A Method of Transforming Alternating Electric Currents of any Tension into Continuous Currents also of any Tension, and Conversely, and Apparatus for that Purpose.
Year: 1892

page_text: Date of Application, 6th Oct., 1892
Complete Specification Left, 19th June, 1893-Accepted, 6th Oct., 1893
PROVISIONAL SPECIFICATION.
A Method of Transforming Alternating Electric Currents of any
Tension into Continuous Currents also of any Tension, and
Conversely, and Apparatus for that Purpose.
We, MAURICE HUTIN, of No. 463 Rue Canmartin, Paris, Engineer, and
MAURICE LEBLANC, of No. 63 Allee du Jardin Anglais, Le Raincy, Seine & Oise,
France, Engineer, do hereby declare the nature of this invention to be as follows:-
I. OBJECT OF THE INVENTION.
:-
The methods hitherto employed by us for passing from an alternating to a
continuous electric current depend upon the use of apparatus where an external
revolving field acts on an internal armature analogous to that of continuous current
Imachines. The phenomena which occur in apparatus thus employed are identical
with those which occur in the said machines.
The method which forms the subject of the present invention depends upon the
use of apparatus in which the circuits traversed by the primary and secondary
currents are coiled on the same magnetic cores and conspire in the same manner to
produce acting currents.
The phenomena which occur in these apparatus are the same as those which
occur in ordinary alternate current transformers.
This process has the advantage of allowing the use of magnetic circuits
completely closed within masses of iron, that is to say along magnetic circuits as
permeable as possible, whereby excellent utilisation of the material is obtained,
also a large production, and the loss of energy due to necessary commutation is
completely avoided, the adjustment of the brushes being independent of the
production of the apparatus. Finally, our process admits of commutating apparatus
of the greatest simplicity.
When our method, without condition of synchronism is employed with our
alternating machines, or, with synchronism, is applied to any alternating machines,
it furnishes a complete solution practical as well as theoretical of the problem to
convert an alternating into a continuous current and conversely.
The variation of the number of ampère turns in terms of time may be represented
by the curve Fig. 1, the times being the abscissæ and the number of ampère turns
the ordinates. It is to be noted that nothing would be changed in the magnetic
and electric effects produced by or in this circuit if, instead of sending through it.
t
an alternating current having intensity A sin. 2 T it were traversed by a current
T
of constant intensity by varying the number N of convolutions, or simultaneously
[PSI
A

page_text: varying the intensity and number of convolutions in such manner that their
product X should always be represented by the expression N A sin. 2.
t
Indeed at any moment t of the period T in all cases the number of ampère turns
is the same.
And it is known that in any electro-magnetic circuit the magnetic
and electric phenomena always depend solely on the numbers of the ampère turns
in the various electric circuits of this kind.
Likewise, when we consider an ordinary alternating current transformer with its
two circuits coiled around a single magnetic core, we note that nothing will be
changed in the mutual inductions and transmissions of energy from the one circuit
to the other if the number of convolutions in one of the circuits is kept constant
while the intensity in it is varied according to the law of the sine above stated, and
if, on the contrary, the intensity should be kept constant or at least always in the
same direction in the other circuit by varying the number of convolutions in such
manner that the number of ampère turns of the latter circuit shall vary with the
time according to the sinusoidal law. This has led us to the contrivance of
apparatus transforming alternating currents of any intensity into continuous
currents also of any intensity, and conversely.
III. GENERAL MODE OF APPLICATION.
We construct apparatus having the following arrangements. A B and A B
(Figure 2) represent two equal and similar magnetic cores in which by means of
primary coils wound on them traversed by alternating currents suitably timed, we
develop two alternating flows of equal frequency and intensity, having a difference
of phase of a quarter of a period. C is an ordinary collector of a continuous
current machine, which in the following explanations may be considered stationary,
while two diametrically opposite brushes are turned around it. In Figure 2 the
magnetic cores are shewn developed. On each of them we coil 2n secondary
bobbins having respectively the following numbers of convolutions.

