close

Вход

Забыли?

вход по аккаунту

?

Патент USA US2124682

код для вставки
July 26, 1938.
P. L. SPENCER
2,124,632
ELECTRICAL GASEOUS DISCHARGE DEVICE
Filed May 19, 1952
2 Sheets-Sheet 1
..i2
uuuuunn
E621.
A,
000.000.000.00
17/
mom/Er '
Patented July 26, I938
2,124,682
PATENT OFFICE
' UNITED STATES
2,124,682
ELECTRICAL GASEOUS DISCHARGE
DEVICE
Percy L. Spencer, West Newton, Mass., assignor,
by mesne assignments, to Raytheon Manufac
turing Company, Newton, Mass, a corporation
of Delaware
~
Application May 19, 1932, Serial No. 612,235
28 Claims. (Cl. 250-—27)
This invention relates to gaseous discharge de- . tubular section 1. Also it is possible to make it
vices. An object of the invention is the provision
of such a device in which an electrical current
ilow of large magnitude is'capable of being con
5 trolled by a comparatively small magnetic ?eld.
The foregoing and other objects of my‘ in
vention will be best understood from the follow-,
ing description of exempli?cations thereof,
reference being had to the accompanying draw
ings, wherein:
Fig. 1 is a cross-sectional view of one embodi
ment of my invention showing a discharge device
with one cathode and one anode, together with a
diagrammatic representation of a circuit which
may be used therewith;
Fig. 2 is a view similar to that of Fig. 1, show
ing a different form of discharge device having
one cathode and two anodes;
Fig. 3 is a similar view showing a discharge
device having two cathodes and one anode; and
Figs. 4, 5 and 6 are curves for analyzing the
relationships between the current, voltage and
magnetic variations.
In Fig. 1, i represents a hermetically-sealed
glass envelope having an enlarged chamber 2
at one end thereof within which is supported a
thermionic cathode 3 at the inner end of a re
entrant stem 4. The cathode 3 is supported by
two lead-in wires 5 and 6 which pass through and
are sealed in the inner end of the reentrant stem
4. The cathode preferably comprises a metallic
?lament, such as, for example, nickel coated with
some material to increase the electron emissivity
of said ?lament. Such a coating may consist,
J for example, of barium or strotium oxide. At
the opposite side of the chamber 2 from the stem
4, the envelope I is formed to provide an elongated
tubular section ‘I. At the opposite end of this
tubular section from the cathode 3, is provided a
4) cooperating anode 8 supported at the inner end of
a reentrant stem 9. The anode 8 is preferably
supported by an anode lead I 0 passing through
‘and being sealed in the end. of said stem 9. The
"anode 8 is formed of some suitable refractory
' conducting
material,
such
as,
for
example,
graphite, carbon, tantalum, or carbonized
nickel. Interposed between the cathode 3 and
the anode 8 and surrounding the discharge path
between them is provided a conductive tubular
50 member Ii. The tubular member II is made of
non-magnetic material, and preferably comprises
a cylinder of thin sheet metal, such as, for ex
ample, tantalum. Member ll may be of any
other suitable form, such as, for example, a wire
55 mesh or a metallic deposit on the walls of the
so that it does not completely surround the dis
charge path within it. The tubular member ll
preferably ?ts snugly within the glass tubular
section 1, whereby said tubular member II is sup 5
ported by the walls of said tubular section ‘I. A
lead-in wire l2 also sealed through the end of
the reentrant stem 9 and electrically connected
to the tubular member ll a?ords an external
electrical connection to said member. In order 10
to protect the inner end of the reentrant stem 4
against the energy generated by the discharge be
tween the cathode and anode, there is provided a
shield I3 supported by one of the cathode leads,
such as, for example, 5. The other cathode lead 15
6 passes through an opening I4 in said shield.
The envelope I after being thoroughly evacuated
in accordance with the usual practice is provided
with some suitable gaseous ?lling which may be,
for example, a metallic vapor, such as mercury 20
vapor. In order to supply this vapor, a small
quantity of mercury 15 is introduced into the
tube. Of course it is to be understood that any
ionizable gas, such as, for example, one of the
noble gases, may be used as the ?lling within the
envelope I. Furthermore, any suitable mixture
of gases and vapors may be utilized in the device.
In order to supply power to the device, there
may be provided a supply transformer l6 hav
ing a primary l1 and a secondary I 8. The ?la 30
ment 3 may be provided with heating current
by a section I9 at one end of the secondary l8.
The opposite end of the secondary 18 ‘may be
connected by means of a conductor 28 through
any desired load device 2| to the anode lead Ill.
The lead-in wire I2 for the tubular member II is
connected through a resistance 22 to the anode
lead-in l0. Resistance 22 is of comparatively
.high value, for example, of the order of about
one-half a megohm in order to limit the current 40
to the member II to a negligible value. It will
be seen that upon energization of the vtrans
former IS, the ?lament 3 will be supplied with
heating current, whereby it will be raised to a -
temperature at which it emits a copious supply of 45
electrons. When the anode 8 becomes positive,
these electrons will travel toward said ‘anode,
producing an intense ionization of the gas within
the envelope, whereupon a current of large value
will ?ow between the anode 8 and the cathode 3. 50
I have discovered in such a device that if a
magnetic ?eld is applied transversely to the dis
charge path between the anode 8 and the cathode
3, no current will pass between these electrodes
when the magnetic ?eld atta'ms a comparatively 55
2, 194,682
low value~ This transverse magnetic ?eld may
be applied in any suitable manner. For example,
in Fig. l, I have shown a magnet 23 external to
the tube. adjacent the tubular member Ii, suit
ably positioned so that its ?eld passes into the
discharge space between the'cathode 3 and anode
8 transversely thereto. Since the value of the
magnetic ?eld at which the tube will not conduct
is fairly critical, I prefer that the magnet 23 be
10 biased, as, for example, by having it in the form
of a permanent magnet, so that its normal ?eld is
slightly below ‘the critical value at which the
tube ceases to conduct. The magnet 23 could,
of course, have an auxiliary winding (not shown)
15 to bias it to the proper value of magnetization.
In order to provide means for controlling the
magnitude of the magnetic ?eld, I provide a
coil 24 wound around the magnet 23 and ener
gized from some suitable source of current, such
20 as, for example, a battery 25. The magnitude of
larger number of electrons will come under its
in?uence. If enough of these electrons come
under the in?uence of this charge, cumulative
ionization results and the full current ?ows.
Cumulative ionization may be explained as fol U
lows. An electron coming under the in?uence of
the charge or ?eld of the anode 8 is accelerated
toward the anode, and may acquire. su?lcient
energy to ionize an atom of gas upon collision
therewith, whereupon it is again accelerated to—
ward the anode. There is, however, some di?u
sion to the walls of the tubular member ll of
electrons, whether coming from the cathode 3 or
being liberated as the result of the ionization
of gas atoms. The electrons reaching the walls 15
of. member ll ?ow out of the tube through the
lead wire i2, and are thus removed or lost from
the discharge path between the cathode and the
anode. If the rate at which electrons are lost to
the member II is greater than the rate at which 20
the current through the coil 24 and consequently
electrons are liberated as a result of the ioniza
the magnetic ?eld may be controlled by some
tion of gas atoms, cumulative ionization cannot
occur and the discharge does not start. If, how
ever, the rate at which electrons are sohlost is less
than the rate at which electrons are liberated, 25
cumulative ionization does occur and the dis
suitable means, such as an adjustable resistance
28.
