An Electric Meter.
Year: 1889

page_text: Date of Application, 11th July, 1889
Complete Specification Left, 10th Apr., 1890-Accepted, 10th May, 1890
PROVISIONAL SPECIFICATION.
[Communicated from abroad by the firmn of SIEMENS AND HALSKE, of Markgrafen-
strasse, Berlin, in the German Empire, Electrical Engineers.]
An Electric Meter.
We, SIEMENS BROTHERS AND COMPANY Limited of 12 Queen Annes Gate West-
minster in the County of Middlesex, Electrical Engineers do hereby declare the
nature of this invention to be as follows:-
This invention relates to an electric meter, wherein a counter registers the number
of oscillations of a bar of soft iron subject to the influence of the electrical current
to be measured or of a known fraction thereof.
The bar is pivotted on a vertical axis so that it can oscillate in a horizontal plane.
It is surrounded by two coils, the one coiled transversely to the bar to magnetise it,
and the other coiled longitudinally to cause deflection of the magnetised bar. From
the axis of the bar an arm projects which, as the bar oscillates, operates as a commu-
tator switch making contacts alternately on opposite sides of it, whereby the current
in the longitudinal coil has its direction reversed, and thus the bar being deflected
first to the one side and then to the other, makes in a given time a number of oscilla-
tions proportional to the number of ampères in the exciting current. The oscillating
arm may act directly as an anchor causing rotation of the first wheel of a counter
which by suitable dials and indices, records the number of oscillations of the bar.
It is preferred, however, to work the anchor by a polarised relay arranged with suitable
contacts alternating its action in conformity with that of the deflecting coil. In
order that the current in the magnetising coil may be be constant whilst that in the
deflecting coil is reversed, the one end of the deflecting coil is connected to the
middle of the magnetising coil, its other end being connected to the reversing switch.
The meter is adapted to alternating as well as to continuous currents, because the
alternation, which tells on the one coil, alternating the polarity of the bar, tells also
on the other coil alternating its deflecting influence on the bar.
• T1
1000
ABEL & IMRAY,
Agents for the Applicants.
COMPLETE SPECIFICATION.
An Electrio Meter.
We, SIEMENS BROTHERS AND COMPANY Limited, of 12 Queen Annes Gate, West-
minster, in the County of Middlesex, Electrical Engineers, do hereby declare the
nature of this invention and in what manner the same is to be performed to be
particularly described and ascertained in and by the following statement:
--
The electrical meter which forms the subject of this invention is based on the
following principle of action. If a soft iron bar moveable in a horizontal plane, be
surrounded by two coils, of which the one has a magnetising and the other a deflecting
action on the bar, and if both coils be traversed by the current to be measured, or by
fractions thereof, while by means of a contact apparatus a commutation of the
direction of current be effected in one of the two coils, the iron bar will have a
regular oscillating motion imparted to it, as soon as the current flows through the
coils.
The motive force acting on the bar producing such motion will be proportional to
the product of the magnetism of the bar into the current flowing through the deflecting
coil; if therefore the proportions be so. taken that the magnetism of the bar is
proportional to the current flowing through the iuagnetising coil, the motive force