page_text: -
furnished are to be followed according to the following rule, the + bobbins are to
be coiled in the one direction, the bobbins in the opposite; for instance the
+bobbins may be wound right hand from their entering to their leaving wires,
the entering wire of a bobbin being considered the free end of the first convolution,
and the learing wire being the free end of the last convolution. The bobbins
will thus be coiled left hand. Bobbins, however, producing the same results as the
above may be coiled all in the same direction either right or left, but taking care
in connecting the bobbins, to connect to the leaving wire of the bobbin which
should have contrary direction. Examination of the table shows that any two
bobbins diametrically opposite on a magnetic core have the same number of
convolutions oppositely coiled.
With the 2 n bobbins of the 1st core and the 2 n bobbins of the 2nd core we
form 2 n sections each consisting of two of these bobbins connected in series by
joining the leaving wire of the bobbin on the 1st core to the entering wire of the
bobbin on the 2nd core, but, following the observation made above, when all the
bobbins are wound in the same direction, the connection is reversed for bobbins of
opposite sign.
-
When the sum of the convolutions of a section has to be found as in the following
description, this can be done alegbraically as each section may consist of oppositely
coiled bobbins. The 1st section comprises the bobbins L and 11, the 2nd section
comprises the bobbins 2 and 21, and so on the (2n-1)th section has
bobbins (2n-1) and (2 n − 1), and the 2 nth section has bobbins 2n and 2 n'.
We connect these sections in series and connect the junctions to the successive
segments of a commutator as in the Gramme machine, so that the leaving wire of
No. 1 section which is the leaving wire of bobbin 1' is connected to segment I of
the commutator and to the entering wire of No. 2 section. The leaving wire
of No. 2 section connects to segment 2 of the commutator and to the entering wire
of No. 3 section, and finally the leaving wire of No. 2 n section connects to
segment 2 n of the commutator and to the entering wire of No. 1 section. As
stated above, the number of convolutions of several sections can be summed
alegbraically. In Figure 2, which shews the connections of the entering and
leaving wires of the sections to each other and to the commutator segments, the
respective numbers of convolutions of the different bobbins are indicated by the
dimensions of the rectangles representing the bobbins, the negative bobbins being
marked by shading lines.
-
The case to which this figure applies is that of an apparatus in which 2 n = 12
and a 0. Applying the law of the table, the number of convolutions on 1 and 7
of the 1st core and on 4' and 101 of the second are nil, so that the places which
would be occupied by these bobbins if a had another value, are merely indicated
by vertical lines without distinguishing the entering and leaving wires as being
separate.
1
The two brushes a and b move round the commutator with uniform velocity
indicated as (T being the time occupied in a complete revolution). They always
T'
bear on two diametrically opposite segments and if, for instance, their breadth of
contact is equal to that occupied by a segment and insulating space, they always
short circuit two diametrically opposite sections, each new short circuiting taking
place immediately on the cessation of the previous one. The brushes are connected
to two insulated rings F and F on which are two stationary rubbers ff by which
the current of the secondary circuit is collected. Under these conditions, the
secondary circuit is divided into two elementary circuits from the one brush to the
other. Thus when, as shewn in Figure 2, the brush a is at the segments 1, 2,
while is at the opposite segments 7, 8 (there being 12 segments) the circuit
from a to bis 1st along a first circuit formed by sections 3 + 3' 4 + 4' 5 + 5¹
6+61 7+7¹, and
2ndly along a second circuit formed by the bobbins 9 + 9' 10 + 10¹ 11 + 11¹

page_text: 12+12 1 + 1. The sections 2 + 2¹ and 8+ 81 are short circuited by the
brushes. To every section of the 1st circuit corresponds a section of the 2nd
having the same number of convolutions but oppositely coiled. These two circuits
will therefore always have the same number of convolutions disregarding the
direction of coiling, and consequently their resistances will always be the same and
their coefficients of self induction. Each of these circuits according to the position
of the brushes has a certain number of convolutions coiled in one direction and a
certain number oppositely coiled, all traversed necessarily by the same current as
they are connected in series.
The alegbraic sum of the magnetic effects of two oppositely wound convolutions
in one magnetic core, when they are traversed by the same current is nil, and the
alegbraic sum of their mutual inductions on any other convolution on the same
core is also nil. Consequently the resultant of the magnetic sections of one of the
circuits connecting the brushes at any moment t of the period T which is occupied
by a complete revolution of the brushes, is equal to the alegbraic sense of the
actions of all the convolutions comprised between the brushes, reckoning as positive
all the actions produced by the convolutions coiled in the one direction, and as
negative all those produced by the convolutions oppositely coiled. The same
applies to the resultant of the mutual inductions between the different convolutions
in the circuit and any coil on the maguetic cores. Finally, at every moment of the
period T the effects of the two circuits become added in relation to the magnetic
cores and to every other coil upon them. In other words, the number of ampère
turns of the circuit formed of the different elementary sections is at every moment
of the period T equal to the intensity multiplied by twice the algebraic sum of the
number of convolutions of each circuit from brush to brush. If the brushes be
moved successively segment by segment, six successive positions at six different
moments of the half period are obtained, namely when the brushes bear on segments
.1-2, 2-3, 3-4, 4-5, 5-6 and 6-7 of the commutator which has 12 segments. If
we calculate what at these different moments and those corresponding to them in
the other half period, are the values of the algebraic sums of the convolutions
in the circuits from brush to brush, we see that the law of variation of these values
and consequently of the algebraic sums of the ampère turns with a constant
intensity circulating in the whole of the secondary circuit, is sensibly represented
by the sinusoidal function of the time, which was the object that we have had in
view. But in order to have this constant intensity, the primary current must at
every moment supply an equal amount of energy, for which purpose we employ on
each of the magnetic cores two currents suitably timed in phase, that is to say, in
such conditions that the energy of the one circuit being of the form Q sin.³ 2
T
T
t
T'
t
the other shall be of the form Q cos. 2π the sum of the two energies being
constant. Hereinafter we shall state what currents are suitable for this result, and
how they may be obtained.
The arrangement of our apparatus permits of the use of a very small number of
sections, and this is one of its most important properties.
In the Gramme ring, the division of the conductor coiled on the magnetic core
into a large number of sections has a double object :
1st. It avoids loss of energy in heating work, due to the successive short
circuiting of all the coils of the ring, every short circuited section remaining during
the period of short circuit, the seat of an electro-motive force, which, other things
being equal, is sensibly proportional to the square of the number of convolutions in
the section. The effects of this electro-motive force can therefore be lessened by
increasing the number of sections, into which the coils of the ring are divided.
2nd. To reduce the lead of the brushes so that the lead angle necessary to avoid

