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Патент USA US2567478

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Sept. 11, 1951
A, J, DAwE
2,567,473
TIME IQNTERVAL. CIRCUIT
Filed Dec. 13, 1946
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2,567,473 "
Sept. 11, 1951
' umm sra'rss PATENT OFFICE
$507,473 -
'rnu: INTERVAL cntcUrr 7
Albert J. ml... Milwaukee, wa., asalgnor to
Allen-Bradley Company, Milwaukee, Wis., a
eerperatielefwbeonliu
Application December 1:, 1946. Serial No. 110,038
'
a cm (01. 175-373)
This invention relates to delayed response
electrical apparatus and resides more particularly
ent upon undesirably delicate relays lacking in
the ruggedness preferred for industrial equip
ment. The grid-glow or three element gaseous
in an improved form of delayed-action or interval
discharge tube has heretofore been little used for
timing circuit in which a grid-controlled gas
filied glow-discharge tube or grid-glow tube is g delayed-action circuits because its behavior in
the circuits employed has been considered ?ckle
related with other circuit elements in such
and unreliable. Such unreliability has been at
fashion that ?ring of the .tube is regulated by
tributed to shifting of tube characteristics as a
gradual charging of thegrid and the interval
result of the history of treatment to which the
during which the tube remains conducting upon
tube has been subjected. The grid-glow tube,
?ring is reduced to'a minimum.
however, is possessed of the advantage of being
An object of this invention is to provide #
able to perform without standby demand and
delayed-action interval timing circuit apparatus
without "warm up" delay and may be controlled
dependent for its action upon a grid-glow tube
to continue supply of energy to a relay for any
in which tube life is greatly extended by reason
of a very low ratio of active to inactive time of use 15 interval which may be required to cause its posi
of the tube.
‘
tive operation.
1
Another object of this invention is to provide a
delayed-action interval timing circuit apparatus
Through this invention consistent and depend
able response is obtained in a delayed-action or
interval timing circuit apparatus which is de
dependent for its action upon a grid-glow tube in
which increased dependability and consistency of ” pendent upon a grid-glow tube for its operation
by a novel circuit arrangement in which load is
response “of the tube is obtained due to the com
imposed upon the tube only so long as is required
paratlvely brief periods during which the tube is
for positive relay operation. By reason of the
loaded.
.
,.
very brief intervals during which load is imposed
Another object of this invention is to prOYide a
upon the grid-glow tube, shifting of tube char
delayed-action interval timing circuit apparatus
acteristics is held well within limits such that
possessed of the advantages of constantreadi
practical consistency of operation is obtained.
uses to perform without a "warm up delay!" and ‘
Furthermore, the total time of functioning re
of freedom'from standby current requirements.
quired of the grid-glow tube for a large number
Another object of this invention is to provide
a simpli?ed delayed-action interval
cir
cuit apparatus adapted for operation with filter
nating current supply and capable of repetitive
timing of-successive intervals through i‘fg'ingle
interval
Delayed-action
determining
circuit
instrumentallty.
apparatuses of various
30 of cycles is so short that the life of the tube in
use is greatly extended.
‘
This invention is herein described by reference
to the accompanying drawing in which there is
set forth by way of illustration and not of limi
85 tation one form in which the circuit of this
invention may be embodied.
forms, depending upon the controlled function—
In the drawing the ?gure shows diagrammati
of thermionic or gaseous discharge devices
cally a circuit constructed in accordance with
have been extensively used. In the case of ap—
this invention applied to the regulation of the
paratus depending for operation upon thermionic
devices, disadvantages are involved because of 40 starting function of an alternating current in
the necessity of maintaining standby conditions
involving continuous supply of ?lament or heater
current and because of the large expenditure of
available tube life during idle conditions. A fur- -
ther disadvantage also is the waiting .period for
“warm up" that may be involved. The two ele
ment glow-discharge tube as heretofore employed
has also suffered a disadvantage in that the
quantity of energy available for actuation of a
relay actuated thereby is limi
to the charge
prevailing in the capacitor at the moment of
"striking" of the tube. If for any reason the
relay does not react positively to the quantity of
energy thus delivered, unreliable response is en
. countered. Such circuits are. therefore, depend
duction motor.