In the device as described above, I have found
as that
when the magnetic ?eld is below a certain
minimum, current will ?ow between the anode 8
and the cathode 3, whenever the anode 8 is posi
tive, and therefore a recti?ed current will ?ow
30 through the load device 2|. As the magnitude of
the ?eld is increased by means of regulating the
adjustable resistance 28, the amount of current
flowing through the load device 2i gradually de
creases in value until when a certain maximum
35 ?eld is reached the tube is entirely non-conduct
ing and substantially no resultant current ?ows
through said load device.
According to my present understanding of the
theory of operation of the device, it operates as
40 follows. When the anode 8 and tubular member
H become positive, a small space current ?ows
between the cathode 3 and the end of the tubular
member ll adjacent said cathode. This current
may ordinarily be of the order of about one-tenth
of a milliampere.
Inasmuch as these tubes are
charge starts. Upon the starting of a discharge
the intensity of ionization along the entire dis
charge path increases enormously, and a large
current flows between the cathode and anode.
In absence of a transverse magnetic ?eld, the
rate of loss of electrons in the device as shown is
ordinarily less than that which will prevent
cumulative ionization, and the discharge will
start very soon after the beginning of each half
of the alternating current cycle when anode 8
becomes positive. When the transverse magnetic
?eld, due to the magnet 23, is impressed on the
device, this ?eld acts upon electrons which come
within the tubular member and which otherwise 40
might proceed toward the anode 8 to push them
over against the walls of the tubular member II,
and thus increases the rate at which the loss of
these electrons to the member ll occurs. It will
be seen that the ease with which the electrons are
designed to handle currents of the order of am
controlled by the magnetic ?eld is particularly
peres, this space current is so small as to be prac~
great in the electrostatically ?eld-free space re
tically negligible insofar as the load device is
concerned.’ However, this small amount of cur
50 rent makes a comparatively large number of ions
in the region between the cathode 3 and the end
of the tubular member H.- The member ll being
of conductive material forms an electrostatic
shield around, the space within it. Thus the
CI CA intensity of the electrostatic ?eld, due to
the -negative charge on the cathode, decreases
very rapidly as we go down the tubular member
_l| toward the anode. Likewise the electrostatic
?eld, due to the positive charge on the anode, de
60 creases very rapidly as we go up the tubular
member i I toward the cathode. With ordinary
values of voltage, a portion within the tubular
member intermediate the anode and cathode can
be said to be substantially electrostatically ?eld
65 free. Under these conditions the intensity oi’
ionization decreases very rapidly as we go down
the tubular member from the cathode toward the
anode 8. There are a very few of the electrons
existing within the tubular member ll, however,
70 which come under the influence of the positive
charge on the anode 8. As the voltage on the
anode becomes greater, its positive charge in
creases. As the positive charge on the anode in
creases, its electrostatic ?eld will increase in in
75 tensity inside of the tubular member H, and a
36.
ferred to above. The pushing of the electrons
over- against the walls of the tubular member ll
moves the entire region of more intense ioniza
tion over against these walls, and thus an electron
cannot undergo many ionizing collisions before
it is captured by the wall of member ll. Also
the electrons liberated as a result of. such ionizing
collisions are liberated close to the walls of mem
ber II, and are also soon captured by it, all of
which greatly increases the rate of the loss of
electrons to the member I I. This rate of loss in
creases with the magnitude of the magnetic ?eld.
Thus with each de?nite value of voltage, when the
?eld becomes strong enough, the rate of loss of
electrons becomes so great that cumulative
ionization is impossible,‘ and therefore the dis
charge will not start. However, any lesser value
of ?eld does not produce a su?icient loss of elec
trons to prevent cumulative ionization, and con
sequentiy the discharge starts between cathode 3
and anode 8. The control of. ionization'which is
aiforded by such a magnetic ?eld may be termed a
control of the propagation of ionization along
the discharge path between the cathode and
anode. As soon as the discharge begins, the
enormous increase in ionization referred to above
occurs and a large current ?ows between the
cathode and anode. Since the intensity of ioniza
75
3
9,124,689
tion and consequently the rate at which electrons
are liberated ‘increases so enormously, a magnetic
?eld which may be sufficiently large to prevent
the start of a discharge will ordinarily be unable
01 to increase the rate of electron loss to a su?lcient
degree to stop the discharge after it has once
started.
It should be noted that although the above
analysis refers to the loss 0! electrons to the
10 walls of member’ H, the same e?ect exists al
,though to a lesser degree with respect to posi
tive ions within the space surrounded by the
tubular member. These ions are not only cap~
tured by the walls of member II by di?usion
15 thereto, but are also acted upon by the magnetic
?eld to tend to push them over against the walls
.of member II. The removal of positive ions
from the discharge path removes additional cur
rent carriers, and therefore decreases the tend
ency of a discharge to start. Therefore, it is to
be understood that whenever I refer to the loss
of electrons to the walls oi’ member II, I also
mean that the same thing to a lesser degree
is'occurring to positive ions.
25"‘
The manner in which the magnetic ?eld con
' trols the magnitude of the current _?owing
through the load device 2| may be seen more
until ?nally the tube does not become conductive
until the voltage between the anode' and the
cathode reaches its maximum value i. Thus‘the
tube only is conductive through a quarter of a
complete voltage cycle, namely, from the point
i at which the voltage reaches its maximum
‘value and -the point e at the end of said half
of the voltage cycle. If the magnetic ?eld is in
creased beyond this point, the tube can never
become conductive inasmuch as it would re
1)
quire a voltage greater than the peak value of
the voltage between the anode and cathode to
start the discharge. It can be seen that when
the tube is conductive only during a portion
of the positive half of the voltage cycle, the -
resultant value of current ?owing through the
load device becomes less as the portion 01' said
positive half of the voltage cycle during which
the current ?ows becomes less. Since, as shown
above, the magnitude of the magnetic ?eld de
termines the portion of the voltage cycle during
which the tube is conductive, by controlling the
magnitude of the magnetic ?eld we ‘can con
:I‘ige the amount of current ?owing through the
u
.
~
curve a represents the variation of voltage ap
The provision of the tubular member ll be
tween the cathode and anode performs various
important functions. If we were to attempt to
control the current between the cathode and
plied between the cathode 3 and the anode 8
anode by a transverse magnetic ?eld without the .
with respect to time. Since we can assume. for
the purposes of analysis that the load It is a
provision of such an element as the tubular
member II, we could obtain some increase in
the loss of ions created in the space between
clearly by referring to Fig. 4. In this ?gure,
resistance load, each point on this curve can
represent the amount of current which would
35 ?ow through the circuit if the device were con
ducting at that point. When the ?eld, due to
the magnet 23 and the electromagnetic coil 24,
is below a certain minimum, the device as stated
above becomes conducting whenever the anode
8 is positive. Thus, the device is conductive be
tween the points I; and c of a single voltage and
current cycle during which time the anode 8 is
positive, and is non-conductive between points
0 and (1 during which the anode 8 is negative.
