the Conditions of Electric Currents.
Year: 1886

page_text: Date of Application, 20th Mar., 1886.
Complete Left, 20th Dec., 1886.
Complete Accepted, 8th Mar., 1887.
the Conditions of Electric Currents.
We LOUIS BOLLMANN, of 2nd District, Dianabad, Manufacturer, ERNST BIEDER-
MANN of 1st District Schenkenstrasse 10, Electrician, and DEMETRE MONNIER, of
1st District, Schenkenstrasse 10, Electrician, all in Vienna in the Empire of Austria,
do hereby declare the nature of this Invention to be as follows :-
This Invention relates to improvements in the method and in apparatus for trans-
forming electric currents from a higher to a lower tension by means of particular
connections of closed electro magnets with a commutator whereby a continuous
principal current is used to produce a continuous secondary current of lower tension
and whereby both the principal and secondary currents are flowing in the coils of the
magnets constantly in the same direction.
The electro magnets consist of iron rods connected at both ends to solid iron plates
so as to form a ring magnet or a closed horse shoe magnet. The rods are covered by
several layers of insulated copper wire forming coils which are connected as hereinafter
explained.
The invention is not restricted to the shape or construction of these magnets as any
other suitable shape or construction may be used for the same purpose.
The rotating parts of the commutator are connected to a shaft having bearings in a
frame and driven by any convenient power or by the principal current copper or other
inetal. Springs bearing slightly against insulated metal rings fastened to the before
mentioned shaft act as brushes to transmit the currents to and from the rotating parts.
On the shaft are fastened two drums of wood or other insulating material, having on
their circumference metal ring sections of different sizes suitably disposed and against
this circumference bear sixteen brushes distributed around the circle in eight pairs.

page_text: The shorter parts of the metal ring-sections are connected with one of the before
mentioned rings by means of copper wires, which are insulated and pass between the
shaft and the inner rings the latter being also in connection with the larger part of
the circumference of the drums.
Plates bearing against these inner rings are connected with the cables forming the
secondary circuit leading the induced current of low tension to the lamp or place of
utilization and back again. In a similar manner outside rings are in connection with
the main circuit.
The brushes we make use of are of a peculiar construction they consist of numerous
thin elastic plates fastened to a piece of copper or other metal and so disposed that they
rest on the commutator at an angle to the axial direction and in a radial position to
the centre of the shaft.
There are four brush holders and each of them is connected by a flexible cable to
one end of the coils of the magnets they are respectively marked with the signs +
and
In the brushes marked with the sign + pass the currents from the commutator to
the brush and vice versa in those marked with the
sign.
-
The connection of the coils is such that the currents must flow in each consecutive
one in the opposite direction so that when all are equally magnetized no free magnetism
would appear.
The principal current flows through coils of alternately of the designation + and
and magnetizes the rods to the required degree.
-
As the commutator is moving on the segments change positions with regard to the
brushes but the principal current is never interrupted. At a further rotation of the
commutator the brushes come from the principal into the secondary circuits and
the arrangements of the apparatus according to this invention is such that constantly
six of the magnet rods are in connection with the principal and ten of them with the
secondary circuit.
It is to be observed that while the six coils above mentioned are connected in series
(one after the other) the latter ten coils are connected with the secondary circuit in
parallel (that is to say side by side) Consequently magnetization takes place while
three pairs of coils are connected in series and are magnetized while five pairs of coils
are connected in parallel and demagnetized.
In consequence of the above disposition the tension of the induced current is a much
lower one than that of the principal current.
It is obvious that the quantity or intensity of the induced current is in inverse
proportion to its electromotive force.
In order to prevent the production of sparks when the segments leave a brush the
coils leading to one pair of brushes are connected with rods each of which appertains
to another ringmagnet.
To obtain a more smooth and constant flow of the principal current there may be
used a greater number of magnets of smaller dimensions. Then the brushes would
have to be disposed in such a manner that two brushes are constantly in contact with
the smaller segments and more than four of the larger segments are placed side by
side. The principal current would then flow in two series which are connected two in
parallels.
Sparks will be further reduced if more than two rods be connected to form a closed
circuit and these connected with the brushes in such a manner that each pair of the
latter has connection with rods belonging to different magnetic circuits..
