US2445888A - Pulse generator - Google Patents

Pulse generator Download PDF

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Publication number
US2445888A
US2445888A US582662A US58266245A US2445888A US 2445888 A US2445888 A US 2445888A US 582662 A US582662 A US 582662A US 58266245 A US58266245 A US 58266245A US 2445888 A US2445888 A US 2445888A
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Prior art keywords
discharge
energy
gas
filled
storage devices
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US582662A
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English (en)
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John A Rado
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Hazeltine Research Inc
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Hazeltine Research Inc
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Priority to BE474771D priority Critical patent/BE474771A/xx
Application filed by Hazeltine Research Inc filed Critical Hazeltine Research Inc
Priority to US582662A priority patent/US2445888A/en
Priority to GB6460/46A priority patent/GB608817A/en
Priority to FR950715D priority patent/FR950715A/fr
Priority to CH263131D priority patent/CH263131A/de
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    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03K—PULSE TECHNIQUE
    • H03K3/00—Circuits for generating electric pulses; Monostable, bistable or multistable circuits
    • H03K3/02—Generators characterised by the type of circuit or by the means used for producing pulses
    • H03K3/53—Generators characterised by the type of circuit or by the means used for producing pulses by the use of an energy-accumulating element discharged through the load by a switching device controlled by an external signal and not incorporating positive feedback
    • H03K3/55—Generators characterised by the type of circuit or by the means used for producing pulses by the use of an energy-accumulating element discharged through the load by a switching device controlled by an external signal and not incorporating positive feedback the switching device being a gas-filled tube having a control electrode

