close

Вход

Забыли?

вход по аккаунту

?

Патент USA US2407140

код для вставки
Sept. 3, 1946.
I
c. F.' coAKE
‘
`
2,407,140
ELECTRIG‘ MIçRoGAUGE SYSTEM
-
Filed Aug. 2; 1944
2 Sheets-Sheet 1
_
i
JNVENToA
(Menzis/‘Í í’0941€
BY
'
y
»
Armin/£7
Sept. 3, 1946.-
C. F. COAKE
2,407,140
ELECTRICl MICROGAUGE SYSTEM
Filed Aug. 2, 1944
49
wát; W
_
humus
k.
2 Sheets-Sheet 2
Patented Sept. 3, 1946
2,407,140
UNITED , >STATES PATENT OFFICE
ELECTRIC MICROGAUGE SYSTEM
Charles F. Coake, Indianapolis, Ind., assign‘or‘to
Senn Corporation, New Augusta, Ind., a cor
poration of Indiana
Application August 2, 1944, Serial No. 547,766
20 Claims.
l
(Cl. 177-351)
2
This invention relates to electric micro-gauges
of the type including a variable impedance de
vice the impedance of which is varied in accord
ance with the 'quantity to be measured, and more
particularly to a novel and improved system for
companying drawings in which speciñc embodi
ments have been set forth for purposes of illus
tration.
In the drawings:
Fig. 1 is a schematic diagram of a circuit em
actuating an instrument in response to such
-bodying the invention;
changes in impedance.
Fig. 2 is a schematic >diagram illustrating an
other embodiment of the invention wherein the
tem of the above type having novel and improved
fixed phase voltages are impressed in the output
operating characteristics.
10 circuit of the push-pull stage;
Another object is to provide a system which op
Fig. 3 is a schematic diagram of a bridge cir
erates with> extreme accuracy and dependability.
cuit wherein the condensers are varied while the
Another object is to provide a system of the
inductances remain constant;
above type which is not aiîected by minor changes
Fig. 4 is a schematic diagram of a bridge cir
inthe voltage or in the wave form of the energiz 15 cuit wherein both the condensersand the induct
ing source.
_ances are Varied;
Another object is to provide a system of the
Fig. 5 is a partial schematic diagram showing
An object of the invention is to provide a sys
above type whichmay be readily adjusted to con
the use of a cathode ray oscillograph for measur
form to various operating conditions.
ing the phase shift; and
Various other objects and advantages will be 20 Fig. 6 is a partial schematic diagram showing
apparent as the nature of the invention is more
the use of diode rectiflers for this purpose.
fully disclosed.
Although specific terms have been used here
in for convenience in referring to the various de
tails of the invention, it is to be understood that
_
`
In accordance with 4the present invention the
variations in impedance of the variable imped
ance device are caused to eiîect changes in phase 25 these ter-ms are to be given an interpretation
in an output circuit which are functions of the
commensurate with the state of the art.
variations in the quantity being measured.
Referring ñrst to Fig. 1, the variable impedance
These phase Ichanges are utilized to control theV
elements are shown as comprising a pair of coils
response of a measuring instrument.
More speciiically, the variable impedance de
vice is connected in a Wheatstone bridge circuit
which includes a pair of parallel branches, 'each
containing a condenser and an inductance in se
30
IU, II associated with a magnetic circuit includ
ing fixed cores 9 and an armature I2 mounted
- for movement to vary the reluctance of the mag
netic circuits in an inverse manner for effecting
corresponding changes in the impedances of the
ries, with the elements reversed in the two
coils. The armature I 2 is connected to be ac
branches. ` A source of alternating voltage is con 35 tuated by a stylus I3 which constitutes the meas
nected across diagonal corners of the bridge andY
uring element of the gauge. The construction of
an output circuit is connected across the other
a suitable unit including the parts 9 to I3 is set
diagonal corners. A measuring stylus is con
forth in detail in my copending application Ser.
nected to vary in an inverse sense the impedances
of at least one pair of diagonally opposite ele
ments in a manner to change the phase of the
voltage in the outputl circuit. Suitable means are
No. 548,281, filed August 5, 1944, and only so
40 much thereof is shown herein as is necessary for
an understanding of the present invention.
In accordance with the present invention, the
provided for measuring this phase shift. In one
coils I0 and Il are connected respectively in se
embodiment this voltage of variable phase is
ries with condensers I5 and I6 to form a Wheat- >
superimposed on another voltage of fixed vphase 45 stone bridge circuit having two parallel branches
to obtain unbalanced voltage conditions on Vthe
one of which includes coil I0 and condenser I5
two sides of the output circuit which are suited
in series and the other of which includes coil II
and condenser I6 in series, with the elements re
circuit having a millivoltmeter _connected across
versed in the two branches so that the two coils
suitable points in. its output side.
