Improvements in Electric Generators.
Year: 1886

page_text: Date of Application, 2nd Apr., 1886.
Complete Left, 3rd Jan., 1887.
Complete Accepted, 8th Mar., 1887.
Improvements in Electric Generators.
We, FRANZ FILIPP STOGERMAYR, of I Opernring 7, Vienna in the Empire of
Austria, Electrician, and VICTOR GLASSNER, of I Ebendorferstrasse 7, Vienna,
aforesaid, Gentleman, do hereby declare the nature of this invention to be as
follows:-
According to this invention three bobbins with iron cores wound with insulated wire
are arranged on a common axial line in such a way that when magnetised poles of
opposite name are presented to one another the wire on the two outer or extreme
bobbins is in circuit with a generator of electricity, such as a battery or dynamo
machine. In the same circuit there is included a make-and-break or circuit closer,
which breaks the circuit at rapid intervals.
The coil of the central bobbin is the circuit in which the induced current is
generated. It is connected to the exterior or working circuit, and also by a derivation
to subsidiary coils wound on iron cases which envelop all three bobbins. The current
in the derived circuit has the effect of intensifying the magnetising effect of the
primary current derived from the electric generator in the magnetising circuit. The
make-and-break, or circuit closer, may conveniently be driven by an electric motor,
operated at first by the current from a battery or other generator, and afterwards by
the current generated by the machine itself. It consists of a toothed wheel connected
to one terminal of the circuit, and running in rubbing contact with a spring, which is
the other terminal. In order to keep the speed of the motor constant an automatic
rheostat is inserted in its circuit. This rheostat consists of a vertical solenoid whose
iron core is suspended in such a manner that, when it is drawn with a certain force
into the solenoid, it balances a metallic rod dipping into a fluid of low conductivity.
When the strength of the current increases, the descending solenoid core raises the
metallic rod, and augments the resistance, which corresponds to the height of the column
of liquid beneath the rod, until the increase of the weight of the rod, due to its rise,
again equalises the increased force of the solenoid. When, on the other hand, the
strength of the current diminishes the iron core is raised until the increase of
the upward force of the liquid again balances the loss of force experienced in the
solenoid.

page_text: The detailed construction of this solenoid rheostat, which is especially requisite
when the electro-motor is driven by a current derived from the induced current of the
generator, is as follows:-
Upon the base plate is mounted a metallic frame carrying a light sheave which is
provided on its periphery with a continuous groove and is freely movable in the
bearings of its axis.
In the groove of this wheel there lies a thin catgut cord to one end of which is
attached the core of a solenoid, while the other end there depends a metallic capsule in
a vertical position.
The weight of the metallic capsule together with that of the metallic contact rod,
which is connected to the body of the capsule by means of a screw-thread, is very
slightly greater than that of the solenoid core, so that when no other force but its own
weight acts on the core, the capsule has always a tendency to seat itself on the rim of
the glass tube which is open at the top and bottom. This tube is provided with a
graduated scale of resistances and is fixed by means of cement into a metallic socket
the bottom of which is plated with silver.
When the metallic capsule rests on the rim of the glass tube, the iron core is
suspended with a certain part of its length within the solenoid bobbin. The interior
of the bobbin is of such a diameter and such a depth, that the entire iron core may
be, at times, drawn into it.
а
The glass tube, of corresponding width and height, is nearly filled with a liquid
which is a conductor of electricity.
The rheostat is inserted in the derived circuit, which is to be regulated, after being
adjusted to a normal resistance which is effected by turning the contact rod in its
thread, so as to cause the metallic disc arranged at its lower part to approach more or
less to the metallic bottom of the socket piece.
As the generator produces alternating currents it is often advantageous to commute
them into a continuous current. For this purpose a commutator may be mounted on
the same axis as the make-and-break just described. It is formed of a disc of
insulating material.
The cylindrical surface of this disc carries at both edges metallic rings and from
each of these rings spring as many equi-distant fingers in the direction parallel to
axis of the cylinder, as there are teeth on the disc of the circuit closer; the fingers of
one ring break joint with the fingers of the other ring. A spring presses on each of
the rings which represents one terminal of the circuit of the alternating current.
The induction current impulses coming in one direction are conducted to the one
terminal of the working circuit, and the impulses from the opposite direction to the
other terminal by means of forked contact springs.
One part of each of these springs slides or rubs on the contact finger of the right
hand ring and the other part on the contact fingers of the left hand ring, and both
folks never are in contact with the finger of one and the same ring.
It is evident that the generator may be modified without departure from the
principles of the invention. For instance, the primary or magnetising current may
be derived from an alternate current generator in which case the make-and-break may
be dispensed with; further, more than three bobbins may be employed, and they
may be arranged in a circle, or one large bobbin may be used and both circuits be
wound on it, either side by side, or one over the other.
W. LLOYD WISE,
46, Lincoln's Inn Fields, London, W.C.,
Agent for the Applicant.

