Improvements in or connected with Means for the Supply or Distribution of Electricity.
Year: 1893

page_text: Date of Application, 18th Aug., 1893
Complete Specification Left, 13th Mar., 1894-Accepted, 14th Apr., 1894
PROVISIONAL SPECIFICATION.
Improvements in or connected with Means for the Supply or
Distribution of Electricity.
We WILLIAM GODSON LITTLE of Blendon Grove Bexley in the County of
Kent Engineer and CHARLES WILLIAM GODSON LITTLE of Heckington in the
County of Lincoln Electrical Engineer do hereby declare the nature of this
invention to be as follows:-
The object of our invention is to provide means whereby greater facility and
economy are effected in systems of electrical supply in which accumulators and
dynamo electric machines are used for the supply and distribution of electricity
for electric lighting or other purposes for which electricity may be used.
It is desirable for economy in fuel and plant and to make use of engines which
are worked at or near full load. "When the machinery is in operation at times
when the full power of the generators is not required considerable loss has hitherto
been incurred owing to the capacity of the plant being greater than the demand
then made upon it and at such times it is desirable to work the machinery at nearly
full load and to store up the electrical output which is in excess of the demand to
be utilized when the demand for it arises. This storing up is most conveniently
effected by means of electrical accumulators as hereinafter described arranged and
connected with the system that the accumulators will be charged by excess of
current over the demand as well as during such time as the current is not in use in
the mains and that the said accumulators will discharge into the mains when the
demands thereof necessitate a supply from the accumulators. It is well known that
it is necessary to maintain the potential or in some cases to increase the potential at
the terminals of the generator or generators for supplying current to the mains in
accordance with the nature of the work for which current is required.
Hithertofore considerable difficulty has been experienced in employing accumu-
lators in combination with a generator or generators working under these conditions
and it is the object of our invention to overcome this difficulty and it consists in the
combination with the generator or generators and accumulators of a source of
variable electro motive force such force being made to depend upon and to
automatically vary with the strength of the current in the supply mains in such a
way that the actual potential difference at the terminals at the part of the circuit
including the accumulators and the source of variable electro motive force depends
on the quantity of the current in the supply mains of the external circuit if that
be closed whilst if it be open the generator and the source of variable electro-
notive force together charge the accumulators the combination of the two being so
arranged that as long as the current in the mains is below a certain value the actual
potential at the terminals of the part of the circuit including the accumulators and
the source of variable electro motive force is lower than the potential of the main
generator or generators enabling them to charge the accumulators if desired but as
the current in the supply mains increases beyond a certain value the actual potential
at the said terminals increases in proportion enabling the accumulators to furnish
current to the supply mains along with the main generator or generators.
The hereinbefore mentioned variable source of electro motive force we prefer to
be a magnetic field and an armature so co-acting and controlled by the current of
the outer circuit when that is closed that the field and therefore the said variable
electro-motive force is varied in the required manner by the said current.

page_text: The following is a more particular description of an arrangement according to
our invention which will serve further to make clear its nature but we do not limit
ourselves to the precise arrangement.
The generator which supplies the mains is supplemented by a generator to such
an extent that they between them give a current of sufficient intensity to charge
the accumulators with which both they and the mains are in connection. The
supplementary dynamo constitutes the herein before mentioned variable source of
electro motive force.
The windings and connections of the field magnets of the dynamos are so arranged
that when the main circuit is open the two dynamos can charge the accumulators
but when the mains are closed and the work therein renders it necessary that the
accumulators supply current thereto current passes through the windings of the
field magnets of the supplementary dynamo in a direction to lessen the magnetic
field of that dynamo so that the accumulators can discharge into the mains or in
place of this the current in the mains may be made to raise the potential of the
supplementary dynamo which is then so arranged that it is used to assist the
discharge of the accumulators in which case a less number of cells in the accumulators
can be employed.
Dated this 10th day of 11002
J. H. JOHNSON & Co.,
47, Lincoln's Inn Fields, London, Agents.
COMPLETE SPECIFICATION.
Improvements in or connected with Means for the Supply or
Distribution of Electricity.
We, WILLIAM GODSON LITTLE, of Blendon Grove, Bexley in the County
of Kent, Engineer, and CHARLES WILLIAM GODSON LITTLE, of Heckington in
the County of Lincoln, Electrical 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 :-
The object of our invention is to provide means whereby greater facility and
economy are effected in systems of electrical supply in which accumulators and
dynamo electric machines are used for the supply and distribution of electricity for
electric lighting, or other purposes for which electricity may be used, but our said
invention is more especially useful for use in systems for the distribution of power
for traction or other purposes. It is desirable for economy in fuel and plant to
make use of engines which are worked at, or near, full load. When the machinery
is in operation at times when the full power of the generator or generators is not
required considerable loss has hitherto been incurred owing to the capacity of the
plant being greater than the demand then made upon it, and, at such times,
it is desirable to work the machinery at near full load, and to store up the electrical
output which is in excess of the demand to be utilized when the demand for it
arises. This storing up is most conveniently effected by means of electrical
accumulators, as hereinafter described, so arranged and connected with the system
that the accumulators will be charged by excess of current over the demand as well
as during such time as the current is not in use in the mains, and that the said
accumulators will discharge into the mains when the demands thereof necessitate
a supply from the accumulators. It is well known that it is necessary to maintain
the potential, or in some cases to increase the potential, at the terminals of the
generator, or generators, for supplying current to the mains in accordance with the
nature of the work for which current is required.
Hithertofore considerable difficulty has been experienced in employing accumu-
lators in combination with a generator or generators working under these conditions
as it has been necessary to vary the number of accumulators working in series, in