45 Although in each of my curves I have shown the
discharge starting at zero voltage and stopping
at zero voltage, actually the voltage must rise
to a small starting value before the discharge
will start, and will fall to a value just below the
tube drop voltage when the discharge will stop.
Since in comparison with the operating voltages,
these values are quite small, they may be con
the cathode and anode by forcing electrons over
against the glass walls of the tube by means of
said transverse magnetic ?eld. These electrons
upon reaching the walls of the tube would charge
it negatively. This charge, however, can only be
removed by the neutralization thereof by posi
of electrons becomes so great that su?icient elec
trons to produce cumulative ionization do not
tive ions created within the discharge space. 40
Since these positive ions are relatively heavy
and. diffuse somewhat slowly, the negative charge
upon the walls of the tube becomes fairly large
and repels any additional electrons which may
be forced over against the walls of the tube by
the magnetic ?eld. Thus the rate at which
electrons can be withdrawn from the discharge
path is much less in such a device than with the
provision of a conductive tubular member sur
rounding the discharge space. Since the mem- '
ber H is conductive and is connected to lead
the electrons and positive ions which it captures
out of the tube, the rate at which these current
carriers can be removed from the path of the
discharge is greatly increased. This e?ect can
be obtained to some degree even if ,the member.
ll does not completely surround the discharge
come under the in?uence of the ?eld on anode
path, as shown, and consists merely of a con
sidered as zero at least for purposes of illus
tration.
As the value of the magnetic ?eld is
55 increased by a certain amount, the rate of loss
8 until the voltage on the anode reaches the
60 point e on curve a, and thus the tube will not
_ "become conductive until the voltage between the
Y anode and cathode reaches this point.
Under
‘these conditions, the tube will only conduct be
tween the point 1‘, at which the voltage reaches
65 the value e, and the point e at the end of that
ductive member of extended area placed adjacent
the discharge path. Further, in the absence of
such a conductive tubular member, as H, the
electrostatic ?eld from the anode 8 can act freely
across the whole space, and thus exert a very
strong in?uence upon the electrons throughout
this entire space. However, the tubular mem
As the magnetic ?eld
ber ll acts as an electrostatic shield so that the
is further increased by a certain amount, the rate
of loss of electrons becomes still greater so that
the tube does not start to become conductive
?eld of the anode 8 can extend effectively only
a short distance within said tubular member I l.
half of the voltage cycle.
Therefore, the loss of electrons by being forced
until the voltage between the anode and the catl'r
over against the walls of the tubular member 70
ode reaches a value of g on the voltage curve n.
may be small enough so that there is a con
siderable number of free electrons left within
Thus the tube only conducts from the point h,
,at which the voltage attains the value g, and
the point e at the end of that half of the volt
75 age cycle. The ?eld may be further increased
the tubular member ll, yet due to the electro
static shielding of this member, the ?eld of the
anode 8 is not strong enough to influence these 75
4
2,124,000
electrons to any considerable desree. Under
these conditions, these considerable number of
electrons may‘ exist within the tubular member
ii, and yet cumulative ionization will not occur.
3| and a secondary 31, the opposite ends of
which are connected to the anode leads 88, each
connected to its respective anode 8|, The cath
ode 28 is supplied with heating current from a
This effect likewise exists even though the mem
ber Ii does not completely surround the vdis
heating transformer 88 having a primary 48 and
a secondary 4i, which secondary is connected at
charge space.
opposite ends to the two cathode leads 42 ‘and
As long as the member Ii ac
complishes some electrostatic shielding of the
discharge path, the above advantage exists in
some degree. Thus the control of the discharge
by a transverse magnetic ?eld becomes a com
paratively simple matter by the provision of the
43.
A point intermediate the ends of the sec- '
ondary 31, which is preferably the mid-point
thereof, is connected through some suitable load
device 44 to the cathode 28. This connection
may be completed, for example, by a connector
conductive tubular member H while it is a mat
ter of considerable difficulty without such a
leading to a point intermediate the ends of the
member.
center of said secondary. It will be seen that
upon energization of the transformers 35 and
In one of the tubes‘ which I have con
structed in accordance with the above disclosure,
‘I used a tubular member ii having a diam
eter of one and one-quarter inches and a length
‘of two and one-half inches. In this tube, when
20 110 volts of alternating current are applied be
tween the cathode 3 and anode 8, current ?owed
freely. However, when a transverse magnetic
?eld of about thirty gauss was applied, the cur
rent ceased. Merely a change in this transverse
magnetic ?eld of about three gauss was su?lcient
to change the tube from a conducting to a non
conducting state. This tube operated satisfac
torily with a ?lling of mercury vapor at pres
sure broadly between .001 mm. and .01 mm. of
mercury. If it is desired to use higher pressure
within the tube, the tubular member II should
be made longer or of smaller diameter or both.
The pressure in the tube can be controlled by
properly proportioning the external area of the
glass envelope or by providing additional con
densing chambers removed from the path of the
discharge. Tubes have been constructed in
which variations of about one-quarter of a watt
have been su?lcient to control two kilowatts of
43 power directly.
Instead of having a tube with but a single
cathode and a single anode, it is often desirable
to construct such a device having two anodes
cooperating with the cathode. Such an ar
rangement is shown in Fig. 2. In this ?gure a
hermetically sealed envelope 21 encloses a ther
mionic cathode 28 similar to the cathode 3 in
Fig. 1 and similarly supported within an enlarged
chamber 29. ~The envelope 2'! is provided with
two elongated tubular sections 30 extending from
50
opposite sides of the chamber 29. At the oppo
site end of each of these tubular sections is an
anode 3i cooperating with the cathode 28. Each
of these anodes is similar to the anode 8 in Fig.
1, and is similarly supported. Interposed be
tween each of the anodes 3i and the cathode
28 within each of the tubular sections III is a tu
bular member 82 similar to the tubular member
ii, as shown in Fig. 1, and likewise similarly
60 supported. The tubular members may extend up
around the anodes 3i if it is desired to shield the
discharge paths adjacent the anodes from
charges on the glass walls of the tube. Such an
arrangement, however, is not necessary, the ar
rangement in Fig. 1 being equally as satisfactory.
The interior of the envelope 2'! is provided with
a, suitable gas ?lling, as set forth for Fig. 1,
secondary 4i, which point is preferably at the
38, current will flow during alternate half cycles
between the cathode 28 and one and the other
of the two anodes 8i. As a result, a recti?ed
current will ?ow through the load device 44. In
stead of but a half cycle of the alternating volt
age wave being utilized, as is the case in Fig. 1,
both halves of the alternating voltage cycle are
recti?ed, producing a more uniform ?ow of cur
rent through the load device. In order to con
trol the ?ow of current between each of the
anodes 3i and the cathode 28, I have provided
two magnets 45 each similar to the magnet 28
in Fig. 1, and each also provided with a control
coil 46 similar to the control coil 24 in Fig. 1. 30
Each of the control coils 46 may be energized
by a controlled direct current, as is the case in
Fig. 1, whereupon the current between each of
the anodes 2i and the cathode 28 is controlled
as explained for Fig. 1. If, however is is de 35
sired to utilize alternating current for the en
ergization of each of the coils 46, this may be
accomplished, for example, by means of such a
circuit as is shown in Fig. 2. In this arrange
ment, the two coils 46 are connected in series 40
across the two terminals of the secondary 31.