page_text: COMPLETE SPECIFICATION.
Improvements in Electric Generators.
We, FRANZ FILIPP STOGERMAYR, of I, Opernring, 7, Vienna, in the Empire of
Austria, Electrician, and VICTOR GLASSNER, of IEbendorferstrasse 7, Vienna,
aforesaid, Gentleman, 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 electric current generator which forms the subject of this invention consists
essentially of three bobbins of insulated wire wound upon iron cores, in such a way
that poles of opposite name are presented to one another, when the bobbins are
arranged upon the same axial line. Of these, the two extreme bobbins are in circuit
with a galvanic battery and with a make-and-break or circuit closer while the circuit
of the central bobbin constitutes the main working circuit of the generator and may
contain a commutator designed to switch currents or impulses of alternate polarity
into the same direction.
For the purpose of intensifying the magnetism created by the current which is
passed through the outer bobbins in an intermittent manner, all three bobbins are
enclosed in hollow cylinders of soft iron, wound with an insulated conducting wire
which branches off from the main circuit between the bobbin and the commutator.
The same wire is also wound around the cores of the three bobbins, and has the effect
there of intensifying the magnetizing action of the primary or exciting current at the
moment when it is traversed by the current which is induced at the closing of the
primary circuit. The current which flows through it at the breaking of the primary
circuit effects the change of poles in the cores.
The circuit-closer or make-and-break and the commutator, whose times of action
must correspond, are preferably arranged upon the same axis, which may be driven
from a small electro-motor. The current necessary for driving the latter is, at first,
created by a galvanic battery, in the circuit of which must be placed an automatically
regulating rheostat for the purpose of maintaining a uniform speed of revolution.
Afterwards the motor may be driven by means of a current derived from the current
induced in the working circuit.
In the annexed drawings
Fig. 1 is a diagrammatic representation of the general arrangement of the current
generator, but without the motor which drives the shaft of the commutator and
circuit-closer.
Fig. 2 shews the commutator and circuit-closer in front and side elevation.
Fig. 3 represents (with some parts removed) the rheostat for automatically regulating
the current which drives the motor.
In Figs. 4 and 5, the parts marked a shew the poles formed at the inner ends of the
cores on the outer bobbins upon closing the circuit of the battery, while the views
marked correspond to the breaking of the circuit.
Similarly Fig. 6 shews the left hand end of the central bobbin, first, at a, at the

page_text: moment of the formation of the induced current which is created by closing the
circuit, and, second, at ẞ, at the moment of the formation of the induced current due
to breaking the circuit.
Fig. 7 shews the direction of the current circulating on the inner surface of the
magnets of ring-shaped section.
The electric conductor for the primary current (represented by a thin line, in the
drawing) passes from the galvanic battery A to a terminal of the circuit-closer B and
is continued through the shaft of the latter to the toothed metallic disc b connected
with the shaft. When a tooth b¹ of this disc b touches a contact spring 63, the circuit
is completed by this spring, and through the coils on the iron cores cc of both electro-
magnets CC to the negative pole of the battery. Now, if the motor impart to the
shaft of the circuit-closer a velocity of 200 to 300 revolutions per minute, and if the
disc b is provided with 50 teeth, the circuit of the galvanic current is evidently made
and broken 10,000 to 15,000 times in a minute, and then will result 20,000 to 30,000
induced current impulses per minute in the middle coil..
If the motor of the circuit closer is an electro-motor, an automatic regulating
resistance which will only allow a current of a certain strength to pass, must be
inserted in the circuit of the current driving this motion, in order, that the velocity of
rotation may remain constant, as before said. Fig. 3 represents a rheostat by means
of which this result is obtained. It consists essentially of a vertical solenoid whose
iron core is suspended in such a manner that, when it is drawn with a certain force
into the solenoid, it balances a metallic rod dipping into a fluid of low conductivity.
When the strength of the current increases, the descending solenoid core raises the
metallic rod, and augments the resistance, which corresponds to the height of the
column of liquid beneath the rod, until the increase of the weight of the rod, due to its
rise, again equalises the increased force of the solenoid. When, on the other hand,
the strength of the current diminishes the iron core is raised until the increase of
buoyancy again balances the loss of force experienced in the solenoid.
The detailed construction of this solenoid-rheostat, which is especially requisite when
the electro-motor is driven by a current derived from the induced current of the
generator, is as follows:
Upon the base plate E is mounted a metallic frame e carrying a light sheave e
which is provided on its periphery with a continuous groove and is freely movable in
the bearings e¹ of its axis." In the groove of this wheel there lies a thin catgut cord e³
to one end of which is attached the core e of a solenoid, while the other end there
depends a metallic capsule e in a vertical position.
The weight of the metallic capsule e³, together with that of the metallic contact
rod e, which is connected to the body of the capsule by means of a screw-thread, is
very slightly greater, than that of the solenoid core et, so that, when no other force but
its own weight acts on the core e, the capsule e has always a tendency to seat itself
on the rim e' of the glass tube e8 which is open at the top and bottom. This tube is
provided with a graduated scale of resistances and is fixed at e by means of cement
into a metallic socket the bottom of which is plated with silver.
When the metallic capsule e rests on the rim e' of the glass tube e, the iron core e*
is suspended with a certain part of its length within the solenoid bobbin. The interior
of the bobbin is of such a diameter and such a depth, that the entire iron core may be,
at times, drawn into it.
The glass tube, of corresponding width and height, is nearly filled with a liquid
which is a conductor of electricity. The rheostat is inserted in the derived circuit,
which is to be regulated, after being adjusted to a normal resistance which is effected
by turning the contact rod e in its thread, so as to cause the metallic disc arranged at
its lower part to approach more or less to the metallic bottom of the socket piece e³.
The normal resistance to be imparted to the rheostat is determined by-
a) the strength of current required in the branch circuit;
b) the resistance of this branch circuit ;
c) the resistance of the main circuit, and
A the lowest nossible strength of the current in the main line

