1. No category

Dec. 19, 1950
H. l. sTANBAcK ETAL
2,534,385
ELECTRICAL TIMING CONTROL
Filed March 2, 1949
à
@df/¿M
2,534,385
3
42, the primary of transformer 39 being con
nected to the supply across lines I.
Connected back to back with the electric dis
charge tube 4D is a second tube 45, these dis
charge tubes serving to pass both half cycles of
supply current through the load represented by
the welding transformer 10 supplying a welding
load at 44. Electric discharge tube 45 is ñred by
,
components similar to those set forth with re
spect to tube 48, these constituting the firing ca 10
4
valve 25 conducts, because its cathode is at the
full negative potential of capacitor I5 while its
grid 21 is at approximately one-third of the neg
ative potential of capacitor I6, being electrically
connected to approximately one-third point of
capacitor-bridging resistor 2|. Control grid 21
is positive, therefore, with respect to cathode 26
and will remain so until capacitors I5 and I6
discharge to the cross-over point, where the po
pacitor 52, the discharge valve 46 and charging
tential of capacitor I5 is equal to that at the
tap on the capacitor-bridging resistor 2| and
valve 38.
subsequent positive potentials of the anode 24
'
To secure proper firing of the charging valve
38, the secondary output `of transformer 31 is
fed across a capacity 41 in the grid circuit of
valve 38, in series with the elements supplying
the hold-off bias and constituted .by the second- ,
ary of transformer 5| and the capacitor `48 by»
passed by resistor 49. The capacitor 41 is by
passed by the discharge resistor 6|. In series
with respect to cathode 25 will not ñre the valve
25. Time measuring valve 25 will conduct, there
fore, on the next half cycle after valve 5 ~and
tube I8 conduct and will continue to conduct
during each half cycle during which anode 24
is sufficiently positive with respect to cathode 26
until the above mentioned cross-over point is
reached. Conduction of valve 25 energizes cou
pling transformer 29 which delivers to the grid
with the ñring capacitor 52 and the valve 38 are
the contacts 62 of the thermal flow switch.
The heaters for the thermal flow switches,
circuit of valve 3| a measured number of pulses
equal in number to the number of full cycles o
whose contacts are shown at 68 and 62, are shown
Weld time desired.
at 55 connected in series with each other and
through the primary of transformer 54 to a tap
off point of an auto transformer 53 connected
across lines I. The secondary output of trans
former 54 is fed through the cathode heaters or
filaments of the rectifier tube I8.
' In the drawing, the surge by-pass capacitors `
for the electric valves have been shown but they
have not been described; the grid resistors and
cathode heaters which would be used have been
"
Grid 35 of charging valve 3| receives A. C.
hold-off voltage from transformer 32 output plus
a D. C. component across capacitor 33 which is
charged by valve 3| grid rectification. Each out
put pulse from coupling transformer 29 charges
energy into capacitor 34. This energy is dis
charged into vthe circuit of grid 35 at the be'
ginning of the following half cycle, providing a
voltage signal which overcomes the hold-off bias
on grid 35 and causes valve 3| to conduct;
neither shown nor described as these are con
Conduction of valve 3| chargesñrlng capacitor
ventional elements not essential to the invention,
35 through current transformer 31. Each time
although they would customarily be used in the
capacitor‘36 is charged, valve 3| conduction cur
working circuit.
rent energizes transformer 31 and the outputThe operation of the system is as follows:
from the secondary of transformer 31 delivers
When initiating switch 3 is closed, the output 40 a pulse to the valve 38 grid circuit.
voltage of transformer 2 disappears and capaci
The circuit consisting of grid bias transformer
tor 1 discharges rapidly. The voltage at control
33, capacitor 4| and resistor 42 provides a hold
grid 4 of electric valve 5 quickly changes, there
oif voltage for valve 43. -After -the firing capac
fore, from the near sine wave curve of capaci
itor 36 is charged, lthe tube 43 fires as its grid
-tor 1, consisting of the D. C. voltage due to grid "
voltage becomes less negative and quickly dis
rectification plus the A. C. output of transformer
charges capacitor 36 through resistor 50, induc
>2,’to the sawtooth voltage of capacitor II plus
the steady D. C. voltage of capacitor 8. Valve
l5 ñres at the next sawtooth peak grid voltage
lafter closure of the initiating switch 3. Valve
5 ceases to conduct as soon as timing capacitors
-tor 38, the 'igniter 51 and mercury cathode pool
58 of discharge tube 40. Resistor -5|) and induc
tor 38 serve to shape the discharge pulse of ca
pacitor 36 for best firing performance, the high
current pulse produced by the discharge serving
to initiate conduction of tube 4|) in conventional
I5 and I6 are charged, capacitor 8 being rapidly
discharged through resistor I1. This leaves at
manner.
