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Патент USA US2405121

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Aug. 6, 1946.
P. FEHR
V
1
2,405,121
’ COUNTING DEVICE FOR OVERVOLTAGE
Filed Aug. 5, 1943
|
1
I
INVENTOR
fan! 7%!”
,_________J
HTTORNEY
.
Patented ‘Aug. 6, 1946
2,405,121
UNITED STATES PATENT OFFICE
2,405,121
COUNTING DEVICE FOR OVERVOLTAGE
Paul Fehr, Zug, Switzerland, assignor to Landis
& Gyr A. G., a body corporate of Switzerland
Application August 5, 1943, Serial No. 497,441
In Switzerland November 7, 1942
3 Claims.
(Cl. 235-92)
1
2
There are several devices known in the art for
counting voltage surges on long overhead lines
Figs. 3 and 4 illustrate other forms of embodi
ment.
The invention is based on the utilization of the
due to atmospheric in?uences or switchings.
Such devices are based on magnetic, dynamic,
thermal or chemical action of the current de
?ected by the protective devices in use.
For instance, in a known form of embodiment,
at a voltage-dependent resistance of the over
thermal action of the de?ected current, whereby
this—according to the diagrammatic representa
tion in Fig. 1—is conveyed over a ?lament re
sistance I, which is in the counting tank 2 ?lled
with gas. The closure of the tank 2 forms a ?ex
voltage conductor, a part of the voltage drop
ible metallic diaphragm 3 being in connection
caused by the de?ected (or discharged) current 10 with a counting train 4. Between the overhead
is tapped and conveyed to the tWo coatings of a
line 5 and the ground lies the protective conduc
condenser to which an electro-magnetically 0p
tor 6. The counting device is interposed be
erated counting train is placed in parallel. After
tween protective conductor 6 and grounded con
having been charged, the condenser discharges
ductor 1, whereby the de?ected current passes
itself over the counting train and moves the 15 via the parallel connection of a voltage-depend
same forward by one step.
ent resistance 8 and a reactor (or choking coil)
Another known type utilizes the thermal ac
tion of the de?ected current by passing an end
9. The counting train 4 and the metallic dia
phragm 3 are mechanically interconnected.
less strip of paper longitudinally and transverse
Fig. 2 represents a sectional view of a form of
ly between a spark gap, whereby the strip gets 20 embodiment of the actuating device for the
punctured at the incidence of a voltage surge.
counting train. The numeral 3 designates a di
In addition other arrangements have been
aphragm consisting of a corrugated metallic tube
known, which utilize electro-magnets in connec
or pipe being slightly extensible in axial direc
tion with spark gaps, explosion spark gaps, co
tion. The tube piece with ?ange 10 serves as
herers, &c.
25 connection between the corrugated metallic tube
The purpose of all these known devices is to
provide a check of the behaviour of the overvolt
age conductor during the service and, for in
stance, to ascertain how often the excess voltage
conductor is affected during a, thunderstorm and
thus protects the plant from damage; in which
part of the overhead line the lightning conduc
tors have acted and, if possible, to measure the
approximate strength of the discharged current.
Counting of voltage surges makes considerable
demands on the counting devices, in view of the
fact that the by-passed currents have a. very
and the glass foot sealed onto it. The tank thus
formed accommodates inside a ?lament resist
ance I carried by supports 12 that are adapted
as current leads. The hollow space is ?lled with
an inert gas possessing a small speci?c heat
value. A socket [3 with connecting plug l4 holds
the whole arrangement together. 7
On the lid of the corrugated metallic tube 3
a pin I5 is provided which transfers the move
VI ment of the diaphragm via the lever l6 by means
of toothed segment I‘! and gear wheel l8 onto the
counting train I 9.
short duration, i. e. 10-8 to 10"2 sec. and have a
In axially opposite position there is a compen
sating diaphragm 20 with which the in?uences
peak value of the order of 1000 amperes.
The present invention for counting momentary
of the ambient temperature on the diaphragm
current impulses is characterized by the fact that
a fraction of the de?ected currents ?owing
through the conductance resistance is conveyed
are nulli?ed.
