Патент USA US2591827

April 3, 1952
E. o. JOHNSON
2,591,824
PULSE ENERGIZED GAS TUBE CIRCUIT
Fil‘ed Jan. 2, 1951,
'
INVENTOR
EDWARD U. .T uz-msnn
BY
,
.
ATTORNEY
_
Patented Apr. 8, 1952
2,591,824
UNITED STATES PATENT ‘ OFFICE
\
Edward Oscar Johnson, Princeton, N. J ., assignor
to Radio Corporation of America, ‘a corporation
of Delaware
Application January 2, 1951,.SerialNo-203,951
‘8 Claims. (Cl. 315-849)
2
[.Thisinve‘ntion relates to improvements in elec
tron gas tube systems, and particularly to an
improved system for ‘pulse energizing a gas-?lled
tubes suitable for‘us‘ein the ‘systems of Figs‘..l—3,
and
Fig. 6 is a diagram ‘of a further embodiment
of the invention.
As is explained in‘the above-‘mentioned co—
electron tube of the type wherein the functions
ofioni'zation and of principal current delivery
are separated.
pending application of the present applicant, it
In a copending application of the present ap
is possible to operate a gas-?lled electron tube
withlow voltages and under readily controlled
plicant, Serial No. 185,745, ?led ’September‘p20,
1950, "assigned to the'assign'eeoi the present ‘in
conditions by ‘providing for an‘auxiliary discharge
vention, there is described a gaseous electron 10 current in the tube to generate an ion-electron‘
tube wherein ionization is accomplished by pass‘
plasma which will support the main tube cur
ing current between a pair of electrodes‘ in the
rent. In general, 'itis necessary that ‘thea'auxil
tube in order‘ to permit large ‘quantities of current
iary discharge be established byfmeans of 5 volt
to be passed between two other tube electrodes
age of amplitude su?icient to ionize" the gas in
at voltages lower than that‘ required to ionize the 15 the tube. It‘has been found, however, that the
gas in the tube. In .a- copending application of
ionizing discharge ‘need not be a‘contin‘uous
In Malter, Serial No. 203,923, ?led concurrently
discharge, but that ‘it can be discontinuous‘ or
herewith .‘and. assigned to the assignee of the
pulsating ‘in nature. In Fig. l of the drawing,
present invention, and’ in .a copendin'g applica
there is shown “a ‘system for deriving ionizing
tion 'o'f‘I. Wolff, Serial No. 212,632, ?led Febru 20 pulses for a gas tube from a ‘voltage sourceof
ary23, 1951’, and also assigned to the assignee of
potential less than that required to ‘ionize the
the present invention, there ‘are described meth
tube gas.
7
,
‘
‘
s
_‘
ods and'system for operating gas-?lled electron
tubes by means of pulse ‘voltages.
Referring to Fig.‘ '1, there ‘is showna gas tube
It! having an anode 12, a cathode. M, a control
at
It ‘is a general object of the present‘ inven
tion to provide van improved apparatus‘ for pulse
25 electrode l6, and anauxiliary electrode I’Bl _In
the-embodiment of the'invention presently being
energization of gasi-?lled electron tubes.
A more speci?c object of the invention is the
provision of an improved pulse energizing ar
rangement for gas-?lled electron tubes which is 30
adapted to be operated with a voltage source
described,‘ the auxiliary ‘electrode l8 serves as an
auxiliary anode to which electrons will flowsfrom
the cathode M to ionize the gas in theitube?lll.
However, as will be shown hereinaftenthe auxil
loiger than that required to, ionize the gas in the
tron‘em'itter or cathode with slight modification
tu e.
of the circuit.
~
An additional object of the invention is the
provision of an improved automatic starting'cir
cult for a pulsed gas tube system._
In accordance with the invention, the .fore
going and other related‘ objects ‘and advantages
are‘ attained in a system wherein the voltage de
35
iary electrode l8’ can‘ aswell comprise‘ an'elec
_
a number'of different elements, such asthepri'i
mary winding of a transformer, a‘ loadfrhesistor,
or the‘like. The precise character of the load
veloped across an inductor by interrupting cur 40 26 is not‘ material for present purposes.