page_text: sparking, approaches as nearly as possible to that which corresponds to that for
maximum production, being the position nearest the neutral zones, for the self
induction of each section being reduced by lessening the number of its convolutions,
as stated above, the intensity of the current in this section can be brought to such
a value, that no sparks attend passage of the brushes with a reduced electromotive
force; and this force due to the movement of the section under the brushes in the
inducing field, is so much the less, other things being equal, the more nearly the
movement of the section under the brushes takes place in the neutral zone of
the field.
In our apparatus, where the acting flows are constantly formed within a magnetic
core or magnetic cores, the actions are as in an ordinary alternating current
transformer in which the algebraic sum of the primary and secondary ampère turns
is sensibly nil. If we wished to have this sum in our apparatus without reckoning
the short circuited sections on the secondary circuit it would differ from 0. But
the balance resulting from the ampère turns of these sections restores this algebraic
sum sensibly to 0. The whole energy of the system being thus utilized, there can
be no external loss of energy nor sparking at the brushes, however small may be
the number of the sections. It is thus that we have been able to avoid all these
inconveniences, and notably all sparking at the brushes while developing an electro
motive form of 150 volts with 12 commutator segments.
We have shewn in Figure 3 a modification of the apparatus, the magnetic core
being shewn not developed and the commutator concentric with it. The construction
of this modified apparatus is more simple since there is only one ring, which
moreover is in all respects the same as the ring A B of the apparatus previously
described, and around this ring there is a single primary circuit, which may be
supplied with any alternating current. This apparatus however, does not give
currents rigorously continuous, but of constant direction, for the single alternating
current which feeds it varies in energy and the secondary current must shew like
variations.
We may however, combine with this apparatus condensers which, storing part of
the energy given out by the primary current when it exceeds the mean may give
out this store to the secondary current, when the energy of the primary falls below
the mean, the variations in the energy of the transformed current being thus male to
disappear.
We may also adopt for our apparatus an arrangement which does not require
variation of the number of convolutions on the bobbins according to the
formula V sin. 2 π a V sin. 2 T
V cos. 2 πT
(a + 1/17)
for the one core, and V
(a + /²/n)
2
COS. 2 TT (
1) for the other core (as appears in the table above), but
which may have equal numbers of convolutions, or numbers varying according to
any law, the segments of the commutator being varied in width according to a
conformable law, so as to vary the duration of the passage of the brushes over
them, each opposite pair of segments being nevertheless always equal. The desired
result, namely the variation of the ampère turns according to the sinusoidal law
may be then obtained, as indicated in Figure 4.
IV. MODE OF DETERMINING THE Two FLOWS, WHEN Two MAGNETIC
CORES ARE EMPLOYED.
We have now to explain how, in apparatus in which two associated transformers
are employed, it is possible to determine the two flows suitably timed with respect
to each other, in each magnetic core.
This result is at once obtained by employing two alternating currents of equal
intensity and frequency, but timed at of a period apart (sine and cosine currents)
each led along a special circuit as shewn in Figure 2. This arrangement
requires 4 conducting wires.

page_text: Three wires may be employed supplying 3 alternating currents of equal intensity
and frequency but varying in phase each from the next by 3rd of a period as we
may thus demonstrate.
Let I, I, I, represent the respective intensities of these 3 currents at the moment
t of period T, and let A be a constant intensity, then
We see that the variation of these ampère turns relatively to the time will be of
the same frequency and intensity but timed of a period apart in phase.
It results that it is possible to develop the desired flows in the two magnetic
cores, employing only 3 wires, by coiling each of these cores with convolutions
suitable to the 3 currents separated in phase by of a period, which, supplied by
3 wires as in the apparatus above described, will maintain the energy of the system
constant. The three wires after coiling the cores of the two transformers, are, as
usual, connected in short circuit, so that each in turn serves as return wire for the
currents sent by the other two. This arrangement is shewn in Figure 5, which
suits the case in which a = 0 in the foregoing formulæ. The respective numbers
of convolutions traversed by each current are indicated by the relative dimensions
of the rectangles representing the bobbins, and the direction of coiling is indicated
by the shading lines.
When there is only one alternating current at disposal, the arrangement shewn
in Figure 6 is adopted.
2πT
T
The current is divided into two, intended for two primary currents. One of
them has a self induction bobbin L, the other a condenser of capacity C. The
relation of the quantities L and C, and the quotient R obtained by dividing the
quantity of energy consumed by one of the two primary circuits by the square of
the intensity of its currents, is then obtained R: = L= C. If these relations
T 2 πT
subsist, the two branch circuits will be traversed by equal currents of a period
apart, and these circuits will act as if they had no self induction, and thus will be
produced the conditions resulting from the direct supply of two currents of equal
intensity phased of a period apart.

