Method of and Means for Producing the Synchronous Rotation of Two Axes situated a considerable distance apart.
Year: 1897

page_text: Date of Application, 23rd July, 1897
Complete Specification Left, 20th Apr., 1898-Accep'ed, 23rd July, 1898
TRUVIDIONAL DIECIFICATION.
Method of and Means for Producing the Synchronous Rotation of
Two Axes situated a considerable distance apart.
I, CHARLES DENTON ABEL, of No. 28, Southampton Buildings, Chancery Lane, in
the County of London, Consulting Engineer and Chartered Patent Agent, do hereby
declare the nature of this invention (which has been communicated to me from
abroad by La Société Anonyme pour la Transinission de la Force par l'Electricité, of
13, Rue Lafayette, Paris, France, Manufacturers,) to be as follows:-
It is very easy to obtain the synchronous motion of two axes; it suffices to mount
an alternator of any description upon the one and to drive the other by a synchronous
electromotor, using the currents furnished by the alternator. Or there may be
mounted upon both axes two similar alternators, both driven by motors of any kind
connected in parallel by a conductor passing from one terminal to the other, and
working with resistances connected in shunt between the terminals of their armatures.
It is known that these two alternators would tend to synchronise and that the current
passing through the line would be a simple synchronising current and would require
an intensity considerably weaker than if it served at the same time for transmitting
work. But in order to insure that these systems shall work under favourable con-
ditions, it is necessary that the loss in the line conductor shall be very small; it is
therefore necessary to use currents of high voltage if the line has considerable resist-
ance. Now in certain cases, and notably in the applications to telegraphy and
multiple telephones, it would be of importance to be able to arrange at each end of a
line-wire an axis, both revolving rapidly with perfect synchronism. In this case there
might be line-wires several hundred miles in length, having great resistance, while the
consideration of the security of the staff attending to the same would absolutely
prohibit the use of high pressure currents, say above 50 volts.
It would consequently only be possible to send from the one end to the other of the
line almost infinitesimal currents, which would be unable to transmit any power or to
insure the synchronous motion of the alternators. It will be evident that these
currents could not transmit other than simple indications; but these might be
utilised for regulating the speed of rotation of the two axes so as to maintain their
synchronism. This regulation would however have to be effected perfectly
automatically.
This invention relates to methods of and means. for accomplishing the above
mentioned problem.
'Assuming two axes requiring to have synchronous motion to be arranged one at
each end of a line wire, there are mounted on them identical alternators, the terminals
of whose armatures are connected on the one hand by means of the line wire and on
the other hand by a return conductor, or more generally through earth. The two
axes are driven by continuous current motors. Between the terminals of each
armature is introduced a shunt circuit containing a resistance without self-induction.
Under these conditions, it is known that if the line only had a weak resistance and
a negligable self induction (which might be effected by introducing into the line a

page_text: condenser of suitable capacity), the motors would synchronise and that there would
pass at every moment into the line a current that would increase the load of the
one alternator, which might tend to advance, and would reduce that of the other
alternator which might tend to lag behind the first one.
If the line has great resistance, the intensity I of these synchronising currents
would become too weak for developing an appreciable variation of the resisting
couples developed by the alternators on the axes.
But I will assume that by any means, there be developed at each moment in the
shunt circuits before mentioned an electro motive force e proportional to the
intensity I, that is to say, such, that in designating a constant factor by K, e would
be equal to K I, the factor K being of any desired value, then if we designate by /
the resistance of the line wire, by h' and h² the potentials at its two ends, and by 11
and I2 the intensities of the currents passing through the resistances=R in shunt
between the armature terminals of the alternators, then
h¹ - h2
K
+
C) and a variation in the other equal to
R
h¹ - h²
J
(1+
K
K ).
The action will therefore be as though the resistance of the line had been
divided by the factor I+(-
K
R
-) which factor can be made as large as may be
desired.
The simplest way of obtaining the desired result consists in introducing into each
of the shunt resistances R, the armature of a continuous current dynamo, which
would be driven by the same motor as that of the alternator to which it belongs,
and the reaction of whose induced part would be neutralised as will be shown later on
and whose inducing part is introduced into the line. When the reaction of the
induced part of a continuous current machine is artificially neutralised nothing is
easier than to make it develop a quantity of electrical energy as great as may be
required relatively to the quantity of energy expended for its excitation,
Let us assume that this ratio be equal to 1 : 33. If we employ the current
produced by this machine for exciting a second similar machine, the energy
produced by the second would be 1000 times greater than that expended for exciting
the first one.
In thus connecting 4 machines connected in stage series the ratio would become
equal to 10%.
If several machines thus connected in stage series are employed, it is advisable to
couple the several local circuits with condensers of suitable capacity in order that
the coefficients of self induction of these several circuits may always be considered
as nought.
.
Only the arinature of the last machine would be included in the shunt circuit R
of the station where it is situated.
It will thus be seen that it is easy to give the divisor coefficient +
given a numerical value as great as may be desired.
above
It might be feared that if the variations of the potential difference h¹-h² were
rapid, the action of the working motor would be disturbed by the extra currents
which accompany each change, and that the electromotive force developed in the last
armature of the said machines connected in stage series would not always remain