page_text: According to Ohm's law, a current divides itself in the inverse ratio of the
resistance of the several branches open to it.
If the available current is such that there exists a possibility that it may sink to a
strength of say 20 ampères, and if the resistance of the main line circuit is 10 Ohms,
whereas in the secondary circuit with a resistance of 20 Ohms, a uniform strength of
current of 0.5 ampères is required, the normal resistance of the rheostat i.e. the
resistance of its liquid column, must be adjusted to 390 Ohms, minus the resistance of
the derived circuit and of the solenoid bobbin, when e rests on e; thus, if the
resistance of solenoid bobbin be 30 Ohms the liquid column must be adjusted to
390 (2030) = 340 Ohms ;
-
for if the total resistance in the circuit of the motor amount to 390 Ohms and the total
resistance of the main line to 10 Ohms, according to Ohm's Law the intensity of
current in the main line, at a given total strength of current of 20 ampères will be
which added together gives the available strength of current of 20 Ampères.
Therefore, of this supposed minimum strength of current in the main line,
0.5 Ampères enter the Rheostat adjusted to 340 Ohms, and passing through the
solenoid bobbin, over the contact rod e, and the stand elo, back to the main line.
While traversing the solenoid bobbin, the derived circuit (of strength 0.5 Ampères)
will draw the iron core et into the bobbin.
The column of liquid of the rheostat is definitely adjusted to a lower normal
resistance than 340 Ohms by turning the contact disc b to the corresponding mark on
the scale on the glass tube. If the intensity of the current in the main line be now
increased, it can exert no influence on the strength of the current in the derived
circuit, since any increase in the strength of the derived current flowing through the
solenoid bobbin, results in the descent of the core e and the rise of the contact disc in
the glass tube and thus effects an increase of the resistance in the derived circuit,
which neutralizes the increased strength of current. Thus the strength of the current
in the motor is always maintained at 0.5 Ampères so long as the current does not fall
below 20 (say to 19.5) in the main line and this cannot happen since 20 Ampères was
assumed to be minimum strength of the current available for distribution.
Whenever the primary or battery circuit is closed in the manner described, the
current circulates around the iron cores c c, in the direction shewn by arrows and
excites magnetism the polarity of which (indicated by N and S) may be seen in
Figs. 4 and 5 and is also indicated in Fig. 1 above the centres of the bobbins. The
poles induce opposite polarity in the core of the induction bobbin D, and induce in
the coil wound on it a current (called the current of closing and shewn by long and
short dotted lines), in the direction of the simple arrow.
At the moment of inter-
ruption of the galvanic current, the induced current (called the current of opening) in
the reverse direction i.e. in the direction of the double arrows, sets in.
The derived current (shewn by a stout line in the drawing) branching off from the
induction circuit at y y, is conducted (as shown in Fig. 1) around all three cores c d c
and also around the three hollow iron cylinders c¹ d¹ c¹ of the three bobbins. At the
moment of closing of the primary circuit this induced current runs in the direction of
the simple arrow and at the moment of interruption of the same, in the direction
of the double arrow.
As may be seen from Fig. 1, this branch current assists the
primary current since it runs parallel with it (as shown by the simple arrow) and aids
the production of polarity in the cores c d c; it also creates magnetic poles (Fig. 7)
in the rings c' d¹ c, according to Ampères Laws of peripheral currents in iron cores.
These poles serve to greatly intensify the induction current of closing which is formed
at this moment (see Fig. 6). At the instant when the primary circuit is interrupted,

