Improvements in or relating to "Watt-hour" Counters for Alternating Currents of Electricity.
Year: 1895

page_text: Date of Application, 31st Jan., 1895
Complete Specification Left, 25th Sept.. 1895-Accepted, 31st Jan, 1896
PROVISIONAL SPECIFICATION.
Improvements in or relating to "Watt-hour" Counters for
Alternating Currents of Electricity.
I, GEORG HUMMEL of Bavaria-Ring 16 Munich, in the Kingdom of Bavaria,
Engineer, do hereby declare the nature of this invention to be as follows:-
It is commonly known, that Ferraris has shown, that the motor invented by him
can be used for working electrometers.
Blathy has moreover employed for the same purpose a motor in which for both
phases separate magnetic circuits are used.
a power,
purpose.
While Blathy has constructed according to his principle a useful counter it has
hitherto not yet been possible to utilise Ferraris' method for constructing a useful
electrometer. It is not difficult to find out the reasous therefor. The motor as
indicated by Ferraris has excellent properties, but it is of relatively so small
that it cannot be thought of practically employing it for the intended
The object of this invention consists in constructing a motor to be employed
as a counter and of an essentially greater power though with other theoretical
properties, which purpose cannot be attained without employing iron. By the
iron another manner of working is created and the observations of Ferraris are
no longer rigorously exact, moreover the unavoidable losses of effect as well as
the variations of the permeability of the iron exert an influence difficult to
estimate in advance.
This influence may be compared nearly with that produced by the application
of iron in Watt-meters.
In spite of these several influences the intended effect can however be produced
when besides the iron as a common magnetic conductor for the two phases, a
correspondingly long path of air is provided for the magnetic circuit.
In conformity with these principles of construction the new counting device
according to my invention may be constructed as follows;-
The inducing as well as the induced fields are of iron. Between these a circuit
or way is provided consisting in part of air and in part of copper and having a
magnetic resistance of such an importance, that in comparison therewith the
resistance of the iron disappears almost entirely.
Contrary to the principles of construction of the newest alternating current-
motors the electric-circuit of the armature consists of a copper cup having
relatively thick walls and in the in erior of which is arranged the armature iron,
the resistance of the magnetic circuit being increased correspondingly to the
thickness of the walls of the cup.
The winding of the motor arranged in grooves of the iron consists of two
parts, one of which is the conductor, through which flows the current to be
measured and is wound into the grooves according to the Gramme winding;
this winding method however would give for the induced current conductor too
much trouble on account of the great length of the thin wire required. For
this reason the wire is previously wound up in separate frames and then lodged in
the grooves.
•
The two windings are intercalated, like those of a Watt meter, into the current
to be controlled. The apparatus comprises a vertical shaft with a copper disc

