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Патент USA US3065381

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Nov. 20, 1962
3,065,371
P. W. STUTSMAN
AUXILIARY CATHODE GAS DISCHARGE DEVICE
Filed July 22, 1949
2 Shams-Sheet 1
F16. /
/NVENTOR
PAUL W STUTSMAN
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3,®h5,37l
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Patented Nov. 20, 1952
2
1
the load may be changd to accomplish di?erent purposes
season
with the different currents.
The particular details whereby the foregoing advantages
AUXE'EZ
DISQHARGE
AR‘!
DEVICE
Paui W. Stutsman, Needham, Mass, assignor to Raythean
{Iompan‘ , a corporation of Deiaware
Filed July 22, 1949, Ser. No. 106,179
11 Claims. (Cl. 3l3-—19'7)
are obtained will now be described in detail, reference
Cl
being had to the accompanying drawings wherein:
FIG. 1 represents a longitudinal cross-sectional view
of a device embodying the principles of this invention
taken along line 1-4. of FIG. 2;
This application relates to electron discharge devices
FIG. 2 illustrates a transverse cross-sectional view of
and more particularly to gas-?lled discharge devices 10 the device shown in MG. 1 talren along line 2—2 of
capable of operating over a wide range of discharge cur
FIG. 1 illustrating the details of the auxiliary cathode
rents.
structure;
In previous devices where a gas tube was desired which
H6. 3 is a transverse cross-sectional view of the device
had high grid sensitivity, it has been found necessary to
heat the cathode, either thermionically or ionically to
create a supply of electrons upon which the control grid
shown in FIG. 1 taken along line 3-~3 of FIG. 1',
FIG. 4 illustrates a circuit utilizing the device of FIGS.
l-3 wherein a method of ionically heating the auxiliary
cathode is disclosed; and
PEG. 5 illustrates another circuit utilizing the device of
could act. Where it was required that the device should
pass large currents, the power necessary to heat a cathode
of su?icient size to pass said currents was considerable,
and this heating power had to be applied during the
stand-by condition of the tube to maintain the tube in
readiness for ?ring. If it were desired that this particu
lar tube at any time carry only small currents, it was still
necessary that the large cathode be heated with the result
that the cathode heating power would be large compared
to the useful power realized in a load connected to the
device.
Applicant provides herein a novel means of producing
a device which will have high grid sensitivity and yet
will require relatively low heating power. This is accom
plished by providing for an auxiliary cathode of relatively
small size which is maintained at an electron emitting tem
perature by any desired means such as an ionic discharge
from said auxiliary cathode to a keep-alive anode, or
FiGS. 1—3 wherein means are provided for thermioni
cally heating the auxiliary cathode.
Referring now to F168. 1, 2 and 3, there is shown a
glass envelope 2% consisting of a tube one end of which
is pressed together as at 21 and through which extends a
plurality of lead-in wires. The other end of the glass
tube 29 is curved together and contains at its center a
mass of glass 22 which is used to seal the envelope after
?lling of the envelope with the correct gaseous medium.
Extending upward from the glass press 21 inside envelope
2d are three glass tubes 2.3, 24 and 25 whose axes are
all parallel and lying in the same plane and spaced an
equal distance apart. The center glass tube 24 extends
slightly less than one-third the length of envelope 20.
Inside the glass tube 24 which is hollow, is an anode
rod 25 which extends from the open end of the glass rod
by thermionic heating of the cathode. This auxiliary
cathode is positioned between the main cathode and main
24 toward the glass press 21 through a spacer 27 con
anode and the electrons emitted therefrom are subject
to control by the grid structure.
Thus when a small current is required from the dis
Anode rod 26 is then joined, for example, by Welding
charge device, this current may’ be supplied by the auxil
iary cathode. However, if a larger current is required, a
voltage drop is created between the auxiliary cathode and
main cathode due to current flow in an impedance connect
ing said cathodes with the result that positive ions will fall
onto the main cathode heating the same and initiating a
self-sustaining auxiliary discharge between the main
cathode and main anode. Thus it may be seen that dur
ing the periods when large currents are not drawn by the
device, the main cathode remains cold and when large
currents are required, the main cathode is heated by
ionic bombardment to provide the necessary electrons
for the discharge.