.
v‘the grid 4 of valve 5 only the capacitor II saw
Discharge tubes 40 and 45 accomplish the
tooth voltage which is always sufficiently nega
function of switching the primary current to the
tive to prevent conduction of valve 5, which will,
Welder transformer 10, being connected back to
therefore, conduct for only a portion of a half
back in series with one power line to the Welder
cycle'for each closure of the initiating switch 3.
transformer and serving in effect as a single pole
While valve 5 conducts, capacitors I5v and I6
are charged through rectifier tube I8, said ca 60
The circuits for valves 38, 46 and tube 45 are
pacitors being charged at the same time from
substantially the same as the previously described
the same voltage source, both charging circuits
circuits for valves 3|, 43 and tube 40 respectively.
having the same impedances. Therefore, capac
Valve 38 lires in response to the output pulses of
itors I5 and I6 are charged to the same voltage
and then effectively disconnected from the sup 65 transformer 31 which occur each time valve 3|
conducts. Each of these pulses charges energy
ply transformer I9 as valve 5 ceases to conduct.
into capacitor 41, this 4energy being discharged
Capacitor |6 discharges very slowly through the
into the grid circuit of valve 38 at the beginning
voltage dividing resistor 2|; capacitor I5 dis
of the following half cycle, providing a voltage
charges more quickly through the fixed resistor
70 peak which overcomes the hold-olf bias due to
63 and the weld time adjustment resistor 22.
contactor.
Y
'
'
anode 24 of valve 25 negative with respect to
cathode 26 during the period of conduction of
capacitor 48, resistor 49, and transformer 5|.
When valve 38 fires, it charges ñring capacitor
52, the firing capacitor being discharged by con
valve 5 and rectifier tube I8.
As soon as anode
duction of valve 46, to effect conduction of mer
24 becomes positive with respect to cathode 26,
cury pool tube 45 in the same manner as.' previ
Transformer 23 is so disposed as to make the
‘ acens-so
ously described* Tor the >»interacliion- -cf capacitor
36', vvalve> 43 vand imercury'jpool‘tiibe “L
As may‘be Iseen
reference toy Figure' 2, <the
time during which tube "25 "will yfcol-'ld-uct, or lin
other' terms, vthe time vduring’ which -Weld-ing ~curren't ‘mayiilow V'does not vary with ’fluctuation
the supply voltage. ‘The dotted
‘Waves ‘Vïlï
and V2 Arepresent supply voltage of high- and ïlow
'values respectively. Ci' land -ïGII‘ represent-:the
potentials yci the cathode ’and grid, respectively,
lof valve 25 after `the timing `'capacitors VTE» fand
:source, ».rnezamsI ¿for slowly discharging-ione or :said
capacitors,` ‘means "for vdiscl'iarging ‘the `other .of
Lsaid 'capacitors more rapidly, said last mentioned
means»"being variable îfor adjustably discharging
sai-d- other capacitor, and ‘means-‘connected’ ‘tofsai‘d
capacitors ‘and vresponsive 'to ‘the -di?ference'ï-in
voltage ¿thereon todetermine ‘the ‘itirn‘ing period.
‘4. In :an electrical timing system,~'a pair :of Vca
pac'itors, means for charging said 'capacitorsfs'i
multaneously to the same voltage Afrornjthesame
source,v means including vva high resistance paral
leling Aone of rsaid' 'capaci-tors, means including :a
1:6 have 'been charged 'by' a voltage 'supply -wave
variable 'resistor vparalleling 'the other oi lsaid -ca»
of a 'high value, such 'as' ’that represented ‘by
Ipacitors fior adj us'tably discharging `said ‘other rca
dotted supply'voltage ‘wave> VI, «C2 ‘and G2' 'corre
spondingly represent ‘the “potentials 4'of v*the cath- t pacitor, and means connected iso-said capacitors
rand responsive tothe difference in voltage lthereon
ode and r`grid, respectively, ci valve 25 fa'fter'ïçthe
timing capacitors i5 Jand 1lli >have been charged
a 'voltage ‘supply Awave of" relatively >lovv value,~
to determine the timing period..
