Improvements in Altornate Current Dynamo Electric Machines.
Year: 1894

page_text: Date of Application, 2nd' Nov., 1894'
Complete: Specification: Left, 6th July, 1895-Accepted, 10th Aug, 1895
PROVISIONAL SPECIFICATION.
Improvements in Altornate Current Dynamo Electric Machines.
We,, MAURICE HUTIN, of 46. Rue Caumartin, Paris, Engineer, and MAURICE
LEBLANC, of 63 Allee du, Jardin Anglais, air" Raincy, Seine et. Oise, France,
Engineor, do hereby declare.the nature of this invention to be as follows:-
In the Specification to our, Patent No. 13765.of. 1892 we described the,,use. of
closed deadening. circuits-in, combination with, the inducing circuits of alternate
current dynamo machines for the purpose of insuring, synchronous motion,, such
deadening circuit being traversed by the magnotic flux produced by the armature.
We described. atspecial mode of constructing such deadening. circuits by means of
bolts passing through the polar enlargements of the field magnets, the ends of which
bolts were secured to rings of,,non magnetic.conducting metal.on each side of the
field magnets.
It is possible to consitute, the deadening, circuits in combination with the inducing
circuit itself by connecting, in shunt between the terminal posts thereof, a condenser
of large capacity. This condenser might be electrolytic, provided it is capable of
opposing the passage of the continuous current serving to excite the field magnets;
it might be replaced by an accumulator battery. The effect of this arrangement
would be as though two distinct closed circuits, one in connection with the exciting
machino, and the other in connection with the condenser or accumulator battery,
were coiled upon the cores of the field.magnets. These two circuits would include,
as common to both, the inducing coils themselves.
The self induation of the exciter would oppose the passage of the alternating
currents developed by the variations in the field magnet cores of the flux produced
by the armature of the alternate current machine, butt these currents. would be
freely passed through the condeuser or accumulator battery! Or the other, hand
the latter would oppose the passage of the continuous current of the exbiter.
The arrangement would therefore he as-though two distinct circuits were coiled
round the field magnet cores; the circuit of the condenser, if this were of large
enpacity, would practically behave as a closed circuit for. alternating currents (and
would fulfil the office of deadening cirouit.
The above. described. arrangements as also that described in, our Specification:
No. 13765 of 1892 in reality constitute two distinct machines combined in one and
having a common armature, the one constituting an ordinary alternate.qurront
machine; and the seconda nahine with rotary magnetic fields. The alternate
ourrent machine alone produces or consumes, the electrical energy and developes
the synchronising forces necessary. when the machine is not subject. to.any pulsating
effect, either from periodical variations of the effective potential difference between
the terminal posts of the feeding circuit, or from, periodical variations of, the motor
couple or resistance-developed. on the axis.
1
The motor with rotary magnetic. field-only has, the function of deadening the
effects of the pulsating offorts which, are the most frequent cause of the
desynchronisation of alternate current-machines. There inay however arise incon-
veniences in certain cases in-charging one and the same organ, with two distinct
functions.
Thus the synchronising forces developed by.an.alternato.current machine.are the
greater, the lighter is the armaturo.and the stronger are the field magnets. On the

page_text: other hand the deadening of the pulsating action which may occur is the more
energetic the more powerful the armature is and the greater is its coefficient of
self-induction.
The required conditions will be realised by mounting on one and the same axis
two motors, the one synchronous and the other asynchronous, each having a distinct
armature. The armature of the synchronous machine would be very light, but
subjected to the action of powerful field magnets. The armature of the
asynchronous motor would be very powerful and would react on the induced circuits
closed in themselves.
Notwithstanding the employment of a special asynchronous motor it would always
be advisable to provide the synchronous motor with deadening circuits for
improving its action.
The armatures of the two machines thus coupled together would be mounted in
shunt between the terminal posts of the source of electricity which supplies the
system if the machine acts as a motor, or between the posts of the circuit to be
supplied with current, if the machine acts as a generator.
The above described system should he applied in particular when it is proposed
'to convert alternating currents into continuous current by means of a commutator
driven by a synchronous motor.
In effect, theory shows, and experiment confirms, that the position of the brushes
of the commutator of such a machine can be rendered entirely independent of its
conditions of working if this commutator be moved by means of a synchronous
motor provided with highly conducting deadening circuits, and baving a very light
armature subject to the action of very powerful field magnets.
Dated this 2nd day of November 1894.
ABEL & IMRAY,
Agents for the Applicants.
COMPLETE SPEGILATION.
Improvements in Alternate Current Dynamo Electric Machines.
We, MAURICE HUTIN, of 46 Rue Caumartin, Paris, Engineer, and MAURICE
:LEBLANC, of 63 Allee du Jardin Anglais, au Rainey, Seine et 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 :-
In the Specification to our Patent No. 13765 of 1892 we described the use of
closed deadening circuits in combination with the inducing circuits of alternate
current dynamo machines for the purpose of insuring synchronous motion, such
deadening circuit being traversed by the magnetic flux produced by the
⚫armature.
We described a special mode of constructing such deadening circuits by means of
bolts passing through the polar enlargements of the field maguets, the ends of which
bolts were secured to rings of non magnetic conducting metal on each side of the
field magnets.
It is possible to constitute the deadening circuits in combination with the inducing
circuit itself by connecting, in shunt between the terminal posts thereof, a condenser
of large capacity. This condenser might be electrolytic, provided it is capable of
opposing the passage of the continuous current serving to excite the field magnets;
it might be replaced by an accumulator battery. The effect of this arrangement
would be as though two distinct closed circuits, one in connection with the exciting
machine, and the other in connection with the condenser or accumulator battery,
were coiled upon the cores of the field magnets. These two circuits would include,
"As common to both, the inducing coils theniselves:
".