page_text: proportional to the intensity of the current sent through the line. As to this, it is
sufficient to observe that the said system is only intended for the transmission of
signals and that consequently the axes whose synchronous motion is desired are to
revolve at high speeds and only require to furnish a very small amount of work. The
devices fixed on these axes will always be of a very small size, and fly wheels could
be readily added thereto so that the moment of inertia of the system would be very
great relatively to the variations of the forces acting upon it. Under these conditions
the advance motion which the one axis might assume relatively to the other would
take place exceedingly slowly and the same would also be the case with any variations
of the potential difference developed at the extremities of the line.
The above mentioned auxiliary dynamo for increasing the current may be
constructed in various ways; according to one arrangement, the axis of the machine
carries a Gramme or Siemens ring constituting the armature and provided with a
collector and brushes in the usual manner; the magnetic field is formed of a
laminated ring entirely enclosed in a copper casing, except at the air space, the casing
being formed with lateral extensions or lugs carried on standards.
The annular field magnet is covered by two windings wound round the inner and
outer surfaces, similar to the windings of a Gramine or Siemens ring. The one
winding has its terminals diametrically opposite in a plane passing through the line
of contact of the collector brushes, and the circuit formed of two coils is connected
in series with the armature there being as many turns in the two coils as there are
turns in the armature winding; thus always developing a magnetising force equal to
that of the armature winding, the windings being however so arranged that the two
magnetising forces are opposed to each other. Under these conditions no magnetic
flux can pass through the air space parallel to the before mentioned plane of the brush
contacts, so that there will be no reaction of the armature.
The second winding has its terininals arranged at right angles to those of the first
winding; any current passed through this circuit will develop a magnetic flux at right
angles to the contact plane of the brushes, and this winding will constitute the
inducing circuit proper, into which is passed the current which is to reinforce the
useful energy of the armature.
The armature is for this purpose formed of a number of sections equal to a multiple
of four, the sections of odd numbers being connected together and with the odd
numbered contacts of the collector, while the sections of even number are also con-
nected together and with the collector contacts of even number.
In a machine adapted to multiply the synchronising current say three times as
above described, I fix upon the axis whose motion is to be synchronised, firstly a
continuous current motor the magnetic field of which is excited by a continuous
current froin a local source, which also supplies the armature coils through brushes;
this motor effects the rotation of the axis. On an extension of the armature axis
are mounted collecting rings with brushes for collecting an alternating current pro-
duced by the armature, which current will serve to vary the resisting couple
developed on the armature axis so as to insure its synchronous rotation relatively
to an axis similarly arranged at the other end of the line.
On the said extension of the armature axis are furthermore mounted in succession
say three dynamos the currents produced in the first one being collected by brushes
and serving to excite the second machine, the current from which is in like manner
collected and serves to excite the third machine, the current from which is collected
is sent into a shunt circuit between the collector brushes of the motor, with which
shunt circuit is also connected the line wire, as before described. As the successive
dynamos supply increasing quantities of energy, they have of course to be made of
correspondingly increased dimensions.
32
1
T 1
1001