50 are in diagonally opposite legs and the two con
Although the novel features which are believed
densers are in the other diagonally opposite legs.
to be characteristic of this invention are pointed
An alternating voltage of a ñxed magnitude
out more fully in the claims, the invention will
and wave form is supplied across opposite corners
be better understood by referring to the follow
of the Wheatstone bridge by a circuit including
ing description taken in connection with the ac 55 an alternating current line 20 supplying the pri
to measurement by means of a full wave rec'tiiier
2,407,140
3
84 on the resistor 16 is connected by a line 85 to
the cathodes 62 and 63. A by-pass condenser 86
is connected between the lines 82 and 85.
In the operation of this system, a standard
alternating voltage -is supplied across the Wheat
stone bridge circuit from the line 20 through the
transformer 22 and the secondary 30 of the trans
former 29. A substantially constant Voltage is
obtained by means of the voltage regulating char
acteristics of the transformer 22 and a correct
of standard construction and including a series
condenser 23 which is designed to increase the
current flow through the primary 2| to a value
such that saturation is obtained. The output
voltage of the transformer is accordingly inde
pendent of minor variations in the supply voltage.
The transformer 22 includes a secondary 24
which -is connected across a potentiometer 25
having an adjustable tap 26. The variable por
tion of the potentiometer 25 is connected through
wave form is maintained by means of the tuned
a series choke 21 to the primary 28 of a trans
former 29 having a plurality of secondaries 30 to
33. The secondary 30 is connected across a po
circuit 3| and 40 operating in conjunction with
isolating choke 21, The tap 26 of the poten
tiometer 25 permits adjustments to be made so
that a predetermined voltage may be applied to
the Wheatstone bridge of all units regardless of
tentiometer 35 in series with nxed resistances 36.
The potentiometer 35 is provided with an ad
justable tap 31 which constitutes a Zero adjust
ment, as will be described. The secondary 30 is
also connected by lines 33 and 39 to opposite
differences in the source.
The coils I0 and |I and condensers I5 and I6
are selected so that they are normally of equal
corners a and b of the Wheatstone bridge be- ._
impedance at the frequency of operation. Under
tween the coil II and condenser I6 and between
these conditions the lines 45 and 46 are at the
the coil I0 and condenser I5, respectively,
same potential with respect to line 82 except of
A condenser 49 is connected across the sec
- opposite sign, voltage at point c being 90° out of
ondary 3| and is normally designed to tune the
circuit includ-ing the secondary 3| to the ire
quency of the applied alternating current. This
phase with yoltage at point 41 supplied by wind
ing 32 and voltage at point d being 90° out of
phase with voltage at point 48 supplied by wind
tuned circuit carries a current which is large with
respect to the current in the primary 28 and thus
has a dominating influence on the wave form ol .
the current in the secondary 36. Sincev the oscil
lations in the tuned circuit 3| and 49 are predom
inantly sine wave in form, this same wave form
appears in the secondary 30 regardless of varia
tions in wave form of the applied voltage. If the
capacity predominates in the tunedfcircuit 3| and
40,-«it may not be necessary to tune the circuit to
resonance.
The choke 21 is an isolating device
to lessen the coupling between windings 28 and 24.
The output of the Wheatstone bridge circuit
includes a line 45 which is connected to the point
4
the adjustable tap 31 on the resistor 35. A tap
'mary 2| of a voltage regulating transformer 22
so
ing 33. This. condition exists when the armature
is centrally located. As the grid circuits of the
rectifier tubes 49 and 50 are connected in push
pull to the bridge output lines 45 and 46 and the
return line 82, the grids are normally at the same
resultant potential.
If now the stylus I3 is displaced, the impedance
` of the coil I0 is increased and the impedance of
the coil II is decreased or vice Versa, depending
upon the direction of displacement. Under
these conditions, the impedances of the coils I0
and |I and of the condensers I5 and I6 are no
longer in balance and the voltages in the lines
45 and 46 become displaced in phase in opposite
directions, one Voltage being caused to lead and
line 46 which is connected to the point d between
the other. to lag by equal amounts with little
the condenser I6 and the coil I0. The lines 45
change in the magnitude of the Voltage. The
and 46 are connected through the secondaries 32
and 33 respectively to grids 41 and 48 of space .4 phase shift of the voltage between point a
through coil |I to point c is essentially 90° lag.
discharge devices 49 and 59 which may be in
The phase shift of the voltage between .point a
cluded in- a single envelope if desired.
through condenser I6 to point d is essentially 90°
-Anodes 5i and 52 of the space discharge de
lead. Variations from the above `conditions of
vices 49 and 59 are connected in an output c-ir
cuit including resistors 53, 54 and 55 connected . 90° lag to 90° lead is obtained by movements of
the armature by virtue of impedance variation
in series. A potentiometer 59 is connected be
of the two coils I0 and I| which in turn is re
tween the anodes 5I and 52 and a measuring in
lated to the movement of the stylus I3.
