Improved Apparatus for Converting Electrical Currents.
Year: 1888

page_text: Date of Application, 5th Sept., 1888
Complete Specification Left, 23rd Apr., 1889-Accepted, 31st Aug., 1889
.
Improved Apparatus for Converting Electrical Currents.
We, CARL ZIPERNOWSKY, and MAX DÉRI, both of Buda Pesth, Hungary, Engineers,
do hereby declare the nature of this invention to be as follows:-
This Invention relates to improved apparatus for converting alternating currents
into currents of the same direction, such currents not being intermittent as in all
apparatus heretofore employed for this purpose, but continuous currents such as are
produced in continuous current dynamo machines with Gramme or Pacinotti
commutators.
The same apparatus also serves to convert continuous currents such as are pro-
duced by a dynamo machine with Gramme or Pacinotti commutator; into alternating
currents.
4
For explaining the principle upon which this apparatus acts, let Fig. 1 of the
accompaning drawings represent a continuous current dynamo machine consisting of
a stationary gramme ring R with stationary commutator C and a
rotating electro
magnet A, excited in any suitable manner, or it may be a permanent steel magnet,
with brushes y fixed on the magnet. These brushes are combined with two contact
rings m n which are fixed on the shaft of the machine and have two contact
springs bearing against them. On the rotation of the electro magnet, currents
are generated in the coils of the ring, which pass as currents of the same direction
into a conductor connecting the springs p and q
The magnetic axis of the field induced by the magnet in the ring being turned
through 360° in every revolution, the number of the magnetic lines of force passing
through the separate coils of the ring twice attains its maximum and twice its
minimum.
It is this change in the number of lines of force which generates the current as
electro magnet force.
Obviously this current in the same direction can also be obtained by effecting the
rotation of the magnetic axis in any other manner. If the energy of alternating
currents is employed for causing the magnetic axis to revolve, a continuous current
in the same direction can be produced by such an apparatus, thus converting the
alternating currents into continuous currents.
To effect this, an iron ring (which in order to avoid Foucault currents must be
divided) is provided as shewn in Fig. 2 with two pairs of coils W₁ and W₂, and into
each pair are conducted alternating currents in such manner that the one set of
alternating currents is th of a wave length in advance of the other. Thus two
magnetic fields N S and N¹ S' are produced situated at right angles to each other,
their intensity depending on that of the exciting currents.
If it be assumed that the currents alter in accordance with the law of sines, it can
be shewn that the intensity of the resulting magnetism remains constant; the result-
ing magnetic axis being turned through 360° once for every complete current wave
as indicated in Fig. 3.
Thus at the time I the current in W₁ is at zero, while that in W, is at maximum,
the resulting magnetic axis is therefore NS; at the time II the current in W₁ is
at maximum whilst that in W, is at zero, the resultant will therefore have turned
through 90° for instance to the right; in III the current in W, is again at zero and
that in W, again at maximum, but it has the contrary direction to that in I, con-
sequently the resulting magnetic axis will have turned through an angle of 180°; in
IV W, is at the reverse maximum to that in II and W, is at zero, which corresponds
to an angle of 270° relatively to the position I, while at V the conditions as in I
recur.

page_text: During the passage of one current wave therefore, the axis of the resulting
magnetic field performs a complete revolution, the same as that of the magnet in
Fig. 1.
If therefore the ring be provided with a continuous third coil similar to that of
the gramme ring, there will be produced in this continuously induction currents
which, similarly to the ring dynamo machine in Fig. 1, can be taken off as currents
of the same direction by means of a commutator and rotating brushes. These
brushes must be in the neutral plane, and must consequently rotate synchronously
with the magnetic axis.
Fig. 4 shews an apparatus constructed according to the above described method.
R is the divided iron ring, provided with two pairs of bobbins into which the
alternating currents are introduced through the contacts a band c d, those of the
one pair being th of a wave length in advance of those of the other.