page_text: V. RELATIVE RULES AND CONSTRUCTION OF APPARATUS FOR THE CASES
HEREINBEFORE CONSIDERED.
In all cases where we have to employ distinct magnetic cores, the different
connected transformers comprised in one apparatus should be, if not identical, at
least equivalent, that is to say, around each core should be coiled circuits, having
the same coefficients of self induction and mutal induction, and the same resistances.
The skeletons of the transformers may be of any known kind. The primary
circuits are arranged as indicated in Figures 2, 3 and 5; the secondary circuits are
divided into bobbins of various numbers of convolutions varying according to the
sinusoidal law above stated, where the bobbins are on the same ring, but the
number of convolutions may be the same, or may vary according to any law,
the width of the commutator segments being varied conformably, as indicated in
Figure 4.
The connections of the bobbins, and of the sections of the secondary circuits to
each other and to the commutator segments are shewn in Figure 2 when the bobbins
are placed side by side on the magnetic cores. They might however be superposed
or wound in successive layers on the coils.
The synchronous motor required to give the proportional speed to the brushes
may be one arranged according to our invention, which has circuits closed upon
themselves acting so as to correct deviations from synchronism.
VI. APPLICATION OF THE METHOD WITH THREE OR MORE MAGNETIC
CORES.
In case three phased alternating currents are supplied, it is of advantage to
employ three equal and similar magnetic cores, each for an equal primary current,
and each coiled with a primary circuit. As the currents are of a period apart in
hose their values are respectively
I₁ = A sin. 2π I, A sin. 2π
I, = A sin. 2π
++³).
Each of the 2 sections composing the secondary circuit will then consist of:
3 bobbins coiled around the 3 cores, having their numbers of convolutions
determined according to the following table.

page_text: Figure 7 represents such apparatus in the case where a = O and n = 6. All that
has been said as to the secondary circuits coiled on two magnetic cores is applicable
also to this case.
TT
The method may be thus generalized, by assuming J primary currents, differing
in phase by 2
J'
and providing J magnetic cores, around each of which circulates
one of the J currents, whilst each of the 2n elementary sections of the secondary
circuit consists of J bobbins, coiled around the J cores. In all cases it characterises
our system that the sum of the potential energies of the three elementary
transformers shall be constant, so that there is no loss of energy externally, and no
sparking at the brushes.
VII.
CONSTRUCTION OF A MOVING COMMUTATOR
BRUSHES FOR OUR APPARATUS.
WITH STATIONARY
We have hitherto supposed, for rendering explanation easy, that the commutator
is stationary and the brushes revolve. This arrangement may with advantage be
inverted. For this purpose, each leaving wire of an elementary section may be
connected to a rubber bearing on a revolving ring connected to the corresponding
commutator segment. Figures 8, 9, 10 and 11 represent an apparatus in which
this arrangement is adopted.
A synchronous motor M, having 6 poles, shewn in end view in Figure 8, in
longitudinal section in Figure.9 and in plan on the left of Figure 11, gives rotation
to a commutator C, having 36 segments. It is triple, that is to say, it has three
times as many segments as would be absolutely necessary, so that it only has to
make rd of a revolution during each complete period of the alternating currents
which have to be transformed into continuous currents. The segments may be
considered as numbered successively 1, 2, in 35, 36. To this commutator are
connected 12 rings a₁, ag, as,—U1r
The ring a, connected to segments 1, 13, 25,
"
وو
a
a3
"
"
دو
وو
وو
وو
2, 14, 26
3, 15, 27
and so on. On these rings bear 12 stationary rubbers, B1, B2-B12, connected
respectively to 12 terminals Y₁, Y, Ya-Y₁, to which are connected the leaving
wires of the 12 elementary sections, into which we suppose the secondary circuit
divided as shewn in Figure 2, this being an arbitrary division, given only as an
example. Obviously, by multiplying the number of commutator segments corre-
sponding to each section, we can proportionally reduce the angular velocity of a
commutator suited for the alternating primary current of period T.
Round the commutator is arranged a brush carrier D, carrying two pairs of
brushes a, a, and b, b, diametrically opposite. These brushes which collect the
continuous current produced are connected, each pair by a flexible conductor to an
external terminal.
VIII. RULES FOR THE WORKING OF THE SYSTEM.
The arrangement for varying the lead of the brushes is shewn in Figures 9, 10
and 11, and being equivalent to that usually adopted, need not be described.
Generally, for charging the accumulators the potential maintained between their
terminals has to be varied according to the degrees of charge. It is therefore
desirable to arrange the apparatus for producing the maximum potential. We may
suppose that the current generator maintains a determined potential on each of its
conductors. It will therefore suffice to be able to reduce at will the potential at
the leads to the primary circuits. We can do this for instance, by introducing into
each of the conductors, a self induction bobbin. There must therefore be as many
identical bobbins as there are differentially phased primary currents, and these
bobbins must all be simultaneously adjusted.

