US2838691A - Pulse voltage multiplying system - Google Patents

Description

June 10, 1958 c. T. ZAVALES 2,338,691

PULSE VOLTAGE MULTIPLYING SYSTEM Filed July 12, 1957 INVENTOR. 5002:; 0/4/2455 77 2/71/5155.

Charles T. Zavales, New York, N.

PULSE VOLTAGE MULTIPLYING SYSTEM Y., assignor to F-R Machine Works, Inc., Woodside, N. Y., a corporation The presentinvention relates to a pulse voltage multiplying system particularly adaptable for use in connection with the transmission of intelligence and is of special importance wherein coded pulsing is applied to electronic tubes of the klystron and magnetron types used in radar and similar transmission.

Pulse producing systems for the operation of klystron and magnetron type electronic tubes are presently known to the art but these are subject to certain disadvantages. For example, a so-called line modulator has been heretofore used wherein a single pulse forming network is charged through a rectifying tube and a pulse transformer, uponoperation of a control tube, with the output voltage being determined by the turns ratio of the pulse transformer and the pulse duration controlled by the parameters of the pulse forming network. Although practical pulse transformers have been made wherein the output voltage is as high as 500 kv., this resulting line type of pulser will not produce coded pulsing in which the interpulse period is small, because of the magnetic characteristics of the pulse transformer and the deionization time of the control tube normally used to control the discharge of the pulse forming circuit.

Another circuit arrangement heretofore known for producing coded pulses and commonly referred to as a hard tube modulator utilizes a condenser which is charged from a suitable source by the operation of a control tube wherein its control grid is pulsed to render the tube conductive to discharge the condenser.

While this hard tube modulator circuit has proven satisfactory for the production of coded pulses up to an output voltage of 50 to 60 kv., its limiting factor has been the voltage hold-off characteristic of the control tube. During operation at an output voltage above about 60 kv. the grid tends to lose some of its control. Cold emission, because of surface conditions of the grid and anode, also cause the tube to pass currents.

It is accordingly the primary object of the present invention to provide a pulse voltage multiplying system which obviates the disadvantages of the above-noted prior type coded pulse circuit arrangements.

Another object of the present invention is the provision of a pulse voltage multiplying system wherein an infinite number of circuit elements may be cascaded to produce substantially any desired voltage.

A further object of the present invention is the provision of a pulse voltage multiplying system wherein substantially any desired voltage may be produced and wherein such coded pulse system is self-triggering.

Still further objects of the present invention will become obvious to those skilled in the art by reference to the accompanying drawing wherein the single figure is a diagrammatic illustration of the pulse voltage multiplying system of the present invention.

Referring now to the drawing more in detail which illustrates one embodiment of the present invention, there is shown a three-stage multiplier comprising single stages, AB-C, as divided by the dotted lines on the drawing.

Stats Patent A Inasmuch as each stage is identical, except as hereinafter noted, the arrangement of stage A will be described in detail. Such stage A comprises a capacitor CS-l which is charged from a high voltage source, indicated by the legend KV Source, through isolation elements, comprising an inductance L and resistance R and through a diode type rectifying electronic tube T11 (as well as through the series connected diode rectifier tubes T22 and T-33 of the other stages B and C shown), so that when fully charged the capacitor CS1 is thus at the voltage of the supply source, namely, 35 kv. in the example chosen.

The discharge circuit for the capacitor CS1 includes a control switching tube T-l, which may be a tetrode or triode type but as shown comprises a tetrode tube, and a stabilizing resistor R connected in shunt with a load (throughseries connected stabilizing resistors R and R of the other stages B and C). The switching tube T-l is normally maintained non-conducting by the application of a grid voltage thereto from a source of voltage EG-l, comprising a secondary winding 3 of transformer 6, a silicon or thermionic rectifier CR-Z, a filter capacitor 4, and a series resistance 9. The screen grid of the switch tube T-l is in turn energized from a source of voltage, ES-l, comprising a secondary winding 1 of transformer 6, a silicon or thermionic rectifier CR-l, a filter capacitor 5, a series resistance 3, and an R. F. bypass capacitor 7. It will be noted that the low voltage secondary winding 2 supplies heating energy for the thermionic cathode of switching tube T4 and the rectifying diode tube T-11. Such transformer 6 is of the low capacitance high-voltageinsulated .type having its primary winding 10 connected to an A. C. supply source and in the cascaded three stage pulse voltage multiplying system of the present invention would be insulated for two-thirds of the total output voltageof the complete system.

