IMPROVEMENTS IN APPARATUS FOR DISTRIBUTING AND UTILIZING ELECTRICITY
Year: 1885

page_text: Electricity.
We ROBERT PEROY SELLON Engineer of Surbiton in the County of Surrey S.W.
and JOHN SCUDAMORE SELLON of The Hall Sydenham in the County of Kent,
Esquire do hereby declare the nature of said Invention for "IMPROVEMENTS IN
APPARATUS FOR DISTRIBUTING AND UTILIZING ELECTRICITY" to be as follows:―
The object of our Invention is to provide means whereby a current of high
tension may readily and simply be converted into one of low tension without the
necessity of employing secondary batteries or other intermediate converting
appliances for attaining this end and means for regulating the speed of motors so
that a constant or any desired ratio of difference in speed may be maintained of
the motors whether, they are doing useful work or merely running idle.
In order to carry out our Invention we prefer to employ a dynamo electric or
electro-dynamic machine of which the revolving armature is wound with two
distinct & independent sets of coils each set of coils being carried to a separate
commutator or collector-The iron of the field magnets of this armature is common
to both sets of coils of the armature but the field magnets have coils so arranged
that a portion is in connection with the first set of coils upon the armature & a
portion in connection with the second set of coils upon the armature-By this
arrangement we obtain what may be called a "motor generator" inasmuch as
the passage of a current through one set of coils upon the field magnets & its
corresponding armature coils will cause a revolution of the armature to take place
the speed of such revolution being mainly dependent on the intensity of the
magnetic field in which it revolves-This revolution will cause the second set of
coils upon the armature to be likewise drawn through a magnetic field and thus a
current will be set up in the coils of the second portion of the armature which may
be used for any purpose for example lighting or heating.
The first set of coils upon the armature may thus be wound suitable for use on
a circuit where the current passing is small, but the electro-motive force is high
such strength of magnetic field due to the coils in communication with the first or
motor half of the armature being provided as will cause the armature to revolve at
a predetermined speed when no load or a small load only is thrown upon the
second or generator half of the armature: but it will be obvious that if the load
upon the second or generator half of the armature be increased by switching on

page_text: more incandescent lamps or otherwise absorbing energy, the speed of the armature
would diminish & the potential at the terminals of the second or generator portion
of the machine would fall instead of remaining constant, and it is to obviate this
that we provide a second set of coils upon the field magnets in communication
with the generator half of the armature the action of which is to strengthen the
magnetic field proportionally to the load thrown upon the generator half of the
dynamo or to strengthen the field in which the armature revolves to such an
extent as to maintain the potential (or current as desired) at the terminals of the
generator constant.
The relative ratios between the two sets of coils upon the field magnet may be
if desired so proportioned that when no load ör a very small load is thrown upon
the generator portion of the armature the speed of the armature is extremely low
& this speed only increases to the extent necessary to obtain the required work
from the "motor generator" when an increased load is thrown upon the generator
portion of the armature. When the Invention is applied for the regulation of the
speed of electro motors the circuit external to the generator portion of the armature
may conveniently be dispensed with and' the current drawn off the generator
portion of the armature be caused to circulate around the field magnets of the
machine in an opposing direction to that in which the current in the coils of the
field magnets in connection with the first or motor half of the armature circulates
so as to weaken the field in which the armature revolves. In this case the motor
coils of the armature and the field coils corresponding to them will bear a far
larger ratio to the generator coils and their corresponding field coils than would
be the case in the machine when arranged as previously described. In most cases
a motor which is arranged to run at a certain speed while a normal load is placed
upon it will vary considerably in speed as the load is altered and eventually will
attain a speed which is excessive. By the application of this Invention the
difficulties referred to are obviated inasmuch as an increase of speed on the part
of the armature when load is removed causes an increase of electro motive force
to be developed by the generator portion of the armature which in turn by
strengthening the effect of its corresponding field coils weakens the magnetic field
in which the armature revolves so far as to maintain it at a practically constant
speed.
"
This system of regulation is not confined to motors placed upon a circuit of high
electro motive force and constant current generally known as the "series system
but is equally applicable to motors inserted in a "parallel arc
"circuit.