page_text: thereon which is actuated by the motor and rotates between the poles of a
permanent magnet so as to consume the work of the motor.
In order to balance partially in the described motor, the weight of the revolving
parts, the iron core of the copper cup is stationary, so that owing to the electro-
magnetic attraction in using correspondingly strong fields of alternating currents
the action on the copper cup is so considerable that it is lifted so as to relieve the
pivot. This feature is of an extraordinary importance for the counter, for if the
weight of the revolving parts could entirely be compensated by the method above
indicated a sensibility and accuracy would be attained by this apparatus, equal to
those of the finest measuring-instruments. Though this purpose may scarcely be
entirely obtained by this arrangement, an accuracy will certainly be obtained, which
hitherto has been thought impossible. Hitherto it has been assumed, that the
losses occurring in the motor could be neglected. Really they play however a
rôle, which is not to be neglected at all.
If for instance in a motor-counter for one hundred lamps the losses by friction
constitute one hundredth part of the maximum work performed by the motor,
such a counter will start only at a charge of more than one lamp and it will
constantly register one lamp too low.
The losses of effect to be taken here into consideration may be divided into two
kinds-one in. direct proportion to the number of revolutions and the other to
the square of them.
Losses of effect increasing with the higher powers may be neglected.
To render the losses of the first and second power unobjectionable, two motors
are employed, each of which compensates the work produced by the corresponding
losses. The losses of the first order require a motor the tractive power of which
remains constant at several speeds. For this purpose a constant inducing-magnet
field shunted from the tension in use is preferably employed. The losses of effect
of the second order require an inducing field, which is proportional to the number
of revolutions, and for this the utilised current or a certain fraction thereof is
employed.
In constructing, these auxiliary motors commonly-known principles may be
employed. They may consist for instance of a revolving copper disc, wherein an
inducing system, say a laminated horse-shoe magnet produces currents exerting
'attractive force on an adjacent iron piece which also may be composed of horse-
shoe shaped laminæ.
Both the motors may have the same copper disc' as a common armature and they
may have in common the same magnetic circuit.
In the latter case the horse shoe magnet is simultaneously excited by the shunt
winding and by the winding of the main current. The armature disc may be
used also as a damping, disc for the permanent magnet. If it be desired to com-
pensate the losses of effect of the first order, that is to say especially the work
lost in friction the main motor may be provided with a device, by means of which
by the shunt current alone a tractive power is exerted corresponding approximately
to the "negative tractive power" of the friction. As the motor above described
is completely symmetrical, it has without the main current not the tendency to run
either in one or the other direction. But when the magnetic or electric symmetry
is disturbed, that is to say, when the magnetic lines of power produced from the
inducing system by the shunt winding do not 'extend in completely symmetrical
fashion, the motor has the tendency to start with the shunt alone in a determined
direction. The disturbance of the magnetic symmetry may be effected for instance
by arranging iron pieces between the poles close to the armature in such a manner,
that they are not exactly between two poles, but are nearer to one of them. Any
want of symmetry of the pole-pieces themselves, say a unilateral lengthening of
them, is also sufficient for producing a turning effect in a determined direction.
The same effect is produced by unsymmetrically-arranged iron masses within the
iron tube of the armature. Such arrangements may be adjustable to adapt them
to the actual resistances of friction.

page_text: A similar effect is attained, when a pole-piece is surrounded with a short-
circuited winding.
100K
BOULT & WADE,
Agents for the Applicant.
Improvements in or relating to "Watt-hour" "Counters for
Alternating Currents of Electricity.
I, GEORG HUMMEL, late of Bavariaring 16, but now of 3 Dreimühlen-strasse
Munich, in the Kingdom of Bavaria, Engineer, 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 :-
.
.
It is commonly known, that Ferraris has shown, that the motor invented by
him can be used for working electricity meters.
Blathy has moreover employed for the same purpose a motor, in which for both
phases separate magnetic circuits are used.
While Blathy has constructed according to his principle a useful. counter it has
hitherto not yet been possible to utilise Ferraris' method for constructing a
useful electricity meter. It is not difficult to find out the reasons therefor. The
motor as indicated by Ferraris has excellent properties, but it is of relatively so
small a power, that it cannot be thought of practically employing it for the
intended purpose.
The object of this invention consists in constructing a motor to be employed as
a counter and of an essentially greater power though with other theoretical
properties, which purpose cannot be attained without employing iron. By the
iron another manner of working is created and the observations of Ferraris are
no longer rigorously exact, moreover the unavoidable losses of effect as well as the
variations of the permeability of the iron exert an influence difficult' to estimate
in advance.
This influence may be compared nearly with that produced by the application of
iron in Watt-meters.
,
In spite of these several influences the intended effect can' however be produced;
when besides the iron as a common magnetic conductor for the two phases, a
correspondingly long path of air is provided for the magnetic circuit.
In conformity with these principles of construction the new counting device
according to my invention may be constructed as represented diagrammatically in
vertical central section and plan in Figures 1 and 2 respectively as follows :—
The inducing as well as the induced fields E.E' are of iron. Between these a
circuit or way is provided. consisting in part of air and in part of copper and
having a magnetic resistance of such an importance, that in comparison therewith:
the resistance of the irou disappears almost entirely.
Contrary to the principles of construction of the newest alternating current-
motors the electric circuit of the armature consists of a copper cup having
relatively thick walls and in the interior of which is arranged the armature iron E,
the resistance of the magnetic circuit being increased correspondingly to the
thickness of the walls of the cup.
The winding of the motor which is placed in the grooves of the fixed iron
consists of two parts, one part is the conductor H, through which flows the
current to be measured and which is wound in grooves after the fashion of
Gramme's winding, the other part is the conductor n which is in shunt circuit;
for this one the above mentioned method of winding would give too much trouble
on account of the great length of the thin wire. Therefore the wire is first
wound in a special frame and then placed in the grooves.