The magnetism of those rods whose coils are connected to the largest segments of
the commutator belonging to the secondary circuit can be discharged only so far as
that the energy of induction by its demagnetization is yet capable of producing an
electro motive force in the surrounding coils which corresponds to the number of volts
required for the secondary current. If the demagnetization has not the energy to
induct a current of that tension the current from the other coils would flow backwards
through this coil instead of going through the lamps or place of utilization.

page_text: When a coil passes from the principal into the secondary circuit the demagnetization
is at first energetic but the action is gradually diminished the more so as the current
flows in these coils in the same direction as the principal current was before flowing
which tends to retard the demagnetization.
To make the apparatus capable to discharge the entire magnetism and to increase
its power we make use of a modification of the arrangement wherein as many pairs of
brushes are connected in series with the principal current as there are pairs in parallel
connected with the secondary circuit. In this case we employ six ring magnets and
six pairs of brushes three of which are connected in series and three in parallel.
The wire connection is such that in the two coils of the same rod the directions of
the currents are opposite to each other, one of them being connected with the principal
circuit and the other being connected with the secondary circuit both changing
circuits at the same moment.
In consequence of this connection and of the movement of the brushes, the rods of
the magnets become magnetized and demagnetization in the opposite sense is
accelerated. Both the magnetization in one sense and demagnetization in the opposite
sense causes induction in the upper coils in the same directions and the current thus
inducted passes in the secondary circuit.
In every coil the current flows (in any position of the brushes) always in the same
directions and only the circuits with which they are connected are changing
alternatively but the magnetism is alternatively changing its polarity. Thereby the
energy of induction and the power of the apparatus will be much increased and
amount to more than four times that produced by single coils.
The induced current must always flow through four coils (two upper and two lower
ones connected together) before it flows off whereby the intense action of induction at
the beginning of discharge is considerably reduced because this strong current tends
to retard the demagnetization of iron so that the current will flow constantly.
In order to reduce the sparks on the brushes which are caused while the brushes
pass from the principal into the secondary current, the combination may be such that
the second coils of the same magnet rods do not receive the opposite principal current
at that moment but afterwards, so that the demagnetisation by the opposite current
may commence after the brushes have passed into the secondary current. This may
be accomplished by using seven instead of six pairs of magnets and brushes three of
which are always in the principal and four in the secondary circuits.
In general every induction of a current involves the generation of a secondary
current of the same intensity in an opposite direction which causes alternating currents
in the conductor or in the coils, which are within the influence of the inducing magnet
or current.
In our apparatus the second and opposite currents are always extra-currents started
within the principal current and opposite to it. They equalize and equal the quantity
of energy of the principal current which represents the equivalent of dynamic force
transformed as secondary current. Consequently the opposite current never exists as
such but consume the principal current and become united with it.
This Invention relates further to an arrangement by means of which the shaft of
the apparatus may be suitably rotated by a small electrodynamo motor attached to it.
For this purpose an iron arm is fastened at one end of the shaft. One end of the
arm is provided with two iron rods wound with coils and forming an open electro-
magnet. The other end is made of a different metal and serves as counter weight.
The ends of the wires of the coils pass through a hole in the centre of the shaft and
are respectively connected with rings mounted on the shaft so that a part of the
principal current must pass through the coils of the before mentioned arm.
Eight small electromagnets are disposed in a circle so as to correspond with the one
at the arm the ends of their wires are connected to one of the brushes of the same
designation also in shunt so that the eight magnets and the one at the arm always
repulse each other.
The currents of the brushes vary in strength when passing from the secondary to

page_text: the principal circuit; therefore the connections must be so made that the rotating
magnet on the arm always stands just opposite to one of the eight magnets which are
in connection with the brush.
The magnet on the arm will therefore be repulsed and the required motion bo given
to the shaft.
By making the connections between the upper and lower coils somewhat differently
as before explained, the difference of the intensity of current will be greater and the
power of driving the shaft more energetic.
J. HENRY JOHNSON,
47, Lincoln's Inn Fields, London, W.C.,
Agent.

page_text: the Conditions of Electric Currents.