Definitions

  • This invention relates, in general, to pulse generators and is particularly directed to high-frequency pulse generators for developing a plurality of time-spaced pulses bythe periodic charging and discharging of energy-storage devices.
  • the term high-frequency pulse generator is here used to designate an arrangement for producing pulses which have a high repetition frequency, or a short time separation.
  • Gas-filled electron-discharge means or tubes are particularly useful in arrangements of the foregoing character for discharging transmissionline sections, since these tubes, when conductive, have low anode-cathode impedances and low internal losses, and are able to conduct much larger currents than vacuum tubes of corresponding physical dimensions because of electron augmentation due to impact with gas molecules. Consequently, to develop a given amount of power, the operating potentials required for gas-filled tubes may be of considerably lower values, thus eliminating the need for high-voltage equipment, rigorous insulation-breakdown precautions, and shock safeguards.
  • a high-frequency pulse generator for generating a plurality of time-spaced pulses in accordance with the present invention comprises a plurality of energy-storage devices and means for charging the energy-storage devices.
  • the generator includes gas filled electron discharge means having a predetermined deionization characteristic and adapted to provide a single discharge path common to each of the plurality of energy-storage devices.
  • the generator further includes means for successively completing discharge circuits through the single discharge path provided by the gas-filled means from each of the energy-storage devices in a predetermined sequence with a time separation between succeeding steps of the sequence which is less than the deionization interval of the gas-filled means, consecutively to discharge the plurality of energystorage devices and produce a corresponding plu- 3 rality of output pulses having a. predetermined time separation.
  • Fig. l is a schematic representation of a high-frequency pulse generator in accordance with the invention.
  • Fig. 2 includes t a series of graphs utilized in explaining the operation of the Fig. 1 arrangement.
  • a high-frequency pulse generator for generating a plurality 'of'time-spaced pulses.
  • the illustrated arrangement when keyed into operation by an applied control signal, produces a pair of time-spaced pulses having. a de-.
  • the generator includes a plurality, more specifically a pair, of energy-storage devices individually havingthe form of an artificial'or simulated transmission-line section.
  • One such line section It has high-potential terminals H, H and a lowpotential terminal Hi.
  • the line is formed of lumped circuit elements, including series-connected inductors t2, [2, i2 and intermediate shunt condensers l3, i3, is arranged to simulate a transmission line.
  • a sufficient number of series and shunt elements is provided so that line section iii, in discharging, may deliver energy to a load circuit substantially continuously during a desired pulse interval.
  • the pulse interval is determined by the product of the total inductance and total capacitance of the line section, which is'selected in accordance with the desired pulse duration.
  • a damping resistor i5 is bridged across inductor elements l2, it.
  • the other line section it which is also utilized as an energy-storage device in the generator, has a similar construction and includes a high-potential terminal 2t: and a low-potential terminal 25. It is formed of lumped circuit elements shown as series-connected inductors ll, ii and shunt-connected condensers it, l8, IS. A damping resistor is is bridged across inductors ll, ll.
  • line sections Hi are so constructed that theproduct of the total inductance and total capacitance of each section is equal to a preselected constant value. While this product is the same for both sections, the condensers of line section iii are selectedso that the total capacitance of this section exceeds that of section it. The purpose of this selectionwill be made clear hereinafter.
  • the lines if made of uniformly distributedparameters, have different characteristic impedances.
  • the line sections are connected in cascade during a portion of the pulse-generating process and, therefore, it is preferable that each take the form of a tapered transmission line in order that this connection may be effected with substantial impedance matching to avoid reflection phenomena.
  • the series-inductance and shunt-capacitance elements are selected so that each line section has the aforementioned inductance-capacitanceproduct and an impedance characteristic which varies from a maximum at one end to a minimum at theopposite end..
  • terminal of line section it is coupled to terminal 28 of line section it, and the construction is such that the impedances at the adjacent ends of the sections are substantially matched.
  • a unidirectional conductive device connects terminal 2
  • Means are coupled to thi parallel arrangement for simultaneously charging each of the line sections to a particular level.
  • This means consists of a source of unidirectional potential, indicated +13, coupled to the junction of terminals H and 25 by way of a duo-diode 2t and a saturable charging inductor 2?.
  • the charging circuit is completed by a ground connection 28.
  • Inductor 27 represents the major inductive reactance of the described charging circuit and is selected of such value as to form, with the total capacitance of the two line sections it and it, a series-resonant charging circuit. The circuit is resonant at a frequency approximately equal'to one-half the maximumrepetition frequency of the paired pulses.
  • the generator also includes a gas-filled: tetrode Stl, constituting gas-filled electron-discharge means having a predetermined deionization characteristic, for discharging each of line sections is and it.
  • the cathode of tube 30 is maintained at ground potential, and a bias-potential source ill and grid resistor 32 apply an operating bias to the control electrode thereof for normally maintaining the tube in a nonconductive condition.
  • a similar potential source 33 applies a negative potential to the shield electrode of the tube.
  • the primary winding of a pulse transformer 35 power transfer is obtainable from the generator to a load, represented by resistor 36 coupled to the secondary winding of pulse transformer 35.
  • Tube 50 is normally maintained in a nonconductive condition by means of a bias-potential source ll coupled between its cathode and control electrode through the secondary Winding of a pulse'transformer 42 and a resistor-4 3;
  • the shield electrode is biased to a suitable operating potential through a second source 44.
