Year: 1887

page_text: Date of Application, 12th May, 1887
Complete Left, 28th Dec., 1887
Complete Accepted, 10th Feb., 1888
[Communicated from abroad by LA SOCIÉTÉ ANONYME POUR LA TRANSMISSION DE LA
FORCE PAR L'ELECTRICITÉ, of 1, Boulevard St. Denis, Paris, France, Electrical
Engineers.]
I JOHN CLAYTON MEWBURN, of 169 Fleet Street, in the City of London, Fellow of
the Institute of Patent Agents, do hereby declare the nature of this invention to be as
follows:-
This invention consists of apparatus whereby a portion or fraction, variable at
will, of the intensity of a main electric current can be derived, or shunted to a
derived circuit, without expending the remainder in useless work as would be the
case if simple resisting derivations were employed; the object is effected by intro-
ducing a counter electro motive device in the main circuit and another counter
electro motive device in the derived circuit, the force or power of these devices
being capable of regulation at will.
When a device having a counter electro motive power is introduced or inter-
ealated in the circuit of an electric current a portion of the main current can be
derived at the extreme points of such device. The derived circuit being supposed to
be of constant resistance the portion derived is determined by the counter electro
motive force of the interposed device; it is therefore constant if the force is
constant and variable with the force if the latter is variable.
In carrying out the invention there is introduced in the circuit of the main current a
counter electro motive device, and in the derived circuit thereby obtained there is
introduced another counter electro motive device. These devices may with advantage be
two induced armatures or rings of dynamo electric machines. The two rings are
mechanically connected together by being for example keyed on the same shaft.
They thus rotate together and at the same speed. They are each placed under the
influence of a set of inductors. If the inductors of the device interposed in the
main circuit are alone excited this device will produce a counter electro motive force
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page_text: equal to the difference of potential engendered by the main current between the con-
necting points; this force will therefore be derived or taken up by the derived
circuit with its whole intensity. If on the other hand the inductors of the device
interposed in the derived circuit are alone excited this device will take up all the
power and prevent any current passing into the derived circuit with a result the same
as if this circuit did not exist." If again the inductors of both devices are excited
together these will each receive a counter electro motive force in proportion to the
magnetic field given to it; the current will be divided between the main circuit and
the derived circuit in the inverse ratio of these forces. The proportion of the
intensity which is derived and of that which is left in the main circuit can thus be
regulated as required.
When the counter electro motive devices employed are armatures or rings of
dynamo electric machines the inductors may either be supplied from the main current
by simple winding or by a combined double winding, comprising on the one hand the
main current and on the other a derivation therefrom. By dividing the circuits
wound on the inductors into sections leading to a commutator the current can be
sent into any desired number of the sections. By moving the commutator the
sections traversed by the exciting current may be only those of the inductors con-
nected with the device in the main circuit or only those of the inductors connected
with the device in the derived circuit or partly the one and partly the other, the
proportion being variable. The counter electro motive forces of the two devices can
thus be modified at will and therefore the amount of electric energy expended in the
derived circuit can be regulated.

page_text: A communication from abroad by LA SOCIÉTÉ ANONYME POUR LA TRANSMISSION
DE LA FORCE PAR L'ELECTRICITE, of 1, Boulevard St. Denis, Paris, France,
Electrical Engineers.
1 JOHN CLAYTON MEWBURN, of 169 Fleet Street, in the City of London, Fellow of
the Institute of Patent Agents do hereby declare the nature of this invention and
in what manner the same is to be performed, to be particularly described and
ascertained in and by the following statement :-
This invention consists of apparatus whereby a portion or fraction, variable at will,
of the intensity of a main electric current can be derived, or shunted to a derived
circuit, without expending the remainder in useless work as would be the case if
simple resisting derivations were employed; the object is effected by introducing
counter electro motive device in the main circuit and another counter electro-motive
device in the derived circuit, the force or power of these devices being capable of
regulation at will.
EL
When a device having a counter electro motive power is introduced or intercalated
in the circuit of an electric current a portion of the main current can be derived at
the extreme points of such device. The derived circuit being supposed to be of
constant resistance the portion derived is determined by the counter electro-motive
force of the interposed device; it is therefore constant if the force is constant an:l
variable with the force if the latter is variable.
In carrying out the invention there is introduced in the circuit of the main
current a counter electro motive device, and in the derived circuit thereby obtained
there is introduced another counter electro motive device. For example in a
circuit L T Figure 1 there is introduced at A G a counter electro motive device E the
result of which is a derivation in the circuit A B C D F G; and in this circuit there
is introduced another counter electro motive device E¹. The devices E and E' may
with advantage be two induced armatures or rings of dynamo electric machines
though other means may be employed. The two rings are mechanically connected
together by being for example keyed on the same shaft O. They thus rotate
together and at the same speed. They are each placed under the influence of a set
of inductors marked in the Figure I and 1' respectively. If the inductors I of the
device E are alone excited this device will produce a counter electro motive force
equal to the difference of potential engendered by the main current between the
points a and d; this force will therefore be derived or taken up by the derived
circuit A B C D F with its whole intensity. If on the other hand the inductors I³ of
the device E are alone excited this device will take up all the power and prevent

page_text: any current passing into the derived circuit with a result the same as if this circuit
did not exist. If again the inductors I and I' of both devices E and E¹ are excited
together these will each receive a counter electro motive force in proportion to the
magnetic field given to it; the current will be divided between the main circuit and
the derived circuit in the inverse ratio of these forces. The proportion of the intensity
which is derived and of that which is left in the main circuit can thus be regulated as
required.
When the counter electro motive devices employed are armatures or rings of
dynamo electric machines the inductors I and I (see Figure 2) may either be
supplied from the main current by simple winding or by a combined double winding,
comprising on the one hand the main current and on the other a derivation therefrom.
By dividing the circuits wound on the inductors into sections leading to a com-
mutator C¹ the current can be sent into any desired number of sections. By moving
the commutator the sections traversed by the exciting current may be only those of
the inductors I or only those of the inductors I¹ or partly the one and partly the other
the proportion being variable. The counter electro motive forces of the two
devices E and E' can thus be modified at will and therefore the amount of electric
energy expended in the derived circuit can be regulated.
Having now particularly described and ascertained the nature of my said Invention,
and in what manner the same is to be performed, as communicated to me, I
declare that what I claim is :-
1. For obtaining derived currents of variable intensity from a main electric
current, an apparatus comprising a counter-electro motive, device introduced in the
main circuit and another electro motive device introduced in the derived circuit the
force or power of these devices being capable of regulation at will, substantially as and
for the purpose set forth.
2. For obtaining derived currents of variable intensity from a main electric
current, an apparatus comprising two dynamo-electric-machine-armatures or rings
mechanically connected together, the one being introduced in the main circuit and
the other in the derived circuit, and being placed respectively under the influence of
two sets of inductors in such manner that by means of a commutator the excitation
can at will be applied entirely to the one or entirely to the other of the sets of
inductors, or partly to the one and partly to the other, substantially as and for the
purpose set forth.
Dated this 28th day of December 1887