rent‘ ?ow therethrough is added to the voltage
of" the current source supplying the inductor in
such a way as to provide voltage pulses of ampli=
I ‘
The main tube anode I2 ‘is connected ‘to a
voltage source, shown‘ as a battery 22, through‘ a‘
load 26. The load 20 may comprise anyone‘ of
" _
The ‘auxiliary electrode l8 ‘also'is connectedlin
circuit‘with ‘the cathode I4 through an inductor
' 24 and the voltage‘ source'22. A capacitor‘z‘? is
tude vsuiiicient to ionize the gas‘ inthe tube.
connected in parallel with the series combination
A more complete u‘nd'erst'anding'o'f, the inven 45 offthe ‘inductor 24 and the voltage source 22.‘
tion can be had by referring to the‘ ‘following de
Also, a resistor 28 is connected across the capaci
scription of‘ illustrative embodiments‘ thereof,
tor 26 i'n'series'with'a switch‘30.
‘7
when considered in connection with the accom
Assuming
that
the
voltage
of
the‘
source
'22
is
p'anying drawing, wherein:
less than that required’ to ionize the gas in the
Fig. 1 is a‘ schematic diagram of an electron 50 tube l 0,, it can be‘ seen that no appreciable cur
gas‘ tube system arranged in accordance with the
invention,
rent will ?ow in the tube ‘l0 under static“ con‘
ditions. However, if the switch 30 is closed
‘ Figs. 2 and 3 are schematic diagrams of modi
brie?y, current will flow through the inductor ‘24
?ed formsof the system shown in Fig. 1,
'
and through the resistor 28. If, now, the switch
' Figs. '4 and 5 illustrate the structure of gas 55 30' is opened, the e?‘ect of suddenly interrupting
2,591,824
3
4
gas in the tube III. The remainder of the cir
cuit function will be essentially the same as in the
circuit of Fig. 1.
Thus far, no consideration has been given to
the type of cathode I4 in the tube ID in Figs. 1
and 2. In the usual case, it is preferable to use a
thermionic emitter. This, however, introduces
a starting problem. Either it is necessary to pro
the current ?owing through the inductor 24 will
be to develop across the inductor a voltage sub
stantially equal to that of the source 22. Also,
the polarity of this voltage across the inductor
24 will be suchas to add to the source voltage,
so that the voltage between the cathode I4 and
the auxiliary electrode I8 will be approximately
twice the voltage of the source 22. If this total
vide a separate energization circuit for the cath
voltage between the electrodes I4, I8 is sufficient
to ionize the gas in the tube I0, current will ?ow 10 ode heater element, so that the cathode can be
heated before main circuit operation is started,
‘ between the electrodes I4, I8. Also, the ioniza
or some means is required for supplying circuit
tion produced by this ?ow of current from the
interrupting action after the tube cathode has
cathode I4 to the electrode I8 will allow current
reached operating temperature. In Fig. 3, there
to ?ow from the cathode I4 to the main anode
I2 and through the load 28.
15 is shown a completely automatic starting circuit
Within a short time after current flows between
the electrodes I4, I8, the voltage across the in
ductor 24 will decrease sufficiently to stop the ion
izing current flow between the electrodes I4, I8.
However, current will continue to ?ow through
the inductor 24 and into the capacitor 26, thereby
wherein the closing of a single switch will initiate
the desired circuit action.
In the circuit in Fig. 3, the gas tube I0 is pro
vided with a heater element I5 for the cathode
I4. This heater elementis connected to the volt
age source 22 through a switch 34. The cathode
I4 is connected to the voltage source 22 through
a holding winding 36 of a relay 38. The relay 38
capacitor circuit 24, 26. This willcause the volt
has a second winding 48 which is connected in
age between the electrodes I4, I8 again to build up
to the point necessary to ionize the gas in the 25 series between the voltage source 22 and a mov
able contact 42 of the relay. The circuit for the
tube. In this way, a periodic or pulsating cur
setting up an oscillatory action in the inductor
rent will ?ow between the electrodes I4, I8, at a
frequency determined by the inductance of the
inductor 24 and the capacitance of the capacitor
30
26.
, As is explained in the above-mentioned co
pending Malter application, if the current pulses
between the cathode I4 and the electrode I8 are
of su?icient intensity and recur rapidly enough,
a substantially constant current can be drawn ‘
from the ‘cathode I4 to the main anode I2.