We LOUIS BOLLMANN of 2nd District Dianabad Manufacturer ERNST BIEDERMANN
of 1st District Schenkenstrasse 10, Electrician and DEMÊTRE MONNIER of 1st District
Schenkenstrasse 10 Electrician all in Vienna in the Empire of Austria 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 improvements in the method of and in apparatus for
transforming continuous electric currents of high tension to electric currents of lower
tension by the combination of a number of electro magnets with a coinmutator whereby
the several coils of the magnets are divided into two separate circuits in one of which
is led the primary current of high tension through a number of the said coils connected
in series while in the other circuit the induced current of low tension is led away from
the other coils connected with it in parallels. By the action of the commutator the
coils are successively brought in connection with the one and then with the other of
these two circuits in such a manner that in cach coil both the primary and secondary
currents flow successively but always in the same direction.
We will proceed to describe this Invention with reference to the accompanying
drawings, Figures 1 and 2 of which are views at right angles to each other of one of
the electro magnets employed. Figure 3 is an elevation and Figure 4 a longitudinal
section of the commutator with parts of the frame shown in section. The remaining
Figures are details and diagrams which will be hereinafter referred to.
The electro magnets consist of iron rods A. A (Figures 1 and 2) connected at both
ends to solid iron plates B. B. so as to form closed or ring magnets, or they may be
formed of iron wire, wound to a closed ring. These rods (or the wire rings) are
covered by layers of insulated copper wire, forming coils, the ends of which are
connected as explained hereafter.
The form and construction of these magnets form no part of this invention. Eight
such magnets are shown in Figure 1 placed side by side.
The rotating parts of the commutator are fastened to the shaft C mounted in bearings
in the frame D, and is rotated at the required speed by any convenient power, or by
the primary current, as will be explained hereafter.
E E E E are four metal rings each fastened to, but insulated from the shaft C.
L are the bushes, which transmit the currents to and from the rotating parts.
G G H H J J J J are ring sections forming the surface of the commutator
they are fastened to the wooden drums FI FII and their relative positions are shown
clearly in Figure 12 which represents the circumference of the drum from s to t
supposed to be stretched out flat.
Against this circumference bear sixteen brushes K, which are distributed around the
circle in eight pairs as shewn in Figure 3. In Figure 12 the position of their bearing
surfaces on the commutator are shown by the hatched squares."

page_text: The segments GI G" (of which only GI can be seen in Figures 3 and 4) are each
connected to one of the transmitting rings EI EI by means of copper wires which
are insulated and pass between the shaft and the inner rings E E as shown on the
left hand side of Figure 4. The brushes L which bear against the outer rings E¹ EIV
form part of the primary circuit therefore the segments GI Ğ" are in constant connection
with the primary current.
The segments, H¹, H" forming the larger parts of the circumference are similarly
connected to the inner rings E" E by the parts H and the brushes. I, bearing on
the said rings E E are in connection with the cables of the secondary circuit, which
conduct the induced low tension current away from the segment H through the ring E"
and returns the same through the ring E to segment H". The brushes L are
fastened to but insulated from the frame D).
The four narrow segments JI JII JIII JIV are connected in pairs by rods n n which
pass underneath the segments, JI JII forming one pair, and the segments J JIV form
the other pair. The spaces between the segments are filled with a hard nonconducting
substance.
The brushes K bearing against the segments must be so constructed that their
contact surfaces are not altered in position and width when they wear away. This is
accomplished by making them in the form, shown in the Figures 5, 6 and 7. They
consist of thin elastic strips or wires, which are preferably fastened in bundles in
notches cut into the body as shewn in the side view, Figure 6. They stand at an
angle to the axis of the collector (Figure 4) but in radial direction, as seen from the
front (Figure 3) and they are fastened between two metal plates forming the brush
holder k, so that they can be adjusted more or less outwards to compensate for wear.
These plates constituting the brush holder extend to near the commutator, in order
to prevent the strips bending sideways, and also to assist in leading away the current
and thus prevent heating.
The holders can swing freely on the four shafts M and springs v of india rubber or
spiral springs are stretched between proper projections w to press the holders and
brushes to the collector. Each holder is insulated as shown in the lower part of
figure 4, which is a section on the line y y in Figure 3. The holders are so disposed,
that the faces of the brushes bear on the commutator in four rows at equal distances
from each other, as shown in Figures 3 and 4 and by the hatched squares in the
diagram Figure 12. Each brusholder is connected by a cable to one end of one of
the coils of the magnets, as indicated by P in Figures 3, 5 and 7. These connections
are illustrated by the diagram Figure 10 in which the circumference of the commutator
and the bearing faces of the brushes are drawn narrower than in Figure 12 to save
space.