page_text: The self induction of the exciter would oppose the passage of the alternating
currents developed by the variations in the field magnet cores of the flux produced
by the armature of the alternate current machine, but these currents would be
On the other
freely passed through the condenser or accumulator battery.
band the latter would oppose the passage of the continuous current of the
exciter.
The arrangement would therefore be as though two distinct circuits were coiled
round the field magnet cores; the circuit of the condenser, if this were of large
capacity, would practically behave as a closed circuit for alternating currents and
would fulfil the office of deadening circuit.
It is of advantage to increase considerably the number of transverse bolts passing
through the polar enlargements as compared with those described in Patent
No. 1376599.
The above described arrangements as also that described in our Specification
No. 13765 of 1892 in reality constitute two distinct machines combined in one and
baving a common armature, the one constituting an ordinary alternate current
machine, and the second a machine with rotary magnetic fields. The alternate
current machine alone produces or consumes the electrical energy and developes the
synchronising forces necessary when the machine is not subject to any pulsating
effect, either from periodical variations of the effective potential difference between
the terminal posts of the feeding circuit, or from periodical variations of the motor
couple or resistance developed on the axis.
The motor with rotary magnetic field only has the function of deadening the
effects of the pulsating efforts which are the most frequent cause of the
desynchronisation of alternate current machines.
There may however arise inconveniences in certain cases in charging one and the
same organ with two distinct functions.
Thus the synchronising forces developed by an alternate current machine are the
greater, the lighter is the arinature and the stronger are the field magnets. On
the other hand the deadening of the pulsating action which may occur is the more
energetic the more powerful the armature is and the greater is its coefficient of self
induction.
r
Assuming for example that it were required to construct a synchronous
that is to be subject to sudden and momentary increases of the load, it,ould be
necessary, in order that the motor couple should always remain equal to the resisting
couple, that the coefficient of self induction of the armature should be very small
relatively to its resistance, that is to say, its circuit should contain as small an
amount of copper as possible.
If the chargings and dischargings of the motor succeed each other rapidly, the
motor will be the seat of oscillating movements in addition to its rotary movement,
and which in increasing gradually in extent would tend to bring about
desynchronisation. It would then be necessary for the armature to have a large
amount of wire for reacting on the deadening circuits which surround it.
The required conditions will be realised by mounting on one and the same axis
two inotors, the one synchronous and the other asynchronous, each having a distinct
armature. The armature of the synchronous machine would be very light, but
subjected to the action of powerful field magnets. The armature of the
asynchronous motor would be very powerful and would react on the induced circuits
closed in themselves.
Notwithstanding the employment of a special asynchronous motor it would always
be advisable to provide the synchronous motor with deadening circuits for improving
its action.
The armatures of the two machines thus coupled together would be mounted in
shunt between the terminal posts of the source of electricity which supplies tho
system if the machine acts as a motor, or between the posts of the circuit to be
supplied with current, if the machine acts as a generator.
The above described system should be applied in particular when it is proposed