page_text: will be proportional to the square of the main current, as both the magnetising and
the deflecting current are proportional to the main current.
As the number of oscillations in a unit of time is proportional to the square root of
the motive force, in the case in question this number of oscillations of the iron bar
will be proportional to the current to be registered. If therefore the number of
oscillations produced be registered on a counter the latter will indicate directly the
number of Ampère hours consumed in the main circuit.
On the accompanying drawing Figure 1 shews by way of example a vertical
section and Figure 2 a sectional plan of one arrangement of apparatus for carrying
out the above described mode of action, which may however be carried out in a great
variety of ways.
In the drawing the coils are shewn in their simplest form, that is, as two frames
on which the coils are wound, and which are at right angles to each other so that the
convolutions of the deflecting coil A are laid parallel to the iron bar S while those
of the magnetising coil M are at right angles to the bar S.
These coils may however, as already stated, assume other forms.
The circuit connections of the apparatus may for example, be as shewn at the
diagram Figure 5, where the main current or a fraction thereof is passed through
the magnetising coil M while the deflecting coil A is connected at one end to the
moveable lever P of a contact apparatus C, and at the other end to the middle of the
magnetising coil M, the two contacts of the apparatus C being respectively connected.
to the plus and the minus terminals of the coil M. With this arrangement the
direction of current in the magnetising coil always remains the same, while, according
to the position of the contact lever P the direction of current in the deflecting coil A
is alternately reversed.
If a polarised relay RR be introduced either parallel to or in series with the deflecting
coil A the moveable contact lever thereof will vibrate in accord with the lever P.
This motion can consequently be utilised for imparting motion in any suitable
manner to a counter Z.
In the apparatus shewn at Figures 1 and 2, the connections of which are shewn
in the diagram at Figure 3, S indicates the iron bar, M the magnetising coil, O the
middle thereof, A the deflecting coil, R R the polarised relay, C the tongue of the
relay, the extension of which to the left hand forms the lever P while that to the right
hand forms a spring F insulated from P; G a fork fixed to the bar S, c¹ c' the
contacts for passing the current through the deflecting coil, c³ ³ and c³ ³ contacts
for passing the current through the polarised relay, LL² the two main conductors
of a two lead circuit, Z the counter.
The contacts c c are connected to the ends of the magnetising coil M, the
contacts are connected to the two main conductors, while the contacts c³ ³ form
the electrical connection of the fork G with the contact spring F.
The polarised relay has, as is well known, the property that its tongue is always in
contact with the one or the other of its stops, excepting the short duration of the
transit, so that one of the contacts c' must be closed; a current consequently always
passes from one of the two ends of the magnetising coil M through one of the
contacts to the tongue C and through its pivot as also through the deflecting coil to
to the middle O of the magnetising coil; when the tongue moves over to the other
contact the current in the coil A changes its direction.
...
The moving over of the tongue is effected by the polarised relay R. The two bobbins
thereof are permanently interposed between the two main conductors L' L³, but so
that the action thereof on the tongue is neutralised.
The contacts c² are also connected to the two main conductors, and the contact
spring F fixed to but, insulated from the relay tongue must always lie against the one
or other contact c², excepting the short duration of the transit.
If now the fork G.connected to the wire between the two relay bobbins lies against
one of the contacts c³, one of the two relay bobbins is short circuited, so that the
other one alone acts upon the relay tongue and causes this to move over to the
other side.

page_text: The momentary currents passing through the relay only depend upon the potential
difference existing between the two main conductors, and not upon the current to be
registered, passing through one of them, for instance L'; they are without influence
on the motion of the iron bar, as these momentary currents passing through the relay
only have to effect the reversal of tho contact lever.
If the second main conductor L is not to be used for working the apparatus, the
polarised relay can be actuated by the same currents as those which pass through the
deflecting coil; the relay will then best be connected in parallel with the deflecting
coil, as shewn at Figure 4, and the contact spring F be in conducting connection with
the lever P.
The reversal of the lever P can also be effected mechanically by the motion of the
fork G on the bar S; in that case the contacts c³ and the relay bobbins are dispensed
with, so that of the relay there only remains the magnet system that is, the two iron
pole pieces that lie against, the one pole of the said magnet, and a moveable iron
tongue that lies against the other pole; as soon as the tongue moves nearer the one
pole piece than the other, it will be attracted by the magnetic action, and will be
held thereby.
This magnetic system may also be replaced by a mechanical catch device.
In order to prevent sparking at the contacts it is preferred to interpose between the
breaks non-inductive resistances.
The above described electric counter can be used both for continuous and for
alternating currents, as with the latter there will also be a motion in one direction of
the iron bar so long as the direction of current changes simultaneously in the mag-
netising and in the deflecting coils; if at the reversal of the contact lever the connection
of the deflecting coil be so changed that the direction of the current in the same in
under equal circumstances, the reverse of that which existed before the reversal, the
movement will be effected in the contrary direction.
The law which expresses the dependence of the duration of oscillation upon the
strength of current will also remain the same with alternating currents.
Having now particularly described and ascertained the nature of this inven-
tion and in what manner the same is to be performed, we declare that what we
claim is :-
1. An electric meter consisting of a soft iron bar capable of oscillating on a central
axis, and situated within two coils through which the current to be measured, or a
fraction thereof, is made to flow, the one such coil having a magnetising action on the
iron bar, while the other has a deflecting action thereon, and has the direction of its
current alternately reversed so that an oscillating motion is imparted to the iron bar
which is communicated to a counter or registering mechanism, substantially as herein
described.
2. In an electric meter such as is referred to in the preceding claim arranging the
magnetizing coil in the main circuit of the current to be measured, while the deflecting
coil has its one end connected to the middle of the magnetising coil and its other end
to the moveable lever of a contact apparatus, the two contacts of such apparatus being
connected to the two ends of the magnetising coil, whereby the direction of current
will be maintained constant in the latter, while that of the deflecting coil will be
alternately reversed, substantially as described.
3. In an electric meter such as is referred to in the first claim, the arrangement of
a polarised relay, or equivalent apparatus, in series with or parallel to the deflecting
coil, or between the two main conductors and connecting the contact lever carrying a
fork that actuates the counter mechanically with the tongue of the relay, motion
being imparted electrically to these parts by a fork carried by the iron bar, the
oscillating motion of which effects alternating contacts, substantially as herein described.
Dated this 10th day of April 1890.
ABEL & IMRAY,
Agents for the Applicants.