In a similar manner stages B and C contain the identical elements above enumerated with respect to stage A, and since their respective capacitors CS2 and CS-3 are connected in parallel with stage A capacitor CS1, to the 35 kv. source, all capacitors are simultaneously charged, so long as the rectifying diode tubes T-ll, T-22 and T-33 are conductive. Also, during this charging cycle the control switching tubes T-Z and T3 for stages B and C are rendered non-conductive by the application of a screen grid voltage from the respective sources ES2 and ES3 and by the biasing potential supplied by the voltage sources E64. and EG-3, respectively, to the control grid of the switching tubes T-2 and T-3. Likewise the low capacitance transformer 16 for stage B, which is insulated for one-third the total output voltage of the system, supplies heating energy .to the thermionic cathodes of tubes T-Z and T-22 and has its primary winding 25) connected to the A. C. supply source, while transformer 26 of stage C is similarly connected to such source and to its respective tubes T-3 and "5-33 and performs the same functions as does the transformers 6 and 16 of stages A and B.

It will be noted from the drawing that the control grid of switchingtube T3 is connected to a source of energy, indicated by the legend Trigger Input, through a coupling condenser 12 so that when a slightly more positive pulse is applied between the control grid and grounded cathode, such switching tube T-3 becomes conductive, allowing previously charged capacitor (IS-3 to begin to discharge through stabilizing resistor R Charging rectifier tube T-33 is simultaneously rendered non-conductive upon the discharge of capacitor CS3 because the-anode of .such rectifier tube T-33 becomes negative with respect to ground just as soon as this switching tube T-3 conducts. Switch tube T-Z has its cathode connected to the top of stabilizing resistor R while the control grid thereof is connected through a coupling condenser 13 to a point on such resistor R somewhat closer to ground than the cathode which thus makes the control grid more positive than the cathode when current flows through resistor R resulting in switching tube T-Z likewise self-triggering and becoming conductive.

Upon switching tube T-Z becoming conductive, current then flows through stabilizing resistor R from charged capacitor CS-Z and rectifier tube T-22 simultaneously becomes non-conductive, since its anode is now negative with respect to the cathode. In a manner similar to that of stage B, the cathode of switching tube T-l is connected to the top of resistor R while the control grid thereof is connected through a coupling condenser 14 to a point on R closer to ground which makes the grid positive and rendering switching tube T-1 conductive to pass current from charged capacitor CS1 through resistor R At the same moment charging rectifier tube T-ll also becomes non-conductive because its anode becomes negative with respect to ground.

When all three switching tubes T1, T2 and T-3 thus become conductive, the full charge of all three capacitors CS1, (38-2 and CS3 is supplied directly to the load with the total voltage of the system being approximately three times that of the charging voltage for the respective capacitors CS1, CS2 and CS-3, less the slight voltage drop in the control tubes, or about 105 kv. This output voltage can of course be still further increased to an even higher voltage by the addition of still more stages to the cascaded system as herein shown.

From the foregoing it will be seen that in the cascaded pulse voltage multiplying system of the present invention, the capacitors CS-l, CS2 and CS-3, of each respective stage ABC are connected in electrical parallel with the 35 kv. source and hence are charged in multiple through their respective inductance L L L their resistors R 1 R22 R33, and diode rectifier tubes T-11, T-22 and T-33, with one or more of the latter tubes being in series with each other during charging of such capacitors. Also, during such charging cycle the respective control switching tubes T-l, T-2, and T-3 are rendered non-conductive by the application of a suitable voltage to the screen grid and biasing voltage to the control grid of each tube from the sources hereinbefore described.

Moreover, when a trigger pulsing voltage is applied to the control grid of switching tube T-3 (or the first such tube in any greater number of stages in cascade arrangement) this immediately interrupts the charging circuit for the then fully charged capacitors CS-1, CS-2 and CS3 by rendering charging rectifier diode T-33 nonconducting, and simultaneously makes switching tube T-3 conducting to allow discharge of capacitor CS-3. A self-triggering chain reaction immediately follows current flow through switching tube T3 and stabilizing resistor R by which switching tubes T-Z and T-3 become conductive in almost instantaneous succession rendering their respective charging rectifier diodes T-22 and T-11 non-conductive and enabling the capacitors CS1, CS2 and 08-3 to accordingly discharge in series relation through the load, which may comprise a klystron or magnetron type tube, with the total voltage supplied to the load being determined by the number of stages in cascade arrangement.