7
.
a
As depicted in the drawing the time delay ap
paratus of this invention depends for its opera
tion upon a cold cathode grid-controlled gas
?lled glow-discharge tube I. The cathode of tube
1 constituting one of its main electrodes is con
nected by a lead 2, a resistor 3, normally closed
switch contacts I and lead I with an adjustable
tap 8 of an auto transformer ‘I. The anode of
tube I constituting the other main electrode is
connected by lead I and lead I 'with one end of
the winding of a relay II. The opposite endof
the winding of the relay II is connected by lead
H with terminal I! of the auto transformer ‘I.
In this manner a plate circuit is provided through
2,507,473
.
conducting.
.
4
cycle and then immediately drops to start a new
timing interval. For each energization of the
relay III the tube I remains excited for only a very
which current may be passed to the relay III for
energizing the same whenever the tube I becomes
I
brief period. Usually two or three current cycles
are su?'lcient to cause the relayI? to move. The
life of tube I thus is‘ greatly extended even though
a large number of timing cycles is employed since
The grid I3 oi! tube I is arranged to be charged
at a regulated rate through the action or half
wave‘ recti?er I4. Recti?er I4 is connected on
one side by lead I5 and lead II with terminal I2
of the auto transformer 1 and on'the opposite-side
through-leads I5 and I1 with a capacitor I8. 'The
even under conditions of. repeated timing cycles
the ‘total active time 01' the tube I is extremely
capacitor I3 is connected on its opposite side 10
The interval timing circuit above described
through a lead I9 with resistor 3 and thence
may be employed for any purpose which requires
through switch'contacts ,4 and lead 5 with the
a switching function automatically regulated to
tap-5 of transformer 1. In this way, with trans;
former 1 supplied with alternating current “occur -at pre-determined intervals. One such
through leads 29 and 2I, the capacitor I3 be
requirement» is the successive reduction or the
small.
.
‘
'
comes charged through the action oi! the recti?er -.
secondary resistance of a wound rotor induction
I4, and lead I1 connected thereto is rendered
‘motor during starting. The drawing shows the
positive with respect to lead I9.‘
,
timing circuit of 'this invention thus applied.
Connected to lead I1 as shown is a variable ' - As shown in the drawing a motor 39 is connected
v resistor 22 having a movable side tap which is 20 through leads 40, M and“ with a load contactor
connected’ in turn through switch contacts 23 and
-43 which is connected in turn with power supply
lead 24 with one side 014a capacitor 25.‘ Alterna
._ tively connected to lead I1 is a variable resistor
mains 44, 45 and 45. Control current for closing .
the contactor 43 is supplied from main 46 and
22' which is connected in turn through switch '
from thence passes through normally closed stop
contacts 23' and lead 24 with the capacitor 25 as
switch 41, normally open start switch 49, lead 52
shown. The opposite side of capacitor 25 is con
and overload control 49 to the coil of contactor
nected through lead 25v with lead I9 and, conse
43 from which connection to supply main 45 is
quently, ‘with-‘the cathode of tube I. Lead 24 is
provided by lead 59. Upon closure of the start
connected by lead 21, resistor 29 and lead 29 with
ing switch 48 the contactor 43 closes-and in so
the grid I3 of tube I. Thus when current is sup 30 doing establishes a maintaining circuit through
plied to the auto transformer 1 and lead I1 be
stop switch- 41, lead 5|, auxiliary contacts 53,
comes negative, current ?ows through the rela
I lead 52', overload control 49 to the coil of con
tively high resistance of resistor 22 .(or resistor
tactor 43.thus causing the contactor 43 to re
22' depending upon the position of switch con
main closed‘ until the stop switch 41 is opened. -
tacts 23 and 23')‘ at a limited rate with the result 35
Upon closure of start switch 48 or of main
that capacitor 25 gradually becomes charged.
The .rate at which capacitor, 25 becomes charged
taining contacts 53, current also becomes sup
will cause ?ring of tube I may be adjusted.
contacts 51,-~to' be described in greater detail
plied to the transformer 1 by reason of lead 54
may be altered by adiustment oi resistor 22 or
which joins with lead 2I and by reason of the
resistor 22' as the case may be so that the time
connection of lead 29 to switch 55, which in turn
required for the ,grid I3 to reach a charge which 40 is connected through lead 55, normally closed
Having selected an adjustment for the resistor
22 and having applied current to the auto trans-1
Iormer 1 the grid I3 or tube‘ I will at some pre
later, and lead 58 with main 45.‘ As a result of
theclosure oi.’ contactor 43,'assuming switch 55
determined interval after commencement of ex- - -
citation of transformer 1 reach a potential at
which the tube I ?res thus admitting current to‘
the winding oi.’ relay I0.