In this series connection are placed one or more
condensers 41 of a value to make this series cir
cuit substantially resonant to the frequency of
the applied voltage. Thus the current ?owing
through the coils 46 and consequently the vari
ation in the magnetic ?eld will be substantially
in phase with the voltage applied between each
of the anodes 3i and the cathode 28. However,
I wind my coils 46 in such a direction that the
variation in magnetic ?eld takes place in the
opposite direction to the variation in voltage be
tween the corresponding anode and the cathode.
I also bias the initial and average magnetiza
tion of each of the magnets 45 to a certain de?
nite value, either by providing auxiliary perma
nent magnets (not shown) or additional ener
gizing coils 48 fed by direct current from a bat
tery 49, and cooperating with each of the mag
nets 45. To prevent the oils 46 from inducing
excessive currents in coils 48, I provide a choke
48' in series with the coils 48. In order to con
trol the magnitude of the current through each
of the coils 46 and the consequent magnitude of
magnetic variation, I provide an adjustable re
sistance 58 in the above-mentioned series circuit.
The manner in which the resultant variation in
the magnetic fields of each of the magnets 25
which ?lling may be a vapor supplied, for ex
ample, from a quantity of mercury 33 within the controls the magnitude of the discharge in the
70 envelope 21. Each of the tubular members 32 ‘ tube, can be best understood by referring to Fig. 70
are connected to its corresponding anode 3i
5. In Fig. 5 curve It represents the variation in
voltage applied between one of the anodes 3i
through resistance 34 corresponding to the re
and the cathode 28, and as with Fig. 1, assuming
sistance 22 in Fig. 1.
The device in Fig. 21s supplied with a power that the load 44 is a resistanceload for the pur
75 from a supply transformer 35 having a primary pose of analysis, each point on this curve can 75
2,124,682
represent ‘the amount of current which would
?ow from the load if thedevice were conduct
ing at that point. The voltage between the other
anode and the cathode is, of course, 180“ out ‘of
phase with the voltages represented by curve It.
At some value of magnetic ?eld, which may be
represented by the line I, the loss of electrons
to the corresponding tubular member 32 de
creases to such a point that the discharge is
able to start. ‘Under such conditions, each of
the magnets 45 is biased so that its initial and
average value of magnetization, which may be
represented by the line 111., is greater than the
value represented by I. At some setting of the
15 adjustable resistance 5|), the variation in mag
netic ?eld due to the variation in the coil 46
follows the curve 11.
It will be seen that with
this variation of the magnetic ?eld, the value 1
is reached when the voltage curve 76 has pro
gressed through a quarter of its entire cycle.
The discharge path between the corresponding
anode 3| and the cathode thus becomes con
ducting at this point, which may be represented
at o, and the discharge continues to the point
25 p at the end- of that half of the voltage cycle.
If the resistance 50 is adjusted so as to decrease
the current through the coil 46 and the conse
quent decrease in the magnitude of the variation
of the magnetic ?eld, it will be seen that the
30 magnetic ?eld never decreases to the value I,
a greater electron emission. Each of the oath
odes 52 consists of a hollow member 53' closed
at one end and carrying a series of radial ?ns
54' on the outside. thereof. Both the ?ns and
the external surface of the member 53’ are pref
erably covered with a material to increase'their
electron emissivity, which material may be, for .
example, the oxides of alkali earth metals. In
order to heat the electroncemitting surfaces to
their emitting/temperature, a‘ heating ?lament 10
55 is provided within the hollow member 53'.
This heating ?lament is supported within said
hollow member by means of ?lament leads 56
and 51 sealtednthrough the end of the reentrant,
stem 54. In order to prevent undue radiation
of heat from the electron-emitting surfaces and.
thus maintain them more e?iciently at their
emitting temperature, a metallic heat shield 58
is provided which ‘surrounds hollow member 53'
and its ?ns 54', and is mechanically connected
to said hollow member at one end thereof. ,The
entire cathode structure may be supported by
two wires 59 and 60 also sealed in the end of
the reentrant stem 54, one of which wires, for
example so, may extend through the end of said
reentrant stem and form an external electrical
connection .for the cathode. Intermediate the
ends of the envelope 5| at substantially the cen
ter point of a tubular section 6| thereof, I pro
vide a single anode 62.
This anode is made of 30
and therefore the discharge will not start be
tween the corresponding cathode and anode. If,
some suitable refractory conducting material,
such, for example, as speci?ed for the anodes
however, the resistance 50 is adjusted so as to
in Figs. 1 and 2. The anode 62 is supported at
the inner end of a reentrant stem 63 by means
of an anode lead 64 sealed in the end of said...
stem. Interposed between each of the cathodes
and the opposite faces of the anode 62 are tu
bular members 65 similar to the tubular mem
increase the current through the coil 46, and
35 consequently the magnitude of the magnetic var
iation, the ?eld of the magnet 45 will follow
some such curve as may be represented by q.
Under these conditions the magnetic ?eld will
reach the value I sooner in the voltage cycle 16
40 than before. Thus the discharge path between
the corresponding anode and cathode will be
come conductive at the point r at which the
magnetic variation q reaches the value I, and
this discharge path will continue to be conduc
45 tive from said point r to the point p at the end
of that half of the voltage cycle.
As the value
of the current through 46 increases as a result
of the adjustment of the resistance 50, the cor
responding discharge path will become conduc
50
5.
tive sooner during the voltage cycle. , Thus, as
explained for Fig. 4, the resultant value of cur
rent through the respective discharge path can
be controlled by controlling the adjustable re—
sistance 50. The analysis applies with equal
55 force to the discharge path between theopposite
anode and the cathode, except that each of the
variations is displaced exactly 180° from that
as shown in Fig. 5. Thus each half of the volt
age cycle is directed through the load device 44
60 in the same direction, and is controlled as ex
plained above.