page_text: ROBERT PEROY SELLON Engineer of Claremont Villa Surbiton S.W. and JOHN
SCUDAMORE SELLON of The Hall Sydenham in the County of Kent Esquire 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:
The object of our invention is to provide means whereby a current of high
tension may readily and simply be converted into one of low tension without
the necessity of employing secondary batteries or other intermediate converting
appliances for attaining this end; or, equally, a current of any given strength may
be converted into a current (whether alternating or continuous) of any other
desired strength; that is to say, the electrical energy absorbed by the hereinafter
described apparatus may be transformed into electrical energy capable of being
supplied at a pressure and current strength differing from that at which it was
communicated; and our invention further provides means for regulating the speed
of motors so that a constant or any desired ratio of difference in speed may be
maintained of the motors under varying conditions of load.
"
In order to carry out our Invention we prefer to employ a dynamo-electric or
electro dynamic machine-which we will hereafter speak of as a "transformer
of which the armature is wound with two distinct and independent sets of coils,
each set being carried or connected to a separate commutator or collector.
The field magnets of this armature are common to both sets of the armature
coils; and the said field magnets are preferably wound so that a portion of their
coils is in connection with the first sets of coils upon the armature and another
portion of their coils is in connection with the second set of coils upon the
armature.
The two sets of field coils act in assistance of one another in strengthening the
magnetic field.
In some cases the second set of coils upon the armature would have in connection
with them no coils upon the field magnets.
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Thus good results are obtainable more especially when the conditions of supply
are those commonly known as 'constant Potential where the coils of the field
magnets in connection with the first set of coils upon the armature are on a "shunt"
with their armature coils while the field coils in connection with the second set of
armature coils are in "series" with their armature coils and the corresponding
external circuit, and this arrangement is more especially suitable where the current
is to be supplied from the second set of armature coils or "generating" portion of
the machine at what is commonly known as "Constant Potential."

page_text: In some cases however as mentioned above, the field coils in connection with the
second or "generating" coils, may be dispensed with.
Under the conditions above quoted, the "transformer" would preferably revolve
at a constant speed; but it might be advantageous in some instances to vary
the speed in accordance with the load upon the " generator" portion of the
"transformer."
Thus we obtain what may be called a "motor generator" inasmuch as the passage
of current through the first or "motor" set of coils will cause a revolution of the
armature to take place this revolution will cause the second or "generator" portion
of armature coils to be drawn through a magnetic field whereby a current of
electricity will be set up in them.
The first or motor set of coils may be wound suitably for use on a circuit
where the current passing is small but is supplied at a high potential, the second
or 'generator" set of coils being wound to allow of a current of greater quantity
and at a lower pressure being drawn off.
"
33
Obviously this Invention is not limited to cases where the conditions of working
are those of "Constant Potential" supply to the first or "motor" portion of the
"transformer" and "Constant Potential" supply from the second or "generator
portion of the "transformer" as the conditions of working may in some instances
be those known commonly as "Constant Current" supply to the "motor" portion
and "Constant Current" supply from the "generator" portion of the "transformer."
Or the conditions of working may in many instances be those of "Constant Current"
supply to the "motor" coils and "Constant "Potential " supply from the "generator'
coils But these conditions are all included within this Invention.
"
Figure 1 shows a "transformer" constructed according to our Invention from
which, parts unnecessary to the explanation of our Invention are omitted. A is
the armature wound with two sets of distinct and independent coils. This is clearly
shewn at figure 2 which shews a part of the said armature wound in the required
manner. Here B B¹ indicate coils of the one set which are connected to a suitable
commutator or collector, and CC indicate coils of the other set likewise connected
to a commutator or collector distinct from that to which the coils B B¹ are con-
nected. Obviously these coils need not be wound B B¹ alternately with C C¹
or side by side as shewn, as they may be wound over one another or in any manner
convenient in practice. F and G figure 1 are the aforesaid collectors of the machine
each of which has one set of the armature coils connected with it. M M are the
field magnets of the machine the coils of which as already described may be either
in two circuits respectively in connection with each set of armature coils but dis-
connected from one another or the whole of the coils of the field magnets may be
in connection with the motor set of armature coils-Obviously the field coils where
two sets are used may be wound on the same or on independent limbs of the field.
magnets or in any other convenient way.
When the machine is used only as a motor the second set of armature coils and
the set of field magnet coils corresponding to them are used to generate a current
which will weaken the total magnetic field and so tend to maintain a constant speed
of the motor under varying conditions of working by neutralising the strength
of the magnetic field in proportion as the speed of the machine and consequently
the current generated by the generator set of armature coils tends to increase.
By this Invention a means is afforded of dispensing with the necessity of bulky
and costly main leads since a single generator placed at any convenient distance
from the region in which the provision of electricity is required may supply
electricity at a high potential to "transformers" placed in suitable positions in that
region which shall in turn supply electricity to consumers at a low and consequently
harmless pressure,
We are aware of the Specification of Zipernowsky and Déri's Invention the
subject of Letters patent 99828 and we do not claim such an arrangement under
the present application

page_text: Having thus fully described and ascertained the nature of our said Invention and
in what manner the same is to be performed we declare that what we claim is
First. A "transformer" of electrical energy constructed or arranged substantially
as hereinbefore described whereby such electrical energy supplied under given con-
ditions of current and. potential may be converted into electrical energy available
under some other desired conditions of current and potential.
88
Second. A transformer" having an armature wound with two distinct sets of
coils and field magnets which have a portion of their coils in connection with
each of the set of armature coils substantially as and for the purposes herein before
described.
Third. A transformer" having an armature wound with two distinct sets of
coils and field magnets of which the coils are in connection with the first or
"motor" portion of the armature substantially as and for the purposes hereinbefore
described.
J. HENRY JOHNSON,
Agent.