The action of the aforementioned device is as
follows:
If a discharge occurs in conductor 6, the de
over a resistance which is in a tank ?lled with
gas, whereby the gas expands under the in?uence 45 ?ected current produces at the voltage-depend
of the ensuing heating and actuates the counting
device through the medium of a ?exible dia
ent resistance 8 a voltage drop. This voltage
drop results in the transfer of a fraction of the
de?ected current over the ?lament resistance I,
phragm.
The fundamental principle of the inventive
idea may appear from a given form of embodi
heating it. The heat thus produced is given off
50 to the gas in the counting tank, which gas ex
ment according to the accompanying drawing, in
which
Fig. 1 showsa diagram of the arrangement.
Fig. 2 is a cross-section of the gas-?lled count
65
ing tank and
pands in consequence of its warming and drives
the diaphragm 3 forwards, so that the pin [5
presses against the lever I6 which-by means of
the toothed segment I'l—turns the gear wheel
I8 and hence the counting train l9.
2,405,121
4
moves upwards, the disk is set free and performs
an almost complete revolution, that is until an
value is an inverse function of the current pass
arresting stud 2'! engages the pin l5. By this ro
ing through. Thus, as the current due to a surge
tation the counting train has meanwhile been
rises in intensity, the drop across resistance 8
driven through one ?gure only.
may rise somewhat with the current and there
When the gas in the counting tank 2 cools off,
after remains at a predetermined maximum
the pin i5 moves downwards thereby releasing
value. Since the ?lament resistance is connected
the arresting stud 21; the disk 25 continues to r0
directly across resistance 8, it is clear that the
’tate until the'arresting stud 25 again impinges on
limit of maximum voltage drop across resistance &
serves to protect the ?lament resistance against 10 pin l5 and the original position is again restored.
The aforedescribed arrangement is adapted inv
excessive currents being forced through it. Thus,- : >
its employment for the counting and in combina
resistance 8 has a tendency to smooth or ?atten
tion witha suitable recording device for deter
the voltage rise across it as current goes up and
mining the approximate strength or“ the de?ected
preserves ?lament resistance i from destruction
Resistance 8 preferably is of the type whose
in case of intense discharge.
"
'
15
current, whereby the expansion of the diaphragm
is utilized as a base value.
The reactor 9 connected in paralle1 to the volt
It will be evident that equivalents of the parts
age-dependent resistance 8 has in turn for ‘its
of the arrangement employed to accomplish the
task to withhold from the counting tank the suc
action of my said device might readily be devised
ceeding current emanating from the line voltage,
which current flows after the proper rush dis“ 20 which, however, would not depart from the scope
of my invention.
charge. This is achieved by selecting such a
Having now particularly described and ascer
value for the inductance of the reactor 9 that its
tained the nature of my present invention and in
impedance for the rush discharge is very high.
what manner the same is to be performed, I de
A comparatively small inductance is required for
this purpose due to the steep current surge. Such 25 clare that what I claim is:
i. A device for counting momentary power
a small inductance, however, offers a low imped
ance for the succeeding current after the initial
steep wave front has passed. Such deviation of
the succeeding current is necessary because its
IZRt-Value may assume very high ?gures, and this
would lead to the destruction of the filament re
surges such as caused by lightning on a transmis
sistance.
wi . the gas oeing heated by said resistance, a
line, said .
1
ce including a main current con
ducting path, a resistance shunted across said
main current conducting path, a gas-?lled ex
oarsi‘cle cherub-er surrounding said resistance
The device may likewise be so disposed that
the pin :5 of the diaphragm directly controls a
contact
(Fig. 3) which operates a relay 22,
thus actuating the counting train ‘3-. It is further
conceivable that the counting train be driven by
a clockwork 23 (see Fig. 4) and that the axial
shifting of the pin !5 causes the clockwork to run
counting device associated with said expansible
chamber to be operated by each expansion cycle.
2. The system of claim 1 whereby said main
current conducting path comprises an inductance.
3. The system of claim 1 wherein said main
current conducting path has a resistance charac
teristic such that the voltage drop across said
down or arrests it by releasing the disk 25 for one
revolution at a time. This, for instance, is brought
about so, that the pin 55 in its rest position im
pedes the disk 25 from rotating because it is in
the path of an arresting pin 25. If the pin I5
path tends toward a maximum value irrespective
01‘ increase in current whereby said resistance
shunted across said path is protected against
excessive voltages.
PAUL FEHR.
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