strument, such as a millivoltmeter 51, is connected
In order to measure the amount of this phase
between one end and a variable tap 58 of the
shift, an alternating voltage of fixed phase is sup
potentiometer 5S. The usual by-pass condensers
plied to lines 45 and 46 through secondaries 32
69 and 6| are connected between the anodes 5I
and 33 respectively. This fixed phase corre
and 52 and cathodes 62 and 63Y respectively of
sponds to the phase of the voltage across the
the space discharge devices 49 and 50.
lines 38 and 39. These voltages of fixed phase
The cathodes 62 and 63 are provided with
heaters 65 and 66 which are supplied from a sec 60 when combined with a leading Voltage in the
line 45 and a lagging Voltage in the line 46 or
ondary 61 of the transformer 22. The anode and
vice versa produce a voltage differential on the
grid biasing potentials are supplied through a
two grids 41 and 48 respectively which is a func
rectifying system including a rectifying tube 19
c between the condenser I5 and coil I| and the
having anodes 1I connected across a secondary
i tion of the amount of phase shift across the lines
12 'of the transformer 22 and havinga cathode 65 45 and 46. This voltage differential causes dif
ferent plate currents to now through the corre
13 provided with a heater 14 which is energized
sponding tubes and through the resistors 53 and
from a secondary 15 of the transformer 22. A
55, thus changing the potentials of the two plates
voltage divider resistance 16 is connected by a
and producing a voltage differential across the
line 11 to the midpoint of the seco-ndary 12 and
by a line 18 to the cathode 13. The usual by 70 potentiometer 59 which is ymeasured by the volt
meter 51. The readingof the voltmeter 51 thus
pass condenser 19 is connected across the resistor
constitutes a measure‘of the movement of the
16. The positive end of the resistor 16 is con
stylus I3.
.
»
.
’
nected by a line 80 to an adjustable tap 8| on the
The tap 58 provides a sensitivity >adjustment
resistor 54, The negative end of the resistor 16
is connected by a line 82 through a resistor 83 to 75 which may be varied in accordance with the
2,407,140,
order of the quantities ubeing measured. The tapv
B'Iion the resistor 54 -providesan adjustment'ior
balancinglthe tubes and resistors. The tap‘31 on
theresistor 35 `may be varied to‘robtain an initial
zero‘ balance 'While 'the iixed resistors 35~lirnit
the range Vof adjustment so as to avoid over
compensation. The tap 84 is adjusted to »apply
a‘lgrid bias suited to cause the tubes 49 and 50
to operate below the straight portion of their
characteristic curves.
It will be noted that the above described» sys
tem is responsive to phase changes and is ac
cordingly insensitive to minor variations in oper
ating Aconditions of the various space discharge
devices or to minor changes »in voltage of the,
supply line such as those which may not `be en~
tirely eliminated by the voltage regulating trans~former 22.
The system may be used to measure micro-vari- .
ationsto which the stylus I3 is responsive as, for
example, variations in hydraulic or air pressures
which may be measured by the displacement »of
diaphragms, micro movements of temperature
regulators or thermometers, the reading of bal
ances, a strain gauge or a micrometer or the like
invwhich measurements of millionths of an inch
may be» mad-e. The arrangementmay be made
to produce a 909er greater total phase shift
between extremes of .0I-inch of movement of the
stylus
I3.
l
»
It is to be understood that various »circuits may
be used to measure the phase displacement across
the lines 45 and 45. - A modified circuit for this
purpose is ‘shown in Fig. 2 in which the voltage
of fixed phase is impressed on the output circuit
of'` the tubes 49 and 45t instead of on the input
densers 92a and 93a across the ‘secondaries ‘52
andv 93 to maintain a sine'wave form.
'
'
‘
In the operation of this system, the voltages
supplied across the lines 45 and 45 to the grids
41 and 4S vary in phase in accordance with -the
changes in impedance of the vcoils ‘It and II.
The anode potentials on the plates 5I and 5i!`
are of iixed phase corresponding to the phase of
the supply line 90. Consequently, the space ‘cur
rent passed by the tubes 49 and 55 varies in ac
cordance with the phase displacement between
the grid potentials and the anode potential-s.
When these potentials are 90° displaced between
grid and plate of each triode balanced conditions
exist and no potential diiierence is developed
' across the meter IIU.
However, when these po
tentials or voltages become displaced other than
90° due to variation of phase between grid and
plate of each triode such as 35“ between 41 and
5I and 95° between 48 and 52, a potential dif
ference existsfdue to the unequal current iiowing
through the resistors Quand It() and the meter'
III! responds accordingly.
The adjustable tap
IGI provides means for adjusting the circuit to
balance the tubes and resistors. The ñlter cir-.
Cuit III and H2 prevents the alternating current
from passing through the miilivoltrneter IIS and
makes the latter responsive only to the voltage
differential across the resistors 93 and ißt. Con
denser` II2 could be eliminated if inductance III
is sufíicient to keep A. C. voltage from meter I I 0.