  • the generator has means for successively completing discharge paths through; gasfilled tube 33 from each of. the plurality of energy-storage devices Of the generator in a predetermined time sequence with a time separation between succeeding steps of the sequence which Preferably, the
  • St is rendered conductive, a matching The an-' 5. is less than the deionization interval of tube 30, consecutively to discharge each of the energystorage devices to produce a corresponding plurality of output pulses having a predetermined time separation.
  • This means includes a pair of terminals 50, o coupled to the input circuit of tube through a condenser 5
  • the means under consideration for successively completing discharge paths for the energy-storage devices also includes a timedelay network 52 having input terminals 54, 54 coupled across terminals 50, 5B. Delay network '52 is short-circuited at its remote terminals, as indicated at 53.
  • the network may have any conventional construction and is selected to effect a predetermined total delay of an applied pulse, the delay being less than the deionization interval of tube 36, for any operating condition to be encountered.
  • the primary winding of transformer 42 is coupled to input terminals 54, 54 of the delay network to apply a delayed control signal derived therefrom to the control electrode of the second gas-filled tube 40.
  • a resistor 55 is coupled across this winding of transformer 42 to terminate network 52 in its characteristic impedance.
  • the windings of transformer 42 are poled to obtain a polarity reversal of signals applied to its primary winding.
  • both gas tubes 30 and 4B are in their normal nonconductive condition and that line sections I5 and It are acquiring a charge from source +B.
  • the charging circuit for line section :6 is completed through diode 25 and the line sections are charged in parallel.
  • the voltage established across the highand lowpotential terminals of each line section approaches twice +B.
  • the magnitude of the line potential results from the fact that in a series-resonant charging circuit, the potential developed across its inductive or capacitive reactance may readily approach twice the value of the charging source.
  • This potential at the line terminals raises the potential level of the cathode elements of charging tube 26 a corresponding amount, biasing this tube to anode-current cutofi and interrupting the charging circuit.
  • the generator is now in condition to respond to an applied keying or control signal applied to input terminals 50, 50 to supply to load impedance a pair of time-spaced pulses.
  • curves of Fig. 2 represent the response of the generator to such a keying signal.
  • curve A represents the keying signal
  • curves B and C indicate the resulting control pulses applied to the control electrodes of tubes 30 and 49, respectively.
  • Curves D and E designate, respectively, the potential relative to ground of the anode of tube 39 and the cathode of tube 4%
  • Curve F represents the pulses generated in response to the discharging of line sections In and I6, and curve G shows these pulses as applied to load impedance 36.
  • both line sections are fully charged as stated above.
  • the anode and cathode of tube 30 are directly coupled between high-potential terminal I l and lowpotential terminal I4 of line section 10, causing the anode potential to be at approximately twice the value of source +B.
  • the anode and cathode electrodes of tube 40 are coupled across the high-potential terminal 20 and low-potential the value of the charging source terminal 2
  • the described potential conditions are represented in curves D and E of Fig. 2.
  • a pulse of positive polarity is applied to terminals 50, 50. It is directly applied with the same polarity to the control electrode of tube 30 and to the input terminals of delay network 52, and is applied with reversed polarity through transformer 42 to the control electrode of tube 40, as shown by curves B and C.
  • the control signal initiates an electron discharge in tube 30 but has no effect on tube 40 which remains in its nonccnductive condition.
  • the deionization interval is determined by the characteristics of the tube and the operating conditions of the generator. For the case under consideration, it is indicated tz-ts. Consequently, at the time is, the following conditions exist in the generator: the first pulse P1 has been produced; the anode of tube 30 is at substantially ground potential; tube 40 is in its normal nonconductive state but its cathode has a negative potential relative to ground approximately equal to twice the value of source +13; and the deionization process of tube 3D has started.
  • a reflection of the keying signal of curve A appears at the network terminals 54, 54.
  • the reflected signal results from the short-circuited termination 53 and is of negative polarity. It is applied directly to the control electrode of tube 30, but has no effect on this tube which continuesto deionize.
  • the reflected or delayed control signal is also applied to the control electrode of tube 40, but with positive polarity, receiving a polarity reversal in translation through transformer 42.
  • the delayed control signal renders tube 40 conductive at time ts, which is delayed with reference to time is such that the interval tz-ts is less than the deionization interval of tube 30.
  • line section Iii-remains terminated in a matching impedance at terminal M since tube 30 is still ionized.
  • Terminal '2I, at the opposite end of line section it, is effectively grounded through conductive tube 40, completing a discharge path for line section it. This path extends from terminal 20 through line section I 0, pulse transformer 35, tubes 3t and 3B in series, to terminal 2 I.
  • the described discharge circuit establishes thesame terminal conditions for line section I6 as those of line section M when tube is. initially rendered conductive to generate thefirstpulse P1.
  • line section I6 is terminated in a matched impedance by line section I0, while the opposite end thereof, including terminal 2i, is open-circuited.
  • line section 16 discharges in a manner similar to the discharge of line section ducin at terminal 20 a second pulse P2 of curve F.
  • the duration of this pulse corresponds to the time interval ifs-t4 required completely to discharge line section I0.
  • Pulse P2 is directly applied to terminal I I of line section Hi and is translated th'erethrough, in conventional manner, to load impedance 36 by Way of pulse transformer 35.
  • the interval TS includes the total time delay t1t3 of delay network 52, plus the one-way delay of line section I 0.
  • the generated pulses P1 and P2 have equal pulse. durations Ta since each of line sections it and I6 has the same inductanc -capaci'tance product. However, condensers i3, l8, it of line section I6 have a greater total capacitance than condensers I2, I2, I2 of line section Iii, in order that the paired pulses P1 and P2 may also have substantially the same amplitudes.