In addition to these two pairs of bobbins, the ring carries the third induced
coil, the separate sections of which are connected to the sectors of the fixed com-
mutator in the same manner as the divisions of a Grammne ring are connected to the
corresponding commutator sectors. Within the ring is a piece of iron A mounted to
revolve upon the shaft which serves to close the passage of the lines of force passing
out of the ring and to which also the commutator brushes y are fixed. This
piece of iron always tends to remain in the direction of the magnetic axis and there-
fore revolves synchronously with it.
The brushes therefore when once situated in the neutral plane remain in it.
A mechanism can however be provided for enabling the brushes to be adjusted
during the rotation. The brushes are furthermore connected to two contact
rings m n, from which the current is taken off by the contact springs p q.
In order to effect the ready starting of the machine, the revolving iron armature is
provided with a coil returning into itself, in which, at starting induction currents are
first produced which magnetise the closing armature and increase the tangential force
between the armature and the ring. These induction currents disappear entirely
when the synchronism has been obtained.
This coil can also be arranged as a shunt to the continuous current coil, and the
iron piece can also have in addition to a coil returning into itself a shunt coil or
a coil introduced into the secondary main circuit in order to produce the synchronous
rotation with greater certainty.
Fig. 5 shows a construction of this apparatus which is based upon the same principle
as the above described one, but which differs from this in that the alternate current
coils are situated upon a divided iron drum T arranged stationary within a continuous
current ring R. In addition to these two parts there is an armature to which
are rigidly connected a pair of brushes y which rub on the fixed commutator ()
synchronously with the displacement of the resulting magnetic axis. Contact
rings m n with springs p q serve for leading off the continuous current.
By reversing the construction shown at Fig. 4 an apparatus is obtained as shown
at Fig. 6.
In this case the ring R revolves with its alternate current and continuous
current coils and with the commutator C.
The brushes y as also the armature A which has both a coil returning into
itself and a shunt coil, are stationary.
With this construction the contact rings for taking off the continuous current are
dispensed with, but on the other hand there are provided four or at least three con-
tact rings for introducing the two alternating currents (namely two supply rings and
a common return ring) together with contact springs a b c therefor.
The adjustment of the stationary brushes x y is easier and more simple than in the
rotating arrangement at Figs. 4 and 5.
The above described construction may be variously modified.
For example, in
Fig. 4 the revolving armature A can be arranged externally to the ring R or at
either side or both sides of it.
In Fig. 6 the fixed armaturé. A may also be arranged within the ring R or at the

page_text: side, or on both sides of it. Also, the alternate current and continuous current coils
may be arranged on two separate masses of iron which are connected rigidly together
and which may have a common armature or two separate armatures.
In the arrangement shown in Figs. 4 and 6 the ring can be replaced by a drum
with two alternate current coils and a continuous current coil similar to the coil of a
continuous current dynamo machine drum. In this case the closing armature will
surround the drum.
In Fig. 5 also, the lower drum can have the continuous current coil, and the com-
mutator and outer ring the alternating current coils.
In all cases it is advisable to form the rings and drums with indentations at the
parts where they are presented to each other or to the closing armature, and to lay
the wires or bands in the spaces in order that the air passages for the lines of force
may be shortened as much as possible.
Assuming that the alternating currents have 80 changes of pole in a second, these
correspond to 40 current waves per second, and 2400 waves and consequently as
many revolutions of the apparatus per minute.
In order to reduce this somewhat large number of revolutions, it is advisable to
employ in place of only two pairs of alternating current bobbins, 4, 6, 8, or other
even number of such bobbins so arranged as to form a multiple polar ring or drum.
A corresponding number of brushes must in that case be used, or the correspondingly
placed commutator sectors must be connected together in the known manner for
working with only two brushes. The closing armature as in Figs. 4 and 6, must
then be multipolar, that is to say it must be of star shape in order to close the
passages of the lines of force as much as possible.
