Improvements in or relating to Means for Producing Differences of Phase in Alternating Current Apparatus, specially applicable to Meters, Motors, and the like.
Year: 1896

page_text: Date of Application, 8th Jan., 1836
Complete Specification Left, 4th July, 1896-Accepted, 15th Aug., 1896
PROVISIONAL SPECIFICATION.
Improvements in or relating to Means for Producing Differences of
Phase in Alternating Current Apparatus, specially applicable
to Meters, Motors, and the like.
I, GEORG HUMMEL, of 3, Dreimühlenstrasse, München, Germany, Engineer,
do hereby declare the nature of this invention to be as follows:-
This invention relates, inter alia, to alternating current meters constructed on the
well known principle of Ferrari. The present improvements have for their chief
object to render the apparatus available for use also when it is desired to measure
the energy of the current in electrical circuits having a high self-induction.
As is well known the meters as heretofore constructed on the aforesaid principle
could not be employed for such measurements because such meters do not correctly
take into account the difference of phase.
The reason for this is that the difference of phase, which should be 90° in the
constant shunt circuit, is not produced, and cannot be produced by the means
heretofore employed. A difference of phase of 90° would be possible in an electric
circuit only when the whole of the losses in that circuit were nil.
As is well known the angle of the difference of phase is represented by the
equation cos = ; in which the watts measured by the watt-meter,
W
EJ
and EJ the apparent watts of the said circuit.
If the meter is to be used only in circuits having resistances without induction,
then the meter may certainly be empirically gauged even though there be a smaller
difference of phase in the shunt-circuit; but as soon as there is a difference of
phase in the main circuit, the meter will generally indicate too little it may even
remain stationary when the difference of phase in the main circuit is equal to that
in the shunt circuit, or it may even run backwards when the difference of phase in
the main circuit is greater than that in the shunt circuit.
Herr Raabe was probably the first (German Patent No. 9462) to publish a
method of obviating this disadvantage. But this method, although correct in itself,
is difficult to carry into practice, because the necessary second or additional motor,
renders the meter expensive and complicated. My invention has for object to solve
this problem, which plays such an important part in the meters as heretofore
constructed, and for this purpose it consists in producing the difference of phase
of 90° in the magnetic circuit, instead of as heretofore in the electrical circuit,
and do this by influencing the said magnetic circuit by means of two or more
electric circuits instead of merely energizing it by a single coil as heretofore.
1 shall now proceed to describe by means of the accompanying drawings, a few
examples of how I may carry my invention into practice.
In the diagrams of phases, the radii marked Mh and Mn represent the magnetiza-
tion resulting from the main and shunt circuits respectively; and 1, "
represent the angles of the respective differences of phase. The coils N' N"
Hi H
shown diagrammatically in Figs. 3 to 7, produce the magnetizations
of the field-magnets, these magnetizations being indicated by Mn Mn"
Mh Mh:
(1) Fig. 3 shows the combination of the main-current coil H with two shunts, of
which one N¹ is inductive, and the other N" is without induction. The magnetiza-
tions Mn' and Mn" (Fig. 3^), with the phase angles o' and 180° produced by the

page_text: two shunt coils, give a resultant magnetization Mn which has its phase shifted
by 90° with relation to that of the main current Mh.
(2) The employment of a second separate shunt has however the disadvantage
that the coustant loss of current in the meter increases. It is therefore advisable,
instead of using the separate shunt to produce (see Figs. 4 and 44) by the throttling
coil N by means of some secondary convolutions, the current potential or strength
that is required by the second shunt-winding N
(3) It is not necessary that the shunt circuit. Nu should be without induction.
It may even, as shown in Figs. 5 and 5, receive a difference of phase of
180°x".
(4) Also, as indicated by Fig. 6, a difference of phase of 90° between Mu
and Mh may be produced by a division of the main current. But in this case the
oppositely connected convolutious H" must have included in front of them an
inductive resistance W which serves to shift the phase of this current circuit
through an angle of 90°. Then Mh' and Mh produce the magnetization Mh
which encloses with Mn an angle of 90°.
Fig. 7 shows a further possible means of producing a difference of phase of 90°.
A part T of the circuit with an inductive resistance W is branched off from the
main circuit H. According to the choice of this resistance, there is produced in
the coils a difference of phase for Mh which amounts to 90° with relatio
to Mu. The same method is of course also applicable to the shunt.
In addition to this difference of phase of 90° of the one current circuit relative to
that of the other current circuit which is produced by one of the means hereinbefore
described, the peculiar arrangement of the shunt magnet field in the motor or
moving part of the meter has for result that the said shunt magnet field itself
constitutes a resistance with the highest possible self induction, so that it becomes
unnecessary to insert a special inductive resistance.
Figs. 1 and 2 illustrate an alternating current meter constructed according to
this invention. H is the main winding of the meter through which the consumer's
current passes. This winding lies in holes or slots either in a stationary iron
armature E or in the iron body E', or, as shown in the figure, in both, and
energises the magnetic field indicated by mom, m. The lines of force traverse the
metallic bell-shaped body G which is capable of rotating freely and concentrically
about the stationary iron armature E by means of the two journals Z, and Z
One, namely N1, of the two shunt windings surrounds the iron body E as a core,
and also constitutes, together with the latter, the inductive resistance of the highest
possible self induction. The lines of force thereby produced energise the magnetic
field mm. Nis the second shunt winding with included inductionless resistance W,
in accordance with the arrangement for producing a difference of phase of 900
herein before described with reference to Figs. 3 and 34. E³ is an iron piece which
serves as a yoke or closing piece for a portion of the lines of force in the iron
piece E for the purpose of enabling the self induction and with it, the strength of
the shunt current in N', to be varied as desired within certain limits, by bringing
it to a suitable distance from the iron piece E. By means of this adjustment, and
also by the equalization of the inductionless resistance W, it is possible to produce
the desired difference of phase of 90° between the magnetic circuits, and, further,
to impart to the rotating part, which effects the registration of the consumption of
energy by means of a counting-mechanism, the speed that, given gearing of a certain
ratio, is required for the constant 1 of the meter. The yoke E may, however, be
dispensed with if the two limbs of the magnet be arranged so as to be capable of
adjustment relatively to each other, and, for instance, the distances of the poles be
varied.
The energy of the motor may be consumed in any desired manner, for instance
by means of vane or paddle wheels or by means of a "damping" or deadening
disc rotating between permanent magnets. For this purpose there may, however,
be employed the "damping" effect experienced by the metallic bell in rotating
within a powerful shunt-field my m₁ my.