_
_
‘
Upon excitation of the winding'of relay ID the
movable member of contact 4 is shifted into en
GI)
' gagement with stationary contact '4' which is
is in closed position, a timing interval is initiated
inthe timing circuit, and at the same time the
motor 39 becomes energized with a maximum of
resistance in its secondary circuit.
At the end of the ?rst timing interval, assum
ing switch 34 to be open, normally 'open contacts
59 become closed momentarily and in so doing
establish a circuit extending from line 45 through
connected through lead 30 with the grid lead 21.
In this way the capacitor 25 is caused to dis
charge through the resistor 3 which reduces the
charge on the grid I3 of tube I, thus preparing
the same for a‘ succeeding timing function. At
the same time normally open contacts 3| become
closed and this establishes a circuit through leads
lead-53, lead 59, lead H to the winding of con
tactor 52 and thence through leads 53, 54, 55
and the contacts 59 to the lead 85 and thence
through lead 54 and maintaining contacts 53,
lead Ill and stop switch 41 back to power line 45.
The establishment of this circuit causes contactor
52 to close and to short out the resistances 51 in
‘ 32 and 33 which causes the capacitor I8 to empty
'
its charge through the resistor 3 likewise. , At the 60 the secondary of motor 39.
Upon closure of contactor 52 a maintaining
circuit for causing the same to be retained in
same time normally closed contacts 4 open thus
breaking the supply of current to the cathode of
tube I.
In order that the relay III remain excited when
desired after a single timing interval a maintain
closed position is established through auxiliary
contacts 58' and lead 59.
05
I ing circuit is provided which extends from line
At the same time
through mechanical interlock 52' contacts 23ware
opened and contacts 23', closed.
_
Following the ?rst momentary closure of relay
I I through relay coil III, leads 9 and 8, and thence
I0, normally closed contacts 19 re-engage and
through resistor 35, switch 34, recti?er 35, nor
upon such re-engagement a subsequent step cir
mally open contacts 31 and lead 33 back to line 5.
This maintaining circuit is subject to being con 70 cuit, prepared by the closure of the auxiliary
trolled by the switch 34 which when closed com
pletes the maintaining circuit described. With
the switch 34 open, the relay III upon ?ring of
.
tube i, moves to the closed position which pre
pares the circuit tor the starting .of a new timing 75
contacts 53, becomes completed. This subsequent
step circuit extends from contacts .58 through
lead 55 and through the contacts 10 and leads ‘II
and 12 to the winding of interlock relay’ 13, the
other end of which winding is joined with lead
2,507,473
5
lo. Relay 1:, therefore, immediately closes and
I claim:
6
.
v
-
1. In an interval timing circuit a current
upon closing maintains itself in closed position
through the action of auxiliary contacts ‘I4 con
nected by lead 15 with lead 64 as shown.
The closure of relay ‘I3 through closure of its
contacts 16 then sets up but does not complete
source adapted to be controllably activated; a
grid-glow tube having main electrodes ‘and a
grid; a charging circuit for said grid including a
resistor and a grid charging capacitor; said ca
pacitor being connected on one side to one of
the main electrodes of said tube and to one side
of said'current source and connected on its other
side through said resistor to the other side of
an energizing circuit for a contactor 11. The cir
cuit thus prepared extends through lead 13, the
winding of contactor 11, lead 19, contacts 13, lead
90 to a pair of normally open contacts 9|. The
said current source to said current source and
contacts 8| are joined in turn through a lead 33
with lead 66. By reason of this preparatory
action upon occurrence of the second succeeding
closure of relay In at the end of ‘the second timing
interval, contactor ‘l1 closes and in so doing elimi
nates the remaining resistances 93 from the sec
ondary of motor 39. It will be understood that
the duration of the first timing interval will be
to said grid for charging the same to a'striking
potential at a pre-determined interval after
activation of said current source: and a relay
connected through said main electrodes of said
grid-glow tube to a source of actuating current,
said relay including contacts interposed in the
connections joining said relay with said actuat
ing current source to interrupt the supply of
determined by the adjustment of resistor 23
while the duration of the following interval will 20 actuating current for said relay and including
be determined by the adjustment of resistor 22’.