In the above described embodiments the coils
I8 and II have been described as of variable
impedance.
It is to be understood,` however,
l that the coils IIJ and II may be designed to have
a constant impedance and the impedanoe'of thel
circuit as shown in Fig. 1. Y The bridge elements
condensers l5 and I6 may be varied as indicated
and the input and output circuits to the bridge
in the bridge circuit of Fig. 3. In this case the
in Fig. 2 are similar to those above described and
capacity of the condensers I5 and I8 isindicated
have been given the same reference characters. 40 as variable in unison, but in an inverse sense in
In Fig. 2, however, power is supplied from an
response to the movement of the stylus. The
A.-C. line 90 to a transformer 9i having secon
operation` of this bridge is otherwise similar to
daries 92 tov 85. The secondary~95 is connected
that above described.
to the input lines 38 and 39 to supply voltage to
Another embodiment of the invention is illusn
the input circuit of the~bridge. The secondary
trated in Fig. 4 in which both the coils I0 and
54 is connected to ‘supply heating current to the
II and the condensers I 5 and I6 are shown as
filament 65 of the tubes'ds and 50. The output
variable. In this embodiment the impedances
lines 45 and 46am connected directly to the grids
of the coils I0 and II are varied in unison but
41 and 48 of the tubes 49 and 58. Otherwise »the
in an opposite sense and the capacities oi the
supply circuit to the bridge and to the tubes 4B „ condensers I5 and I6 are likewise varied in uni
and 58 is similar to that above described.
son but in opposite sense in response to moveV‘In¿Fig. 2 plates 5I and 52 are connected by
ment of the stylus. The operation is similar to
lines Se and 81 to secondaries 92 and 53 respec~
that above described` except that a greater phase`
tively which are-connected in series lthrough re~
shift is produced than in the case where only
sistances 88, 83 and ltd. The resistance 98 is
the coils or the condensers-are varied.
provided with an adjustable tap IIN which isv
The embodiment shown in Fig. 5 is similar in
connected by a line I02'through a resistance u|513 ,
general to the embodiment of Fig. 1 so far as the
to the catliodes 62 and 63. Resistanoes 98, 99
bridge and input circuits are concerned. _ In this
and Idil are'by-passed to the cathodes by con
embodiment, however, the output lines 45 and 46
densers IM and H15. A millivoltmeter Il@ is
andthe return line 82 which constitutes the out
connected in series with a filter circuit including 60 put circuit of the bridge are connected to a cath
an inductance III and condenser II2 across the
ode ray oscillograph |20 which is designed to
resistors 93, 59 and Illii. The'windings 92 and
indicate phase variations in the lines 45 and 66
53 are so connected with respect to each other>
with respect to line 82.
that potentialsof opposite sign' are applied to
Fig. 6 illustrates the use of diode full wave
the anodes 5I and 52. Grid 41 and anode 5I and 65 rectifiers in the output circuit from the variable
grid 48 and anode 52 are 90° outof phase when
impedance bridge. In this figure the bridge and
the ’armature I2 is centrally located, thereby
input circuits are similar to those described above.
causing each tube to draw equal anode current
Lines 45 and 46, constituting the output circuit
and producing zero voltage across the meter I It.
of the bridge, are connected to diode rectiiiers
A voltage regulating transformer similar to the
|30 and .ISI respectively which, in turn, are `con
transformer 22 of Fig. 1 may be connected‘be
nected through the secondaries 92 and 93 (of
tween the power line 80 and the transformer 9|
Fig. 2) and resistors I32 and |33 to the return
if desired `and the circuit may `include means,
lead 82 so as to make the cathodes of tubes |35
su'ch as the choke >2210i? -î‘ligi‘ 1V and tuning con~ 75 and -I3I 180° .out of- phase. «By-pass -condensers
2,407,140>
7
|34 and |35 are shown connected across the re
sistors |32 and |33. A millivoltmeter |36 is likewise connectedv across the rectiñer side of the
two resistors.
This embodiment operates in a manner similar
to Fig. 2, the rectiñers |30 and |3| passing a
current which is determined by the phase of the
voltage supplied by the lines 45 and 46 with re
in said output circuit which is a function of said
variation, means superimposing a voltage of iixed
phaseon said output circuit to be combined with
said voltage of variable phase to produce a voltage
unbalance across said output circuit, a pair of
space discharge devices, means connecting vsaid
output circuit to the inputs of said devices in
push-pull relationship to produce correspond
ingly unbalanced space currents therein and
92 and 93. When the voltages are such as to 10 means measuring said unbalance in space cur
rents.