In Fig. 5 this is not necessary, as the closing is effected either by the ring or the
drum, and the armature only forms a shunt closure for the lines of force.
The number of alternating current coils and continuous current coils has to be-
calculated according to the desired proportion of transmission between the average
tension of the alternating current and that of the continuous current.
These tensions can be equal to one another, or an alternating current of high or
low tension can, without the aid of another apparatus, be converted into a continuous
current of low or high tension.
These apparatus may also be used for converting continuous currents into alter-
nating currents. For this purpose the greater part of the available continuous current
is passed, in the constructions shown in Figs. 4 and 5, over the springs p q through
the contact rings m n and through the brushes a y, and, in the construction shown
at Fig. 6, it is passed directly through the brushes ay into the commutator and so
into the continuous current coil; a small portion of the current is used by the aid of
the contact rings in Figs. 4 and 5 and without these directly in Fig. 6, for
magnetising the closing armature.
The apparatus being thus caused to rotate as an ordinary continuous current
machine there will be produced in the alternating current coils two alternating
currents, one th of a wave length in advance of the other, which are taken off by
means of fixed contacts in Figs. 4 and 5, and in Fig. 6 by means of 4 or 3 contact
rings and springs, to be employed as may be desired.
Dated this 5th day of September 1888
ABEL & IMRAY,
Agents for the Applicants.
COMPLETE SPECIFICATION.
Improved Apparatus for Converting Electrical Currents.
We, CARL ZIPERNOWSKY and MAX DERI, both of Buda Pesth, Hungary,
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:-
This invention relates to improved apparatus for converting alternating currents

page_text: into continuous currents, such currents not being intermittent as in all apparatus
heretofore employed for this purpose, but continuous currents such as are produced
in continuous current dynamo machines with Gramme or Pacinotti commutators.
The same apparatus also serves to convert continuous currents such as are produced
by a dynamo machine with Gramme or Pacinotti commutator into alternating
currents.
For explaining the principle upon which this apparatus acts, let Figure 1 of the
drawings accompanying the Provisional Specification represent a continuous current
dynamo machine consisting of a stationary grammne ring R with stationary com-
mutator C and a rotating electro magnet A excited in any suitable manner, or it
may be a permanent steel magnet, with brushes a y fixed on the magnet. Theso
brushes are combined with two contact rings mn which are fixed on the shaft of the
machine and have two contact springs p4 bearing against them.
On the rotation of the electro magnet currents are generated in the coils of the
ring which pass as currents of the same direction into a conductor connecting the
springs p and J.
The magnetic axis of the field induced by the magnet in the ring being turned
through 360° in every revolution, the number of the magnetic lines of force passing
through the separate coils of the ring, twice attains its maximum and twice its
minimum.
It is this change in the number of lines of force which generates the current as
electro magnetic force.
Obviously this current in the same direction can also be obtained by effecting tho
rotation of the magnetic axis in any other manner. If the energy of alternating
currents is employed for causing the magnetic axis to revolve a continuous current in
the same direction can be produced by such an apparatus, thus converting the
alternating currents into continous currents.
To effect this an iron ring (which in order to avoid Foucault currents must be
divided) is provided as shewn in Fig. 2 with two pairs of coils W₁ and W2, and into
each pair are conducted alternating currents in such manner that the one set of
alternating currents is th of a wave length in advance of the other. Thus two
magnetic fields N S and N' S₁ are produced situated at right angles to each other,
their intensity depending on that of the exciting currents.
If it be assumed that the currents alter in accordance with the law of sines it can
be shown that the intensity of the resulting magnetism. remains constant, the
resulting magnetic axis being turned through 360° once for every complete current
wave as indicated in Fig 3.