page_text: Instead of working the synchronous motor which is always comparatively small,
with alternating currents from the generator, a special circuit might be coiled on
each magnetic core of the transforming apparatus, furnishing induced currents of
low tension very suitable for the motor.
IX. CAPABILITY OF THE SYSTEM FOR INVERSION.
In virtue of the general laws of induction, all the applications of our system
are capable of inversion, that is to say-by sending a continuous current
into the brushes of the secondary circuit, which then becomes primary and
revolving the brushes, we can obtain in the circuits formerly primary, but now
secondary an alternating current, or several differently phased alternating
currents, having their frequency determined solely by the speed of rotation of the
brushes.
1
1003
ABEL & IMRAY,
Agents for the Applicants.

page_text: COMPLETE SPECIFICATION.
.
A Method of Transforming Alternating Electric Currents of any
Tension into Continuous Currents also of any Tension, and
Conversely, and Apparatus for that Purpose.
We, MAURICE HUTIN, of No. 46 Rue Canmartin, Paris, Engineer, and
MAURICE LEBLANC, of No. 63 Allee du Jardin Anglais Le Raincy, Seine &
Oise, France, Engineer, do hereby declare the nature of this invention and in what
manner the same is to be performed to be particularly described and ascertained
in and by the following statement :--
. I. OBJECT OF THE INVENTION.
The methods hitherto employed by us for passing from an alternating to a
continuous electric current depend upon the use of apparatus where an external
revolving field acts on an internal armature analogous to that of continuous current
machines. The phenomena which occur in apparatus thus employed are identical
with those which occur in the said machines.
The method which forms the subject of the present invention depends upon the
use of apparatus in which the circuits traversed by the primary and secondary
currents are coiled on the same magnetic cores and conspire in the same manner to
produce acting currents.
The phenomena which occur in these apparatus are the same as those which
occur in ordinary alternate current transformers.
This process has the advantage of allowing the use of magnetic circuits com-
pletely closed within masses of iron, that is to say, along magnetic circuits as
permeable as possible, whereby excellent utilisation of the material is obtained,
also a large production, and the loss of energy due to necessary commutation is
completely avoided, the adjustment of the brushes being independent of the
production of the apparatus. Finally, our process admits of commutating apparatus
of the greatest simplicity.
When our method, without condition of synchronism is employed with our
alternating machines, or, with synchronism, is applied to any alternating machines,
it furnishes a complete solution practical as well as theoretical of the problem to
convert an alternating into a continuous current and conversely.
11
DRIVOtto

page_text: and electric phenomena always depend solely on the numbers of the ampère turns
in the various electric circuits of this kind.
Likewise, when we consider an ordinary alternating current transformer with its
two circuits coiled around a single magnetic core, we note that nothing will be
changed in the mutual inductions and transmissions of energy from the one circuit
to the other if the number of convolutions in one of the circuits is kept constant
while the intensity in it is varied according to the law of the sine above stated, and
if, on the contrary, the intensity should be kept constant or at least always in the
same direction in the other circuit by varying the number of convolutions in such
manner that the number of ampère turns of the latter circuit shall vary with the
time according to the sinusoidal law. This has led us to the contrivance of
apparatus transforming alternating currents of any intensity into continuous currents
also of any intensity, and conversely.
III. GENERAL MODE OF APPLICATION.
Referring to the drawings filed with our Provisional Specification we construct
apparatus having the following arrangements A B and A' B¹ (Fig. 2) represent
two equal and similar magnetic cores in which by means of primary coils wound on
them traversed by alternating currents suitably timed, we develop two alternating
flows of equal frequency and intensity, having a difference of phase of a quarter of a
period. C is an ordinary collector of a continuous current machine, which in the
following explanations may be considered stationary, while two diametrically
opposite brushes are turned around it. In Fig. 2 the magnetic cores are shewn
developed. On each of them we coil 2 n secondary bobbins having respectively the
following numbers of convolutions.
-
This table shews at once, for each bobbin on each magnetic core, its number of
convolutions, this number for half the bobbins ou each core having the + sign and
for the other half the sign. In the construction the indications thus furnished
are to be followed according to the following rule, the + bobbins are to be coiled
in the one direction, the bobbins in the opposite; for instance the + bobbins may
be wound right hand from their entering to their leaving wires, the entering wire
of a bobbin being considered the free end of the first convolution, and the leaving
wire being the free end of the last convolution. The bobbins will thus be coiled
-
°