Furthermore, this current can be modulated by
applying a modulating voltage between the con
trol electrode I6 and the cathode I4 through in
put terminals 32. Thus, it becomes possible to
inductor 24 is completed through the resistor 28
and through the ?xed contact 44 of the relay. A
spring 4| normally biases the contact 42 against
the ?xed contact 44.
.
When the switch 34 is closed, current will be
gin to flow through the heater I5 to begin heating
the cathode I4. vAlso, current will begin to flow
through the inductor 24, the contacts 42, 44, the
resistor 28, and the winding 40. Before the heater
I5 has warmed up, very. little current will flow
through the holding winding 36. However, a sub
stantial current will flow through the winding 40,
causing the contacts 42, .44 to open. As soon as
these contacts open, the current through the
winding 40 will be cut off, and the contacts 42, 44
operate the gas tube II] from a source of voltage
again will close. This action will continue, each
lower'than that required to ionize the gas in the
time generating suf?cient voltage at the auxiliary
tube, and to control the tube current by means
electrode I8 of, the tube I0 to cause an ionizing
of an external control voltage.
As was previously stated, the auxiliary elec 45 discharge. However, until the cathode I4 becomes
heated no discharge will take place.
trode I8 in Fig. 1 could as well comprise an auxil
As soon as thecathode I4 becomes heated, a
iary cathode. An arrangement of this type is
current pulse will flow from the cathode I4 to
shown in Fig. 2.
‘
the auxiliary electrode I8. Also, the current will
In Fig. 2 the various elements all correspond
with similar elements in the circuit of Fig. 1, with 50 increase. through the holding windings 38 as the
heater I5 warms up, so that when the cathode I4
the exception that the auxiliary electrode I8a in
becomes fully heated the current through the
the tube III is an electron emitter rather than
an electron collector. This necessitates a slight
change in the circuit con?guration. The polarity
winding 36 will-keep the contacts 42, 44 open.
Thereafter, the circuit will operate in substan
of the voltage source 22 remains the same so that 55 tially the same manner as has already been de
scribed for the circuit in Fig. 1.v
_
a positive voltage will be applied between the tube
. Although details of tube structure form no part
anode I2 and the main cathode I4. However, the
of the present invention per se, for the sake of
concreteness there‘is shown in Fig. 4 a sectional
source 22 rather than to the positive terminal as 60 view of a gas tube such as might be used in the
circuits of Figs. 1 and 3. In Fig. 5 there is shown
in the circuit of Fig. 1. As in Fig. 1, a capacitor
a similar view of a tube such as might be used
26 is in shunt with the series combination of the
in the circuit of Fig. 2.
voltage source 22 and the inductor 24. Also, a
The tube shown in Fig. 4 has a gas tight en
resistor 28 and a switch 38 are in series across
65 velope I6, within which there is placed a cathode
the capacitor 26.
auxiliary cathode IBa is returned through the
inductor 24 to the negative terminal of the voltage
In the circuit of Fig. 2, temporary closing of the
switch 30 will establish current ?ow through the
inductor 24 and the limiting resistor 28. When
the switch 30 is opened, a voltage will be devel
l4, surrounded by ‘a mesh-type control grid I6
and, outside the grid I6, by an anode I2. An
additional electrode I8 is provided adjacent to
the cathode I4 to receive ionizing current there
voltage of the source'22, making the total voltage
ample, comprise two rods disposed on opposite
sides of and parallel with the cathode I4.
oped across the inductor 24 which will add to the 70 from.
between the auxiliary cathode IBa and the anode
This auxiliary electrode I8 may, for ex
The tube shown in Fig. 5 comprises a gas tight
I2 approximately twice the source voltage.
envelope I0 provided with a cathode I4. A U
Thereupon, current will flow from the auxiliary
cathode I8a to the main anode l2, ionizing the 75 shaped control electrode or grid I6 and a U
ggteiiiieii.
6
:shapedianode ‘ I 2 ’ partially'surroun'd"themathode
throughva: “COTIduC?VB'jpM'Smw"?lial ‘fseparately
"I4: ' \j'I’he‘jgridI 6'“comprisesra'plurality-ref parallel
ionized" gas‘ tube I‘ with a voltage"v drop-‘ias‘llow fee
wires I l'jjwhi‘ch are ‘supported in" space'drelation.