The lower eight brushes, bearing on the segments G H J JI, are marked + and
those bearing on the upper segments G H JI JIV are marked with the negative
sign; and lettered a b c d e f g h. Two brushes of the same letters one marked +
and the other always belong to the same circuit. The coil of the magnets, with
which each brush is connected is marked with the same letter and sign.
It is to be remarked, that the two magnet rods marked with the same letters for
example (a + and a - ) do not belong to one ring magnet but to different magnets
standing side by side, and that the connections between these two coils is such, that
the current must flow in each, in different directions around the rods, as is indicated
by arrows.
Suppose the commutator to rotate so, that its circumference moves in the direction
of the arrow Z, and the primary current to flow towards GI as above explained, and
then through the brush a + which covers it to the coil a + and then to coil a -
and
through brush a -, to the segment J, with which the latter is in contact; from JIII
it passes through rod n to J thence it passes through the brush b+ to the coils b+b-
brush b to segment JIV; through rod n to J" from where it circulates again through
brush c+coils c + c- brush c- to the segment G" from which it passes away to
to the principal cable leading to the dynamo.
-

page_text: -
The primary current flows therefore through the coils a + a, b+, b, c + c −,
and magnetizes the rods belonging to them to the required degree.
-
As the commutator moves on, the segments change positions in relation to the
brushes so that for example in the position shewn by the diagram Figure 11 the
segments GI GI are nearly leaving the brushes a + and c-, while they are already
covered by those + and d- whereby the principal current is never interrupted.
Going on further GI G will come in relation to the brushes + and d into the
same position as they were before to a + and e- and the latter (a + c) have then
passed out of contact with the primary circuit and got into contact with the large
segments H H of the secondary circuit. The brushes to the right side of segment G"
are therefore entering the primary circuit and the magnet rods of the coils belonging
to them, are being newly magnetized until their bushes get to the left side of G₁ out
of contact with the primary and again into contact with the secondary circuit.
-
-
Thus the rods h+h have been previously magnetized and are now demagnetized,
which causes the induction of a secondary current in the coils surrounding them,
which is of equal direction to the primary current that has magnetized the iron. This
secondary current flows through the brush h to the segment H2 and then through
HI E and brush L into the cable, leading to the lamps, returning then to H¹ to
complete the circuit; and as the commutator moves on further, new coils pass from the
primary into the secondary circuit so that there are constantly six of the coils in the
primary and ten coils in the secondary circuit.
But while the six coils are connected with each other in series, that is to say one
after the other, the latter ten coils are connected with the secondary circuit in parallels
or side by side. This causes the tension of the induced current to be much less than
that of the primary. If the resistance of two coils is then the resistance of three
pairs in series is 3; and of five pairs in parallels it is ; the difference of both is
therefore as 3 to 5, or as 1 to 15; but under the same electromotive force the
difference of tension is proportional to the difference of resistance. It is obvious, that
the quantity or intensity of the induced current is in inverse proportion to the tension.
At the moment the segments G¹ G leave a brush, the current tends to flow on,
while the iron is being demagnetized; this is liable to produce sparks on the brushes;
and this would be especially the case, if the two coils belonging to one pair of brushes,
for example a + and a -, were belonging to the same ring magnet, because the entire
magnetism would then be reduced or discharged at once. But as the rods a + and a-
belong to separate ringmagnets the tendency to spark is very much reduced for the
rod belonging to the same magnet to which a + belongs has been previously
disconnected and its magnetism partly discharged. The magnetic moment of the
entire ring, magnet is therefore now only of that which it would be, if both rods h
and a had the primary currents in their coils; for it has been proved by experiments
that in rings, the magnetic moment is almost exactly the same in every part of the
circle, wherever the magnetizing coil may be situated on it. While previously both
bars h and a + were magnetized (as are now those a - and b+ of the next ring)
the magnetism was double what it is now after h - has been disconnected; and if a +
is now disconnected, the remaining of the magnetism is vanishing as well in h. - as
and
in a +; consequently the induced current is again divided between the coils /
a+so that for this reason the tendency to spark is reduced to one fourth.