page_text: accordance with the rise and fall of current in the mains. It is the object of our
invention to overcome this difficulty and it consists in the combination with the
main generator or generators and the accumulators of a source of variable electro-
motive force such force being made to depend upon and to automatically vary with
the strength (quantity) of the current in the supply mains in such a way that the
actual potential difference at the terminals of the part of the circuit including
the accumulators and the source of variable electromotive force depends on the
quantity of the current in the supply mains of the external circuit, if that be
closed; whilst, if it be open, the main generator or main generators and the
source of variable electromotive force, together charge the accumulators, the
combination of the main generator or main generators and the source of variable.
electromotive force being so arranged that as long as the current in the mains
is below a certain value the actual potential at the terminals of the part of the
circuit including the accumulators and the source of variable electromotive force
is lower than the potential of the main generator or main generators enabling
it or them to charge the accumulators if desired but as the current in the supply
mains increases beyond a certain value the actual potential at the said terminals
increases in proportion enabling the accumulators to furnish current to the supply
mains along with the main generator or main generators.
By this means the charging and discharging of the accumulators can be effected
without varying the number of cells working in series.
The hereinbefore mentioned variable source of electromotive force we prefer
to be a magnetic field and an armature so co-acting and controlled by the
current of the outer circuit when that is closed that the field and therefore.
the said variable electromotive force is varied in the required manner by the said
current.
The following is a more particular description of an arrangement according to-
our invention which will serve further to make clear its nature but we do not limit
ourselves to the precise arrangement.
The generator which supplies the mains (which we will designate generator A).
is supplemented by a generator (which we will designate dynamo B) to such an
extent that they between them give a current of sufficient intensity to charge the
accumulators with which both they and the mains are in connection. The
dynamo B constitutes the hereinbefore mentioned variable source of electromotive
force. The windings and connections of the field magnets of the generator A and
dynamo B are so arranged that when the main circuit is open the generator A and
dynamo B can charge the accumulators but when the mains are closed and the
work therein renders it necessary that the accumulators supply current thereto
current passes through the windings of the field magnets of the dynamo B in a
direction to lessen the magnetic field of that dynamo.
The dynamo B when the demand on the mains increases to a sufficient extent is
reversed and it will then assist the discharge of the batteries into the mains.
We will describe with reference to the accompanying diagram a manner in
which our invention may be carried into effect but we wish it to be understood
that our invention is not limited to the precise arrangement illustrated by the said
diagram.
G and H illustrate windings which encircle the field magnet or magnets of the
dynamo B, and R indicates a resistance. Findicates the series winding of the
main generator A and E indicates the shunt winding of the same. C indicates a
battery of accumulators and M and N are wires from an outside circuit.
When the outside circuit is open all the current generated by the generator A
will be used to charge the cells C, and will pass by the wire D through the
winding G causing the dynamo B to develope electromotive force in the direction
proper for charging the cells C, the current passing through the armature of the
dynamo B to the cells. A small portion of the current may pass by the series
coils F and resistance R.
When a small current is allowed to flow in the outside circuit M N this will be

page_text: supplied by the generator A and will pass to the line by the windings F and H.
A small portion may also pass through DG R and H this depending upon the
resistance R. The action of the current in H is to diminish the magnetism of the
dynamo B by opposing the magnetising effect of the current in G thus diminishing
the charging electromotive force of the dynamo B. It will then be seen that the
charging electromotive force of the dynamo B will diminish as the current in the
outside circuit increases will become zero, and will ultimately increase in the opposite
sense so allowing, and assisting, the accumulators to discharge, and supply current
to the outside circuit. When the cells C discharge into the line two paths are
open for the current one through GDFK and H the other through R and H,
the relative amounts of current so passing depending upon the resistance R. When
the current in the outside circuit again falls the discharging electromotive force
of the dynamo B will diminish finally reversing in direction and assisting to again
charge the cells C. If necessary we insert a variable resistance between D
and K as shewn at R2 whereby the compounding of the main generator may be
modified.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed, we declare that what we
claim is :-
1. In combination with a system of electrical supply in which a dynamo
generator, or dynamo generators, and an accumulator, or accumulators, are
employed, a source of variable electromotive force dependent upon, and auto-
matically varying with, the strength (quantity) of current in the supply mains,
in such a way that the actual potential differences at the part of the circuit
including the accumulator, or accumulators, and the source of variable electro-
motive force, depends upon the quantity of current in the supply mains of the
external circuit and the accumulator, or accumulators, is, or are, charged when the
demands of the external circuit are less than the normal output of the main
generator, or main generators, and are caused to discharge when the demands of the
external circuit are greater than the normal output of the main generator, or
main generators, whilst if the external circuit be open the main generator or
main generators and source of variable electromotive force together charge the
accumulators, the whole being arranged and combined substantially as, and for the
purpose, hereinbefore described.
2. In a system of electrical supply, or distribution, the combination of a
generator, an accumulator, and a source of variable electromotive force, all being
connected, and operating, substantially as, and for the purpose, hereinbefore
described and illustrated.
Dated this 13th day of March 1894.
JOHNSONS & WILLCOX,
Agents.