Thus at the time I the current in W₁ is at zero, while that in W, is at maximum,
the resulting magnetic axis is therefore NS; at the time II the current in W, is at
maximum whilst that in W, is at zero, the resultant will therefore have turned
through 90°, for instance to the right; in III the current. in W, is again at zero
and that in W, again at maximum, but it has the contrary direction to that in I
consequently the resulting magnetic axis will have turned through an angle of 180°;
in IV W, is at the reverse maximum to that in II and W₂ is at zero, which
corresponds to an angle of 270° relatively to the position 1, while at V the conditions
as in I recur.
1
During the passage of one current wave therefore, the axis of the resulting
magnetic field performs a complete revolution, the same as that of the magnet in
Fig. 1.
If therefore the ring be provided with a continuous third coil similar to that of
the gramme ring, there will be produced in this continously induction currents which,
similarly to the ring dynamo machine in Fig. 1 can be taken off as currents of the
same direction by means of a commutator and rotating brushes. These brushes
must be in the neutral plane, and must consequently rotate synchronously with the
magnetic axis.
Fig. 4 shews an apparatus constructed according to the above described method.
R is the divided iron ring provided with two pairs of bobbins into which the

page_text: alternating currents are introduced through the contacts a b and c d those of the one
pair being th of a wave length in advance of those of the other.
In addition to these two pairs of bobbins, the ring carries the third induced
coil, the separate sections of which are connected to the sectors of the fixed com-
mutator in the same manner as the divisions of a Gramme ring are connected to the
corresponding commutator sectors.
Within the ring is a piece of iron A mounted to revolve upon the shaft which
serves to close the passage of the lines of force passing out of the ring and to which
also the commutator brushes a y are fixed. This piece of iron always tends to
remain in the direction of the magnetic axis and therefore revolves synchronously
with it.
The brushes therefore when once situated in the neutrál plane remain in it.
A mechanism can however be provided for enabling the brushes to be adjusted
during the rotation. The brushes are furthermore connected to two contact rings m n
from which the current is taken off by the contact springs p q.
In order to effect the ready starting of the machine, the revolving iron armature
is provided with a coil returning into itself in which, at starting, induction currents
are first produced which magnetise the closing armature and increase the tangential
force between the armature and the ring. These induction currents disappear entirely
when the synchronism has been obtained.
This coil can also be arranged as a shunt to the continous current coil, and the
iron piece can also have in addition to a coil returning into itself a shunt coil or a
coil introduced into the secondary main circuit in order to produce the synchronous
rotation with greater certainty.
Fig. 5 shows a construction of this apparatus which is based upon the same
principle as the above described one, but which differs from this in that the alternate
current coils are situated upon a divided iron drum T arranged stationary within a
continuous current ring R. In addition to these two parts there is an armature A to'
which are rigidly connected a pair of brushes y which rub on the fixed com-
mutator synchronously with the displacement of the resulting magnetic axis.
Contact rings m n with springs p q serve for leading off the continuous current.
By reversing the construction shewn at Fig. 4 an apparatus is obtained as shewn
at Fig. 6. In this case the ring R revolves with its alternate current and continuous
current coils and with the commutator C.
The brushes ay as also the armature A which has both a coil returning into itself
and a shunt coil, are stationary.
With this construction the contact rings for taking off the continuous current are
dispensed with, but on the other hand there are provided four or at least three
contact rings for introducing the two alternating currents (namely two supply
rings and a common return ring) together with contact springs a b c therefor.
The adjustment of the stationary brushes a y is easier and more simple than in the
rotating arrangement at Figs. 4 and 5.
The above described construction may be variously modified. For example, in
Fig. 4 the revolving armature A can be arranged externally to the ring R or at either
side or both sides of it.
In Fig. 6 the fixed armature A may also be arranged within the ring R or at the
side, or on both sides of it. Also, the alternate current and continuous current coils
may be arranged on two separate masses of iron which are connected rigidly together
and which may have a common armature or two separate armatures.
In the arrangement shewn in Figs. 4 and 6 the ring can be replaced by a drum
with two alternate current coils and a continuous current coil similar to the coil of a
continuous current dynamo machine drum. In this case the closing armature will
surround the drum.