-
-
-
-
The other rod a - - belonging to the same pair of brushes cannot fully demagnetize
at the moment of passing out of the primary circuit because its partner 6+ is still
being magnetized the iron of this ring can therefore be demagnetized one half, and only
one half of the induced current due to this reduction can act on the coil a -, while the
other half is acting on the coils 6+ tending there to strengthen the primary current.
This system of reducing the tendency to spark may be further extended, by using a
larger number of magnets of less dimensions. The brushes would have then to be so
disposed, that two brushes are constantly bearing on the segments G² G" and more
than four segments J, connected in pairs by rods n, would have to be used side by
side. The primary current would then flow in two series which are connected together
in two parallels.

page_text: More than two rods may be connected to form one closed magnetic circle, or more
than two coils may be placed on one ring, and connected to the brushes in such a
manner that each pair of the latter has connection with more than two magnetic rings,
whereby the sparks will be further reduced.
In the above described arrangement the magnetism of those rods, whose coils are
connected to the secondary circuit can be discharged only so far, that the energy of
induction by its vanishing, is yet capable of producing an electromotive force, in the
coils surrounding the rods, which corresponds to the tension required, for if the
vanishing of the magnetism, has no longer that energy, the current from the other
coils, also connected to the seginents H H would flow backwards through this coil,
instead of going through the lamps. The speed of the commutator must therefore be
so regulated, that the coils are passed out of connection with the secondary circuit,
before the energy is so far reduced.
In order to make the apparatus capable of discharging the entire magnetism and
of increasing its power of action, the following modification may be used, which is
illustrated by the diagram Figure 13.
There are as many pairs of brushes connected in series with the primary circuit, as
there are connected in parallels with the secondary circuit namely 3 pairs of each and 6
(instead 8) ring magnets. Each rod has two separate coils, which are connected with
each other and with the brushes as follows:-
Commencing again with the brush a + which is in contact with G the wire passes
first to the lower coil and the rod d +, to which it is connected so, that the current,
coming from G must flow in the opposite direction to the current in the upper coil, of
the same rod. The other end of that coil is connected to the lower coil, of the rod d
of the next ring, also in opposite direction, so that the current must flow in it opposite
to the current in the upper coil das well as to that in the lower one d +
-
From coil d
the upper coil of a
arrangement.
below connection is made, with the upper coil of a + and then with
in the same directions, as described with reference to the first
-
-
and
In the same way the wire of the brush + is passed to the lower coil e +, which is
connected to the lower coil e and this again to the upper coils b + and b
brush -1
and so on in the following orders, brush c + lower coils f+f-upper
coils c, c, brush e- ; brush d + lower coils a + a-, upper coils d, +d-
brush d; brush e + lower coils b + b upper coils e+, e-, brush e -; brush f+,
lower coils cc-; upper coils f+f-brush f-
In one of the two coils of the same rod there is constantly the primary current whilst
in the other coil there is a constant secondary current.
-
-
In the arrangement Figure 13 when the brushes ƒ + - change connections, by
passing from the segments GI JIV over to H, H" the brushes c +, c
change also
from HH to JG". The magnetism of the rods f+f- commences then to
vanish and induce in the upper coils a current in the same direction; as the primary
current was flowing previously in them. At the same time the lower coils off+f-
commences to receive from the brushes c + c - the primary current in the opposite,
direction, which tends to magnetize the rods in the opposite sense, and thereby accelerate
the demagnetisation; when the former magnetism has completely vanished, the iron
is magnetised by the current in the lower coils in the opposite sense. Both the
demagnetisation and the magnetisation induces a current in the upper coils in the
same directions, and the current thus induced passes into the secondary circuit.
When the brushes have reached the positions d +d, the iron will be oppositely
magnetized; and when they pass into the positions c + c -
the circuits in the upper
and lower coils are changing again. The lower coils, which are connected with the
brushes come now into the secondary circuit, and the upper ones receive the
primary current from the brushes c + c
-
The rods cc are now demagnetised and magnetised in the same manner but in
opposite direction to that before described for the positions ƒ +ƒ - The rods are
therefore now alternately in opposite senses; but the currents flow in every position of
the brushes always in the same directions. The energy of induction and the power of

page_text: the apparatus is much increased by this arrangement, and will be more than four times
that produced by single coils.