contactsconnected in discharging relationship
to said capacitor to discharge said grid charg
These two intervals may thus be independently
ing capacitor upon excitation of said relay,
varied within the limits of adjustment available.
whereby said relay on closing immediately re
Closure of contactor ‘I1 also establishes its own
maintaining circuit through maintaining con 25 opens to- restore the circuit to a conditionper
mitting repetition of a timing cycle.
tacts 84 and lead 85 causing it to remain closed
2. In an interval timing circuit a current
after re-opening of relay l0. At the same time
source comprising means adapted to be supplied
upon closure of contactor 11 the normally closed
with alternating current and to rectify the same;
contacts 51 previously referred to are caused to
open, thus interrupting power supply to the 30 a grid-glow tube having main electrodes and a
grid; a charging circuit for said grid including a
transformer ‘I so as to terminate further repeti
resistor and a grid charging capacitor, said ca
tion of timing intervals by the timing circuit.
pacitor being connected on one side to one of
The motor 39 thus is brought up to operating
the main electrodes of said tube and to one side
speed through three successive stages of resist
ance in its secondary circuit and this sequence 35 of said current source and connected on its other
is performed automatically without intervention
side through said resistor to the other side'of said
current source to said current source and to said
of the operator once the starting switch 48 is
grid for charging the same to a striking poten
closed. In order to stop the motor the stop
tial at a pre-determined interval after activa- '
switch 41 is opened causing contactors 43, 62 and
11 to drop open closing contacts 51 and also de 40 tion of said current source; and a relay connected
through said main electrodes of said grid-glow
energizing relay 13. The circuit is thus brought
tube to a source of actuating current, said '
into condition for execution of a new starting
*relay including contacts interposed in the con
sequence whenever start switch 48 is again closed.
If it is desired that the motor 39 be run at re
nections joining said relay with said , actuat
duced speed switch 55 may be opened before
closing of the starting switch 49. In this case
ing current source to interrupt the supply of
actuating current for said relay and including
the motor 39 will continue to run with maximum
resistance in the secondary circuit. If it is de
contacts connected in discharging relationship to
said capacitor to discharge said grid charging
sired that the motor run at an intermediate rate
capacitor upon excitation of said relay, whereby
said relay on closing‘ immediately‘ reopens to re
the switch 55 may be closed and the switch 34
also. Under such circumstances a single timing
store the circuit to a condition permitting repe
tition of a timing cycle.
sequence only will ~occur and the motor 39 will
be caused to run with the resistance 83 only in
the secondary circuit. It will be understood
that for normal starting, switch 55 is closed and
switch 34 is allowed to remain open.
It will be observed that the tube i is subjected,
in the operation of the circuit of this invention,
.
3. In an interval timing circuit a current
source adapted to be controllably activated; a
grid-glow tube having main electrodes and a
grid; a resistor; a grid charging capacitor con
nected to one side of said current source through
said resistor and to said grid for charging the
same to a striking potential at a pre-determined
required for the relay Hi to positively close, an 60 interval after activation of said current source:
a connection joining the other side of said cur
action aided by the capacitor 96. Immediately
rent source to one of the main electrodes of said
on closing of relay ID the opening of contacts 4
tube; a relay having an actuating coil connected
terminates passage of current through the tube
through said main electrodes of said grid-glow
I. The actual period of loading of tube I need
tube to asource of actuating current, said relay
not be more than 2 or 3 current cycles and this
including contacts interposed in the connection
interval is so short that no perceptible change
joining said relay coil to said actuating current
in the characteristics of the tube results. The
source to interrupt the supply of actuating cur
response on repetition of successive timing in
rent for the actuating coil of said relay‘ when I
tervals, therefore, remains reasonably constant
and reliable for a very large number of timing 70 said relay is actuated, and contacts connected
to load carrying conditions only for so long as is
functions. The principle involved further ob
in shunt relationship to said grid charging ca
viously is not limited to but two successive tim
pacitor to discharge the same upon excitation of
ing intervals since the timing circuit will repeat
said relay, said contacts acting immediately upon
as often as need be to meet the requirements of
any control circuit dependent thereon.