page_text: left hand. Bobbins, however, producing the same results as the above may be
coiled all in the same direction either right or left, but taking care in connecting
the bobbins, to connect to the leaving wire of the bobbin which should have
contrary direction. Examination of the table shows that any two bobbins
diametrically opposite on a magnetic core have the same number of convolutions
oppositely coiled.
With the 2 n bobbins of the first core and the 2 n bobbins of the 2nd core we
forin 2n sections each consisting of two of these bobbins connected in series by
joining the leaving wire of the bobbin on the 1st core to the entering wire of the
bobbin on the 2nd core, but, following the observation made above, when all the
bobbins are wound in the same direction, the connection is reversed for bobbins of
opposite sign.
When the sum of the convolutions of a section has to be found as in the following
description, this can be done algebraically as each section may consist of oppositely
coiled bobbins. The 1st section comprises the bobbins 1 and 11, the 2nd section
comprises the bobbins 2 and 2¹, and so on; the (2n
n- 1)th section has
bobbins (2n-1) and (2n-1), and the 2 nth section has bobbins 2 n and 2 n¹.
We connect these sections in series and connect the junctions to the successive
segments of a commutator as in the Gramme machine, so that the leaving wire
of No. 1 section which is the leaving wire of bobbin 1' is connected to segment 1
of the commutator and to the entering wire of No. 2 section.
The leaving
wire of No. 2 section connects to segment 2 of the commutator and to the entering
wire of No. 3 section, and finally the leaving wire of No. 2n section connects to
segment 2 n of the commutator and to the entering wire of No. 1 section. As
stated above, the number of convolutions of several sections can be summed
algebraically. In Fig. 2, which shews the connections of the entering and leaving
wires of the sections to each other and to the commutator segments, the respective
numbers of convolutions of the different bobbins are indicated by the dimensions of
the rectangles representing the bobbins, the negative bobbins being marked by
shading lines.
―
The case to which this figure applies is that of an apparatus in which 2 n 12
and α 0. Applying the law of the table, the number of convolutions on 1 and 7
of the 1st core and on 4' and 10¹ of the second are nil, so that the places which
would be occupied by these bobbins if a had another value, are merely indicated
by vertical lines without distinguishing the entering and leaving wires as being
separate.
1
י T
The two brushes a and b move round the commutator with uniform velocity
indicated as
They
(T being the time occupied in a complete revolution).
always bear on two diametrically opposite segments and if, for instance, their
breadth of contact is equal to that occupied by a segment and insulating space, they
always short circuit two diametrically opposite sections, each new short circuiting
taking place immediately on the cessation of the previous one. The brushes are
connected to two insulated rings F and F on which are two stationary rubbers ff¹
by which the current of the secondary circuit is collected. Under these conditions,
the secondary circuit is divided into two elementary circuits from the one brush to
the other. Thus when, as shewn in Fig. 2, the brush a is at the segments 1, 2
whilst is at the opposite segments 7, 8 (there being 12 segments) the circuit
from a to bis 1st along a first circuit formed by sections 3 + 3¹, 4 + 4', 5 + 51
661, 7+ 7' and
2ndly along a second circuit formed by the bobbins 9 + 9¹, 10 + 101, 11+ 11,
12+121, 1+ 11. The sections 2 + 21 and 8+ 81 are short circuited by the
brushes. To every section of the 1st circuit corresponds a section of the 2nd
having the same number of convolutions but oppositely coiled. These two circuits
will therefore always have the same number of convolutions disregarding the
direction of coiling, and consequently their resistances will always be the same and
their coefficients of self induction. Each of these circuits according to the position

page_text: of the brushes has a certain number of convolutions coiled in one direction and a
certain number oppositely coiled, all traversed necessarily by the same current as
they are connected in series.
T
2
The algebraic sum of the magnetic effects of two oppositely wound convolutions
in one magnetic core, when they are traversed by the same current is nil, and the
algebraic sum of their mutual inductions or any other convolution on the same core
is also nil. Consequently the resultant of the magnetic sections of one of the
circuits connecting the brushes at any moment t of the period T which is occupied
by a complete revolution of the brushes, is equal to the algebraic sense of the
actions of all the convolutions comprise.l between the brushes, reckoning as positive
all the actions produced by the convolutions coiled in the one direction, and as
The same
negative all those produced by the convolutions oppositely coiled.
applies to the resultant of the mutual inductions between the different convolutions
in the circuit and any coil on the magnetic cores. Finally, at every moment of the
period T the effects of the two circuits become added in relation to the magnetic
cores and to every other coil upon them. In other words, the number of ampère
turns of the circuit formed of the different elementary sections is at every moment
of the period T equal to the intensity multiplied by twice the algebraic sum of the
If the brushes be
number of convolutions of each circuit from brush to brush.
moved successively segment by segment, six successive positions at six different
moments of the half period are obtained, namely when the brushes bear on
segments 1-2, 2-3, 3-4, 4-5, 5-6 and 6-7 of the commutator which has
12 segments. If we calculate what at these different moments and those corre-
sponding to them in the other half period, are the values of the algebraic sums
of the convolutions in the circuits from brush to brush, we see that the law of
variation of these values and consequently of the algebraie sums of the ampère
turns with a constant intensity circulating in the whole of the secondary circuit, is
sensibly represented by the sinusoidal function of the time, which was the object
that we have had in view. But in order to have this constant intensity, the primary
current must at every moment supply an equal amount of energy, for which purpose
we employ on each of the magnetic cores two currents suitably timed in phase, that is to
, in such conditions that the energy of the one circuit being of the form Q sin. 22,
the other shall be of the form Q cos.³ 2 π the sum of the two energies being
constant. Hereinafter we shall state what currents are suitable for this result, and
how they may be obtained.
say, i
T
t
T'
t
The arrangement of our apparatus permits of the use of a very small number of
sections, and this is one of its most important properties.
In the Gramme ring, the division of the conductor coiled on the magnetic core
into a large number of sections has a double object.
1st. It avoids loss of energy in heating work due to the successive short circuiting
of all the coils of the ring, every short circuited section remaining during the
period of hort circuit, the seat of an electro motive force, which other things being
equal, is sensibly proportional to the square of the uumber of convolutions in the
section. The effects of this electro motive force can therefore be lessened by
increasing the number of sections, into which the coils of the ring are divided.
2nd. To reduce the lead of the brushes so that the lead angle necessary to avoid
sparking, approaches as nearly as possible to that which corresponds to that for
maximum production, being the position nearest the neutral zones, for the self
induction of each section being reduced by lessening the number of its convolutions,
as stated above, the intensity of the current in this section can be brought to such
a value, that no sparks attend passage of the brushes with a reduced electromotive
force; and this force due to the movement of the section under the brushes in the