make the phase angle between the cathode and
4. An electric measuring system comprising a
anode of each rectifier equal to 90°, equal cur
Wheatstone bridge circuit including a pair of par
rents are passed by the two rectifiers and flow
allel series resonant branches each having an in
through the two resistors |32 and |33. Hence,
no voltage drop exists across the meter |36. 15 ductive leg and a capacitive leg connected in
series with the elements of the two branches re
When the above mentioned voltages are other
versed in order so that like elements appear in
than 90° out of phase, diiferent currents are
diagonally opposite legs, means supplying a given
passed by the two rectiñers and a voltage differ
alternating voltage across opposite corners of said
ential exists across the meter |36 which is a
spect to the voltage supplied by the secondaries
20 bridge and an output circuit connected across
.
other opposite corners of said bridge, means op
Although a specific embodiment of the inven
positely varying the reactance of a pair of like
tion has been shown herein for purposes of illus
elements of said bridge in accordance with the
tration, it is to be understood that the invention
quantity being measured to produce a phase shift
is capable of various uses as will be apparent to
a person skilled in the art. The invention is only 25 in said output circuit which is a function of said
variation, means superimposing a voltage of fixed
to be limited in accordance with the scope of
phase on said output circuit to be combined with
the following claims.
said voltage of variable phase to produce a voltage
What is claimed is:
unbalance across said output circuit, a pair of
1. An electric measuring system comprising a
Wheatstone bridge circuit including a pair of par 30 space discharge devices, means connecting said
output circuit to the inputs of said devices in push
allel series resonant branches each having an in
pull relationship to produce correspondingly un
ductive leg and a capacitive leg connected in series
balanced space currents therein, anode circuits
with the elements of the two branches reversed in
connected to said devices having means varying
order so that like elements appear in diagonally
opposite legs, means supplying a given alternat 35 the anode voltages in accordance with variations
in space current and a measuring circuit con
ing voltage across opposite corners of said bridge
nected between said anode circuits to respond to
measure of the phase displacement.
and an output circuit connected across other cp
posite corners of said bridge, means oppositely
varying the reactance of a pair of like elements. of
said bridge in accordance with the quantity be
ing measured to produce a phase shift in said out
put circuit which is a function of said variation,
and means measuring said phase shift.
2. An electric measuring system comprising a
Wheatstone bridge circuit including a pair of
parallel series resonant branches each having an
inductive leg and a capacitive leg connected in
series with the elements of the two branches re
versed in order so that like elements appear in
diagonally opposite legs, means supplying a given .
alternating voltage across opposite corners of
said bridge and an output circuit connected
across other opposite corners of said bridge, means
oppositely varying the reactance of a pair of like
elements or" said bridge in accordance with the
quantity being measured to produce a phase shift
in said output circuit which is a function of said
variation, means superimposing a voltage of ñxed
phase on said output circuit to be combined with
said voltage of variable phase to» produce a voltage
unbalance across said output circuit and means
measuring said voltage unbalance.
3. An electric measuring system comprising a
Wheatstone bridge circuit including a pair of par
the unbalance in anode voltages.
5. An electric measuring system comprising a
Wheatstone bridge circuit including a pair of par
allel series resonant branches each having an in
ductive leg and a capacitive leg connected in series
with the elements of the two branches reversed in
order so that like elements appear in diagonally
opposite legs, means supplying a given alternat
ing voltage across opposite corners of said bridge
and an output circuit connected across other 0p
posite corners of said bridge, means oppositely
varying the reactance of a pair of like elements of
said bridge in accordance with the quantity be
ing measured to produce a phase shift in said
output circuit which is a function of said varia
tion, means combining said voltage with another
voltage having a phase relationship suited to pro
duce a voltage unbalance in said output circuit,
and means measuring said voltage unbalance.
6. An electric measuring system comprising a
Wheatstone bridge circuit including a pair of par
allel series resonant branches each having an in
ductive leg and a capacitive leg connected in series
with the elements of the two branches reversed
in order so that like elements appear in diagonally
opposite legs, an input circuit including lines con.
nected across opposite corners of said bridge to
supply an alternating voltage thereto, an output
circuit including lines connected across the other
allel series resonant branches each having an in
ductive leg and a capacitive leg connected in
opposite corners of said bridge and a common
series with the elements of the two branches re
return line, means connecting said common re
versed in order so that like elements appear in
turn
line to a neutral point on said input circuit,
diagonally opposite legs, means supplying a given
alternating voltage across opposite corners of said 70 means oppositely varying the reactance of a pair
of like elements of said bridge in accordance with
bridge and an output circuit connected across
the quantity being measured to produce a phase
other opposite corners of said bridge, means oppo
shift in said output circuit which is a function
sitely varying the reactance of a pair of like ele
of said variation, means supplying another voltage
ments of said bridge in accordance with the
quantity being measured to produce aphase shift
to said output circuit suited to be combined with,
2,407,140 »
9
~said variable phase voltage to cause an unbalance
, in the voltage on said first output lines with re
spect to said common return line, means measur
ing said unbalance, and means adjusting said
neutral point to obtain desired zero reading con
ditions in said measuring means.