page_text: In addition to the employment of this invention in meters on the Ferrari or
Blatby principle, it may also be employed with advantage generally in all cases
where it is desired to produce two current cirits with any desiret differences of
phase for example, in phase-indicators, and in all instruments in which a determined
magnetic difference of phase is to be produced.
Dated this 8th day of January 1896.
Improvements in or relating to Means for Producing Differences of
Phase in Alternating Current Apparatus, specially applicable to
Meters, Motors, and the like.
1, GEORG HUMMEL, of 3, Dreimühlenstrasse, München, Germany, 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:
This invention relates, inter alia, to alternating current meters constructed on
the well known principle of Ferrari. The present improvements have for their
chief object to render such apparatus available for use also when it is desired to
measure the energy of the current in electrical circuits having a high self-
induction.
As is well known the meters, as heretofore constructed on the aforesaid principle,
could not be employed for such measurements because such meters do not correctly
take into account the difference of phase.
The reason for this is that the difference of phase, which should be 90° in the
constant shunt circuit, is not produced, and cannot he produced by the means
heretofore employed. A difference of phase of 90° would be possible in an
electric circuit only when the whole of the losses in that circuit were nil.
As is well known the angle of the difference of phase is represented by the
equation cos += in which w the watts measured by the watt-meter,
=
10
EJ;
and EJ the apparent watts of the said circuit.
If the meter is to be used only in circuits having resistances without induction,
then the meter may certainly be empirically gauged even though there be a smaller
difference of phase in the shunt-circuit; but as soon as there is a difference of
phase in the main circuit, the meter will generally indicate too little; it may even
remain stationary when the difference of phase in the main circuit is equal to that
in the shunt-circuit, or it may even run backwards when the difference of phase in
the main circuit is greater than that in the shunt circuit.
Herr Raab was probably the first (German Patent No. 9462) to publish a method
of obviating this disadvantage. But his method, although correct in itself, is
diflicult to carry into practice, because the necessary second or additional motor,
renders the counter expensive and complicated. My invention has for object to
solve this problem, which plays such an important part in the meters as heretofore
constructed by producing the difference of phase of 90° in the magnetic circuit,
instead of as heretofore in the electrical circuit, and I do this by influencing the
said magnetic circuit by means of two electric circuits or coils instead of merely
energizing it by a single circuit or coil as heretofore.
I shall now proceed to describe by means of the drawings, filed with my

