Method of Combined Application of Continuous and Alternating Currents for Exciting Magnetic Fields, and Combination Apparatus for Producing by this Method Electrical Energy and Mechanical Power.
Year: 1898

page_text: Date of Application, 15th June, 1898-Accepted, 24th Sept., 1898
COMPLETE SPECIFICATION.
Method of Combined Application of Continuous and Alternating
Currents for Exciting Magnetic Fields, and Combination
Apparatus for Producing by this Method Electrical Energy
and Mechanical Power.
I, MAX DERI, of Wipplingerstrasse, No. 30, Vienna, Austria, Electrician, 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 the combination in a dynamo of two different arrange-
ments for exciting the magnetic field and for the induction, whereby the machine
is enabled to produce simultaneously continuous current and alternating current,
or to be worked as motor by both descriptions of currents, or again to operate
as a motor-generator for converting the one kind of current into the other.
When operating as generator of continuous current or as continuous current
motor, this machine works in the ordinary way with commutator or collector and
brushes; when working as alternate current generator or alternate current motor,
it operates with short circuited armature; the two different actions are produced
by an armature common to both, and a field magnet common to both, of which
the latter is excited simultaneously by continuous current and alternating current.
The arrangements by which the combined action is produced will be understood
from the following examples. In the accompanying drawing F shews the field
magnet and A the armature. The field magnet has two groups of windings. The
field windings from s¹ to 8 are connected by four series poles (at 12 53, 54 55, 56 $7
and s) and form, as shewn by the arrows indicating the magnetic flow of force,
a quadri-polar field.
These windings take up the current C a in the described sequence, that is,
according to the present example, simple alternating current taken from a
transformer T and led into the field winding at stand 8.
The field windings from 9 to 21 on the other hand are so connected that they
only have two series poles (at 20, and at $14 s) and form a bi-polar field. To
these windings is supplied à continuous current Ce at s9 and 20 for example from
a battery Be. While both fields have different numbers of poles (in the present
example 4 and 2) the electromotive forces induced in their windings or coils
neutralise each other so that the sum of them in one group is nil. Consequently
no inducing action of one group of windings on the other can occur, notwithstand-
ing that the groups of windings s¹-8 and 9-s20 have a common field magnet
and, to a certain extent, the same directions of lines of force. By this arrange-
ment it is therefore possible, by passing currents of different kinds through two
differently disposed groups of windings, to excite simultaneously in one field
magnet two kinds of magnetic field without the one destroying or influencing the
other. In the present instance the groups of windings are so disposed that a
quadri-polar alternating field and a bi-polar constant field are produced.
In an analogous manner, instead of an alternating field a rotary field can be

page_text: produced simultaneously with the constant field by using instead of the exciting
simple alternating current Ca a polyphase alternating current; there is thus
obtained the combination of a rotary constant field with a stationary constant field
which likewise exert no inducing action on each other, if the number of their poles
be different.
It is clear that according to the arrangements here described the two kinds of
excitation of field magnet may be produced consecutively instead of simul-
taneously in which case common field windings with corresponding change of con-
nection for different numbers of poles can be employed for the consecutive
continuous-alternate-current excitation.
The armature A, which is shewn in the drawing as a drum armature but may
also be a ring armature, is provided with a winding which, analogously to the
field coils, is disposed in two different groupings for 4 and 2 poles. As shewn
in the drawing the wires or rods t¹ etc. on the one hand are connected in a deter-
mined series in groups of 4 (for example t¹, ts, 15 and 12) and form a number of
short-circuited four-wire windings with respect to the four-polar alternating field;
the points 1 and 11, 2 and 21 &c. which are equipotential, with respect to the
four-polar field, on the other-hand, are connected with each other, or with a con-
necting circuit in such a way that the current flowing from to 11, 2 to 21 etc.
produces a bi-polar armature field. If now the equipotential points are connected
among themselves and with the sectors of a collector in the determined sequence
as in the known drum winding of dynamo machines (in this case shewn, in the
series 1-3-3-5-5-7-7-2-2-4-4-6-6-1-1¹) and the collector
brushes be placed in the proper positions, the armature forms with the above
described arrangement a continuous current armature of the usual kind, which
produces a continuous current in a bi-polar constant field, or when fed with a
continuous current, form a bi-polar motor armature. In the drawing the collector
brushes are shewn connected with the leads from a continuous current source C c,
for example a battery Bc.
If now the two windings of the field magnets are excited, the four-polar one
with an alternating current, the bi polar one with a continuous current then
assuming these to occur simultaneously they will conjointly act upon the arma-
ture for producing motive power, or instead of both kinds of current occurring
simultaneously, the one kind may be made to occur in the one circuit at one time
and the other kind in the other circuit at another time, thereby producing corre-
spondingly varied actions in the armature circuits during those times. Thus
for example a motor constructed according to this invention might be started
by means of a continuous current in the bi-polar winding and after a certain
speed had been attained the motor might be worked by an alternating current in
the four polar winding.
Again if the motor be rotated at a speed greater than the synchronous speed,
then, as is well known, the armature can give rise to an alternating current in
the field winding and the machine will consequently work as an alternate current
generator; it can also however, excite a constant electromotive force between the
brushes and produce a continuous current or, if a continuous current be led into
the armature through the brushes, it can produce a moment and motive power
by means of the constant field of the armature. The two-fold function-as
already described-can proceed at the same time without mutual disturbance
and each of the two functions can be regulated without influencing the other.
By this arrangement the apparatus is therefore in a condition to produce,
either at the same time, or at different times, continuous current and alternating
current (mono- or poly-phase) or to exert power as a motor driven simultaneously
or at different times by a continuous current and by a mono- or poly-phase alter-
nating current; or to operate on the one hand as a motor, on the other hand as a
generator, and thus operate as a converter for transforming a mono- or poly-phase
alternating current into a continuous current or a continuous current into a mono-
or poly-phase alternating current.