- 75
closing of said relay to cause the same to reopen
to placethe circuit in condition for repetition of
9,507,473
.
a timing
mated to
a control
said load
cycle; load contacts operatively con- said relay to be actuated thereby; and
circuit responsive to the actuation of
contacts by said relay adapted to as
8 ‘
\
vated: a grid-glow tube having main electrodes
and a grid; a relay having a winding- normally
open resetting contacts closed when said relay is
excited,normally closed resetting contacts opened
sume successive circuit positions in response to
successive timed interval actuations 01' said relay.
4. In an interval timing circuit ‘a current
when said relay is excited, and load contacts; re
lay circuit connections extending through the
main electrodes of said grid-glow tube through
source adapted to be controllably activated; a
grid-glow tube having main electrodes and a
grid: interval regulating variable resistor means:
said normally closed resetting contacts and
through the winding 0! said relay to said source of
alternating current; a ?rst capacitor; a recti?er;
initial grid control circuit connections joining said
a grid charging capacitor connected on one side
through said resistor means to one side of said
?rst capacitor through said recti?er and said nor
mally closed resetting contacts of said'relay to
said source of alternating current for charging
side to one of the main electrodes of said tube
and to_ the other side of said current source for 15 said ?rst capacitor upon activation 01' said alter
charging said grid to a striking potential at pre
nating current source; a second capacitor; a tim
ing resistor; intermediate grid control circuit con
determined intervals aiter commencement of
charging of said capacitor; a relay having an ‘ nections Joining a ?rst side of said second capaci
actuating coil connected through said main elec
tor through said timing resistor to a ?rst side of
trodes of said grid-glow tube to a source of actu 20 said ?rst capacitor and joining the other side of
saidsecond capacitor to the other side or said
ating current, said relay including contacts
interposed in the connections joining said coil to
?rst capacitor and to one of the main electrodes
said actuating current source to interrupt the
of said tube to cause said second capacitor to be
' supply of actuating current for the actuating
gradually charged at a rate regulated by said tim
coil ot'said relay upon actuation of said relay. 25 ing resistor when ?rst capacitor becomes charged;
contacts connected in shunt relation to said ca_
?nal grid control circuit connections joining the
pacitor, to discharge said grid charging capacitor
?rst side of said second capacitor to the grid of
said grid-glow tube adapted to apply a striking
upon excitation of said relay, and load contacts;
and a control circuit responsive to the actuation
charge thereto when said second capacitor be
of said load contacts by said relay coil including 30 comes charged to a pre-determined potential:
current source and to said grid and on its other '
shiitable means responsive to successive closures
of saidzload contacts cooperatively engaging said
time interval regulating variable/resistor means,
and. discharging circuit connections connected
through the normally open resetting contacts of
the relay in shunt relation to said ?rst and
to successively vary the same upon successive
second capacitors for discharging the'same when
actuations oi’ said relay whereby the duration of 35 said relay moves to excited position whereby the
successive timing intervals is altered successively.
timing circuit is prepared at the end or one tim
5. In an interval timing circuit a current
ing function for a succeeding timing function.
source'adapted to be controllably activated; a
7. In an interval timing circuit a source 01'
grid-glow tube having main electrodes and a
alternating. current adapted to be controllably
grid; a relay having a winding, normally open 40 activated; a grid-glow tube having main elec
resetting contacts closed when said relay is ex
trodes and a grid; a relay having a winding,
cited. normally closed resetting contacts opened
normally open resetting contacts closed when
said relay is excited, normally closed resetting
contacts opened when said relay is excited, main
taining contacts and load contacts; relay circuit
when said relay is excited, and load contacts;
relay circuit connections extending through the
main electrodes of said grid-glow tube through
said normally closed resetting contacts and
through the winding of said relay to said source
oi’ current; initial grid control circuit connec
15
tions connected to one of the main electrodes of
connections extending through the main elec
trodes of said grid-glow tube said normally closed
resetting contacts and through the winding of
said tube and extending through said normally
said relay to said source of alternating current;
a ?rst capacitor; a recti?er; initial grid control
closed gresetting contacts of said relay to a ?rst
side oi said source of current; a capacitor; 9.