page_text: Provisional Specification, a few examples of how I may carry my invention into
practice.
In the diagrams of phases, the radii marked Mh and Mn represent the magneti-
zation resulting from the main and shunt circuits respectively; and '¹
represent the angles of the respective differences of phase. The coils N N
HH" shown diagrammatically in Figs. 3 to 7, produce the magnetizations
of the field-magnets, these magnetizations being indicated by Mn Mn"...
Mh' Mh".
(1) Fig. 3 shows the combination of the main-current cail H with two shunts,
of which one N is inductive, and the other N is without induction. The
magnetizations Mn' and Mn (Fig. 3A), with the phase angles o¹ and 180°, produced
by the two shunt coils, give a resultant magnetization Mn which has its phase
shifted by 90° with relation to that of the main current Mh.
(2) The employment of a second separate shunt has however the disadvantage
that the continual loss of current in the meter increases. Instead of using the
separate shunt it is advisable to produce by the throttling coil, by means of some
secondary convolutions, the current potential or strength that is required by the
second shunt-winding N" (see Figs. 4 and 4^).
(3) It is not necessary that the shunt circuit N should be without induction.
It may even, as shown in Figs. 5 and 5ª, receive a difference of phase of 180° + "
in which case we get the diagram shown by Fig. 5ª.
(4) Also, as indicated by Fig. 6, a difference of phase of 90° between Mu
and Mh may be produced by a division of the main current. But in this case the
oppositely connected convolutions H" must have included in front of them an
inductive resistance W, which serves to shift the phase of this current circuit
through an angle of 90°. Then Mh and Mh" produce the magnetization Mh
which encloses with Mn an angle of 90°.
(5) Fig. 7 shows a further possible means, of producing a difference of phase
of 90°. A part T of the circuit with an inductive resistance W is branched off
from the main circuit H. According to the choice of this resistance, there is
produced in the coils a difference of phase " for Mh, which amounts to 90°
with relation to Mn. The same method is of course also applicable to the shunt.
In addition to this difference of phase of 90° of the one current circuit relatively
to that of the other current-circuit, which is produced by one of the means herein-
before described, the peculiar arrangement of the shunt magnet field in the motor
or moving part of the meter has for result that the said shunt maquet field itself
constitutes a resistance with the highest possible self-induction, so that it becomes
unnecessary to insert a special inductive resistance.
Figs. 1 and 2 illustrate an alternating current meter constructed according to
this invention. H is the main winding of the meter through which the consumer's
current passes. This winding lies in holes or slots either in a stationary iron
armature El or in the iron body E³, or, as shown in the figure, in both, and excites
the magnetic field indicated by momo mo. The lines of force traverse a metallic
bell-shaped body G which is capable of rotating freely and concentrically about
the stationary iron armature E' by means of the two journals Z, and Z. One,
namely N', of the two shunt-windings surrounds the iron body E as a core, and
also constitutes, together with the latter, an inductive resistance of the highest
possible self-induction. The lines of force thereby produced excite the magnetic
field mm. Nis the second shunt-winding with included inductionless resistance W
in accordance with the arrangement for producing a difference of pha-e of 90°
hereinbefore described with reference to Figs. 3 and 34. L3 is an iron piece
which serves as a yoke or closing piece for a portion of the lines of force passing
from the iron piece E, for the purpose of enabling the self-induction and with it,
the strength of the shunt current in N', to be varied as desired within certain
limits, by bringing it to a suitable distance from the iron-pice E. By means of
this adjustment, and also by the compensation of the inductionless resistance W,
it is possible to produce the desired difierence of phase of 90° between the magnetic

page_text: circuits, and, further, to impart to the rotating part, which effects the registration
of the consumption of energy by means of a counting-mechanism, the speed that
given gearing of a certain ratio, is required for the constant 1 of the meter. The
yoke E may, however, be dispensed with if the two limbs of the magnet be
arranged so as to be capable of adjustinent relatively to each other, as, for instance,
by varying the distances of its poles from one another.
The energy of the motor portion of the meter may be consumed in any desired
manner, as for instance by means of vanes or a paddle wheel or by means of a
"damping or deadening disc rotating between permanent magnets. For this
purpose there may, however be employed the damping" effect experienced by
the metallic bell in rotating within a powerful shunt-field m' in' m'.
6.
In addition to the employment of this invention in meters on the Ferrari or
Blathy principle, it may also be employed with advantage generally in all cases
where it is desired to produce two current circuits with any desired differences of
phase-for example, in phase-indicators, and in all instruments in which a deter-
mined magnetic difference of phase is to be produced.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed I declare that what I
claim is :-
1. In motors, meters, and other alternating-current apparatus, whether con-
structed on the Ferrari or Blathy principle or otherwise, producing a difference
of phase of approximately 90° between two magnetic circuits by causing the
magnetization if one or both of them to be influenced by means of two or more
electric current circuits having different phases, substantially as hereinbefore
described.
2. A motor so constructed and arranged that the magnetic field excited by a
constant shunt-current is formed by a horse-shoe-shaped iron magnet, whilst the
winding for the variable main current is passed through slots or holes in the said
iron magnet or in a stationary iron core, or through holes in both, substantially
as hereinbefore described.
3. Regulating the speed of a motor of the kind specified in the second claim,
by varying the magnetic resistance of the shunt-field, whether this be effected by
means of an adjustable magnetic yoke, by varying the distance between the poles
of the magnet, or otherwise, substantially as herein before described.
4. The improved alternating-current meter constructed, arranged, and operating
as hereinbefore described with reference to and represented diagrammatically in
Figs. 1 and 2 of the drawings herein referred to.
5. My improved means for producing differences of phase in alternating-current
apparatus, herein before described with reference respectively to and shown
diagrammatically in Figs. 3 and 34, in Figs. 4 and 44, in Figs. 5 and 5ª, in Figs. 6
and 6 and in Figs. 7 and 7 of the drawings herein referred to.
Uated the 4th day of In. 1906
Dated this 4th day of Inly 1906.
For the Applicant,
W. LLOYD WISE,
46 Lincoln's Inn Fields, London, W.C., Chartered Patent Agent.