In order to reduce the tendency to sparking when the brushes pass from the primary
into the secondary circuit, the combination may be such, that the second coils of the
same magnet rods do not receive the opposite primary current at the same moment, but
a little afterwards so that the forced demagnetization may commence after the brushes
have passed into the secondary circuit. The first discharge of the magnetism will then
be like in the first arrangement, only by its own energy and is not forced by the
action of the opposite primary current in the other coils. This may be accomplished
by using three pairs of brushes in the primary and four pairs in the secondary circuit.
When a current is induced in a coil, by the start or by the vanishing of a primary
current, a second current of equal intensity but of opposite direction must always be
induced in the same coil, when the primary current vanishes or starts again. Now in
this apparatus this is really the case although the currents appear to flow constantly in
the same directions. The arrangement is such that the second and opposite currents
are alway extracurrents induced within the coils, carrying the primary current to
which they are always opposite; they equalize the energy of the primary current,
which represents the equivalent of dynamic force transformed as secondary current.
The opposite currents can not therefore come into existence as such but are consumed
by the primary current.
Figures 8 and 9 show an arrangement for driving the commutator shaft C by the
primary current. On the end of the shaft C is fastened the iron arm B which carries
at one end two iron rods, wound with insulated copper wire forming an open electro-
magnet and the opposite end of the rod R carries a counterweight of some nonmagnetic
metal. The wire ends of these two little coils pass into and through a hole or passage
in the centre of the shaft C and are connected the one to the ring E¹ and the other to
the ring EV (Figure 4) so that a part of the primary current is shunted off to pass
through these coils.
S are eight small electromagnets disposed in a circle with the shaft C at its centre;
their wire ends are each connected to one of the brushes marked with the same letters
also in shunt, so that the magnets S and R repulse each other in every position of R.
The primary and the secondary currents will flow alternately through the coils S
but as the connections are in shunt the high tension of the primary current will drive
a much stronger current through them than the secondary one. The difference of these
two shunted currents will produce the driving power.
Having now particularly described the nature of this Invention we desire to
state that we do not confine ourselves to the particular form constructions and
connections of the magnets and of the commutator herein described which may be
varied in many ways for example the commutator may have a reciprocating or vibrating
motion instead of a rotating one in which case the transmitting rings E and brushes L
may be dispensed with the connections of the outer circuits being then made by
flexible cables or by quicksilver contact.
The numbers of the brushes, segments J cables or magnets as well as their dimensions
and projections may be varied according to circumstances but what we claim for the
transformation of electric currents is.
First. A commutator or its equivalent in combination with closed electro magnets,
substantially as shown and described, which are intermittently or alternatingly
magnetized by the primary current that passes through a number of the coils of the
said magnets connected with each other in series while the other coils of the magnets
are connected in parallels to each other with the secondary circuit to lead of the
current induced therein, by the said change of magnetism in the iron, which is caused
by the primary current as setforth.
Second. A commutator or its equivalent in combination with the coils of the electro
magnets whereby the currents from some of the latter pass one after the other on one
side into the primary circuit while currents from other of the coils pass in like order
B

page_text: on the other side into the secondary circuit substantially as described and whereby the
primary and secondary currents flow uninterruptedly and continuously as setforth.
Third. The arrangement of the commutator brushes with the cables leading to the
coils of the magnets substantially as shown and described whereby the primary and
secondary currents are caused to flow successively through each coil always in the
same direction.
Fourth. The connection of the brushes or their equivalents with the electro magnets
substantially as described, the currents coming through one brush passing through
two, four or more coils which belong to different ring magnets before passing off
through the next brushes for the purpose of reducing the sparks as setforth.
Fifth. The application of two sets of coils or series of coils on each magnetic rod or
its equivalent as herein setforth the principal current passing through one set while
the secondary current passes off in the opposite direction through the other set as
herein before described.
Sixth. The brushes K with their holders substantially as herein described their
plates or wires constituting the brush being placed radially or nearly so to the
circumference of the commutator and at an angle to the axis substantially as set
forth.
J. HENRY JOHNSON,
Agent.