y
‘1I-n «fain-electrical timing system, a pair lof fca
pacitors, fof the v"saine capacity, means `for charg
such as* that represented -'by Jdottec'l sine wave» VL
'Valve 5 lvéfhich -'charges'capacitors I5 and '|56 is "20 ing ‘said capacitors ¿to the same‘voltage, means iin»
cluding ‘fixed bleeder resistances'paralleling 'each
cut off Vand «ceases to'conduct‘when the-rca-pacitors>
o’f said capacitors, means including a variable re
have ‘been charged y'and -’remains ‘non-conducting
sistance paralleling one of said capacitors :and
until'the initiating switch i8 is again operated.
variable to affect a linear change in timing vfor
Capacitors "f5 and I6 are, therefore, eiîectivély
disconnected `from the vsupuply during the `dis- l
charging or ètiming 'period -so ‘that the timing pe
riod isv vsubstantiall-y independent'of 'variations' of
voltage therein.
‘It `will 'be seen, "therefore, ‘that under vdifferent
or varyingconditions of supply voltage, the "time f
`required for -the‘potentials 'fof the grid -andcath
ode of the Ytiming value i5l 'to ‘become equal is
substantiallythesame. "Therefore for any'se'tting
of `the bleeder "resistor 2'2, the tim-ing `valve- 2’5
will conductduring substantially‘the same length
of time regardless of variations ‘Tin 'the ~supply
voltage.
The *'ñxed `‘resistor Llili '--in 'thefg'r'id «circuit of ‘valve
25- 'is `of high value rto `insure 'that any “cross
bleeding” between the timing l'capacitors during
_the timing period -is negligible. *The »resistor 6'4
'which parallels the Vcapacitor ¿t6- is -also of high
a linear change in resistance, and means Acon
nected vitc `said capacitors and responsive to `.the
di-iîerence in voltage thereon to »determine the
timing `period.
6'.v Inf'fan ìelectrical timing system, fa pair‘o'ffca
pacitors of lthe --same capacity, .means 'for charg
ing `said capacitors :simultaneously .to «the >same
voltage `from »the -same source, means including
a »voltage `>divider paralleling lone -of :said capaci~
tors, means >including "a variable lresistor parallel#
ing 'the -other of said ~capacitors and capable fof
varying 'the 'difference in discharge rates oi‘ said
capacitors, and means `responsive -to the »diiïer
ence between the voltage of a -point on said Avolt
age divider and the voltage-oi -said other capaci
tor to vdetermine 'the'timing period.
'
7. VIn van electrical timing system, a pair of ca
value and l'serves' ‘to admit `a "grid ¿hold-oli' 'bias-to
pacitors oi y'the same capacity, means for »charg
ing :said capacitors :simultaneously lto the same
the ‘grid of valve ï2'5 iduring the period‘fduring
:which -the 4timing >capacitors Iare not charged.
resistive >voltage divider p'aralleling one of «said
-
'While certain preferredem'bodiments oflthev‘i-n- Y
vention have ' been Vspecifically disclosed, it . is nn
Jderstorui that ‘the vinvention Vit ' not limited ‘ thereto,
as 'many variations 'will lbe readily `apparent 'to
thosey `skilled in ‘the art and `the 'invention âis `vtofbe
given its 'broadest ïpossible interpretation within
the terms -of fthe following claims.
'What Vïisfclairned is:
voltage <from >the same source, `means including fa
capacitors, means including a .resistor of substan
tially ‘the fsame resistance `as said voltage l'divider
>paralleling the other of ‘sa-id capacitors, »means
including a variable resistor `-’also ‘paralleling said
other capacitor and variable to 'eïîect a 'linear
change in timing lfor ia linear Achange ‘in resistance, @and means :responsive tothe difference ibe
tween ithe voltage -of a point on >said voltageadi
1. ‘In an Av'electrical timing' system, a »pair of ca
Vider and the voltage of said ~other -capacitor 'it
Y
pacitors, means hfor 'charging said capacitors to "55 determine the timingzperiod.
the-‘same'vol-tage, -means for-adjustably discharg
î8. `In .an electrical timing system, -a pair of fea
pacítors --of the same capacity, Ameans -for ncharg»
ing at'leastlon'e of said capacitors, 'said ‘ila-stenen
ing vsaid capacitors lsimultaneously to ¿the same
'tioned means being capableof varyingithe differ
voltage :from Athe >same source, ¿means including
ence *in discharge-rates "of `said capacitors, 'and
a resistance voltage divider ‘paralleling »one of
means connected to said capacitors and respon
sive Eto the 4difference `in voltage Athereon 'to de
termine the ‘timing period.