page_text: The two windings are intercalated, like those of a Watt-meter, into the current
to be controlled. The apparatus comprises a vertical revolving shaft a and a
copper disc K thereon which is actuated by the motor and rotates between the
poles of a permanent magnet M so as to consume the work of the motor.
Figure 3 is a diagramatic section at right angles to the plane of Fig. 1.
In order to balance partially in the described motor, the weight of the revolving
parts, the iron core E' is stationary, so that owing to the electro-magnetic buoyancy
in using correspondingly strong fields of alternating currents the action on the
copper cup is so considerable that it is lifted so as to relieve the pivot. This
feature is of an extraordinary importance for the counter, for if the weight of
the revolving parts could entirely be compensated by the method above indicated,
a sensibility and accuracy would be attained by this apparatus, equal to those of
the finest measuring-instruments. Though this purpose may scarcely be entirely
obtained by this arrangement, an accuracy will certainly be obtained, which
hitherto has been thought impossible. Hitherto it has been assumed, that the
losses occurring in the motor could be neglected. Really they play however a
rôle which is not to be neglected at all.
If for instance in a motor-counter for 100 lamps the losses by friction
constitute 1/100th part of the maximum work performed by the motor, such a
counter will start only at a charge of more than one lamp and it will constantly
register one lamp too low.
66
If it be desired to compensate the losses of effect especially the work lost in
friction the main motor may be provided with a device, by means of which by the
shunt current alone a tractive power is exerted corresponding approximately to the
negative tractive power" of the friction. As the motor above described is
completely symmetrical, it has without the main current not the tendency to run
either in one or the other direction. But when the magnetic or electric symmetry
is disturbed, that is to say, when the magnetic lines of power produced from the
inducing system by the shunt winding do not extend in completely symmetrical
fashion, the motor has the tendency to start with the shunt alone in a determined
direction. The disturbance of the magnetic symmetry may be effected for instance
by arranging iron pieces as G 1 Fig. 4 between the poles close to the armature in
such a manner, that they are not exactly between two poles, but are nearer to one
of them. Any want of symmetry of the pole-pieces themselves, say a unilateral
lengthening of them as E 2, is also sufficient for producing a turning effect in a
determined direction. The same effect is produced by unsymmetrically-arranged
iron masses within the iron tube of the armature. Such arrangements may be
adjustable to adapt them to the actual resistances of friction.
A similar effect is realised when one pole of the magnet is surrounded on one
side with a short-circuited winding such as n 1; the latter surrounds the pole as
can be seen in the drawing Fig. 4, only partially and is placed with one side in a
groove of the pole-piece.
Having now particularly described and ascertained the nature of the said
invention and in what manner the same is to be performed, I declare that what I
claim is :-
די
:―
1. A Watt-hour-counter for alternating current having one phase formed by the
main current and the other by the shunt current branched off from the used
tension and characterised by the application of iron as a common magnetic
conductor for the two phases in the induced system as well as in the inducing
One in combination with a sufficiently long path of air for the magnetic circuit.
2. A form of constructing the counter characterised in Claim 1 in which the
main winding is arranged as a Gramme winding and the shunt winding on a frame n
placed into grooves of the inducing system.
3. In the counter characterised in Claim 1 a metal cup G and an iron tube E¹
concentric thereto as armature.
4. In the counter characterised in Claim 1 the arrangement of a stationary iron.

page_text: armature E' for the purpose of compensating for the most part by the electro-
magnetic attraction the weight of the metal
cup.
5. In the counting motor characterised in Claim 1 the arrangement of the
inducing system in such a manner that the electric or magnetic symmetry of the
same is disturbed in such a manner that by the shunt winding alone a tractive.
power compensating the friction is given to the motor.
Dated this 25th day of September 1895.
BOULT & WADE,
Agents for the Applicant.