By the use of a hollow cathode for the main cathode,
applicant has produced a structure which will conserve
the heat of the cathode, and in addition will tend to con
serve the supply of electron emissive material of the
cathode sincematerial torn or sputtered off from the
main cathode by the discharge will to a large extent re
deposit on the main cathode. Also, by the use of this
of main cathode which is rugged and rigid, the tube may
be placed in any position during operation without detri
mental results.
By means of adequate grid shielding of the anode com
prising a glass tube surrounding the anode rod and a cup
shaped grid covering the end of the anode rod and glass
tube, relatively high anode to cathode voltages may be
applied to the device without breaking down the space
therebetween.
Also, applicant discloses herein circuits particularly
adapted to utilize this discharge device. Since a feature
of the device is the ability thereof to operate at either low
or high discharge currents, a circuit is provided whereby
sisting of a wire spirally wrapped around anode rod 26.
to a lead~in wire 28 which extends through the glass
press 21.
The end of the tube M which is open, is covered by a
cup-shaped grid 29 of wire mesh which may be made of
60 x 60 strands per inch screening using .005 inch nickel
wire. The diameter of the cup-shaped grid 29‘ is slightly
larger than the diameter of the glass tube Z-t and extends
for somewhat more than one diameter of the glass tube
over the end of said rod. The bottom of said cup-shaped
grid 29 is in close proximity but not touching the end
of the tube 24 and the anode element 2.6. Cup-shaped
grid 29 is supported by being attached as by welding to
a strap 30 at the lip of said cup-shaped grid. The strap
3t} extends around the tubes 23 and 2-5 thereby rigidly
supporting the grid 29“. The tubes 23 and 215 are some
what longer than the tube 24 and extend further into
the envelope 2!) past the end of tube
and the grid
29. A lead-in wire 31 is attached to the strap 3% as by
welding and extends along the side of envelope 2% through
the glass press 21.
Extending the length of rods 23 and 25 which are hol
low, is a pair of support rods 35 which are butt welded
to lead-in members 31’: extending through the glass press
21. The rods 35 contain spacers 37 thereon similar to
the spacer 27 on anode rod 26. The rods 35 extend out
of the open ends of the glass rods 23‘ and 25 for a dis
tance equal to approximately half the diameter of envelope
and then pass through a mica plate 33. The mica plate
30 is ?at and has a shape conforming to the inside con
tour of the envelope 2d at a section taken at the right
angles to the rods 35. Tabs 35a are welded to rods 35
on both sides of plate 38, thereby preventing movement
of plate 38 on rods 35.
A cathode 39 is supported between the rods 35 in the
3,065,871
0
space ‘between the mica plate 38 and the bottom of the
cup-shaped grid 32. This cathode consists of a helically
wound wire coated with electron emissive material, the
diameter of said helix being approximately equal to the
diameter of the glass tube 24‘. One end of said helically
be on the order of 1500 ohms ‘for a B-}- voltage of 150
volts. The value of resistor 6% is such that when a dis
charge current of 100 milliamperes is drawn through load
65, the voltage drop across resistor 69 due to said discharge
current is insut?cient to cause ions from the discharge to
fall on cathode 56 with enough velocity to create a self
wound wire is attached as by welding to one of the rods
35 and the other end to the other rod 35.
sustaining arc. The value of resistor ‘69 will vary with
Between the cathode 39 and the cup-shaped grid 32
the particular tube design, and for the particular design
there is positioned a keep-alive ‘grid 49. This grid is a
illustrated herein may be on the order of 100 ohms. If it
semicylindrical piece of screening of the same type used 10 is desired at any time to use the tube to feed a large cur
to make grids 2% and 32.. The axis of the semicyiindrical
rent to a load, for example, to the second load 66, the
contacts 68 are closed by deenergization of the relay 67.
screen is approximately concentric with the axis of the
helical cathode 39. The ‘diameter of the cylindrical screen
[all is slightly greater than the helix of the cathode 39
The impedance of the load 66 is on the order of a few
ohms such that 100 amperes passing through the load will
create a voltage drop thereacross on the order of 140 volts.
