radio-diffusion et de télévision

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR793162A (fr) * 1934-08-09 1936-01-18 Loewe Opta Gmbh Poste èmetteur de radio-diffusion et de télévision

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2798153A (en) * 1953-02-19 1957-07-02 Vitro Corp Of America Switching circuitry
US2956158A (en) * 1957-04-23 1960-10-11 Sperry Rand Corp Voltage discriminating circuit
US3131248A (en) * 1961-12-04 1964-04-28 Sigel David Amplitude modulator
US3240859A (en) * 1962-07-11 1966-03-15 Horace N Rowe Electronic tremolo unit

Also Published As

Publication number Publication date
DE823605C (de) 1951-12-06
BE489276A (en))
CH280042A (fr) 1951-12-31
FR967489A (fr) 1950-11-03
GB669364A (en) 1952-04-02

Similar Documents

Publication Publication Date Title
US2358428A (en) Thermionic valve amplifier circuit arrangement
US2237661A (en) Keying device for ultra-short-wave transmitters
US2518341A (en) Pulse modulation system
US2572792A (en) Thermionic valve circuits
US2427500A (en) Cathode-ray tube modulator in a pulse multiplex transmitter
US2521741A (en) Deflection circuit
US2794077A (en) Gain-modulated amplifier
US2256512A (en) Dual channel amplifier
US3651339A (en) Feedback clipper
US2537807A (en) Thermionic amplifier
US2031639A (en) Method of and means for modulation
US2644105A (en) Television circuit
US2862046A (en) Stabilized direct-coupled amplifier
US2498526A (en) Balanced modulation
US2315073A (en) Electric circuits
GB526437A (en) Improvements in or relating to modulated high frequency transmitters
US2379042A (en) Modulator
US2227492A (en) Television receiving apparatus
US2484107A (en) Oscillograph circuit to modulate a signal
US2797389A (en) Pulse modulation circuits or the like
US2436802A (en) System of modulation utilizing a cathode follower
US2202613A (en) Television transmission apparatus
US2434916A (en) Trigger operated carrier telegraph transmitter
US2235549A (en) Modulator
US2569321A (en) Compensating amplifier for facsimile recording lamps