bers II and 32 in Figs. 1 and 2.- These tubular
members 65 are supported within the tubular
section 6| substantially as are the tubular mem
bers referred to in Figs. 1 and 2. Each of the
tubular members 65 is provided with a lead 66
sealed in the end of the reentrant stem 63, and
affording an external electrical connection for 45
each of said tubular members. It is desirable
to prevent electrons and positive ions from pass
ing from the discharge space on one side of the
anode to the discharge space on the opposite
side thereof. If this is not done, ions created 50
in one discharge path pass into the other dis
charge path, and a considerable number of ions
exist near the anode at the start of the active
cycle in said other discharge path. The pres
ence of these ions increases the tendency of the 55
discharge to start, and renders the control by the
magnetic ?eld more difficult. In order to pre
vent this drawback, the ends of the tubular
members 65 adjacent the anode 62 are brought
fairly close to the surface thereof at a distance
so that passage of electrons or positive ions from
Instead of utilizing two anodes with a single one side of the anode to the other is substan
cathode, it may be desirable to utilize a tube tially prevented. In order that this passage of
having two cathodes cooperating with a single electrons and positive ions be more completely
65 anode. Such an arrangement is shown in Fig. ' prevented, the anode 82 is preferably made some 65
3. In this ?gure a hermetically sealed envelope what larger than the inner diameter of each of
5| encloses two thermionic cathodes 52 at each the tubular members 65 so as to effectively shield
the discharge path on one side of said anode
end thereof. Each of these cathodes is con
tained within an enlarged chamber 53, and is to the discharge path on the opposite side there
70 supported at the inner end of a reentrant stem of. The interior of the envelope 5| is provided 70
with suitable gas ?lling, such as set forth for
54. Although these cathodes. may be of the ?l
amentary type, as disclosed in Figs. 1 and 2, yet Figs. 1 and 2. Each of the tubular members 65
in some instances I prefer to use an indirectly is connected to the anode through a resistance
12 corresponding to the resistances 22 and 34
heated type of cathode inasmuch as such acath
76
75 ode can be operated more ef?ciently and with in Figs. 1 and 2.
6
2,124,689
_
.
In order to supply the device in Fig. 3 with
conducting. Consequently the discharge between
power, I have provided a power transformer ‘'I
having va primary 68 and a secondary it. .Each
the corresponding cathode and anode will only
be conducting between the point a and the
point 1: at the end of the voltage cycle a. Thus
this discharge path conducts only but a portion
of the positive half of the voltage cycle. If,
however, 0 is decreased by increasing the resist
of the heating ?laments BI is supplied with heat
ing current from sections 10 at opposite ends of
The cathode-emitting sur
faces may be connected to opposite ends of the
' the secondary 63.
secondary 68, for example, by having the oath
ode lead 60 electrically connected to one 01’ the
10 heating ?lament leads 51.
A point intermediate
the ends of the secondary 88, which is preferably
the mid-point thereof, is connected through some
suitable load device ‘H to the anode lead 64. It
will be seen that upon energization of the trans
15 former 61, current will ?ow during alternate half
cycles between the anode 62 and \one or the
other of the cathodes 52, whereupon‘a recti?ed
current will ?ow through the load device ‘H. In
order to control the ?ow of current between each
of the cathodes 52 and the anode 62, I have pro
vided two magnets 13 similar to the magnets
45 in Fig. 2. Each of these magnets is provided
with a control coil ‘Hi similar to the coils I“
in Fig. 2. The magnetization of each of the mag
25 nets " may be controlled in any desired man
ner, for example, either' by such an arrange
ment as shown in Fig. 1 or such a one as shown
in Fig. 2. -'However, it may be desired to utilize
a still di?erent mode of control for these mag
30 nets, and an example of a still further control
arrangement is illustrated in Fig. 3. The two
coils ‘II are connected in seriesacross the ‘two
terminals of the secondary 69. In this series
connection are placed one or more condensers 15,
35 the total value of which is much smaller than
that needed for resonance. As a result, the cur
rent‘ through the coil ‘H and .consequently the
variation in the magnetic ?elds of each of the
ance ‘r, the point u will more closely approach
the point 1: and the period of a voltagev cycle
during which the corresponding discharge path 10
is conducting will ‘be decreased.
Consequently
the resultant amount of current which ?ows
through this discharge path is decreased. Like
wise ‘if 0 is increased by decreasing the value of
the resistance 16, the resultant current through
the corresponding discharge path will be in
creased. Instead of theparticular phase-shifting
device illustrated, any suitable phase-shifting
device may be employed for changing the phase
angle between the applied voltage s and the‘ cur
rent t through the coil ‘I4. If desired, 'a'phase
shifting device may be employed which will en
able the operator to shift the phase of t through
180°. Thus the current between the cathode
and the anode could be made to start at any
point in the positive half of the applied volt
age 3. The above analysis applies with equal
force to the discharge space between the other
anode and the cathode, except that the curves
applying to that discharge space are 180° dis
magnetic ?eld if the load device contains a con
siderable amount of inductance. I have further
placed an adjustable resistance 16. By adjust
ing the'resistance 16, the angle between the cur
rent through the coils ‘I4 and the voltage ap
plied
between the cathodes and the anode is
45
discovered, however, that this di?lculty may be
entirely eliminated by placing a bypass resist
'ance around the discharge pathrso that a small
amount of alternating current may initially pass
55 that point. Curve t represents the current ?ow
ing through the coil ‘I4, leading the curve s by a
certain angle which may be called 0. Curve t
thus also represents the variation in the magnetic
?eld oi' each of the magnets 13. It should be
noted at‘this point that these magnets 13 may
be biased as suggested for the magnets in Fig. 2,
although it is possible to secure suf?cient varia
tion in the ?elds of these magnets 13 without any
biasing. The various constants of the magnet
13 may be so chosen that whenever the curve t,
as shown in Fig. 6, is at a slightpositive value,
the magnetic ?eld of the magnet 13 is su?lciently
large so that a discharge cannot start between
the corresponding cathode and anode. Thus we
70 see that when the current through coil 14 fol
30
I have found in each of the devices which I
each of the cathodes 52 and the anode 62. In
series with the coil 14 and the condensers ‘I5 is
the tube. In Fig. 6, curve 8 represents the varia
tion in voltage applied between one of the oath
odes 52 and the anode 62, and as stated for Figs. 4
and 5 may also represent at each point the
value of current which would ?ow through the
load device ‘ii if the tube were conducting at
25
plained for Fig. 2, the current due to each half
of the voltage cycle is directed through the load
device ‘II in the same direction, and the magni
tude of this current is controlled by the varia 35
tion of the magnetic ?elds of the magnets 13.
magnets ‘I3 leads the voltage applied between
changed. By referring to Flg.-6, we can see how
20
placed from those shown in Fig. 6. Thus, as ex
have described that it is'ordinarily di?lcult to
control the discharge by means of the transverse
this relationship between the magnetic field and
the applied voltage controls the current through
15
through the inductance of the load device. The
value of this shunting resistance may be sum
ciently high so that the amount of current so
?owing is negligible with respect to the total load
current. ’ In Fig. 3 I have shown such shunting 50
resistances at 11 and 18, each of said resistances
being in parallel with the discharge path between
one of the cathodes and the anode. With a tube
having‘ dimensions, such as I have referred to
above, and having 110 volts A. C. impressed be
tween each cathode and the anode, each of the
resistances ‘I1 and 18 were about 500 ohms. With
such an arrangement, an inductive load of con
siderable amperage was readily controlled. Of
course it is to be understood that wherever I 60
have quoted particular dimensions and ?gures,
such are for the purpose of illustration only and
are not to be construed in any limiting sense
inasmuch as these particular values will be dif
ferent in each application of my device and can 65
have a very' wide range of values. Other ar
rangements for controlling an inductive load
could be used, such as, for example, bypassing
oi the load itself with a capacity in order to re
duce the resultant alternating current impedance. 70
I wish it to be understood that the various con
1 lows the curve ‘t, the magnetic ?eld is sufficiently
strong during the initial portion of the voltage trol systems, as shown in Figs. 1. 2 and 3, can
be used interchangeably in each of the devices
cycle 8 so as to prevent a discharge from start
ing. It is not until the curve t passes the point it as shown in any of said ?gures. In addition, any
75 that the corresponding discharge path becomes other suitable control circuit may be utilized. 75
7
2,124,682
a,
intense ionization upon the passage of said dis
charge, a separate electrically conductive mom
being connected to anode 8 merely through a re
sistance could be left entirely free. With such an I ber having an extended surface within said en
arrangement, the electrons forced over to the velope‘, surrounding the discharge path between
member ii would charge it negatively and thus each cathode and said anode, and means for im
attract positive ions which would neutralize the pressing a magnetic ?eld on each of the discharge
negative charge. In this manner the removal of paths surrounded by said electrically-conductive
electrons and. positive ions from the discharge members and transversely to said discharge path.