When the tube is ?red and the larger current is drawn
41 welded thereto and which are attached to bands 42
from cathode 39, this current passing through resistor 69‘
mounted on the tubes 23 and 25. The grid 40 is con
will create an initial drop between the cathodes which is
nected to a lead-in wire 43 which extends along the side
large compared with the drop across the load, so that the
of envelope 2%) through the glass press 21.
20 potential of the auxiliary cathode 2.? is raised well above
The mica support member 38 has a hole 53 therein
the main cathode 56. Thus many positive ions will fall into
approximately equal in diameter to and concentric with
the cathode 56 and release secondary electrons in suffi
the inside diameter of the glass anode shielding tube 24.
cient quantity to cause the anode-auxiliary cathode plasma
A second mica member 54 similar in shape to the mica
to extend to the main cathode 56, whence a self-sustaining
member 38 and having a hole 55 therein somewhat larger 25 are, capable of carrying high amperage current is pro
duced.
in diameter than the hole 53 in mica member 38 but con
centric therewith, is positioned parallel with the member
Referring now to FIG. 5, there is shown a circuit where
38 and spaced slightly therefrom on the opposite side of
by the auxiliary cathode 39 may be thermionically heated.
such that grid 4% is in close proximity with the cath
ode 39. The grid 46 is supported at each end by straps
member 38 from the cathode 39.
Above mica member 54 is another cathode 56 compris
The ends of cathode 39 which as shown in ‘FIG. 1 termi
30 nate in two lead members 36, are connected to the sec
ing a metallic cylinder 57 which may be, for example, of
nickel whose diameter is somewhat smaller than the di
ameter of envelope 2-81 and whose length is somewhat
greater than its diameter. The lower end of the cylinder
ondary winding 74 of a ?lament transformer 75, the
primary 76 thereof being connected to a suitable voltage
source. Secondary winding 74 is center tapped, the center
tap being connected to ground through the resistor 69.
‘57 rests on the mica member 54 and has an end plate 35 Since the ionic discharge between the cathode 39 and the
58 which may be of nickel and which has a hole 59
electrode 4-0 is no longer required for heating purposes,
therein, concentric with holes '53 and 55, whose diameter
electrode 4% is connected to grid 29 through a current
is somewhat less than the inside diameter of the rod 24.
limiting resistor 77. However, if desired, the electrode
The upper end of the cylinder 57 is sealed by a second
4t) could be eliminated altogether. Obviously the loads
end plate 60, and rests against a mica member 61 simi
and switching arrangement illustrated in FIG. 4 may be
lar to member ‘54.
A member 62 is attached to the cen
used in the modi?cation of FIG. 5 and are illustrated dia
ter of end plate 60 and extends through the hole in mica
member 61. Attached to the member 62 is a lead-in
member 63 which extends through the glass seal 22 in
the upper end of envelope 20. Inside the cylinder 57 45
grammatically therein by the box 78. The remaining ele
is wound a wire 64 which contains electron emissive ma
Since this type of tube does not use a main cathode
which is liquid, such as mercury, an inert gas ?lling may be
terial said wire completely covering the inside of cyl
ments of FIG. 5 are similar to those of FIG. 4 and the
method of operation, except for the method of heating
auxiliary cathode 39, is identical.
inder 57.
used. The ?lling used herein is xenon; however, argon
Referring now to FIG. 4, there is shown a circuit uti
and krypton may be used. Since these gases have relative
lizing the discharge device of FIGS. l—3 comprising a 50 1y low thermal conductivity, relatively high pressures, for
first load 65 connected between anode 26 and B+ and a
example, 30 millimeters of mercury, may be used which
second load 66 in parallel with load 65. A relay 67 is
tend to inhibit the loss of cathode coating due to sputter
provided having a pair of contacts 655 in series with the
ing. Further, due to their relatively low ionization poten
second load 66 such that ‘when relay 67 is energized from
tial and high secondary electron yield, due to their large
any desired source, contact 68 will open disconnecting 55 mass, a relatively low starting voltage is produced.
load 66 from the circuit.