7. An electric measuring system comprising a
Wheatst-one bridge circuit including a pair of
parallel series resonant branches each having an
inductive leg and a capacitive leg connected in
series with the elements of the two branches
reversed in order so that like elements appear
in diagonally opposite legs, an input circuit in
cluding lines connected across opposite corners
`necting-said- common return line to a neutral
point on said input circuit, means oppositely vary
ing the reactance of a pair of like elements of
said bridge in accordance with the quantity being '
measured to produce a phase shift in said out
put circuit which is a function of said variation,
means supplying another voltage to .said output
circuit suited to be combined with said vvariable
phase voltage to cause an unbalance in the volt
age on said iirst output lines with respect to said
common return line, a pair of space discharge
tubes having input circuits connected iny push
pull to said output lines, and having output `cir
cuits carrying the space current of the respective
of said bridge to supply an alternating voltage 15 devices, means comparing said space currents,
and means adjusting the response characteristics
thereto, an output circuit including lines con
of 'said comparing means.
Y
nected across the other opposite corners of said
l0. An electric measuring system as set forth
bridge and a common return line, means connect
in claim l in which said alternating voltage sup
ing said common return line to a neutral point
on said input circuit, means oppositely varying 20 ply means comprises a transformer having a, pri
mary supplied with alternating voltage anda
the reactance of a pair of like elements of said
pair of secondaries, one of said secondaries being
bridge in accordance with the quantity being
connected acrossv said iirst corners to supply volt,
measured t0 produce a phase shift in said output
age to said bridge, and a condenser connected
circuit which is a function- of said variation,
across the other of said secondaries to form a
means supplying another voltage to said output
tuned oscillating circuit adapted to carry a cur
circuit suited to be combined with said variable
rent suited to control the Wave form of the volt
phase voltage to cause an unbalance in the volt
age in the first secondary.
`
¿
age on said first output lines with respect to said
11. An electric measuring system comprising a
common return line, a pair of space discharge
tubes having input circuits connected in push
pull to said output lines, and having output cir
cuits carrying the space current of the respec
tive devices, and means comparing said space
currents.
i
8. An electric measuring system comprising a
Wheatstone bridge circuit including a pair of
Wheatstcne bridge circuit including a. pair of
parallel series resonant branches each having an
inductive leg and a capacitive leg connected in
series with the elements of the two branches re
versed in order so that like elements. appear in
diagonally opposite legs, an input circuity con
nected across opposite corners of said bridge, an
parallel series resonant branches eachl having
output circuit including linesV connected across
an inductive leg and a capacitive leg connected
in series with the elements of the two branches
reversed in order so that like‘elements appear
the other opposite corners of said bridge, va source
of supply voltage including a transformer having
a primary and a plurality of secondaries, means
connecting one of said secondaries to supply volt
age to said input circuit, means connecting other
of sai-d secondaries to supply a voltage of fixed
phase to said output circuit, means oppœitely
neet-ed across the other opposite corners of said 45 varying the reactance of a pair of like elements
of said bridge inV accordance with the quantity
bridge and a common return line, means connect
being measured to produce a phase shift in said
ing said common return line to a neutral point on
said input circuit, means oppositely varying the
output circuit which isa function of said varia
reactance of a pair o-f like elements of said bridge
tions, means combining said ñxed phase voltage
in accordance with the quantity being measured 50 with said variable phase voltage to produce a
to produce a phase shift in Isaid output circuit
voltage unbalance in said output ,circuit lines,
ywhich is a function of said variation, means sup
and measuring means responsive to said voltage
plying another‘voltage to said output circuit
unbalance.
suited to be combined with said variable phase
12. An electric measuring system comprising a
voltage t0 cause an unbalance in the voltage on 55 Wheatstone bridge circuit including a pair of par
said first output lines with respect to said com
allel series resonant branches each having an in
mon return line, a pair of space discharge tubes
ductive leg and a capacitive leg connected in se
having input circuits connected in push-pull to
ries with the elements of the two >branches re
said output lines, and having output circuits car
versed in order sothat like elements appear in
rying the space current of the respective devices, 60 diagonally opposite legs, an input circuit con
in diagonally opposite legs, an input circuit in
cluding lines connected across opposite corners
of said bridge to supply an alternating voltage
thereto, an output circuit including lines con
means comparing said space currents, and means
adjusting 4said neutral point to obtain desired
zero reading conditions in said comparingmeans.
9. An electric _measuring systemlcomprising a
Wheatstone bridge circuit including a pair of
parallel series resonant. branches each having an
inductive leg and a capacitive leg connected in
series with the elements of the two branches
nected across opposite corners of said bridge, an
output circuit including lines connected across
the other opposite corners of said bridge, a source
of supply voltage including a transformer having
a primary and a plurality of secondaries, means
connecting one of said secondaries to supply volt
age to said input circuit, means connecting a pair
of other secondaries to supply voltages of ñxed
reversed in order so that like elements appear f phase to the respective output circuit lines,
in diagonally opposite legs, an input circuit in 70 means oppositely varying the reactance of a pair
of like elements of said bridge in accordance with
cluding lines connected across opposite corners
the quantity being measured to produce a phase
of said bridge to supply an alternating voltage
shift in said output circuit which is a function
theretdan output circuit including lines con
of said variations, means combining said iixed
nected across the other opposite corners of said
bridge and a common return line, means con
phaâe Voltage with said variable phase voltage
2,407,140
11
12
to produce a voltage unbalance in said output
circuit lines, and measuring means responsive -to
said voltage unbalance.