said capacitors, >means including a resistor of
substantially 'the same resistance as said voltage
2. In qan Velectrical timing system, ta, pair voft ca
divider -paralleling the other of >said capacitor,
meansincluding a variable resistor also parallel
fing Asaid other 'capacitor and variable to eiïectfa
linear `change in timing for ‘a 'linear change fin
resistance, :an electric valve, and means-connect
pacitors, 'means for charging said ucapacitors lsi
Vn'm'ltaneously -to the same voltage from ‘the'sanre
source, means for adjustably discharging at least
oneo‘f i said capacitors, :said fla-st mentioned means
being capable of vary-ing the »difference vvindis
'charge v'rates of ysaid capacitors, and means vcon
nected to said capacitors and responsive -tc'the
difference in rvoltage thereon >to determine the
'timing period.
'
'
.3. In an rrelectrical Atiming system, a pair ‘of 'ca
ing said electric valve vto a point on said voltage
divider and to said other capacitor so that v'the
conduction of said valve is dependent »upon vthe
difference ’betwecn'the voltages 'of said point and
of said other capacitor.
Y ‘9. 'In an electrical timing system, a pair loi?.
pacitors, means 4for 'charging nsaid Á‘capacitors si
capacitors, :means ’for -charging said capacitors
`mu'ltaneously f'to îthe *same voltage yfrom 'the “same ‘175 «to Athe 'same voltage, y:means including va y'voltage
2,534,385,>
7
8
divider paralleling one of said capacitors, means
means connecting elements of said electric valve
including a variable resistor paralleling the other
of said pair of capacitors and capable of vary
ing the difference in discharge rates of said ca
pacitors, an electric valve, and means connect
ing said electric valve to a point on said voltage
divider and to said other capacitor so that the
conduction of said Valve is dependent upon the
difference between the voltages of said point and
of said other capacitor.
_ .
to said capacitors so that the conduction of said
valve is determined by the difference in the volt
ages `of said capacitors.
16. In `an electrical timing system, a pair of
capacitors, means for charging said capacitors,
means for adjustably discharging at least one of
said capacitors, said last mentioned means be
ing capable of Varying the difference in discharge
10 rates of said capacitors. and means connected `to
10. In an electrical timing system, a pair of
`Said capacitors and responsive to the diii'erence
capacitors, means for _charging said capacitors
in voltage thereon to determine the timing period,
simultaneously to the same voltage from the same
source, means_including a voltage divider paral
leling >one of said capacitors, means including a
variable resistor paralleling the other of said pair
of capacitors and capable of varying the differ
ence in discharge rates of said capacitors, an
electric valve, and` means connecting said, elec
tric Valve to a point on said voltage divider and
to said other capacitor so that the conduction of
said valve is dependent 'upon the difference» be
said charging means including initiating means
providing for the passage of but a single charging
point and said other capacitor.
tion of said timing circuit, a grid bias normally
pulse until the initiating means is reactuated. ‘
_ 17. In an electrical timing system, a timing cir
cuit, an electric` valve controlling the energization
of said timing circuit, a grid bias normally im
posed on the control .grid of said valve and `con
stituted by the resultant of> at least iirst and
second added capacitors and a third opposed ca
pacitor, the first vand second added capacitors
tween the voltages of said point and of said other
normally maintaining a negative bias onthe con
capacitor.
trol grid at least while the valve anode is posi
11. In an electrical timing system, a pair oi
tive, means for charging said capacitors, initiat
capacitors, means for charging said capacitors to
ing means for the timing circuit including means
the same voltage, means including a resistive
for interrupting the charging of said first and
voltage divider paralleling one of said capacitors,
third capacitors, means for quickly discharging
means including fixed and variable resistors> par
the ñrst capacitor so that the third capacitor
alleling the other of said capacitors, said íixed 30 overrides the second capacitor to provide for con
resistor being of substantially the same resistance
duction of the valve for a single half cycle, and
as said voltage divider, said variable resistance
means discharging the third capacitor when the
effecting a linear change in timing for a linear
valve conducts so that the second capacitor alone
change in resistance, an electric valve, and means
has control of the valve grid to prevent conduc
connecting said electric valve to a point on said 35 tion ci. the valve thereafter until the initiatin
voltage divider and to said other capacitor so
means is reactuated.