page_text: to convert alternating currents into continuous current by means of a commutator
driven by a synchronous motor,
In effect, theory shows, and experiment confirms that the position of the brushes
of the commutator of such a machine can be rendered entirely independent of its
conditions of working if this commutator be moved by means of a synchronous
motor provided with highly conducting deadening circuits, and having a very light
arroature subject to the action of very powerful field magnets.
We will describe by way of example the arrangement of a synchronous motor
combined with a machine for converting the alternating currents into continuous
currents, and we will assume that a motor with four poles serves to impart motion
to a machine for converting single phase currents into continuous current.
The commutator shewn at Fig. 1 has four contact plates a a', bb', of which
only bare shewn. The contact plate a' which is diametrically opposite to a is
covered by the others.
Two rings C and D are mounted on the axis O. O. of the apparatus. The
ring C communicates with the contact plates a and a' and with a terminal post m,
while the ring D communicates with the plates and and a terminal post n.
Two series of brushes Fi F, and F, F,(not shown) the points of contact of which
with the commutator are situated in two lines so arranged that the planes passing
through them and through the axis of the apparatus are at a right angle to each
other, communicate respectively with a terminal post P" and with a terminal
post (not shown).
I
On the rings C and D bear frictional contact plates and . The plates
which bear on the ring C, communicate with a terminal post Qand those which
bear upon D communicate with a terminal post. Q₁.
At the left hand end of the commutator is arranged a synchronous motor
indicated by Sat Fig. 1 and shewn in front view at Fig. 2. We have assumed
by way of example that the armature of this motor consists of a Paccinotti ring A A
mounted on the shaft 00. All the bobbins of this ring are connected in series.
By dividing this ring into four quadrants, the bobbins included in the quadrants 1
and 3 are coiled in the same direction; those included in the quadrants 2 and 4 are
coiled in the contrary direction to the others. The circuit formed by these hobbins
in series is connected between the posts mand n of Fig. 1.
This moveable armature, with its axis O O, revelves within an inductor with four
poles I, 1,,The bobbins which serve to excite these poles are united in one
and the same circuit connected between the posts P, P, of the apparatus.
The polar enlargements of the inductors 1, I, I¸', are traversed by a series of
bolts rivetted at their ends in two copper rings such as shewn at ab Fig. 2.
At the right hand end of the commutator is shewn an asynchronous motor T,
Fig. 1, the armature of which is fixed while the induced circuits which are closed
in themselves revolve with the axis 00. Fig. 3 shews the front view of this
motor.
The fixed armature has its body made of crown sheet iron rings having grooves
as shewn at oue half of the figure. In these grooves are arranged windings such
as those shewn on the other half of the figure of the winding shewn composed of
a series of galvanometric frames the branches of which occupy the grooves
symmetrically arranged relatively to the two rectangular plaues a* * and e* *
passing through the axis of the system, is only intended to serve as an example.
The bobbins constituted by the galvanometric frames which are symmetrical with
reference to the plane a*b* are coiled in the same direction and the others are
coiled in the reverse direction to the above.
All these bobbins are mounted in series and are connected between the posts Q
and Q, shewu at Fig. 1. The induced circuits closed in themselves of this motor
are constituted by means of boits enclosed in a magnetic mass and rivetted at their
two ends in two copper rings such as the ring K7 Fig. 3.
The posts Q and 'Q'₁, Q, and Q¹, are normally connected two and two and are
put in connection with the source of alternating currents which have to be

page_text: converted into continuous current; but at the moment of starting the apparatus it
is necessary to put out of circuit the asynchronous motor, which would uselessly
consume current. This is the reason why we have connected its armature to
separate posts.
The commutator shown at Fig. 1 is of a size similar to that of the motors,
because the apparatus shewn is, as explained, simply a converter of alternate
currents.
If this apparatus is to be used as a synchronous motor or generator, this
commutator should still be retained in order to insure the exciting of the inductors
of the synchronous motor but its dimensions should then be very much reduced.
What has been stated in the case of monophase currents is equally applicable in
the case of polyphase currents. It suffices to replace the armatures of the
synchronous and asynchronous motors by distinct armatures having as many
circuits regularly shifted relatively to each other as are required to produce currents.
of different phases.
It will be expedient always to make this number even; the commutator would be
replaced by a collector and the several circuits of the two armatures would be
connected between the consecutive plates of the collector, either directly or through
the medium of friction contacts and rings, in a similar manner to that in which the
several circuits of the armature of a continuous current machine are connected
between the plates of its collector.
Having now particularly described and ascertained the nature of our said inven-.
tion and in what mauver the same is to be performed, we declare that what wo
claim is :-
1. In an alternate current machine of tho kind berein referred to, the use of a
condenser of considerable capacity, either of the ordinary or of the electrolytic
kind, or a battery of accumulators, connected in shunt between the posts of the
inducing circuits, substantially as and for the purposes described.
2. In an alternate current machine of the kind herein referred to, imounting on
one and the same axis with the synchronous alternate current machine an
asynchronous alternate current machine having the same number of poles, the
armature of which is arranged to receive as many alternating currents of distinct
phases as are required to be produced or utilised by the armature of the
synchronous motor, the corresponding circuits of the two armatures being mounted
in shunt and connected between the posts of the same sources of electricity,.
substantially as described.
ABEL & IMRAY,
Agents for the Applicants.