page_text: In this converter the pressure of the secondary current is not dependent on that
of the primary current. For the pressure of the continuous current produced will
be proportional to the number of windings of the armature which on the contrary
is without influence on the function as an induction motor since the armature
winding for the last named function is used short circuited.
In the example described and shewn there are four poles for the alternating
field and two poles for the constant field; obviously however other numbers of
poles instead of 2 and 4 can be used. The described combinations and their
double mode of working is possible if for the exciting continuous current there
be chosen an even number of poles and for the exciting alternating current also
an even number of poles but a different one from the above. The constant field
may have a smaller number of poles than the alternating field or vice versa.
In the example here described the arrangement is so chosen that the field
magnet remains stationary and the armature rotates, but under certain conditions
this arrangement may be reversed. So also the manner of winding and the layers
of the windings and coils on the field magnet and the armature, their number
construction and form are without importance; they are determined by the
known rule for constructing dynamo machines and electro motors.
Having now particularly described and ascertained the nature of this invention
and in what manner the same is to be performed, I declare that what I claim
is:
1. A method for the combined application of continuous current and mono- or
poly-phase alternating current for exciting magnetic fields consisting in the
use of a field magnet with two windings of which one arranged for a certain
number of poles takes the continuous current, and the other, arranged for a
different number of poles, takes the alternating current or in the use of one field
winding which with an appropriate arrangement for a certain number of poles
takes one kind of current, and with another arrangement for a different number of
poles, takes the other kind of current, the arrangement being such that a constant
field and an alternating or rotary field with a different number of poles are
obtained simultaneously or alternately. and independently of each other in one
and the same field magnet substantially as described.
2. A combination current generator consisting of a field magnet in which a
constant and an alternating or rotary field with different numbers of poles are
maintained by excitation by means of a continuous current and a mono- or poly-
phase alternating current according to Claim 1 and of an armature provided with
windings so disposed that the windings or coils on the one hand form short
circuits having the number of poles corresponding with the alternating field and
on the other hand form with the lamellae of a collector circuits connected in
corresponding series having the number of poles corresponding with the constant
field, so that when the armature is rotated in the combined field with a speed
greater than the synchronous speed, there can be obtained either at the same time
or at different times, a mono- or poly-phase alternating current from the inducing
field coils excited by alternating current and a continuous current from the
collector substantially as described.
3. A combination electro motor consisting of a field magnet in which a constant
and an alternating or rotary field with different numbers of poles are produced
by excitation by means of a continuous current and a mono- or poly-phase alter-
nating current according to Claim 1, and of an armature provided with windings
so disposed that the windings or coils on the one hand form short circuits having
the number of poles corresponding with the alternating field, and on the other
hand form with the lamellae of a collector circuits connected in corresponding
series having the number of poles corresponding with the constant field so that by
passing a continuous current into the collector of the armature and into the one
field winding and a mono- or poly-phase alternating current into the other field
winding or into the same one, but correspondingly differently connected, power

page_text: moments are obtained by means of both currents at the same time or by means
of one and the other current alternately which may be used as a source of power.
4. An asynchronous converter consisting of a field magnet in which a constant
and an alternating or rotary field with different numbers of poles are produced
by excitation by means of a continuous current and a mono- or poly-phase alter-
nating current according to Claim 1, and of an armature provided with windings
so disposed that the windings or coils on the one hand form short circuits having
the number of poles corresponding with the alternating field, and on the other
hand form with the lamellae of a collector circuits connected in corresponding
series having the number of poles corresponding with the constant field so that
either by passing mono- or poly-phase alternating currents into the respective
field coils the short circuit armature is rotated and a continuous current is obtain-
able from the collector or by passing a continuous current into the collector and
into the respective field coils, the armature is rotated with a speed greater than the
synchronous speed and mono- or poly-phase currents are obtainable from the
inducing field coils, excited by means of an alternating current, substantially as
and for the purposes described.
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1000
ABEL & IMRAY,
Agents for the Applicant.