->
that the conduction of said valve is dependent
`i8. In an electrical timing system, 4a timing
upon the diiïerence between the 'voltages of said
circuit, an electric valve controlling the energica
l
-12. In an electrical timing system, a pair of 40 imposed on the control grid of said valve and
capacitors, means for charging said capacitors to
the same voltage, means for adjustably discharg
ing at least one of said capacitors, said last men
tioned means being capable of varying the diiier
constituted by the resultant of at least nrst and
second added capacitors and a third opposed
capacitor, means connecting said iirst capacitor
ence in discharge rates of said capacitors, an .
fication of said valve, means including rectifiers
charging said second and third capacitors, the
ñrst and second added capacitors normally main
taining a negative bias on the control grid at least
Vsuch that said capacitor is charged by grid recti
electric valve, and means connecting elements of
said electric valve to said capacitors so that'the
`_conduction of said valve is determined by the
difference in the voltages of said capacitors.
While the valve'anode is positive, initiating means
including means for interrupting the Voltage sup
13. In an electrical timing system, a pair of
capacitors, means for charging said capacitors
ply to said first and third capacitors, means for
quickly discharging the ñrst capacitor so that
the third capacitor overrides the second capaci
tor to provide for conduction of the valve for
a single half cycle, and means discharging the
third capacitor when the valve conducts so that
the second capacitor alone has control of the
valve grid to prevent conduction of the valve
thereafter until the initiating means is reactu
simultaneously to the same voltage from the
same source, means for adjustably discharging
at least one of said capacitors, said last men
tioned means being capable of varying the dif
ference in discharge rates of said capacitors, an
electric valve, and means connecting elements of
said electric valve to said capacitors so that the
conduction of said Valve is determined by the
difference in the voltages of said capacitor.
60
14._In an electrical timing system, a pair oi
capacitors, means for charging said capacitors,
means for adjustably discharging at least one
oi said capacitors, said last mentioned means be
ated.
.
19. In an electrical timing system, a timing cir
cuit, an electric valve controlling the energiza
tion of Said timing circuit, a grid biais normally
imposed on the control grid of said valve and
ing capable of varying the difference in discharge 65 constituted by the resultant of at least ñrst and
rates of said capacitors, and means connected to
second added capacitors and a third opposed ca
said capacitors and responsive to the difference
pacitor, means connecting said ñrst capacitor
in voltage thereon to determine the timing pe
such that said capacitor is charged by grid recti
iication of said valve, means including rectiñers
15. In -an electrical timing system, a pair of
charging said second and third capacitors, the
capacitors, means for charging said capacitors,
first and second added capacitors <normally main
means for adjustably discharging at least one of
taining a negative bias on the control grid at
said capacitors, said last mentioned means being
least while the valve anode is positive, initiating
capable of varying the difference in discharge
means including means for interrupting the volt
riod.
,
.
_rates of said capacitors,l an electricpvalve, and .7.5 age Supply- t<LSais1„fi1ïSt-and third. capacitors
9,534,385
9
10
v
means including a circuit of relatively low resist
pacitor, the first and second added capacitors
ance for discharging said ñrst capacitor so that
normally maintaining a negative bias on the con
trol grid at least While the valve anode is posi
tive. initiating means for the timing circuit in
cluding means for interrupting the charging of
the third capacitor overrides the second capacitor
to provide for conduction of the valve for a single
half cycle, means for discharging said third ca
said ñrst and third capacitors, means for quickly
discharging the iirst capacitor so that the third
capacitor overrides the second capacitor to pro
vide for conduction of the valve for a single half
alone has control of the valve grid to prevent
conduction of the valve thereafter until the ini 10 cycle, and means discharging the third capacitor
pacitor including a circuit of relatively low resist
ance connected through the valve circuit so that
after the valve conducts the second capacitor
tiating means is reactuated.
20. In an electrical timing system, a timing
circuit including a pair of capacitors, means in
cluding an electric valve controlling the charg
ing of said capacitors, means for slowly discharg
when the valve conducts so that the second ca
pacitor alone has control of the valve grid to
prevent conduction of the valve thereafter until
the initiating means is reactuated.
'
ing one of said capacitors, means for discharging
the other of said capacitors more rapidly, said
HARRIS I. STANBACK.
ERNEST G. ANGER.
REFERENCES CITED
last mentioned means( being variable for adjust
ably discharging said Íother capacitor, and means
The following references are of record in the
connected to said «capacitors and responsive to 20. file of this patent:
the difference in voltagethereon to determine the
UNITED STATES PATENTS
timing period, a gridï’bias normally imposed on
Number
Name
»
Date
the control grid of said valve and constituted by
the resultant of at -"least additional ñrst and
second added capacitors and a third opposed ca- 25
2,409,522
Woll _____________ _„ Oct. 15, 1946
2,454,167
Hartwig _________ __ Nov. 16, 1948