In Fig. 5 also, the inner drum can have the continuous current coil, and the
commutator and outer ring the alternating current coils.
In all cases it is advisable to form the rings and drums with indentations at the
parts where they are presented to each other or to the closing armature, and to lay

page_text: the wires or bands in the spaces in order that the air passages for the lines of force
may be shortened as much as possible.
Assuming that the alternating currents have 80 changes of pole in a second, these
correspond to 40 current waves per second, and 2400 waves and consequently as
many revolutions of the apparatus per minute.
In order to reduce this somewhat large number of revolutions it is advisable to
employ in place of only two pairs of alternating current bobbins 4, 6, 8, or other even
number of such bobbins so arranged as to form a multiple polar ring or drum.
A corresponding number of brushes must in that case be used or the correspondingly
placed commutator sectors must be connected together in the .known manner for
working with only two brushes. The closing armature as in Figs. 4 and 6, must
then be multipolar that is to say it must be of star shape in order to close the
passages of the lines of force as much as possible.
In Fig. this is not necessary as the closing is effected either by the ring or
the drum, and the armature only forms a shunt closure for the lines of force.
The number of alternating current coils and continuous current coils has to be
calculated according to the desired proportion of transmission between the average
tension of the alternating current and that of the continuous current.
These tensions can be equal to one another or an alternating current of high or
low tension can, without the aid of another apparatus, be coverted into a continuous
current of low or high tension.
These apparatus may also be used for converting continuous currents into alternating
currents. For this purpose the greater part of the available continuous current is
passed, in the constructions shewn in Figs. 4 and 5 over the springs through the
contact rings m n and through the brushes a y, and in the construction shewn at
Fig. 6 it
passed directly through the brushes x y into the commutator and so into
the continuous current coil, a small portion of the current is used by the aid of the
contact rings in Figs. 4 and 5 and without these directly in Fig. 6, for magnetising
the closing armature.
The apparatus being thus caused to rotate as an ordinary continuous current
machine there will be produced in the alternating current coils two alternating
currents, one th of a wave length in advance of the other, which are taken off by
means of fixed contacts in Figs. 4 and 5, and in Fig. 6 by means of 4 or 3 contact
rings and springs, to be employed as may be desired.
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. As apparatus for converting alternating into continuous electric currents, the
combination of a stationary divided iron ring wound with one pair or with several
pairs of coils for the alternating currents, so connected that the current in one of each
pair has its phase one quarter of a wave length differing from that of the other, a set
of coils for induction wound on the ring and connected as in a Gramme machine to
plates of a stationary commutator an electro magnetic armature revolving and carrying
suitable pairs of brushes around the commutator, contact rings connected to these
brushes and springs pressing on the rings to convey the continuous currents which
are induced in the Gramme coils, substantially as herein described.
2. The modified form of apparatus wherein the coils are on a divided iron drum
revolving within a stationary electro magnetic armature, the revolving drum carrying
contact rings for the alternating currents and carrying also a revolving commutator
which is rubbed by stationary brushes to convey the induced continuous current,
substantially as described.
3. The modified form of apparatus wherein a stationary divided iron drum is
surrounded by a stationary iron ring, either the drum or the ring being wound with
one pair or with several pairs of coils for the alternating currents and either the
ring or the drum being wound with the coils for induction having their stationary
commutator on which rub suitable pairs of brushes revolving with an iron anchor

page_text: along with rings pressed on by stationary springs for conveying the induced
continuous current.
4. The use of apparatus such as are referred to in the preceding claims for converting
continuous into alternating currents by leading the continuous current through the
brushes and commutator to the continuous coils, providing the anchor with a coil
closed on itself and also with a continuous current coil, and connecting the alternate
current pairs of coils so that the current in one of each pair is in a phase differing
by one quarter of a wave length from the other, substantially as described.
Dated this 23rd day of April 1880
ABEL & IMRAY,
Agents for the Applicants.