‘Oppositej‘the ‘open-ends‘of the gridf'IG and the
anode‘ IZthere is mounted‘an auxiliary cathode
I?a. As is explained in the above-mentioned‘ap
plication of“ the presentapplicant, it is advan
tageous'to concentrate the auxiliary cathode‘
ionizingjcurrent by surrounding the auxiliary.
0:1 volt.
'
_
'Dueito electrode con?guration, the1controlel'ec
trode I3 in @the tube Illa' will’l'i'ave littlelcontrol
over ‘the work'circuit'current. Thiselectrode I3
can be left disconnected or “floating'i’as-shown.
It‘ should‘ be ‘noted, however, that‘a mesh-‘type
control‘ ‘electrode surrounding the cathode ‘I4
cathode v'Iilirwith a cylindrical'focusing electrode 10 could be provided for workcircuit current control
1 swliich has‘ an elongated'slot Z‘I facing‘the' open
if desired‘.
7
ends‘ of ' the-grid and ‘anode ' structures.
From the foregoing, it will be seen- that ‘the
present invention provides a simple iandre?icie'n‘t
scrib'edfwith vparticular ‘reference to gas‘ tubes
system vfor operating a gas-?lled ‘tube from a
having,_.electrode structures'suitable for ‘grid con 15 source of voltage less than that f-r'equired ‘to ionize
trolofcurrents drawn through a conductive ion
thetubegas.
electron plasma at low voltage drop. Many con
' ' What is‘ claimed is:
ventional gas tubes do not have an electrode
l. A pulse energizing system “for a gase?lle'd
structure that is suitable for this type of‘ opera
electron tube having a ?rst'pair of‘ electrodes ‘for
tion. In‘ Fig. 6, there is shown a gas tube circuit‘
passing ionizing current through the tube ‘and
having a ‘second pair of electrodes'including at
in which the principles of the present invention
are used. to advantage even though no grid con
least one electrode in addition-‘to said ?rst pair
trol isnhad of the work circuit current.
for passing ‘current through the gas ‘so ionized,
_ ‘Thus far,=.the, present‘ invention has been ‘de
'Th'eici'rcuit of Fig. 6 includes ‘a gas-?lled ‘tube
a source of voltage of amplitude ‘less ‘than that
Ina of a commercial‘typ'e‘widely known as a “2050 25 required to ionize the tube gas, an inductor, 1a
thyratron,” taken as typical of many similar con
?rst circuit connecting said inductor to said
ventional gas tubes. The tube Ilia has a cathode
source to establish current ?ow through said in
I4, usually heated by a ?lament (not shown) ,‘ a
ductor, a second circuit connecting said inductor
control electrode I3, a so-called shield electrode
and said source between said ?rst pair of elec
I2, and an anode I8. In the circuit of Fig. 6, the 30 ‘trodes, a circuit connecting said source between
shield electrode I2 actually serves as an electron
said second pair of electrodes, and means to in
collector or anode, and the anode I8 serves as ‘an
terrupt the ?ow of current in said first‘j circuit
auxiliary or ionizing electrode. Therefore, these
to develop a voltage su?lcient to cause ionizing
electrodes, I2 and I8, will be referred to herein
current ?ow between said first pair of electrodes.
after as the anode I2 and the auxiliary electrode 35 2. A gas tube system “comprising a gas-filled
88 to conform with the functions thereof.
electron tube having a plurality of electrodes in
As in the circuits of Figs. l-3, the auxiliary
cluding a cathode, a ‘source of voltage of ampli
electrode It in Fig. 6 is connected to the cathode
tude less than that required to ionize the gas in
I4 through an inductor 24 and a voltage source
said tube, an inductor, a circuit connecting said
22. Similarly, a capacitor 25 is connected in 40 voltage source and said inductor in series between
shunt with the inductor 24 and the source 22,
said cathode and another of said electrodes, a
and a resistor 28 and switch 30 are connected in
switch, a second circuit connecting said switch
series across the capacitor 26, as in Figs. 1-3.