4. In combination, a- space discharge device
path can be accomplished, although the effect
comprising a hermetically sealed envelope en
10 may be less than if the resistance 22 were pro
closing two electrodes in an ionizable atmosphere,
vided. However, theabove arrangement still pro
said electrodes adapted to support a discharge
duces the ?eld-{rec space together with its vari
between them, the pressure of said atmosphere
ous advantages as well as other factors which re
being su?iciently high to produce intense ioniza
sult in the fact that the discharge in such a de
tion upon
the. passage of said discharge, an elec l5
H 01 vice can also be easily controlled by the transverse
.
magnetic ?eld. Also the tubular member I I could trically conductive member having an extended I »
surface within said envelope adjacent the dis
be biased with respect to the anode 8 by any suit
able source of voltage. These and various other charge path between said electrodes, means for
impressing between said electrodes an alternat
circuit connections will readily suggest them
ing potential, means for impressing on said dis 20
20 selves to those skilled in the art. Any other de
charge space transversely to said discharge path
sired arrangement of electrodes can-also be uti
lized, it being merely necessary to provide at least a magnetic ?eld varying in magnitude at the
same frequency as‘the voltage applied between
two electrodes adapted to have an electrical dis
charge between them to which discharge path my said electrodes and out of phase with said ap
plied voltage, and means for varying the phase 25
25 novel control may be applied.
The invention is not limited to the particular angle between said applied voltage and said
For example, the tubular member ll instead of
details of construction, materials, quantities and
magnetic ?eld.
values, or processes as described above, as many
5. In combination, a space discharge device
comprising a hermetically sealed envelope en
closing two electrodes'in an ionizable atmos 30
equivalents will suggest themselves to those skilled
30 in the art. It is accordingly desired that the ap
pended claims be given a broad interpretation
commensurate with the scope of the invention
within the art.
What is claimed is:
35
'
1. A space discharge device comprising a her
metically sealed envelope enclosing two electrodes
in an ionizable atmosphere, said electrodes adapt
ed to support a discharge between them, the
pressure of said atmosphere b'eing su?iciently
40 high to produce intense ionization upon the pas
sage of said discharge, said envelope being pro
vided with a tubular section surrounding a por
tion of the discharge path between said elec
trodes, a hollow tubular electrically~conductive
member positioned within said tubular section,
the transverse cross-section of said tubular mem
ber being substantially equal in size and shape
with the inside transverse cross-section of said
tubular section, whereby the outer wall of said
tubular member lies closely adjacent the inner
wall of said tubular section, and means for im
pressing a magnetic ?eld on the discharge space
within said hollow tubular electrically-conduc
tive member and transversely to said discharge
1:1 in path within said hollow member.
2. A space discharge device comprising a her
metically sealed envelope enclosing a thermionic
cathode, two anodes cooperating with said cath
ode and adapted to support a discharge with
said cathode, an ionizable atmosphere in said
envelope at a pressure su?iciently high to pro
duce intense ionization upon the passage of said
discharge, a separate electrically-conductive mem
ber having an extended surface within said en
'
phere, said electrodes adapted to support a dis
charge between them, the pressure of said atmos
phere being su?iciently high to produce intense
ionization upon the passage of said discharge, an
electrically conductive member having an ex 35,
tended surface within said envelope adjacent the
discharge path between said electrodes, means
for impressing between said electrodes an alter
nating potential, means for impressing on said
discharge space transversely to said discharge 40
path a magnetic ?eld varying in magnitude at.
the same frequency as the voltage applied be
tween said electrodes and opposite to said ap
plied voltage in time phase, means for biasing
said magnetic ?eld so that'its average value is 45
greater than that which will allow a discharge
to. start between said electrodes, the variations
in said ?eld being such that the minimum values ‘
of said ?eld are less than that value which will
allow a discharge to start between said elec 50
trodes, and means for controlling the magnitude
of ‘said variations.
6. In combination, a space discharge device
comprising a sealed envelope enclosing two elec
trodes in an ionizable atmosphere, said'electrodes,
55
adapted to have impressed thereon an alternat
ing potential and adapted to support a discharge
between them, the pressure of said atmosphere
being sufficiently high to produce intense ioniza
tion upon the passage of said discharge, a mem
ber surrounding the discharge path between said
electrodes, means for impressing on the dis
charge space , within said member and trans
versely to said discharge path a varying mag
netic ?eld, and means for causing the magnetic 65
?eld to drop‘ below the minimum value which will
each anode and said cathode, and means for im
pressing a magnetic ?eld on each of the discharge prevent a discharge from starting between said
paths surrounded by said electrically-conductive electrodes during one-half of the alternating po
members and transversely to said discharge path. tential cycle and to be greater than said value ‘
during the other half of said cycle.
3. A space discharge device comprising a her
'7. In combination, a space discharge device
metically sealed envelope enclosing an anode,‘
two thermionic cathodes cooperating with said comprising a sealed envelope enclosing two elec
anode and adapted to support a discharge with trodes in an ionizable atmosphere, said electrodes
said anode, an ionizable atmosphere within said adapted to have impressed thereon an alternat
75 envelope at a pressure sufficiently high to produce ing potential and adapted to support a dis 75
velope surrounding the discharge path between
8
9,194,689
charge between them, the pressure of said at
mosphere being suiiiciently high to produce in
tense ionization upon the passage of said dis
charge, a member surrounding the discharge
path between said electrodes, means for impress
ing on the discharge space within said member
and transversely to said discharge path a vary
ing magnetic ?eld, means for causing the mag
netic ?eld to drop below the minimum value
10 which will prevent a discharge from starting be
tween said electrodes during one-half of the al
ternating potential cycle and to be greater than
said value during the other half of said cycle,
and means for varying the time at which the
magnetic ?eld passes through said value.
8. A space discharge device comprising an en
velope enclosing two electrodes in an ionizable
20
discharge path between said ‘electrodes adjacent
said surface, the pressure of said atmosphere be 10
ing su?iciently high to produce substantial ion
ization upon the starting of’ said discharge and
to vcause said discharge to continue in the pres
ence of said transverse magnetic ?eld.