Thus it may be seen that applicant has provided a gas
Main cathode 56 is connected to ground, and the two
?lled tube which may be operated with either an ionically
leads 36 of auxiliary cathode 39 are connected together
heated or a directly heated auxiliary cathode, which has
and to ground through a resistor 69 to ground. Keep
a relatively high grid sensitivity, and which will pass cur
alive electrode 46 is connected to B+ through a voltage 60 rents ranging from steady fractional currents to high amp
dropping resistance 7% which may be on the order of 4.500
erage peak currents, with the permissible peak currents
ohms. The control grid 29 is connected to a signal input
far exceeding the current capacities of the small auxiliary
source through a DC. blocking condenser '71 and to
cathode which requires only low heating power.
ground through a biasing battery 72 and a grid load re
This completes the description of the embodiments of
sistor 73.
the invention illustrated herein. However, many modi?
In operation the auxiliary cathode 39 is heated by an
cations thereof will be apparent to persons skilled in the
ionic discharge therefrom to the electrode 46. This dis
art, for example, a plurality of grids similar to grid 29
charge will provide a reliable source of electrons with a
might be employed as well as different spacing and posi
discharge current of, for example, 30 milliamperes. How
tioning of the tube elements. Therefore, applicant does
ever, lower keep-alive currents may be used if desired. 70 not Wish to be limited to the speci?c details of the modi
When the load selector relay 67 is energized and the
?cations described herein except as described by the ap
second load 66 is disconnected from the anode circuit, the
pended claims.
impedance of the ?rst load 65 is of such a value that a
What is claimed is:
discharge in the tube will be limited to a current on the
order of 100 milliamperes. This load impedance would
1. An electron discharge device comprising an envelope
containing a gaseous medium, a cold cathode, an anode
3,065,871
5
comprising a rod-shaped member, a cylindrical insulating
member positioned around said anode, one end of said
insulating member being open thereby presenting a por
tion of said anode to said cathode, a grid substantially
covering the open end of said insulating member, and an
auxiliary source of free electrons positioned in the space
between said cathode and anode.
2. An electron discharge device comprising an envelope
containing a gaseous medium, an anode, a cold, hollow
cathode having electron emissive material on the interior
surface thereof, a grid substantially shielding said cathode
from said anode, and an auxiliary thermionic source of
free electrons positioned in the space between said cathode
and anode.
3. An electron discharge device comprising an envelope 15
containing a gaseous medium, an anode, a cold cathode,
a grid substantially shielding said cathode from said an
ode, and an auxiliary source of free electrons positioned
containing a gaseous medium, a ?rst cathode, a ?rst anode
surrounded by a sleeve of insulating material, a cup
shaped grid surrounding said insulating sleeve and said
?rst anode, and means for maintaining an electron dis
charge in the space between said ?rst anode and said ?rst
cathode independent of electron ?ow from said cathode
to said anode comprising a second cathode and second
anode between said ?rst cathode and said ?rst anode,
said ?rst cathode having an electron emitting capacity sub
stantially greater than said second cathode and being sup
ported from one end of said envelope, said second cathode
being supported by lead~in means from the other end of
said envelope, insulating means surrounding said lead-in
means in the vicinity of said ?rst anode, and said second
anode being supported from said insulating means.