13. An electric measuring system comprising a
Wheatstone bridge circuit including a pair of
parallel series resonant branches each having an
inductive leg and a capacitive leg connected in
series with the elements of the two branches
other of said secondaries to supply a voltage of
ñxed phase to'said output circuit, means oppo
sitely varying the reactance of a pair of like ele
ments of said bridge in accordance with the quan
tity being measured to lproduce a phase shift in
said output circuit which is a function of said
variations, means combining said ñxed phase
voltage with said variable phase voltage to pro
duce a voltage unbalance in said output circuit
~ reversed in order so that like elements appear in
diagonally opposite legs, an input circuit con
10 lines, measuring means responsive to said voltage
unbalance, a condenser connected across another
output circuit including lines connected across
of said secondaries to form a closed circuit tuned
nected across opposite corners of said bridge, an
the other opposite corners of said bridge and a
to the frequency of the supply voltage and adapted
common return line connected to a neutral point
to carry a current for controlling the wave form
of said input circuit, a source of supply voltage 15 applied to the bridge input circuit, and supply
including a transformer having a primary and a
lines connected to said primary and a choke in
plurality of secondaries, means connecting one of
said last lines to prevent transference thereto of
said secondaries to supply voltage to said input
circuit, means connecting other of said second
oscillations from said tuned secondary.
'
16, An electric measuring system comprising
aries to supply a voltage of fixed phase to said 20 a Wheatstone bridge circuit including a pair of
parallel series resonant branches each having an
inductive leg and a capacitive leg connected in
series with the elements of the two branches re
versed in order so that like elements appear in
which is a function of said variations, a pair of 25 diagonally opposite legs, an input circuit con~
space discharge devices having input circuits
nected across opposite corners of said bridge, an
connected in push-pull to said output circuit
output circuit including lines connected across
lines to develop space currents which are normal
the other opposite corners of said bridge, a source
ly balanced but become unbalanced in response
of supply voltage including a transformer having
to said variations in phase in said bridge output, 30 a primary and a plurality of secondaries, means
and measuring means responsive to said unbal
connecting one of said secondaries to supply
output circuit, means oppositely varying the re
actance of a pair of like elements of said bridge
in accordance with the quantity being measured
to produce a phase shift in said output circuit
voltage to said input circuit, means connecting
14. An electric measuring system comprising a
other of said secondaries to supply a voltage of
Wheatstone bridge circuit including a pair of
fixed phase to said output circuit, means oppo
parallel series resonant branches each having an
sitely varying the reactance of a pair of like ele
inductive leg and a capacitive leg connected in
ments of said bridge in accordance with the quan
-series with the elements of the two branches re
tity being measured to produce a phase shift in
versed in order so that like elements appear in
said output circuit which is a function of said
diagonally opposite legsJ an input circuit con
variations, means combining said fixed phase
nected across opposite corners of said bridge, an 40 voltage with said variable phase voltage to pro
output circuit including lines connected across
duce a voltage unbalance in said output circuit
the other opposite corners of said bridge, a source
lines, measuring means responsive to said voltage
of supply voltage including a transformer having
unbalance, a condenser connected across another
a primary and a plurality of secondaries, means
of said secondaries to form a closed circuit tuned
connecting one of said secondaries to supply volt
' to the frequency of the supply voltage and adapted
age to said input circuit, means connecting other
to carry a current for controlling the wave form
of said secondaries to supply a voltage of ñxed
applied to the bridge input circuit, supply lines
phase to said output circuit, means oppositely
connected to said primary and a choke in said last
varying the reactance of a pair of like elements
lines to prevent transference thereto of oscilla
of said bridge in accordance with the quantity
tions from said tuned secondary, and a voltage
being measured to produce a phase shift in said
regulating transformer supplying said last lines.
output circuit which is a function of said varia
17. An electric measuring system comprising a
tions, means combining said ñxed phase Voltage
Wheatstone 'bridge circuit including a pair of
with said variable phase voltage to produce a
parallel series resonant branches each having an
voltage unbalance in said output circuit lines,
inductive leg and a capacitive leg connected in
measuring means responsive to said voltage un
series with the elements of the two branches
balance, and a condenser connected across an
reversed in order so that like elements appear in
other of said secondaries to form a closed circuit
diagonally opposite legs, an input circuit includ
ance in space currents.