12. A space discharge device comprising an 15
envelope enclosing two electrodes in an ionizable
atmosphere, said electrodes adapted to support
atmosphere, said electrodes adapted to support
a discharge between them, a control unit inter
a discharge between them, means for controlling
the propagation of ionization along the dis
charge path between said electrodes, comprising
means for creating in the discharge path be
posed between said electrodes comprising an elec
trically-conductive member having an extended 20
surface within said envelope surrounding the
discharge path between said electrodes, said sur
face being freely exposed to access by the elec
trons emitted from said cathode during the ab
tween said electrodes an unobstructed substan
tially ?eld-free space freely exposed to access
by the electrons emitted from said cathode dur
ing the absence of said discharge, and means for
impressing a magnetic ?eld transverse to the
discharge path between said electrodes in said
substantially ?eld-free space, the pressure of said
atmosphere being su?iciently high to produce
substantial ionization upon the starting of said
discharge and to cause said discharge to con
tinue in the presence of said. transverse mag
netic ?eld.
9. A space discharge device comprising an en
velope enclosing two'electrodes in an ionizable
sence of said discharge, and means for impress
ing a magnetic ?eld transverse to the discharge
path within said conductive member, the pres—
sure‘ of said atmosphere being sufficiently high
to produce substantial ionization upon the start
ing of said discharge and to cause said discharge
to continue in the presence of said transverse
magnetic ?eld.
.
'
envelope enclosing a thermionic cathode and an
anode in an ionizable atmosphere, said elec 35
trodes adapted to support a discharge between
them, means for controlling the propagation of
a discharge between them, means for creating
ionization along the discharge path between said
exposed to access by the electrons emitted from
said cathode during the absence of said discharge
comprising a control unit interposed between
said electrodes, said control unit having a con
45 ductive surface positioned adjacent the discharge
path between said electrodes, and means for im
pressing a magnetic field transverse to the dis
charge path between said electrodes in said sub
stantially ?eld-free space, the pressure of said
atmosphere being su?lciently high to produce
substantial ionization upon the starting of said
discharge and to cause said discharge to con
tinue in the presence of said transverse magnetic
?eld.
10. A space discharge device comprising an
55
envelope enclosing two ‘electrodes in an ionizable
electrodes comprising means for creating in the
discharge path between said electrodes an un
obstructed substantially ?eld-free space freely
exposed to access by the electrons emitted from
said cathode during the absence of said dis
charge, and means for impressing a magnetic
?eld transverse to the discharge path between
said electrodes in said substantially ?eld-free
space, the pressure of said atmosphere being
su?iciently high‘ to produce substantial ioniza
tion upon the starting of said discharge and to ,
cause said discharge to continue in the presence 50
of said transverse magnetic'?eld.
14. A space discharge device comprising an
envelope enclosing» a thermionic cathode and an
anode in an ionizable atmosphere, said electrodes
adapted to support a discharge between them, a 55
control unit interposed between said electrodes,
atmosphere, said electrodes adapted to support
said control unit having a conductive surface po
a discharge between them, a control unit inter
sitioned adjacent the discharge path between
posed between said electrodes, said control unit
60 having a conductive surface positioned adjacent
the discharge path between said electrodes, said
surface being freely exposed to access by the
electrons emitted from said cathode during the
absence of said discharge, and means for im
65 pressing a magnetic ?eld transverse to the dis
charge path between said electrodes adjacent
said surface, the pressure of said atmosphere be
ing su?iciently high to produce substantial ion
ization upon the starting of said discharge and
70 to cause said discharge to continue in the pres~
25
13. A space discharge device comprising an
atmosphere, said electrodes adapted to support
in the discharge path between said electrodes an
40 unobstructed substantially ?eld-free space freely
50
posed between said electrodes comprising an elec
trically-conductive member having an extended
surface within said envelope surrounding at least
in part the discharge path between said elec
trodes, said surface being freely exposed to ac
cess by the electrons emitted from said cathode
during the absence of said discharge-and means
for impressing a magnetic ?eld transverse to the
11. A space discharge device comprising an
envelope enclosing two electrodes in an ionizable
said electrodes, said surface being freely ex
posed to access by the electrons emitted from 60
said cathode during the absence of said dis
charge, and means for impressing a magnetic
?eld transverse to the discharge path ‘between
said electrodes adjacent said surface, the pres
sure of said atmosphere being sufficiently high 65
to produce substantial ionization upon the start
ing of said discharge and to cause said dis
charge to continue in the presence of said trans
verse magnetic ?eld.
15. In combination, a space discharge device 70
comprising an envelope enclosing two electrodes
in an ionizable atmosphere, said electrodes
adapted to support a discharge between them,
atmosphere, said electrodes adapted to support
75 a discharge between them, a control unit inter
the pressure of said atmosphere being su?iciently
high to produce substantial ionization upon the 75
ence of said transverse magnetic ?eld.
'
9
9,124,682
the discharge path between said electrodes, said
surface being freely exposed to access by the
electrons emitted from said cathode during the
transverse to said discharge path to such a value
that said discharge starts under the application
of said voltage to said electrodes.
19. In combination, an electron discharge de
vice comprising an envelope containing a cath
ode, an anode, and an electron-de?ecting cham
absence of said discharge,‘ and means for im
pressing a magnetic ?eld transverse to the dis
charge path between said electrodes adjacent
ber positioned between the cathode and anode,
said chamber having a discharge opening, a
source of electromotive force connected between
passage of said discharge, a control unit inter
posed between said electrodes, said control unit
having a conductive surface positioned adjacent
the ‘cathode and anode, an ionizable medium in 10
said envelope, means mounted exteriorly of the
said control unit surface and one of said elec
trodes, and means for limiting the amount of venvelope for causing the electrons in the de
current, ?ow in said electrical connection to a ?ection' chamber to be de?ected away from said
negligible amount as compared with the normal opening, said means including a magnetic ?eld
of su?icient strength to restrain current from 15
15 load current ?owing between said cathode and
10 said surface, an electrical connection between
anode.
‘
16. In combination, a ‘space discharge device
comprising an envelope enclosing twov electrodes
in an ionizable atmosphere, said electrodes
20 adapted to support a discharge between them,
the pressure of said atmosphere being su?iciently
high to produce substantial ionization upon the
passage of said discharge, a control unit inter
posed between said electrodes, said control unit
having a conductive surface positioned adja-'
cent the discharge path between said electrodes,
said surface being freely'exposed to access by
the electrons emitted from said cathode during
the absence of said discharge, and means for
30 impressing a magnetic ?eld transverse to the
discharge path.between said electrodes adjacent
said surface, an electrical connection between
said control unit surface and one of said elec
trodes, said connection containing a current
limiting impedance.
17. In combination, a space discharge device
comprising an envelope enclosing two electrodes
in an ionizable atmosphere, said electrodes
adapted to support a discharge between them,
40 a control unit interposed between said electrodes,
said control unit having a conductive surface po
sitioned adjacent the discharge path between
said electrodes, said surface being freely exposed
to access by the electrons emitted from said
45 cathode during the absence of said discharge,
medium having a pressure under operating con
ditions su?icient to support an arc-like dis
?el
.