  • the only impedances in the discharge path of line section l0 correspond to those of transformer anddischarge tubeti
  • the discharge path of line section I6 includes additional impedance elements, such. as :the second gas tube 50.
  • the output pulses P1 and Pz may have equal amplitudes.
  • each of the energy-storage devices is to be discharged through the common discharge tube 30.
  • This may be efiected by any suitable means which consecutively couples the energy-storage devices to the common discharge tube in a time sequence such that the succeeding steps of the sequence have a time separation which is less than the deionization interval of the discharge tube.
  • discharge paths are consecutively completed through the common discharge device in a desired succession to discharge each of the devices and generate a corresponding plurality of time-spaced pulses having a preselected time separation. The time separation of the resulting pulses is determined largely by the preselected time sequence in accordance with wiich discharge circuits for the individual stordevices are completed through the common discharge tube.
  • Pulse generators of the type described above may be utilized in communication systems for applying potential pulses to the anode of one or more tubes in the power oscillator circuit of a transmitter.
  • circuit constants are given as illustrative of values of circuit elements which may be utilized in the circuit of Fig. 1.
  • a high-frequency pulse generator for generating a plurality of time-spaced pulses comprising, a plurality of energy-storage devices, means for charging said energy-storage devices, gas-filled electron-discharge means having a predetermined deionization characteristic and adapted to provide a single discharge path common to each of said plurality of energy-storage devices, and means for successively completing discharge circuits through said single discharge path provided by said gas-filled means from each of said energy-storage devices in a predetermined sequence with a time separation between succeeding steps of said sequence less than the deionization interval of said gas-filled means consecutively to discharge said plurality of energy-storage devices to produce a corresponding plurality of output pulses having a predetermined time separation.
  • a high-frequency pulse generator for generating a plurality of time-spaced pulses comprising, a plurality of energy-storage devices, means for charging said energy-storage devices, gas-filled electron-discharge means having a predetermined deionization characteristic and adapted to provide a single discharge path common to each of said plurality of energy-storage devices, and means for successively completing discharge circuits through said single discharge path provided by said gas-filled means from each of said energy-storage devices in a predetermined sequence with a time separation between succeeding steps of said sequence less than the deionization interval of said gas-filled means consecutively to discharge said plurality of energystorage devices to produce a corresponding p1urality of time-spaced pulses having a predetermined polarity and occurring in a predetermined time sequence.
  • a high-frequency pulse generator for generating a plurality of time-spaced pulses comprising, a plurality of energy-storage devices, means for simultaneously charging said energystorage devices, gas-filled electron-discharge means having a predetermined deionization characteristic and adapted to provide a single discharge path common to each of said plurality of energy-storage devices, and means for successively completing discharge circuits through said single discharge path provided by said gas-filled means from each of said energy-storage devices in a predetermined sequence with a time separation between succeeding steps of said sequence less than the deionization interval of said gasfilled means consecutively to discharge said plurality of energy-storage devices to produce a corresponding plurality of output pulses having a predetermined time separation.
  • a high-frequency pulse generator for generating a plurality of time-spaced pulses comprising, a plurality of energy-storage devices, means for simultaneously charging said energystorage devices in parallel, gas-filled electrondischarge means having a predetermined deionization characteristic and adapted to provide a single discharge path common to each of said plurality of energy-storage devices, and means for successively completing discharge circuits through said single discharge path provided by said gasfilled means from each of said energy-storage devices in a predetermined sequence with a time separation between succeeding steps of said sequence less than the deionization interval of said gas-filled means consecutively to discharge said plurality of energy-storage devices to produce a corresponding plurality of output pulses having a predetermined time separation.
  • a high-frequency pulse generator for generating a plurality of time-spaced pulses comprising, a plurality of energy-storage devices, means for chargin said energy-storage devices, gas-filled electron discharge means having a predetermined deionization characteristic and adapted to provide a single discharge path common to each of said plurality of energy-storage devices but normally maintained in a nonconductive condition, and means for initiating an.
  • a high-frequency pulse generator for generating a plurality of time-spaced pulses comprising, a plurality of energy-storage devices, means for charging said energy-storage devices, gas-filled electron-discharge means having a predetermined deionization characteristic for discharging each of said plurality of energy-storage devices, and means including a time-delay network for successively completing discharge paths through said gas-filled means from eachof said energy-storage devices in a predetermined sequence with a time separation between succeeding steps of said sequence less than the deionization interval of said gas-filled means consecutively to discharge said plurality of energy-storage devices to produce a corresponding plurality of output pulses having a predetermined time separation.
  • a high-frequency pulse generator for generating a pair of time-spaced pulses comprising, a pair of energy-storage devices, means for charging said energy-storage devices, gas-filled electron-discharge means having a predetermined deionization characteristic and adapted to provide a single discharge path common to each of said energy-storage devices, and means for successively completing discharge circuits through said single discharge path provided by said gasfilled means from each of said energy-storage devices with a time separation therebetween less than the deionization interval of said gas-filled means consecutively to discharge said pair of energy-storage devices to produce a pair of. output pulses having a predetermined time separation.