page_text: the induction current of opening is created and runs in the contrary direction to the
former current as shewn by double arrows. At the same moment the direction of
the branch or derived current is, of course, also reversed, and this effects a change
of polarity at all the magnetic poles (as shewn beneath the axis of the bobbins
in Fig. 1.). By these means a much stronger induction current of opening is produced
than could result from simple demagnetisation of the magnet cores.
The face views ẞ in the figures 4, 5 and 7 correspond to the condition of affairs at
this moment. Those shewn under a illustrate the reverse direction of current in the
induction and branch circuits, while the circuit of the primary current (Figs. 4 and 5)
of course, is entirely free from any current at this moment. In the derived circuit
branching off at yy is introduced a resistance r for the purpose of allowing only a
small portion of the induction current to enter this line.
The alternating induction current produced in the manner described, can be
transformed into a current in one direction by means of a commutator.
The arrangement of the commutator F.shown in the drawing is as follows: On the
axis of the circuit closer B is fixed a disc f of insulating material. The cylindrical
surface of this disc carries at both edges metallic rings and from each of these
rings spring as many equidistant fingers f, in the direction, as there are teeth b¹ on
the disc b of the circuit closer B; the fingers of one ring break joint with the fingers
of the other ring. A spring f³ ³ passes on each of the rings f¹f which represents
one terminal of the circuit of the alternating current (see the line consisting of lines
and dots. The induction current impulses coming in one direction are conducted to
the one terminal of the working circuit (see the double line), and the impulses from
the opposite direction to the other terminal z, by means of the forked contact
springs ff. One part of each of these springs slides or rubs on the contact
fingers of the right hand ring and the other part on the contact fingers of the left
hand ring, and, as is seen in Fig. 1, both forks never are in contact with the finger f²
of one and the same ring f. Of course the commencement of the contact between
the fingers and the springs f, as well as the duration of this contact, must be
calculated in such wise that at the moment where the primary current is closed and
broken and the induced currents are created, the working circuit is closed by one or
other of the contacts.
When alternating currents are useful in the work for which the current is produced,
the commutator described may be dispensed with.
In conclusion, be it remarked that the cores c c may also be formed of material
capable of retaining its polarity, and that the induction circuit may be led around
them and also around the hollow cylinders c¹ c¹ in the same manner as the primary
circuit, for the purpose of obtaining a permanent magnetic field which effects an
increase of current until it reaches the maximum magnetisation of the cores.
Having now particularly described and ascertained the nature of this invention and
in what the same is to be performed, we declare that what we claim is
:_
1. A magneto-electric current generator consisting of three coils with iron cores
arranged in the same axial line, both outer bobbins being inserted in the circuit of an
electric generator containing a circuit closer, and so arranged that their cores upon
magnetization present different poles to the core of the central, bobbin inserted in the
working line.
2. Enclosing the three bobbins mentioned under claim (1) in hollow iron cylinders
around which is led a circuit branching from the working circuit in such a manner
that these hollow cylinders are of different polarity to the iron cores; the arrange-
ment of the branch circuit being such that it also intensifies the effect of the primary
current.
3. A commutator for converting the alternating into a continuous current consisting
of a disc of insulating material fixed on the shaft of the circuit closer and carrying at
both edges of its cylindrical surfaces, metallic rings with equidistant contact projections
springing towards each other, and equal in number to the teeth in the circuit closer,
in combination with springs which form the terminals of the alternating current, and

page_text: two forked springs which are connected with the terminals of the working current and
slide upon the contact projections of the rings which break joint with one another so
that each is alternately thrown into contact at the right and left and that one spring
only has contact with the projections on a ring, at a time.
4. An automatic regulating rheostat by means of which the current driving the
electro-motor for the circuit closer is maintained constant, consisting of a cord running
over a pulley and carrying at one end a solenoid core and at the other end a metallic
rod which is connected to the line and dips into a liquid of low conductivity,
the whole so arranged that the attraction exercised on the cord by the solenoid
and the weight of the core counterbalance the weight of the metallic rod, minus its
buoyancy.
W. LLOYD WISE,
46, Lincoln's Inn Fields, London, W.C.,
Agent for the Applicants.