page_text: inducing field, is so much the less, other things being equal, the more nearly the
movement of the section under the brushes takes place in the neutral zone of
the field.
In our apparatus, where the acting flows are constantly formed within a magnetic
core or magnetic cores, the actions are as in au ordinary alternating current
transformer in which the algebraic sum of the primary and secondary ampère turns
is sensibly nil. If we wished to have this sum in our apparatus without reckoning
the short circuited sections on the secondary circuit it would differ from 0. But
the balance resulting from the ampère turns of these sections restores this algebraic
sum sensibly to 0. The whole energy of the system being thus utilized, there can
be no external loss of energy nor sparking at the brushes, however small may be
the number of the sections. It is thus that we have been able to avoid all these
inconveniences, and notably all sparking at the brushes while developing an electro
*motive form of 150 volts with 12 commutator segments.
We have shewn in Fig. 3 a modification of the apparatus, the magnetic core
being shewn not developed and the commutator concentric with it. The con-
struction of this modified apparatus is more simple since there is only one ring,
which moreover is in all respects the same as the ring A B of the apparatus
previously described, and around this ring there is a single primary circuit, which
may be supplied with any alternating current. This apparatus however, does not
give currents rigorously continuous, but of constant direction, for the single
alternating current which feeds it varies in energy and the secondary current must
shew like variations.
We may however, combine with this apparatus condensers which, storing part of
the energy given out by the primary current when it exceeds the mean may give
out this store to the secondary current, when the energy of the primary falls below
the mean,
the variations in the energy of the transformed current being thus made
to disappear.
We may also adopt for our apparatus an arrangement which does not require
variation of the number of convolutions on the bobbins according to the
for the one core, and V cos. 2 σ a
formula V sin. 2 a V sin. 2 · ( a + 2/11)
V cos. 2 T
(a
a + for the other core (as appears in the table above), but which
may have equal numbers of convolutions, or numbers varying according to any law,
the segments of the commutator being varied in width according to a conformable
law, so as to vary the duration of the passage of the brushes over them, each
opposite pair of segments being nevertheless always equal.
The desired result, namely the variation of the ampère turns according to the
sinusoidal law may be then obtained, as indicated in Fig. 4.
IV. MODE OF DETERMINING THE TWO FLOWS, WHEN TWO MAGNETIC
CORES ARE EMPLOYED.
We have now to explain how, in apparatus in which two associated transformers
are employed, it is possible to determine the two flows suitably timed with respect
to each other, in each magnetic core.
This result is at once obtained by employing two alternating currents of equal
intensity and frequency, but timed at of a period apart (sine and cosine currents)
each led along a special circuit as shewn in Fig. 2. This arrangement requires
4 conducting wires.
Three wires may be employed supplying alternating currents of equal intensity
and frequency but varying in phase each from the next by of a period as we
may thus demonstrato

page_text: Let I, I, I, represent the respective intensities of these three currents at the
noment of period T, and let A be a constant intensity, then
V A sin. 2 T * (F-α).
a
We see that the variation of these ampère turns relatively to the time will be of
the same frequency and intensity but timed of a period apart in phase.
It results that it is possible to develop the desired flows in the two magnetic
cores, employing only 3 wires, by coiling each of these cores with convolutions
suitable to the 3 currents separated in phase by of a period, which, supplied by
3 wires as in the apparatus above described, will maintain the energy of the system
constant. The three wires after coiling the cores of the two transformers, are, as
usual, connected in short circuit, so that each in turn serves as return wire for the
currents sent by the other two. This arrangement is shewn in Fig. 5, which suits
the case in which a = 0 in the foregoing formulæ. The respective numbers of
convolutions traversed by each current are indicated by the relative dimensions of
the rectangles representing the bobbins, and the direction of coiling is indicated by
the shading lines.
When there is only one alternating current at disposal, the arrangement shewn
in Fig. 6 is adopted.
One of
The current is divided into two, intended for two primary currents.
them has a self induction bobbin L, the other a condenser of capacity C. The
relation of the quantities L and C, and the quotient R obtained by dividing the
quantity of energy consumed by one of the two primary circuits by the square of
the intensity of its currents, is then obtained R
===
2 T
T
T
L =
2 T
C.
If these
relations subsist, the two branch circuits will be traversed by equal currents of a
period apart, and these circuits will act as if they had no self induction, and thus
will be produced the conditions resulting from the direct supply of two currents of
equal intensity phased of a period apart.
V. RELATIVE RULES AND CONSTRUCTION OF APPARATUS FOR THE CASES
HEREINBEFORE CONSIDERED.
In all cases where we have to employ distinct magnetic cores, the different