page_text: Method of and Means for Producing the Synchronous Rotation of
Two Axes situated a considerable distance apart.
I. CHARLES DENTON ABEL, of Birkbeck Bank Chambers, (but formerly of No. 28,
Southampton Buildings), Chancery Lane, in the County of London, consulting
Engineer and Chartered Patent Agent, do hereby declare the nature of this inven-
tion (as communicated to me from abroad by La Société Anonyme pour la Trans-
mission de la Force par l'Electricité, of 13, Rue Lafayette, Paris, France, Manufacturers,)
and in what manner the same is to be performed, to be particularly described and
ascertained in and by the following statement:-
It is very easy to obtain the synchronous motion of two axes; it suffices to mount
an alternator of any description upon the one and to drive the other by a synchronous
electromotor, using the currents furnished by the alternator. Or there may be
mounted upon both axes two similar alternators, both driven by motors of any kind
connected in parallel by a conductor passing from one terminal to the other, and
working with resistances connected in shunt between the terminals of their armatures.
It is known that these two alternators would tend to synchronise and that the
current passing through the line would be a simple synchronising current and would
require an intensity considerably weaker than if it server at the same time for trans-
mitting work. But in order to insure that these systems shall work under favour-
able conditions, it is necessary that the loss in the line conductor shall be very
small; it is therefore necessary to use currents of high voltage if the line has con-
siderable resistance. Now in certain cases, and notably in the applications to
telegraphy and multiple telephones, it would be of importance to be able to arrange
at each end of a line-wire an axis, both revolving rapidly with perfect synchronism.
In this case there might be line-wires several hundred miles in length, having great
resistance, while the consideration of the security of the staff attending to the same
would absolutely prohibit the use of high pressure currents, say above 50 volts.
It would consequently only be possible to send from the one end to the other of
the line almost infinitesimal currents, which would be unable to transmit any power
or to insure the synchronous motion of the alternators. It will be evident that these
currents could not transmit other than simple indications; but these might be
utilised for regulating the speed of rotation of the two axes so as to maintain their
synchronism. This regulation would however have to be effected perfectly auto-
matically.
This invention relates to methods of and means for accomplishing the above
mentioned problem.
Assuming two axes 0 and 0¹ Fig. 1 requiring to have synchronous motion to be
arranged one at each end of a line wire, there are mounted on them identical
alternators A and A¹ the terminals of whose armatures are connected on the one hand
by means of the line wire land on the other hand by a return conductor, or more
generally through earth Tas shewn. The two axes are assumed to be driven by con-
'tinuous current motors.
Between the terminals e and s of each armature is introduced a shunt circuit
containing a resistance R without self induction.
Under these conditions, it is known that if the line only had a weak resistance
and a negligible self induction (which might be effected by introducing into the line
a condenser of suitable capacity), the motors would synchronise and that there would
pass at every moment into the line a current that would increase the load of the one
alternator, which might tend to advance, and would reduce that of the other alter-
nator which might tend to lag behind the first one.

page_text: If the line has great resistance, the intensity I of these synchronising currents
would become too weak for developing an appreciable variation of the resisting
couples developed by the alternators A A¹ on the axes 0 0¹.
But we will assumed that by any means, there be developed at each moment in
the shunt circuits R R before mentioned an electromotive force e proportional to the
intensity I, that is to say, such, that in designating a constant factor by K, e would
be equal to K I, the factor K being of any desired value, then if we designate by /
the resistance of the line wire by h¹ and h² the potentials at its two ends, and
by I and I2 the intensities of the currents passing through the resistances R R in
shunt between the armature terminals of the alternators A A¹ we have:
Under these conditions, the production of a potential difference - h² between
the two ends of the line will cause a variation in the one alternator A equal to
Wh²
(I + and a variation in the other A¹ equal to
The action will therefore be as though the resistance
divided by the factor (1 +
hi
K
h2
(I +
had been
of the line
which factor can be made as large as may be desired.
The simplest way of obtaining the desired result consists in introducing into each
of the shunt resistances R, the armature of a continuous current dynamo D Fig. 2
which would be driven by the same motor as that of the alternator to which it
belongs, and the reaction of whose induced part would be neutralised as will be
shewn later on and whose inducing part is introduced into the line as shewn
diagrammatically at Fig. 2. When the reaction of the induced part of a continuous
current machine is artificially neutralised nothing is easier than to make it develop a
quantity of electrical energy as great as may be required relatively to the quantity of
energy.expended for its excitation.
Let us assume that this ratio be equal to 1:33. If we employ the current pro-
duced by this machine for exciting a second similar machine as at Fig. 3 the energy
produced by the second would be 1,000 times greater than that expended for exciting
the first one.
In thus connecting 4 machines connected in stage series the ratio would become
equal to 10%
If several machines thus connected in stage series are employed, it is advisable to
couple the several local circuits by means of condensers of suitable capacity in order
that the coefficients of self induction of these several circuits may always be considered
as nought.
Only the armature of the last machine would be included in the shunt circuit R
of the station where it is situated, as shewn at Fig. 3.
It will thus be seen that it is easy to give the divisor coefficient ( 1+ above
given a numerical value as great as may be desired.
It might be feared that if the variations of the potential difference h¹-h² were
rapid, the action of the working motor would be disturbed by the extra currents
which accompany each change, and that the electromotive force developed in the
last armature of the said machines connected in stage series would not always
remain proportional to the intensity of the current sent through the line ll. As to
this, it is sufficient to observe that the said system is only intended for the trans-
Inission of signals and that consequently the axes whose synchronous motion is
desired are to revolve at high speeds and only require to furnish a very small amount
of work. The devices fixed on these axes will always be of a very small size, and fly