It should thus become obvious to those skilled in the art that a cascaded pulse voltage multiplying system is herein provided which will produce a total pulse voltage of high value and wherein the system is self-triggering.

Moreover, due to the cascade arrangement each switch tube must hold off only approximately one third of the output voltage (in the three stage system herein shown),

thereby reducing the voltage burden on the switching 7 4 tube capable of holding ofi kv. is theoretically possible but from a practical standpoint is exceedingly difiicult to build which can reliably operate.

Although one specific embodiment of the present invention has been shown and described it is to be understood that still further modifications thereof may be made without departing from the invention.

I claim:

1. A pulse voltage multiplying system comprising a plurality of cascaded stages, each stage comprising a capacitor adapted to be charged from a high voltage supply source, a rectifying discharge tube connected to said high voltage source for controlling the charging of said capacitor, a discharge circuit for said capacitor including a stabilizing element and a load energizable upon discharge of said capacitor, and a control switching tube having a control electrode and normally operative to prevent discharge of said capacitor; a source of triggering pulse energy connected to the control electrode of said switching tube for rendering the latter conductive to cause discharge of said capacitor and for simultaneously rendering said rectifying discharge tube non-conductive to thus interrupt the charging of said capacitor, said source of triggering pulse energy for the control electrode of said switching tube of each stage except the first comprisin the discharge circuit for the capacitor of the preceding adjacent stage in the cascaded system, and a source of coded triggering pulse energy for the control electrode of the switching tube of the first cascaded stage to cause discharge of its associated capacitor and attendant successive self-triggering of the switch tube of each remaining stage of the entire cascaded system to cause discharge of all the capacitors of the system in electrical series across said load at a voltage determined by the number of stages in the cascaded system.

2. A pulse voltage multiplying system comprising a plurality of cascaded stages, each stage comprising at capacitor, a charging circuit for said capacitor including isolation elements connected to said capacitor and to a high voltage supply source and a rectifying discharge tube for controlling said circuit to cause charging of said capacitor; a discharge circuitfor said capacitor including a stabilizing element and a load energizable upon discharge of said capacitor, and a control switching tube having a control electrode and normally operative to prevent discharge of said capacitor; 21 source of triggering pulse energy connected to the control electrode of said switching tube for rendering the latter conductive to cause discharge of said capacitor and for simultaneously rendering said rectifying discharge tube non-conductive to thus interrupt the charging circuit for said capacitor, said source of triggering pulse energy for the control electrode of said switching tube of each stage except the first comprising the discharge circuit for the capacitor of the preceding adjacent stage in the cascaded system, and a source of coded triggering pulse energy for the control electrode of the switching tube of the first cascaded stage to cause interruption of the charging circuit and discharge of its associated capacitor and attendant successive self-triggering of the switching ;tube of each remaining stage of the entire cascaded system to cause discharge of all the capacitors of the system in electrical series across said load at a voltage determined by the number of stages in the cascaded system. 7

3. A pulse voltage multiplying system comprising a plurality of cascaded stages, each stage comprising a capacitor adapted to be charged from a hi h voltage supply source, a rectifying discharge tube connected to said high voltage source for controlling the charging of said capacitor, a discharge circuit for said capacitor including a stabilizing element and a load energizable upon discharge of-said capacitor, and a control switching tube having a control electrode and normally operative to prevent discharge of said capacitor; a source of triggering pulse energy connected to the control electrode of said switching tube for rendering the latter conductive to cause discharge of said capactior and for simultaneously rendering said rectifying discharge tube non-conductive to thus interrupt the charging of said capacitor, said source of triggering pulse energy for the control electrode of said switching tube of each stage except the first including the stabilizing element connected in the discharge circuit for the capacitor of the next adjacent stage in the cascaded system and operable upon the flow of current through said stabilizing element to apply the triggering pulse to said switching tube, and a source of coded triggering pulse energy for the control electrode of the switching tube of the first cascaded stage to cause discharge of its associated capacitor and attendant current flow through its stabilizing element with successive current flow through the stabilizing element of each preceding adjacent stage and the self-triggering of the switching tube for each remaining stage of the entire cascaded system, to cause discharge of all the capacitors of the system in electrical series across said load at a voltage determined by the number of stages in the cascaded system.