page_text: connected transformers comprised in one apparatus should be, if not identical, at
least equivalent, that is to say, around each core should be coiled circuits having
the same co-efficients of self induction and mutual induction, and the same
resistances. The skeletons of the transformers may be of any known kind. The
primary circuits are arranged as indicated in Figs. 2, 3 and 5; the secondary
circuits are divided into bobbins of various numbers of convolutions varying
according to the sinusoidal law above stated, where the bobbins are on the same
ring, but the number of convolutions may be the same, or may vary according to
any law, the width of the commutator segments being varied conformably, as
indicated in Fig. 4.
The connections of the bobbins, and of the sections of the secondary circuits to
each other and to the commutator segments are shown in Fig. 2 when the bobbins
are placed side by side on the magnetic cores.
They might however be superposed or wound in successive layers on the coils.
The synchronous motor required to give the proportional speed to the brushes
may be, one arranged according to our invention, which has circuits closed upon
themselves acting so as to correct deviations from synchronism.
VI. APPLICATION OF THE METHOD WITH THREE OR MORE MAGNETIC
CORES.
phase, their values are respectively ₁₁ = A 810. 2πT
== A sin. 2 T
T₁₂
T
t
I₁ :
= A sin. 2 T
(+3).
T
Each of the 2 n sections composing the secondary circuit will then consist of
3 bobbins coiled around the 3 cores, having their numbers of convolutions determined
according to the following table.

page_text: IX. CAPABILITY OF THE SYSTEM FOR INVERSION.
In virtue of the general laws of induction, all the applications of our system are
capable of inversion, that is to say, by sending a continuous current into the brushes
of the secondary circuit which then becomes primary and revolving the brushes we
can obtain in the circuits formerly primary, but now secondary an alternating
current, or several differently phased alternating currents, having their frequency
determined solely by the speed of rotation of the brushes.
Having now particularly described and ascertained the nature of our said inven-
tion and in what manner the same is to be performed we declare that what we
claim is :-
:-
1. A method of transforming alternating currents of any tension into currents of
one direction or continuous currents also of any tension, based, first on the
decomposition of the secondary circuit into elementary sections comprising around
the magnetic core or each magnetic core of the apparatus a bobbin having a number
of convolutions variable from those belonging to others of the section or to the same
section on different cores, the said bobbins being coiled successively half in the one
direction, half in the other, upon each core according to the laws hereinbefore
stated secondly the connection in series on each magnetic core, of the bobbins
constituting these elementary sections, the leaving wire of each bobbin being joined
to the entering wire of the next, and the leaving wire of the last to the entering
wire of the first, except when the direction of coiling requires inversion of the
entering and leaving wires to produce the like effect;-thirdly, the connection of
each junction of two successive sections to a commutator furnished with brushes, and
having as many segments as there are sections of the secondary circuit or a multiple
of that number, and the connections of these segments with each other and with the
junctions of the sections being made as herein before described in such conditions
that the secondary circuit is always divided by the brushes into two equal series of
convolutions, whether the brushes revolve or the commutator revolves, substantially
as described.
2. The application of the above method to the construction of an apparatus
receiving in its primary circuit a single alternating current around a single magnetic
core, and furnishing by the relative action of the commutator and brushes a
current of one direction, which may be rendered continuous by the addition of a
condenser, substantially as described.
3. The application of the said method to the construction of like apparatus
receiving two alternating currents differently phased by t of a period, each
circulating around a distinct magnetic core and developing therein a flow varying
by of a period from that developed in the other, the sections of the secondary
circuit being composed each of two bobbins coiled on each core according to the law
hereinbefore set forth; and the primary currents being either sent differently
phased to the apparatus, or being obtained at the apparatus by means of a condenser
and bobbin of self induction, substantially as described.
4. The application of the said method to the construction of like apparatus
receiving Jalternating currents (where J is an integer greater than 2) which,
differently phased by J of a period, circulate around two magnetic cores with
numbers of convolutions determined according to the law hereinbefore set forth,
so as to develop in the two cores two alternating flows of a period apart, and
the sections of the secondary circuit being arranged as above stated.
5. The application of the said method to the construction of an apparatus, which

page_text: J
as in the preceding claim, receives J currents differently phased by of a period,
but which comprises J magnetic cores each having one of the currents circulating
around it with the same number of convolutions, so as to develop in the several
cores flows phased of a period apart, according to the law hereinbefore stated,
the sections of the secondary circuit being in this case composed each of bobbins
upon each of the J cores as described.
6. For apparatus such as are above referred to the construction of commutator
as described, especially in respect of-first, the multiplication of the number of
segments in order to lessen proportionally the regular velocity required, and
secondly the arrangement by which the commutator is rendered rotatable and the
brushes fixed by connecting the junctions of the elementary sections of the
apparatus to rubbers bearing on rings which revolve with the commutator and are
respectively connected to its segments.
7. The inversion of the method whereby a continuous current is transformed into
an alternating current or into several alternating currents differing in phase, the
frequency of which is proportioned to speed with which the brushes revolve round
the commutator or conversely, substantially as described.
Dated this 19th day of June 1893.
ABEL & IMRAY,
Agents for the Applicants.