circuit connections joining said ?rst capacitor
resistor; intermediate grid control circuit
connections joining a ?rst side of said capacitor
through said timing resistor to the other side of
said cilrrent source and joining the other side of
said ‘apacitor through said initial grid control
circ t connections to the ?rst side of said our
rent‘source to cause said capacitor to be gradu
ally charged at a rate regulated by said timing
r-.sistcr when said current source is activated;
?nal grid control circuit connections joining the
?rst side of said capacitor to the grid of said
grid-glow tube adapted to apply a striking charge '
thereto when said capacitor becomes charged
to a pre-determined potential; and discharging
circuit connections connected through the nor-'
mally open resetting contacts oi’ the relay to said
capacitor in shunt'relation thereto for dischargé
ing the same when said relay moves to excited 70
position whereby the timing circuit is prepared
at the end of one timing function for a succeed
ing‘timing function.
_
,
,
v
6. In an interval timing circuit a source of al
ternating current adapted to be controllably acti- Y
through said recti?er and said normally closed
resetting contacts ofisaid relay to said source of
alternating current for charging said ?rst ca
pacitor upon activation oi’ said alternating cur
rent source; a second capacitor; a timing resis
tor; intermediate grid control circuit connections
joining a ?rst side of said second capacitor
through said timing resistor to a' ?rst side or said
?rst capacitor and Joining the other sides of said
capacitors to one another and to one of the main
electrodes 01’ said tube to cause said second capac
itor to be gradually charged at a rate regulated
by said timing resistor when said ?rst capacitor
becomes charged; ?nal grid control circuit con
nections joining the ?rst side of said second ca
pacitor to the grid of said grid-glow tube to apply
a striking charge thereto when said second capac
itor becomes charged to a pre-determined po
tential; discharglng'circuit connections connect
ed through the normally open resetting contacts
of the relay to said ?rst and second capacitors in
shunt relation thereto for discharging the same
when said relay moves to excited position; and a
maintaining circuit controlled by said maintains '
0
8,567,478
ing contacts adapted to maintain excitation of
said relay after opening of said normally closed
resetting contacts.
8. In an electrical apparatus adapted to assume
a plurality of circuit positions and to shirt suc
10
to be actuated thereby upon the ?rst excitation
of said relay, said electro-magnetically actuated
switch having load contacts and shifting means
cooperatively engaging said resistor selecting
switching means to alter the selection of said
cessively at pre-determined intervals subject to
resistor means forming the connection between
said capacitor and said current source, and pre
tion, the combination comprising a grid con
paratory means operative to prepare a succeed-1
trolled tube having main electrodes and a grid; a
ing control switch circuit for actuation by said
current source adapted to supply current at a 10 relay upon the second excitation thereof; and
grid charging potential su?lcient to render said
a second electro-magnetically actuated control
tube conducting; a capacitor connected to a main
switch having load contacts connected through
electrode of said tube and the grid thereof; a
said preparatory means and others 01' said relay
plurality of independently adjustable resistor
contacts to said control current source to be
means each adapted to be selectively connected
actuated thereby upon a second closing of said
relay.
between said capacitor and said current source
to cause charging oi’ said capacitor to a potential
ALBERT J. DAWE.
at which said tube will become conducting at
REFERENCES CITED
rates determined by the particular resistor means
and the position of adjustment thereof forming
The following references are of record in the
the connection between the capacitor and said
tile of this patent:
current source; resistor selecting switching means
UNITED STATES FI'ATENTS \
adapted to be shifted to select the particular re
sistor means forming the connection between the
Number
Name
Date
_
current source and the capacitor; a relay having 25 2,360,721
Rose ____________ __ Oct. 17, 19“
an actuating coil connected through the main
2,370,727
Holden __________ __ Mar. 6, 1945
electrodes of said tube to a source of actuating
2,379,262
Terry __________ __ June 26. 1945
independent adiustment, from position to posi
current to be excited thereby, said relay having
a plurality of contacts movable upon excitation
of its actuating coil; a ?rst electro-magneticalLy 30
actuated control switch connected through some
otsaidrelaycontactstoacontrolcurrentsource
2,442,238
Haungs __________ __ May 25, 1948
OTHER REFERENCES
Ber- NO- 387.673, Schmidt (A.P.C.), published
May 18. 1943.
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