4. A pulse voltage multiplying system comprising a plurality of cascaded stages, each stage comprising a capacitor, a charging circuit for said capacitor including isolation elements connected to said capacitor and to a high voltage supply source and a rectifying discharge tube for controlling said circuit to cause charging of said capacitor; a discharge circuit for said capacitor including a stabilizing element and a load energizable upon discharge of said capacitor, and a control switching tube having a control electrode and normally operative to prevent discharge of said capacitor; a source of triggering pulse energy connected to the control electrode of said switching tube for rendering the latter conductive to cause discharge of said capacitor and for simultaneously rendering said rectifying discharge tube non-conductive to thus interrupt the charging circuit for said capacitor, said source of triggering pulse energy for the control electrode of said switching tube of each stage except the first including the stabilizing element in the discharge circuit for the ca pacitor of the preceding adjacent stage in the cascaded system and operable upon the flow of current through said stabilizing element to apply the triggering pulse to said switching tube, and a source of coded triggering pulse energy for the control electrode of the switching tube of the first cascaded stage to cause interruption of its charging circuit and discharge of its associated capacitor and attendant current flow through its stabilizing element with successive self-triggering of the switching tube and current flow through the stabilizing element of each remaining stage of the entire cascaded system, to cause discharge of all the capacitors of the system in electrical series across said load at a voltage determined by the number of stages in the cascaded system.

5. A pulse voltage multiplying system comprising a plurality of cascaded stages, each stage comprising a capacitor, a charging circuit for said capacitor including isolation elements comprising a series connected inductance and resistance connected with said capacitor and with a high voltage supply source and a rectifying discharge tube for controlling said circuit to cause charging of said capacitor; a discharge circuit for said capacitor including a stabilizing element and a load energizable upon discharge of said capacitor, and a control switching tube having a control electrode and normally operative to prevent discharge of said capacitor; a source of triggering pulse energy connected to the control electrode of said switching tube for rendering the latter conductive to cause discharge of said capacitor and for simultaneously rendering said rectifying discharge tube non-conductive to thus interrupt the charging circuit for said capacitor, said source of triggering pulse energy for the control electrode of said switching tube of each stage except the first including the stabilizing element in the discharge circuit for the capacitor of the preceding adjacent stage in the cascaded system and operable upon the flow of current through said stabilizing element to apply the triggering pulse to the control electrode of said switching tube, and a source of coded triggering pulse energy for the control electrode of the switching tube of the first cascaded stage to cause interruption of its charging circuit and discharge of its associated capacitor and attendant current fiow through its stabilizing element with successive self-triggering of the switching tube and current flow through the stabilizing element of each remaining stage of the entire cascaded system, to cause discharge of all the capacitors of the system in electrical series across said load at a voltage determined by the number of stages in the cascaded system.

6. A pulse voltage multiplying system comprising a plurality of cascaded stages, each stage comprising a capacitor, a charging circuit for said cpacitor including isolation elements connected to said capacitor and to a high voltage supply source and a rectifying discharge tube for controlling said circuit to cause charging of said capacitor; a discharge circuit for said capacitor including a stabilizing element and a load energizable upon discharge of said capacitor, and a control switching tube having a control electrode, a source of biasing potential for the control electrode of said switching tube including the secondary winding of the same low potential transformer used for heating the thermionic cathodes of said rectifying and switching tubes and normally operative to prevent said switching tube from conducting and causing discharge of said capacitor; a source of triggering pulse energy connected to the control electrode of said switching tube for rendering the latter conductive to cause discharge of said capacitor and for simultaneously rendering said rectifying discharge tube non-conductive to thus interrupt the charging circuit for said capacitor, said source of triggering pulse energy for the control electrode of said switching tube of each stage except the first including the stabilizing element in the discharge circuit for the capacitor of the preceding adjacent stage in the cascaded system and operable upon the flow of current through said stabilizing element to apply the triggering pulse to said switching tube, and a source of coded triggering pulse energy for the control electrode of the switching tube of the first cascaded stage to cause interruption of its charging circuit and discharge of its associated capacitor and attendant current flow through its stabilizing element with successive self-triggering of the switching tube and current flow through the stabilizing element of each remaining stage of the entire cascaded system, to cause discharge of all the capacitors of the system in electrical series across said load at a voltage determined by the number of stages in the cascaded system.

No references cited.

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