  • a high-frequency pulse generator for generating a pair of time-spaced pulses comprising, a pair of energy-storage devices, means for charging said energy-storage devices, gas-filled electron-discharge means having a predetermined deionization characteristic for discharging each of said energy-storage devices but normally maintained in a nonconductive condition, means for coupling one of said energy-storage devices to said gas-filled means, svrltching means for coupling the other of said energy-storage devices to said gasfllled means, and means for initiating an electron discharge in said gas-filled means to complete a discharge path therethrough for said one energystorage device and for operating said switching means with a predetermined time delay less than the deionization interval of said gas-filled means ii to complete a, discharge path for said other energy-storage device through said gas-filled means to discharge said energy-storage'devices and produce a pair of output pulses having'a-predetermined time separation.
  • said first gas-filled means a second gas-filled electron-discharge means for coupling the other of said energy-storage devices to said'first gasfilled means but normally maintained in a nonconductive condition, and means for initiating an electron discharge in said'first gas-filled means to'complete a discharge path therethrough for said one energy-storage device and for initiating an electron discharge in said second gas-filled means with a predetermined time delay less than the deionization interval of said first gas-filled means to complete a discharge path for said other energy-storage device through said first gas-filled means to dischargesaid energy-storage devices and produce a pair of output pulses having a predetermined time separation.
  • a high-frequency pulse generator for generating a pair of time-spaced pulses comprising, a pair of energy-storage devices, means for charging said energy-storage devices, a first gas-filled electron-discharge means for discharging each of said energy-storage devices but normallymaintained in a nonconductive condition, said first gas-filled means including a control electrode and having a predetermined deionization characteristic, a second gas-filled electron-discharge means including a control electrode for coupling the other of said energy-storage devices to said'first gas-filled means butnormally maintained in a 'nonconductive condition, and means for applying a control signal to said control electrode of said first gas-filled'means to initiate an electron discharge therein to complete a discharge path 'therethrough for said one energy-storage device and for applying said control signal to said control electrode of said second gas-filled means with a predetermined time delay less than the deionization interval of said first gas-filled means to initiate an electron discharge in said second gasfilled means and complete a discharge path for
  • a high-frequency pulse generator for generating a pair of time-spaced pulses comprising, a pair of energy-storage devices individually having a predetermined capacitance, means for charging said energy-storage devices, gas-filled electron-discharge means having a predetermined deionization characteristic for discharging each of said energy-storage devices but normally maintained in a nonconductive condition, means for coupling one of said energy-storage devices to said gas-filledmeans, switching means for coupling the other of said energy-storage devices to said gas-filled means, and means for initiating an electron discharge in said gas-filled means to complete a discharge path therethrough for said one energy-storage device and for operating said switching means witha predetermined time delay less than the deionization intervalof saidgasfilled means to complete a discharge-path forsaid other energy-storage device through: said gasfilled means to discharge said energy-storage devices and produce-a pair of output pulses having a predetermined time'separation, said capacitances of said energy-storage devices being so proportion
  • a high-frequency pulse generator for gencrating a pair of time-spaoed pulses comprising, a pair of transmission lines individually having in-- ductance and capacitance suchthat the product of' inductance and capacitance of each line is equal to a preselected constant value, means for establishing a predetermined charge condition on each of said lines, gas-filled electron-discharge means having a predetermined deionizationchan "acteristic for discharging each of said lines but normally maintained in a nonconductive condition, means'for coupling one of said lines to said gas-filled means, switching means for coupling the other of said lines to saidgas-filled "means, and means'for initiating an electron discharge in said gas-filled means to complete a discharge path therethrough for said one line and for op-- crating said switching means with a predetermined time delay less than the deionization interval of-said gas-filled means to complete a discharge path for said other line through said gasfilledmeans to discharge said lines and produce a pair of output pulses
  • a high-frequency pulse generator for generating a pair'of time-spaced pulses comprising, a 'pair of transmission lines, means for charging saidpairof linesygas-filled electron-discharge meanshaving'a predetermined deionization characteristic' for discharging each of said lines but normally maintained in a nonconductive condi tion, 'meansfor coupling one of said lines to said gas-filled means, means including a selectively operable switch for coupling the otherof said lines to said gas-filled.
  • a high-frequency pulsegenerator for generating a pairof time-spaced pulses comprising, a pair of transmission lines, means including a first unidirectional conductive device for simultaneously charging said lines in parallel, gasfilled electron-discharge means having a predetermined deionization characteristic for discharging each of said-lines but normally maintained in anonconductive condition, means for coupling one of said lines to said gas-filled means, switching means including a second selectively operable andunidirectional conductive device for coupling said other line to said gas-filled means an electron discharge in said gas-filled means to 13 complete a discharge path therethrough for said one line and for operating said switching means with a predetermined time delay less than the deionization interval of said gas-filled means to complete a discharge path for said other line through said one line and said gas-filled means to discharge said lines and produce a pair of output pulses having a predetermined time separation.