tuned to the frequency of the supply voltage and
ing lines connected across opposite corners of said
adapted to carry a current for controlling the 60 bridge to supply an alternating voltage thereto,
Wave form applied to the bridge input circuit.
an output circuit including lines connected across
l5. An electric measuring system comprising
the other opposite corners of said bridge and a
a Wheatstone bridge circuit including a pair of
common return line, means connecting said com»
parallel series resonant branches each having
mon return line to a neutral point on said input
an inductive leg and a capacitive leg connected 65 circuit comprising a resistor connected across
in series with the elements of the two branches
said input circuit and having an adjustable tap
reversed in order so that like elements appear in
connected to said return line, means oppositely
diagonally opposite legs, an input circuit con
varying the reactance of a pair of like elements
nected across opposite corners of said bridge, an
of said bridge in accordance with the quantity
output circuit including lines connected across
being measured to produce a phase shift in said
the other opposite corners of said bridge, a source
output circuit which is a ’function of said varia
of supply voltage including a transformer having
tion, means supplying another Voltage to said out
a primary and a plurality of secondaries, means
put circuit suited to be combined with said variable
connecting one of said secondaries to supply
phase voltage to cause an unbalance in the voltage
voltage to said input circuit, means connecting 75 on -said first output lines With respect to said
2,407,140
,
f 13
common return line, and means measuring said
unbalance.
18. An electric measuring system comprising a
Wh'eatstone bridge circuit including a pair of par
allel series resonant branches each having an
inductive leg and a capacitive leg connected in
series with the elements of the two branches re
versed in order so that like elements appear in
diagonally opposite legs, an input circuit includ
ing lines connected across opposite corners of
said bridge to supply an alternating voltage
14
in accordance With the quantity being measured
to produce a ph'ase shift in said output circuit
which is a function of said variations, a pair of
space discharge devices having input circuits
connected in push-pull to said output circuit
lines to develop space currents which are nor
mally balanced but become unbalanced in re
sponse to said variations in phase in said bridge
output, space current circuits for said devices in
cluding resistors to cause a variation in anode
voltage corresponding to variations in space cur
rent, anda center reading milliammeter con
nected between said anodes.
thereto, an output circuit including lines con
nected across the other opposite corners of said
20. An electric measuring system comprising
bridge and a common return line, means con
necting said common return line to a neutral 15 a Wheatstone bridge circuit including a pair of
parallel series resonant branches each having an
point on said input circuit comprising a variable
inductive leg and a capacitive leg connected in
resistor and a pair of ñxed resistors connected
series with the elements of the two branches re
in series across said input circuit, said variable
versed in order so that like elements appear in
resistor having a tap connected to said return
line, means oppositely varying the reactance ofy 20 diagonally opposite legs, an input circuit con
nected across opposite corners of said bridge, an
a pair of like elements of said bridge in accord
output circuit including lines connected across
ance with the quantity being measured to pro
the other opposite corners of said bridge and a
duce a phase shift in said output circuit Which
common return line connected to a neutral point
is a function of said variation, means supplying
of said input circuit, a source of supply Voltage
another voltage to said output circuit suited to
including a transformer having a primary and
be combined With said variable phase voltage to
a plurality of secondaries, means connecting one
cause an unbalance in the voltage on said ñrst
of said secondaries to supply voltage to said in
output lines With respect to said common return
put circuit, means connecting other of said sec
line, and means measuring said unbalance.
i9. An electric measuring system comprising a 30 ondaries to supply a voltage of ñxed phase to
said output circuit, means oppositely varying the
Wheatstone bridge circuit including a pair of
reactance of a pair of like elements of said bridge
parallel series resonant branches each having an
in accordance with the quantity being meas
inductive leg and a capacitive leg co-nnected in
ured to produce a phase shift in said output cir
series with the elements of the two branches re
cuit Which is a function of said variations, a pair
versed in order so that like elements appear in
of space discharge devices having input circuits
diagonally opposite legs, an input circuit con
connected in push-pull to said output circuit
nected across opposite corners of said bridge, an
lines to develop space currents which are nor
output circuit including lines connected across
mally balanced but become unbalanced in re
the other opposite corners of said bridge and a
sponse to said variations in phase in said bridge
common return line connected to a neutral point
output, space current circuits for said devices
of said input circuit, a source of supply voltage
including resistors to cause a variation in anode
including a transformer having a primary and a
voltage corresponding to variations in space cur
plurality of secondaries, means connecting one
rent, a center reading milliammeter connected
of said secondaries to supply voltage to said in
between said anodes, and a variable resistor con
put circuit, means connecting other of said sec
nected in shunt With said milliammeter for ad
ondaries to supply a voltage of fixed phase to said
output circuit, means oppositely varying the re
actance of a pair of like elements of said bridge
justment of the sensitivity thereof.
CHARLES F. COAKE.
Документ
Категория
Без категории
Просмотров
0
Размер файла
1 395 Кб
Теги
1/--страниц
Пожаловаться на содержимое документа