20. In combination, an, electron discharge de
vice comprising an envelope containing a cath
ode, an anode, and an electron-de?ecting cham
with the cathode and anode, a source of electro
motive force connected between the cathode and
anode, an ionizable medium in said envelope,
means mounted exteriorly of the envelope for
causing the electrons in the deflection chamber
to be de?ected away from said opening whereby
the number of electrons reaching the anode will
be less than required to produce su?icient cumu
lative ionization to initiate a discharge within
the device, said means including a magnetic ?eld
of su?icient strength to restrain current from
?owing through the opening, and means for
varying the strength of the ?eld whereby initia 40
tion of the discharge is controlled, said ionizable
medium having a pressure under operating con
ditions su?icient to support an arc-like discharge
?owing in the presence of said magnetic ?eld.
21. In the art of controlling the initiation of 45
an arc discharge device, said device being en
ergized by alternating current and comprising an
verse magnetic ?eld. ‘
18. In a space discharge device comprising an
envelope enclosing two electrodes in an ionizable
atmosphere, said electrodes adapted to support
a discharge between them, the pressure of said
atmosphere being sumciently high to produce
substantial ionization upon the passage of said
discharge, means for controlling the propagation of ionization along the discharge path be
tween said electrodes comprising means for cre
ating in the discharge path between said elec
65 trodes an unobstructed substantially ?eld-free
space, the method of operating said space dis
charge device which comprises impressing be
tween said electrodes a voltage su?icient to in
itiate and sustain an ionizing discharge between
70 said electrodes in absence of a transverse mag
netic ?eld, impressing upon said substantially
?eld-free space a magnetic ?eld transverse to
said discharge path therein of su?icient magni
tude to prevent said discharge from starting, and
75 then lowering the intensity of the magnetic ?eld
25
ber positioned between the cathode and anode,
said chamber having a discharge opening in line
and means for impressing a magnetic ?eld trans-_
starting of said discharge and to cause said dis
charge to continue in the presence of said trans
20
chadrge ?owing in the presence of said magnetic
verse to the discharge path between said elec
trodes adjacent said surface, and means for con
trolling the magnitude of said magnetic ?eld,
50 the pressure of said atmosphere being su?iciently
high to produce substantial ionization upon the
55
?owing through the opening, and means for
varying the strength of the ?eld whereby initia
tion of‘ the discharge is controlled, said ionizable
envelope containing a cathode, an anode, a hol
low member through which the electrons pass
on their way to the anode, an ionizable medium 50
in said envelope at a pressure under operating
. conditions su?icient to support an arc-like dis
charge, the method which consists in magnet
ically de?ecting the electrons emitted by the
cathode out of their normal rectilinear paths to 55
such an extent that the number reaching the
anode is less than required to produce su?icient
ionization of the. gaseous medium to initiate a
discharge during a predetermined portion of the 60
positive half-cycle of the anode voltage and the
formation of an arc is restrained during the said
portion of the anode voltage cycle.
22. In combination, an electron discharge de
vice comprising an envelope containing a source 65
of electrons, an electron-receiving member and
an electrode mounted therebetween, an ionizable
medium in said envelope at a pressure under
operating conditions su?icient to support an arc
like discharge, means for producing a magnetic 70
?eld which intercepts the direction of said dis
charge, means including a source of alternating
current for energizing said device and for pro
ducing an alternating ?ux in said magnetic
means, and means including a source of direct 75
1o
_
a
2,184,688
,
cathode away from'the anode by the ?eld there- '
ternating ?ux.
by preventing cumulative ionisation, and vary
_
_
a
23. In combination, an electron discharge de<
vice comprising an envelope containing a source
of electrons, an electron-receiving member and
an electrode mounted therebetween. an ionlsable
medium insaid envelope at a pressure under
operating conditions sumcient to support an arc
' like discharge, means for producing a mag
10 netlc ?eld which intercepts the direction of said
discharge, said means comprising a metal core
having a pole piece mounted transversely of said
‘
_
current forsuperpoaingadirect nation said al
envelope, a plurality of coils on said core. a .
source of alternating current for energizing said
15 device and one of said coils, and a direct current
source for energizing the other of said coils.
24. In the art of controlling the initiation of
a gaseous discharge in a device containing a
cathode. an anode and an ionizable medium by
means of a direct magnetic ?eld, the method
which consists in de?ecting electrons emitted by
the cathode away from the anode by the direct
?eld, thereby preventing cumulative ionization,
and varying the direct ?eld by combining there
with, an alternating ?eld in order to determine
when the discharge shall start.
25. In the art of controlling the initiation of
a gaseous discharge in a device containing elec
trodes and an ionizable medium by means of a
direct magnetic ?eld, the method which consists
in utilizing the magnetic ?eld to cause the elec
trons to move in such a direction as to prevent
inelastic collisions with the positive ions of the
lonizable' medium, and varying the ?eld by pe
riodically
adding
and
subtracting
variable
amounts of magnetic ?eld whereby elastic ioniz_
' ing collisions in predetermined amounts between
the electrons and positive ions are permitted and
the gaseous discharge starts.
26. In the art of controlling the initiation of
a gaseous discharge in a device containing a ,
cathode, an anode and an ionizable medium by
means of a direct current ?eld, the method which
consists in de?ecting electrons emitted by the
ing thedirect-?eldbyperiodically adding and
subtracting variable amounts of magnetic field
whereby cumulative ionisation in a predeter
mineddegreeispremittedin order tostart-the
e.
-
-.
2'1. In the art of controlling a‘ gaseous dis
charge in a device containing a cathode. an
anode and an ionizable medium by a direct mag 10
netic ?eld, said device being energized by alter
nating current and said magnetic ?eld having
a maximum strength sui'ilclent to restrain the
discharge from ?owing during the positive half
cycles oi’ anode voltage, the method which con
sists in utilizing the magnetic ?eld to reduce the 15
number of ionizing collisions between the elec
trons emitted by the cathode and the molecules
of the ionizable medium, and varying the~direct
?eld by combining vtherewith, a variable alter
nating magnetic ?eld whereby the position in
each positive half-cycle of anode voltage at
which the gaseous discharge starts may be con
trolled.
,
28. In combination, a space discharge device
comprising an envelope enclosing two electrodes 25
in an ionizable atmosphere, said electrodes
adapted to support a discharge between them, a
control unit interposed between said electrodes,
said control unit having a conductive surface po
sitioned adjacent the discharge path between 30
.said electrodes, said surface being freely exposed
to access by the electrons emitted from said
cathode during the absence of said discharge,
means for impressing a magnetic ?eld transverse ‘
to the discharge path between said electrodes ad~
jacent said surface, and an electrical connection
between said control unit surface and one of '
said electrodes, the pressure of said atmosphere
being su?lciently high to produce substantial ion
ization upon the starting of said discharge and
to cause said discharge to ‘continue in the
presence of said transverse magnetic ?eld.
PERCY L. SPENCER.
35
Документ
Категория
Без категории
Просмотров
0
Размер файла
1 794 Кб
Теги
1/--страниц
Пожаловаться на содержимое документа