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US582662A 1945-03-14 1945-03-14 Pulse generator Expired - Lifetime US2445888A (en)

Priority Applications (5)

Application Number Priority Date Filing Date Title
BE474771D BE474771A (xx) 1945-03-14
US582662A US2445888A (en) 1945-03-14 1945-03-14 Pulse generator
GB6460/46A GB608817A (en) 1945-03-14 1946-03-01 Electric pulse generating circuit
FR950715D FR950715A (fr) 1945-03-14 1947-07-31 Générateur d'impulsions
CH263131D CH263131A (de) 1945-03-14 1947-12-22 Impulsgenerator.

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Application Number Priority Date Filing Date Title
US582662A US2445888A (en) 1945-03-14 1945-03-14 Pulse generator

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US2445888A true US2445888A (en) 1948-07-27

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US (1) US2445888A (xx)
BE (1) BE474771A (xx)
CH (1) CH263131A (xx)
FR (1) FR950715A (xx)
GB (1) GB608817A (xx)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2605449A (en) * 1948-06-03 1952-07-29 George F Schrader Pulse generator
US20080103529A1 (en) * 2006-10-26 2008-05-01 Old Dominion University Apparatus and methods for performing cellular electro-manipulations

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
BE518324A (xx) * 1952-03-12

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2235385A (en) * 1939-03-23 1941-03-18 Rava Alexander Welding method and apparatus
US2284850A (en) * 1939-04-19 1942-06-02 Hammond V Hayes Speed indicating apparatus

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2235385A (en) * 1939-03-23 1941-03-18 Rava Alexander Welding method and apparatus
US2284850A (en) * 1939-04-19 1942-06-02 Hammond V Hayes Speed indicating apparatus

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2605449A (en) * 1948-06-03 1952-07-29 George F Schrader Pulse generator
US20080103529A1 (en) * 2006-10-26 2008-05-01 Old Dominion University Apparatus and methods for performing cellular electro-manipulations

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BE474771A (xx)
CH263131A (de) 1949-08-15
GB608817A (en) 1948-09-21
FR950715A (fr) 1949-10-05

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