page_text: Under
wheels could be readily added thereto so that the moment of inertia of the system
would be very great relatively to the variations of the forces acting upon it.
these conditions the advance motion which the one axis might assume relatively to
the other would take place exceedingly slowly and the same would also be the case
with any variations of the potential difference developed at the extremities of the
line.
The above mentioned auxiliary dynamo for increasing the current may be con-
structed in various ways: according to one arrangement shewn at Fig. 4, the axis ▸ of
the machine carries a Gramme or Siemens ring constituting the armature and
provided with a collector C C and brushes F F in the usual manner; the magnetic
field is formed of a laminated ring M M entirely enclosed in a supporting copper
casing, except at the air space, the cug being formed with lateral extensions or
lugs P P carried on standards $ S.
The annular field magnet M M is covered by two windings wound round the inner
and outer surfaces, similar to the windings of a Gramme or Siemens ring. The one
winding shewn diagramattically at Fig. 5 has its terminals diametrically opposite in
a plane passing through the line X Y which passes through the points of contact of
the collector brushes F F with the collector, and the circuit thus formed of two
coils X a Y and X 6 Y is connected in series with the armature, there being as many
turns in the two coils X a Y and X 6 Y as there are turns in the armature winding,
thus always developing a magnetising force equal to that of the armature winding,
the windings being however so arranged that the two magnetising forces are opposed
to each other. Under these conditions no magnetic flux can pass through the air
space parallel to the plane X Y of the bush contacts, so that there will be no reaction
of the armature.
The second winding shewn at X1 Y1, Figure 5 has its terminals arranged in the
line at right angles to those of the first winding; any current passed through
this circuit will develop a magnetic flux at right angles to the contact plane of the
brushes, and this winding will constitute the inducing circuit proper, into which is
passed the current which is to reinforce to useful energy of the armature.
The inducing flux being necessarily alternating, it is necessary to take certain
precautions to prevent the commutation from being disturbed.
The armature is for this purpose formed of a number of sections equal to a multiple
of four. At Fig. 6 is shewn a development of the collector CC. At the one side are
shewn the sections of odd number and on the other side those of even number, the
sections of odd numbers are connected together and with the odd numbered contacts
of the collector, while the sections of even number are also connected together and
with the collector contacts of even number.
Assuming that the brushes are applied at the points F F and that their surface of
contact does not entirely cover one plate, then one section of the armature will never
be directly short circuited, there need therefore be no fear of the effects of the
variation of flux to which this section may be subject on passing under the brushes.
Fig. 7 shews in elevation and Fig. 8 in plan the complete apparatus for carrying
out this invention when the synchronising current is subjected to three consecutive
multiplications. I fix upon the axis 0 0 whose motion is to be synchronised, firstly
a continuous current motor D the magnetic field I of which is excited by a continuous
current from a local source, which also supplies the armature coils through brushes f
bearing on the collector Z, this motor effects the rotation of the axis 0 0. On an
extension of the armature axis are mounted collecting rings m n connected to the
brushes of the commutator Z; brushes p¹ 2 bearing on the rings collect an
alternating current produced by the armature, which current will serve to vary the
resisting couple developed on the armature axis 0 0 so as to insure its synchronous
rotation relatively to an axis similarly arranged at the other end of the line.
The line wire which serves to transmit the synchronising currents is connected in
shunt between the brushes p¹ and p². It includes the inducing circuit of the

page_text: strengthening dynamo R¹ and that of the similar machine on the second apparatus
at the other end of the line.
The current produced by the rotation of the machine R¹ is collected by the
brushes F and serves to excite the strengthening dynamo R². Lastly, the current
produced, by the rotation of the machine R³ is collected by the brushes F³ and is
passed into a circuit connected in shunt between the brushes p¹ and p², as above
explained.
As the dynamos R1 R2 R are required to furnish quantities of electrical
energy increasing in strength at each machine, they must be made of proportionally
increasing size, as shewn at Figures 7 and 8.
A heavy fly wheel should be mounted on one of the extended ends, of the
shaft 0 0.
Having now particularly described and ascertained the nature of this inven
tion and in what manner the same is to be performed, I declare that what I
claim is :-
Method of and appliances for producing, the synchronous motion of two axes at a
distance from each other on which are mounted two alternating current machines
connected with the line circuit and actuated by a suitable motive power, which
method and appliances consist in arranging, between the terminals of the armatures
of the said machines a circuit including the armature of a continuous current machine
also actuated by a suitable motive power, the field magnets of this machine being
excited either by the currents passing from the one alternate current machine to the
other along the line connecting them, or by currents whose intensity is at every
moment proportional to their intensity but which are strengthened by the action of
other continuous current machines in stage series with the first machine substantially
as described.
Tatad this 10th day of suil 1000