‘between said cathode andsaid another electrode, '
The inductor 24 has a dual function ‘in the cir
a work circuit including" said voltage source con
cuit‘of Fig. 6. In addition to assisting the’ de
necting two of said electrodes including said cath
velopmentof ionizing pulses as previously de
ode, and a capacitor connected between said last
scribed, the inductor 24 acts as the primary wind
named two electrodes.
ing of a transformer which has a secondary wind
3. A gas tube system comprising a gas-?lled
ing 21. ‘The secondary winding 2‘! is connected
electron tube having, three electrodes including
in series with a resistor 29 between the anode I2
an anode, a' cathode, and a third electrode, a
and the voltage source 2. A ?ltering‘ capacitor
source of voltage of amplitude less than that re
quired to ionize the tube gas, an inductor, a cir
3| is connected across the resistor 29.
By ‘closing and opening the switch 30, suffi
cuit including said voltage source and said in
cient voltage can be built up between the cathode
ductor connecting said anode and said third elec
I4 and the auxiliary electrode I8 tocause pulse 55 trode to ionize the gas in said tube in pulses, a
ionization as previously described. The pulsating
load device, and a "circuit separate from said
current ?owing through the inductor 24,.will in
?rst-named circuit connecting said anode to said
duce a higher voltage in the secondary winding
cathode through said, load device.
21. The anode I2 will cooperate with the cathode
4. A system for operating a gas-?lled tube of
I4 to rectifythe stepped up voltage appearing 60 the type having a plurality of electrodes includ
across *the secondary winding 21, providing a
ing a cathode electrode, said system comprising
unidirectionalvoltage across the resistor-capaci
a source of voltage of amplitude less than that
required to ionize the gas in said tube, a load de
tor combination 28, 3|. This unidirectional volt
age can be utilized in any suitable load' device 33
vice, a work circuit connecting two of said elec
connected to a pair of output terminals 35. Thus, " trodes and including said voltage source and said
the'circuit of‘ Fig. 6 will function as a “D.-C.
load device, an inductor, a circuit including said
voltage source and said inductor to generate a
transformer.” .
The magnitude of the voltage available at the
?rst voltage pulse of amplitude su?icient to ionize
terminals 35 will depend largely on the turns
said tube gas, a circuit connecting said voltage
ratio'of the transformer 25. An important ad
pulse generating circuit between said cathode
'vantage of the system resides in the fact that
and another of said electrodes, a capacitor, and
there will be substantially no voltage lost be
a circuit including said capacitor, said inductor,
tween the cathode I4 and the anode I2. ' As is
said cathode and said another electrode to gen
explained in the above-mentioned Johnson and
erate pulses of amplitude suf?cient to ionize said
Malter applications current can be drawn 75 tube gas subsequent to said ?rst voltage pulse.
2,591,824
7
5. A pulse energizing system for a gase?lled
electron tube having electrodes including an
anode, a cathode and an auxiliary electrode, said
system comprising a source of voltage of ampli
tude less than that. required to ionize the tube
gas, an inductor, a capacitor, a pulse generating
circuit connecting said auxiliary electrode and
another of said electrodes and including said in
8
actuating means connected in said second circuit
for opening said switch in response to current
?ow through said second circuit, a heater for
one of said electrodeshand a circuit including
said voltage source for supplying current to said
heater.
,
g
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>7. Apparatus as de?ned in claim 6 wherein
said switch actuating means and said switch
comprise a relay having a pair of contacts con
ductor and said voltage source, said pulse gen
erating. circuit including a switch operable to 10 treated- in said second circuit and having an op
erating wind-ing connected in said second circuit.
complete a circuit through said inductor in par
8. Apparatus as de?ned in. claim 7 wherein
allel with said source, said capacitor being con
said relay has an additional operating winding
nected- in said pulse generating circuit in parallel
connected in circuit ‘with two of said electrodes
with said switch, and a work circuit connecting
.
said anode-and said cathode through said source. 15 and said voltage source.
EDWARD OSCAR J OHNSON.
6. A pulse energizing system fora gas-?lled
electron tube having a plurality of electrodes,
REFERENCES CITED
said system comprising a source of voltage less
than that required to ionize the gas in said tube.
The following references are of record in the
an inductor, a circuit connecting said voltage 20 ?le of this patent:
source and said inductor in series between two of
UNITED STATES PATENTS
said velectrodes, a switch, means normally bias
Number
Name
Date
ing said ‘switch closed, a second circuit connect
2,130,191
Meier ___________ __ Sept. 13, 1938
ing said inductor and said switch in series across
Meier _____ __'______ May 16, 1939
said voltage source, current responsive switch 25 2,158,564