9. A gaseous discharge device comprising a large area
cathode, a small area anode opposite said cathode and
de?ning a gap therewith, a control electrode in said gap,
means maintaining a continuous keep alive discharge in
a second cathode and means for heating said second 20 said device, means biasing said control electrode for in
in the space between said cathode and anode comprising
cathode comprising an electrode spaced in close proximity
jecting electrons from said keep alive discharge into the
with said second cathode and adapted to produce a dis
charge between said second cathode and said electrode
upon the application of a potential thereacross.
vicinity of said anode, and means biasing said anode to
allow breakdown in the vicinity of said anode only fol
containing a gaseous medium, an anode, a cold, hollow
10. A gaseous discharge device comprising a large area
cathode, a small area anode opposite said cathode and de
?ning a gap therewith, a large area control electrode in said
gap and having an aperture therein, means maintaining
lowing the injection of the electrons from said keep alive
4. An electron discharge device comprising an envelope 25 discharge.
cathode, a grid substantially shielding said cathode from
said anode, and an auxiliary source of free electrons posi
tioned in the space between said cathode and anode com
prising a second cathode and means for heating said sec 30 a continuous keep alive discharge in said device, said dis
ond cathode to thermionic emission temperatures, inde
pendent of the magnitude of said emission.
5. An electron discharge device comprising an envelope
charge being in alignment with said main ‘gap, means bias
ing said control electrode for injecting electrons from said
keep alive discharge through said aperture into the vicinity
of said anode, and means biasing said anode to allow
ode, and means for maintaining an electron discharge in 35 breakdown in the vicinity of said anode only following the
injection of the electrons from said keep alive discharge.
the space between said ?rst anode and said ?rst cathode
11. A gaseous discharge device comprising a large area
independent of electron ?ow from said ?rst cathode to
cathode, a small area main anode opposite said cathode
said ?rst anode comprising a second cathode adapted to be
and de?ning a gap therewith, an auxiliary anode in said
ionically heated and second anode between said ?rst cath
ode and said ?rst anode, said second cathode being sup 40 gap adjacent said cathode, a control electrode in said gap
adjacent said main anode, means biasing said auxiliary
ported on substantially shielded lead-in members.
anode with respect to said cathode to maintain a discharge
6. An electron discharge device comprising an envelope
therebetween, means biasing said main anode relative to
containing a gaseous medium, a ?rst cathode, a ?rst anode
said cathode at a potential su?icient to sustain a discharge
surrounded by a sleeve of insulating material, a cup
containing a gaseous medium, a ?rst cathode, a ?rst an
shaped grid surrounding said insulating sleeve and said 45
?rst anode, and means for maintaining an electron dis~
charge in the space between said ?rst anode and said ?rst
cathode independent of electron ?ow from said cathode to
said anode comprising a second cathode and second anode
between said ?rst cathode and said ?rst anode, said ?rst 50
cathode having an electron emitting capacity substantial
ly greater than said second cathode.
across said gap but insufficient to e?ect breakdown of said
gap, and means biasing said control electrode controlling
the injection of electrons from said discharge into the
vicinity of said main anode to effect breakdown of said
gap.
References Cited in the ?le of this patent
UNITED STATES PATENTS
1,551,970
7. An electron discharge device comprising an enve
1,967,009
lope containing a gaseous medium, a hollow cathode, an
55
2,007,542
anode and means for maintaining an electron discharge
in the space between said anode and said cathode independ
ent of electron flow from said cathode to said anode
and an insulating shield spaced between said cathode and
said discharge maintaining means, and having a hole
30
therein.
8. An electron discharge device comprising an envelope
2,062,268
2,270,324
2,331,398
2,435,246
2,468,417
2,479,846
Schafer ______________ __ Sept. 1,
Hund ________________ __ July 17,
Lubcke ______________ __ July 9,
Knowles _____________ __ Nov. 24,
Marshall _____________ __ Jan. 20,
Ingram ______________ __ Oct. 12,
Stutsman _____________ __ Feb. 3,
Stutsman _____________ .._ Apr. 26,
Lalewicz _____________ __ Aug. 23,
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